CONTENTS page 1 Introduction 1 2 Methods 6 3 Food size . 8 4 Body size 10 5 Crowding 11
6 Light and periodicity , 12
7 Temperature , 13
8 pH 15 9 Oxygen concentration 15
TABLES: 1 Filtering and ingestion rates of some planktonic zoöplankton. 2 Predation rates of some planktonic zoöplankton species.
3 Food of some planktonic zoöplankton species.
Preface
This report deals with the results of an extenslve literature research to zoöplankton feeding.
It is the fourth report of a literature research performed by Mrs. M, Lingeman-Kosmerchock of the Limnological Laboratory of the University of
Amsterdam) in cooperation with Mr. F.J. Los of the Delft Hydraulics Laboratory, The first report deals with the contents of nitrogen phosphorus, silicon
and chlorophyll in phytoplankton cells, the mineralization rates of nutrients from phytoplankton cells and the sinking rates of phytoplankton cells.
The second report considers the relationship between light and photosynthesis and carbon-chlorophyll ratios in phytoplankton cells,
The third report deals with algal respiration.
This research project is part of an extensive assignment by the Environmental Division of the Delta Department to Delft Hydraulics Laboratory in order to develop ecological models, which can serve as tools in providing adequate guide-lines for environmental management in the (future) water basins in the Delta area.
This raulti disciplinary project, called Water Basin Model (WABASIM) is carried out in close co-operation between the Environmental Oivision of the Delta Department and the Environmental Hydraulics Branch of the Delft Hydraulics Laboratory,
ZOÖPLANKTON FEEDING
1 Introduction
One of the earliest feeding studies was done with the marine copepod Calanus by Fuller and Clarke (1936). They observed that the filtering rate did not change with a change in food concentration and thus,feeding rate was directly proportional to food concentration, Similar results were obtained by many of the other early investigators (Lucas 1936, Fuller 1937, Fleming 1939, Harvey
1942, Riley 1946, 1947, & Gauld 1951) and before 1954 it was generally accepted that the filtering rate was independent of concentration of food. Rhyther (1954) found that within a limited range the concentration of algae had a pronounced effect on the filtering rate of Daphnia, This was an impetus
32 for revival in the study of zoöplankton feeding. Rigler (1961) used P
labled yeast to obtain information on the relation between food concentration and feeding rate. His results were similar to those of Rhyther (1954) and Marshall & Orr (1955) and resulted in a phenomenon which later was natned the
"incipient limiting level" (ILL). Rigler found that the feeding rate is
limited by an animal' s ability to filter water. Thus, feeding rate is directly proportionat to food concentration and filtering rate is constant and maximum up to the ILL. Above the ILL the feeding rate is limited by the ingestion or the digestion rate and thus, feeding rate is constant and maximum but filter-ing rate declines to an asymptote at zero. It was suggested by Rigler that a reduction in pumping rate, intermittent pumping, or a rejection of food from the food groove were possible mechanisms which might exist to regulate the filtering rate in high food concentrations, however, he had no direct evidence for this. In later studies with McMahon (McMahon & Rigler 1963) it was shown that in Daphnia two actual mechanisms are used; rejection of food from the food groove, and reduction of the pumping rate.
Although feeding and filtering rates have been determined for a large number of zoöplankton species (Table 1) very little has been done to relate the effect of environmental conditions on the filtering rate. A large portion of the studies relate how a few of the well studied species react to controlled laboratory conditions. McMahon (1965) showed how animal size, water tempera-ture, and light intensity effect feeding of Daphnia above and below the ILL. The effects of food particle size and body size were investigated by Burns
(1968a). She also reported relations between body size, temperature, and filtering rate for several species of Daphnia (Burns 1969). Other physical characteristics which have been studied include: oxygen concentration (Kring
& O'Brian 1976a), pH (Ivanova 1969, Kring & 0'Brian 1976b), light (Buikema 1975, Haney & Hall, 1975), and temperature (Kibby 1975).
_ o —
Quite frequently the results of laboratory studies are used to predict feeding behavior in nature, however, it is important to consider the effect of a
number of siraultaneous factors as is the case in nature. Burns & Rigler (1967) on the basis of laboratory experiments attempted to relate feeding to food concentration, body size, and water temperature. They constructed theoretical feeding rates from observed natural conditions. These theoretical rates were much higher than those measured in nature and in a later paper Burns (1969b)
attempted to find poasible reasons for this difference.
An important approach was made by Schindler (1961) with the use of multilinear regression analysis of light intensity, motion, crowding, food concentration, diet species, reproduction rate, animal weight, and temperature to predict the effect on feeding and production. A short coming of this approach is that a wide range of conditions with one parameter is not necessarily linear, This combined with the fact that Schindler was only able to compare two states of some values tends to limit the predictive value for natural populations under normal field conditions.
Hayward & Gallup (1976) studied the effect of individual environmental factors as well as the simultaneous effect of two or more factors on the feeding rate of Daphnia schoedleri. Their results showed that a change in one environmental parameter can significantly alter the response to a change in a second para-meter. Three environmental parameters, temperature, food concentration, and diet species were found to alter the responses to other parameters in a measureable manner. They suggest that feeding behavior must be thoroughly understood before results froui laboratory or field studies can be used to make estimates of secondary productivity in nature.
Planktonic zoöplankton can be divided into three groups on the basis of feeding habits as filter feeders, carnivorous predators, and scavengers which scrape their food from the substrate. Among freshwater zoöplankton cladocerans and diaptomid copepods are generally herbivorous, cyclopoid copepods are both herbivorous and carnivorous, and harpactacoid copepods and some littoral cladocerans are scavengers. Foods consumed by zoöplankton include algae, bacteria, detritus, and other zoöplankton. The food available to zoöplankton in nature is diverse and generally heterogenous. Most zoöplankton utilize a variety of food sources although frequently a preference can be found for a certain food species, It is difficult to catagorize zoöplankton to one
trophic level. Filter feeders utilize algae, detritus, and other small animals and thus, are not strictly herbivors. Predators incorporate both algae and
3
-other animals and theirs is not strictly a carnivorous diet. Omnivory appears to be a common condition among the zooplanton.
Not all the food that is encountered is accepted by zoöplankton. Reasons for rejection include mechanical inhibition of feeding, toxic or taste properties, and undigestibility, Complete and detailed explanations of the mechanics of filter feeding organisms have been given by Cannon (1928), Fryer (1957 a,b), Gauld (1964), Jorgensen (1955, 1966), Marshall (1973), Storch and Pfisterer
(1925), and Wickstead (1962).
Frequently difficultly is encountered when attempting to culture zoöplankton on one food species, This has prompted several investigators to study the role of detritus and dissolved organic matter in the nutrition of zoöplankton. It was observed in early experiments that the presence of particulate matter improves conditions for growth and reproduction in zoöplankton (Gellis & Clarke 1935, Rodina 1948, and Stuart et al. 1931) and that colloids present in natural water are necessary for growth.
In Lake Erken, Nauwerck (1963) pointed out that Eudiaptomus graciloides could not subsist on phytoplankton alone and porposed detritus was the main compo-nent of its diet. Daphnids have been found to develope when fed on freshly collected lake detritus (Rodina 1963), Detritus along with bacteria is the main food for rotifers such as Anuraeopsis fissa, Brachionus angularis, and Keratella cochlearis (Pourriot 1977) .
In studies with natural zoöplankton Saunders (1969) found that although
detritus was several times more plentiful than algae it was not as nutritious. What he failed to investigate was the effect of the age of the detritus. The nutritional value of detritus has been found to vary with the age and time due to bacterial decomposition (Jorgensen 1966, Otsuki et al., 1968). There has been much discussion about the use of bacteria as a food by zoö-plankton. In the free state bacteria are scarce and too small to be retained byazooplankter's filtering apparatus. It is only the bacteria aggregated into particles large enough to be retained on the filtering apparatus that are valuable as food.
Diaptomus gracilis and D. graciloides are unable to ingest dispersed bacteria but do ingest aggregates (Manokov & Sorokin 1960, Malovitskaya and Sorokin
1961) . The nauplii, however, could ingest and grow on the natural dispersed concentration of bacteria.
Seki & Kennedy (1969) have found that throughout the winter in the Strait of Georgia clumps of aggregated bacteria were enough to support growth when
other food was scarce. Bacteria have also been found to be capable of support-ing growth under laboratory conditions when they are the exclusive food source,
4
-however, the suitability as food varies with species as was found by Stuart and co-workers (1931). They fed pure cultures of eleven species of bacteria to Moina macropa. Some species supported good growth and survival, some species supported no growth or reproduction and some of the species were toxic
Attempts to culture Daphnia pulex on pure cultures of bacteria have been unsuccessful (Tezuka J971) but bacteria appear to be an important factor in the diet of other cladocerans (Sorokin 1959, Monakov & Sorokin 1961a). The bacterial biomass ingested by Daphnia magna was 1.3 times greater when fed on a mixture of bacteria and algae than when fed only bacteria (Gophen 1977a). Ceriodaphnia reticulata when fed a mixture of bacteria and algae preferred and selected for the bacteria (Gophen et al. 1974).
In nature bacteria may constitute a major portion of the food. Manulova (1958) found river water filtered of algae and detritus but with 434,000-1,200,000 bacteria per ml resultated in growth, survival and reproduction in both Daphnia longispina and Simocephalus vetulus and increased survival in Sida crystallina. When the bacterial concentration declined to less than 400,00 per ml the cladocerans died within 2-14 days,
Algae are considered to be the major component of the diet of most filter feeding zoöplankton. Choice of diet species and preferences varies with each species as is illustrated in Table 3,
It was observed in early studies that zoöplankton are generally unable to digest algal cells with thick cellulose walls and gelatinous sheaths such as Scenedesmus, Cosmarium, Merismopedia, and Chlorella. Fryer (1957a) suggested that this is due to the absence of a cellulose digesting enzyme in zoöplankton. It was also observed that many of these cells which can not be digested in normal gut passage are egested and reingested several times by zooplankters. This was first reported by Dehn (1930) and later observed by Jorgensen (1962), Schindler (1968), Narita & Ward (1972), Kersting & Holterman (1973), and
Infante (1973).
In een. early feeding study, Lefevre (1942) studied the food value of species of algae for several cladocerans. This was done by combining information obtained from determining food presence in the digestive tract and on obser-vations of growth in pure cultures of algae. Although his early studies did not include blue green algae or diatoms, in a later study (Lefevre, 1950) he found Aphanizomenon to be an unsuitable food. Since this study much work has been done involving the suitability of blue green algae as food and the possibility of toxic effects from these species. The results are extremely
5
-variable and it appears that the effect of blue green algae is species specific. Several tropical freshwater copepods reject Microcystis even when there is no other food available (Clarke, 1978). Porter (1966) analyzed gut contents of freshwater zoöplankton and found Daphnia to ingest more blue-greens than Diaptomus and Cyclops.
There have been various reports of the toxic effect of blue green algae on aquatic invertebrates (Dillenburg & Dehnel 1960, Vance 1965, and Stangberg 1968, Gentile & Malonely 1969). One of these investigators (Stangberg 1968) feit that the toxic effects of Microcystis on Daphnia longispina was due to the blue-violet pigment which evolves from the cell when it is broken down. One of the most extensive studies of selective feeding of Daphnia pulex was conducted by Arnold (1971). He found when a mixture of food was dominated by blue-greens cladocerans could survive only when the algae were in low numbers.
In the absence of mechanical interference from colonial forms the blue-greens were still rejected more frequently than greens, Survival of Daphnia at high concentrations of blue-greens was lower than at the low concentrations and he suggested this was due to inhibition by blue-greens rather than poor nutrition.
Other investigators (Daley 1973 and Tezuka 1971) found no evidence of toxic effects from blue green algae. Wbrking with Daphnia carina Tezuka (1971) found inhibition of feeding when given Microcystis, however, when the pH was
adjusted prior to experimentation there was no inhibition. He suggests that the inhibition of feeding in the presence of blue-greens is due to elevated pH from vigorous photosynthesis which occurs during bloom conditions of blue-greens rather than toxic substances.
Burns (1968b) presented a combination of factors involved in rejection of blue green algae. These algae are generally filamentous, colonial, or covered by a thick gelatinous sheath. All of these factors cause a mechanical inter-ruption of filtering by the thoracic appendages of cladocerans. She has also observed some blue green algae being rejected in the labral region and suggests that this is evidence that a chemical property of the food might also cause rejection.
The general impression is that blue green algae are used less than other types of algae. There are, however, various reports of ingestion of blue-greens by rotifers, copepods, and cladocerans (Gras et al, 1971, Pejler 1957, 1965, Watanabe et al. 1955, Walter-Geller 1975, Pourriot 1967, Dumont 1977, and Monakov 1972), Other authors have reported that although blue green algae are
ingested they are poorly assimilated resulting in poor growth and survival for the zoöplankton (Lampert 1977b, Malovitskaya & Sorokin 1964, and Schindler
6
-1968). There have also been several cases where blue-greens are assimilated very well and compose a major component of the diet (Sorokin et al. 1965, Moriarity et al. 1973, and Roman 1978).
Schindler (1971) studied the suitability of blue green algae as food. He found Diaptomus gracilis ingested Microcystis at the lowest rate of all algae tested, however, the assimilation of this algae was fairly high (43.3%). The opposite effect was found with Cyclops strenuus which ingested Microcystis at a high rate, however, assimilation was very low (less than 10%),
2 Methods
The most common method of food collection for most copepods and cladocerans as well as a great raany rotifers is by filtration of water to remove the particulate matter in the water. The filtration rate of zoöplankton is the volume per unit time and is a tneasure of the volume of ambient medium con-taining the number of cells eaten by one animal in a given time period
(Edmondson & Winberg 1971). This does not imply that the exact volume of water which passes over filtering apparatus is known, that all particles are removed from the water, or that all particles retained have been eaten. Various terms which have been used in the literature to mean filtering rate include
filtra-tion capacity, speed of filtrafiltra-tion, and grazing rate.
Feeding rate, in contrast, is a measure of the amount of food ingested by an animal per given time. The feeding rate is a measure in cell numbers, volume, dry weight, carbon, or nitrogen. A detailed historical review of the equations used in the estimation of filtering rate is given in Coughlan (1969),
The oldest method to measure the filtration rate is the cell count method (Fuller & Clark 1936). With this method the number of food cells are counted before and after a period of feeding. In early studies the feeding period was several hours long and therefore problems uere encountered with cell growth and sinking during the duration of the experiment. Several precautions were incorporated to overcome these interferences; a control without animals was used (Fuller 1937), and stirring was added to decrease sedimentation (Harvey
1937). The method is now commonly done in closed bottles with continuous rotations. The filtering rate is calculated according to the equation of Gauld (1951);
~ 7 —
Filtering rate
V (log Cc - log ct)
(loge)
V = volume water/animal C = cell count of control
c
C = cell count with animals after time t
t = t ime
There are some disadvantages to this method; 1) it is only valid if filtering rate is independent of concentration, 2) in using controls with no animals it is assumed that the excreatory products of the zoöplankton do not effect the growth rate of the food cells, and 3) food particles can pass through the digestive system and become resuspended and thus give errors in calculations. The advantages to this method are that it requires no expensive equipment and that it can be long term and thus take into account diurnal variations from intermittant feeders.
More recently the use of food cells labeled with a radioactive tracer has become a much used method. This technique which determines the uptake of radioactive isotopes from labeled tracers was developed by Nauwerck (1959) and Monakov & Sorokin (1961). The method uses a much shorter feeding time, improves accuracy, and eliminates the problems of cell growth during the experiments. The three basic ways of applying this method are thoroughly discussed in relation to the advantages and disadvantages in several publica-tions (Edmondson & Winberg 1971, Lampert, 1977a). The filtering rate is cal-culated by the equation;
T1.n . , 1 . - — I , —K counts.min .animal
Filtering rate (ml,animal .hr )
x
counts.min .ml labeled food
60
min. in labeled food
A more recent method which is now frequently applied is the coulter counter method. The advantage of this method using an electronic partiële counter is
that information is obtained not only on the filtering rate but also on the sizes of food particles eaten and possible size selection. This method is thoroughly discussed by Kersting (1973).
An indirect approach to information on filtering and feeding measurement has been taken by McMahon & Rigler (1963), Burns (1966), and Starkweather (1978) who measured raandibular movement of daphnids to provide more information on filtering mechanisme.
i — n mm
Although ie gives no information on the rates of feeding, the examination of zoöplankton gut contents can be used to give an indication of what diet
species were eaten or preferred (Pacaud 1939, Fryer 1957; Lebour 1922, Jorgen-sen 1962, Porter 1975, Clark 1978, Nadin-Hurley & Duncan 1978). This method must be used with caution in making definite quantitative estimates. It has been observed (Clark 1978) that copepods readily regurgitate and defecate
under stress resulting in etnpty or half erapty stomaches, Also, some ingested foods are more quickly digested than others and difficult to identity in stages of decomposition.
The greater portion of feeding studies has been done on isolated species under laboratory conditions. Fewer observations have been made in nature where a much more complex situation exists. Pacaud (1939) and much later Tappa (1965)
compared gut contents of natural zoöplankton to phytoplankton available in natural conditions to obtain information on feeding selectivity,
14
In 1959 Nauwerck introduced the C method to determine filtering rate of natural planktonic communities ^n situ. This method has been improved upon by Richman (1958), Burtis (1966, 1968a), Burns & Rigler (1967), and Lampert (1977a) and is now perhaps the most coimnon method used for in situ studies. Gliwicz (1968, 1969a) introduced an in situ method of estimation of grazing of natural populations by comparing abundances of algae, bacteria, and detrital particles in especially designed plankton traps. This method was later used by Haney (1971) and Crowley (1973) in cotnbination with the isotope method,
A modification of tbe plankton trap method was used by Porter (1977). She used large polyethylene enclosures to study zoöplankton feeding _in situ. Recently Nadin-Hurley & Duncan (1976) have attempted to obtain a more com-plete picture of zoöplankton feeding in situ. They have made simultaneous microscopic examinations of gut contents as well aa food particles available
in reservoir seston. With this method they were able to directly observe the quantity, nature, and size range of food particles being ingested by daphnids in the reservoir.
3 Food size
An early observation on the effect of food size on feeding was made by Fryer (1957) who stated that large species tend to be carnivoirs and small species herbivoirs. Among the herbivoirs the smaller species eat the smallest algae
9
-and the larger algae -and that in this manner the species can co-exist. This theory was later challenged by Edtnondson (1965).
Nauwerck (1963) as well as Lund (1965) feit that large phytoplankton particles are not an important source of food for filtering zoöplankton. However, in view of more recent studies such as Gliwicz (1977) and Herbert (1978) it is most likely this is the result of mechanical inability to digest larger
par-ticles, Sorae zoöplankton species are able to overcome the problem of large size of food particles by size modification. 0'Conner et al. (1976) observed Acartia clausi breaking down chains of Thalassiosira into smaller sizes that it was able to digest. Gauld (1966) has observed copepods in nature to grasp large particles and suck out the contents.
Only recently have ecologists begun to examine the details of size selective grazing. There is now evidence that the size of the food partiële is important for filter feeding zoöplankton (Suschenya 1958, McMahon & Rigler 1965, Gliwicz 1966, McQueen 1970, Porter 1973, Berman & Richman 1974, Burns 1968, 1969a). Studies on both experimental (Burns 1968) and natural populations (Nadin-Hurley & Duncan 1978, Wilson 1973) indicate that the maximum size of food ingested is related to the size of the animal as well as the size of the fil-tering apparatus. Burns fed sphaerical plastic beads (1-80 y in diameter) to six species of Daphnia and Bosmina longirostris. She observed a strong posi-tive correlation between the increase in body size and the increase in the size of beads ingested. She suggested that the equation § = 22x + 4.87 (where c)> is the diameter in y of the largest partiële and x is the carapace length) could be used to predict the availability of various members of phytoplankton to different sized filter feeding Daphnia. In later studies (Burns 1969a) she found no difference in the actual size range ingested by Daphnia mendotae and JD, pulex, however, the larger species ingested a larger percentage of the
large particles.
In the analysis of gut contents of natural zoöplankton species fed on natural phytoplankton as well as artifically prepared particles of known sizes Gliwicz
(1969b) and Neill (1975) were able to determine the maximum partiële size and preferred particle size range for various species of zoöplankton. Alfchough large and small crustacean zoöplankton both ate a large size range of food particles the larger species exhibited their preference for larger particle range.
Rotifers consistantly collect most intensively the particles which are less than 10 ]i in diameter. Pilarska (1977a) working with the rotifer Brachionus rubens found the feeding rate to be very much effected by food size. This
10
-species fed most intensly on the food particles in the 3-8 ]} diameter range. Filtration on smaller cells such as bacteria was 2.5 times lower and when given only larger particles filtering rate was as rauch as 50 times lower. Working with Acartia Wilson (1973) found a corabination of selective and
non-selective raechanisms. He suggests two possibilities; 1) that selection is based on particles grasped and ingested, and 2) that it may be based on
par-ticles touched and not ingested. His hypothesis is that the copepods scan the size distribution of particles available and capture particles larger than the one most previously digested more efficiently than a particle that is smaller,
Size selection of zoöplankton predators is somewhat different than that of the filter feeders. Some of the recent studies in freshwater ecosystems suggested that size-selective feeding by invertebrate predators may have a significant role in species structure of zoöplankton communities (Dodson 1970, Dodson et al. 1976, Kerfoot 1978, Brooks & Dodson 1965). Generally invertebrate predators are limited by the maximum size of prey they can successfully cap-ture or handle. Thus, they exert a,selective impact on smaller more easily manipulated prey (Anderson 1970, Brandl & Fernando 1974, 1975a» 1975b, Kerfoot
1978). Following this course of thinking large prey species would have pro-tection form predators and dominate over small species in an environment with invertebrate predators.
The actual observations of Landry (1975) are contradictory to this theory. He studied the predation of the copepod Labidocera on copepod nauplii. The cap-ture rate increased as a function of the prey size even though the larger naupliar stages were better able to avoid capture.
A different approach to size selective predation was taken by Strickler and Twombly (1975) who have suggest that it is not the size of the prey but the size of the hydrodynamic wake that determines predation rate. When an animal swims through water it creates a wake, which is dependant on the size, shape and speed of the animal. A wake of a certain size induces an avoidance reac-tion in an approaching animal and a wake of a smaller size is not recognized at all.
4 Body size
Filtering rate has been found to increase with an increase in body size in four species of marine copepods (Gauld 1951), with Calanus (Marschall & Orr 1955a), with Daphnia magna (Rhyther 1954, McMahon 1962) with Daphnia
11
-schoedleri (Hayward & Gallup 1976) with Artemia (Reeve 1963), and with Teaiora (Berner 1962) . These were all general observations that larger animals filter at a faster rate. Gauld and Berner used body surface area as a means to measure body size, Egloff & Palmer (1971) used the area of the filtering appendages, while Marshall & Orr and Rhyther used body weight which makes their results difficult to compare to more recent studies which use body length.
Feeding rates of Daphnia exhibited considerable variation from replicate to replicate in studies of Rigler (1961), McMahon (1965), and McMahon & Rigler
(1965) which stitnulated more detailed studies to deterraine what relation existed between filtering rate and body size. The filtering rate has been found to be a cuhic function of body length for Daphnia rosea (Burns 1966, Burns & Rigler 1967), Simocephalus vetulus (Ivanova & Klekowski 1972), and Daphnia pulex (Buikema 3973) and a square function of body length for Daphnia pulex (Ricfrman 1958 as calculated by Buikema 1973) and Daphnia magna (McMahon
1965). The extent of the filtering rate : body length relationship has been shown to be dependant on light intensity (Buikema 1973) as well as temperature
(Chisholm et al. 1975, Burns 1969b). The filtering rate of four species of Daphnia was a function of the approximate square of body length at 15 C but a function of the cube of body length at 20 C (Burns 1969b). Difficulty was encountered by Burns when she attempted to derive a general equation relation filtering rate and by body length.
5 Crowding
The crowding of filter feeding zoöplankton has been found to result in a decrease in the filtering rate (Berner 1962, Cushing 1959, Marshall & Orr 1962, Buikema 1973). In studies with the marine copepod Acartia Hargrave & Geen (1970) observed a decline in feeding rate as the number of Acartia per unit volume of water increased. They indicated that the lowered feeding rate at high zoöplankton densities may be the result of re-filtration of the same water.
Food consumption of Daphnia schoedleri showed no significant difference in food consumption when 5 ml/Daphnia or 10 ml/Daphnia, however, there is a significant difference at 20 ml/Daphnia where food consumption was highest.
12
-6 Light and periodicifcy
The effect of light on the filtering rate of zoöplankton is a factor which has been much overlooked in the study of zoöplankton feeding. Some early
studies showed that zoöplankton copepods exhibited diurnal and seasonal varia-tions in feeding. In studies with the marine copepod Calanus, Winpenny (1938), Fuller (1937), Gauld (1961), and Marshall & Orr (1955A) all observed that there was an increase in feeding activity during the night. Nauwerck (1959), using the C raethod found identical night and day filtering values for the freshwater copepod Diaptomus but found the cladoceran Daphnia longispina exhibited higher values at night. In a more recent study Rhinediaptomus indicus, a tropical copepod, has also been shown to exhibit an increase in feeding during the night (Singh 1972).
McMahon (1965) using Daphnia magna found a consistant filtering rate in the dark and at illuminations up to 500 foofc candles. However, he found that as light intensity was increased from 500-1000 foot candles Daphnia magna
filtered at a rate 1.4 times the value in the dark. Hayward and Gallup (1976)' observed a similar response with Daphuia schoedleri which had a feeding rate
1.5 times higher at 950-1000 foot candles than in the dark. Schindler (1968), also using Daphnia magna, found no significant effect on filtering rate be-tween the dark and 1000 foot candles.
The larger size of the cladoceran Schapholeberus when grown in the light has
been attributed to the increase in feeding activity in the light (Klugh 1927). The predation rate of Leptodora kindti has been found to be effected by light intensity. This crustacean has been found to eat less in the dark than under normal light or 24 hour illumination (Mordukhai-Boltovskaja, 1958).
A different approach was taken by Starkweather (1978) who attempted to make direct observations on feeding behavior of Daphnia pulex by studying mandi-bular activity. His results showed a nocturnal decline in mandimandi-bular activity which indicates a decline in filtering rate and contradicts the work of others who observed an increase in filtering rate at night.
Buikema (1973) used Daphnia pulex to study the relation between body size and acclimation to light intensity on filtering rate. The relationship between filtering rate and body size of unacclimated animals was significantly effected by the light intensity 1.7-3.5 foor candles were simulatory to acclimated and unacclimated animals. The effect was more evident in larger animals. Light intensity greater than 28 foot candles suppressed filtering rate of small unacclimated animals and stimulated the filtering of large
13
-unacclimated anintals. After acclimation there was no effect of intensity above 7 foot candles on the filtering rate of either large or sraall animals, Buikema suggests that perhaps some of the inconsistancies of earlier works may be artifacts which depend on light intensity, size of animal and state of acclimation.
Rhythmic diel patterns in zoöplankton grazing have been observed under labora-tory conditions with Daphnia middendorffiana (Chisholm et al. 1975), Daphnia pulex (Starkweather 1975), natural lake populations (Duval & Geen 1976) as well as in situ studies associated with vertical migration (Haney 1973, Haney
& Hall 1975).
Increases in the epilimnetic zoöplankton conraiunity grazing at night were found by Haney (Ï97I) to be concurrent with the vertical migration of the grazier
to the surface. In later jln situ diel zoöplankton studies in Heart Lake Haney (1973) found the filtering of the entire zoöplankton community to be the same at noon and midnight on one occasion but during a second study the rate was significantly higher during the night.
It has been demonstrated in situ (Haney & Hall 1975) that Daphnia pulex and Daphnia galeata mendotae migrated vertically and exhibited biraodal patterns in their filtering activity, however, no pronounced diel pattern was observed for Diaptontus pallidus. The filtering rate of Daphnia was the lowest during the day when Daphnia were in the deep water. The filtering rate increased during the population ascent at twilight, decreased at midnight and then once again increased before the morning descent. From 1,5 to 4 hours was required to change from the minimum day value to the maximum night value which was as much as 25 times higher. As much as 85% of the daily filtering occurred be-tween dusk and dawn.
There results have important implications for the interpretation of filtering studies. Since there is evidence that most feeding of daphnids occur at night significant errors can be made in the estimation of zoöplankton feeding when it is done on the basis of daytime values.
Haney & Hall (1975) suggest that the regularity and bimodality of the diel filtering rates of Daphnia suggest circadian rhythmicity in the feeding be-havior of Daphnia.
7 Temperature
\ -
1 4-filtering rate of zoöplankton animals. Predation rates are higher at warmer temperatures for both copepods (Gophen 1977b, Brandl & Fernando 1975a, Ander-son 1970, Main 1962) and cladocerans (Monakov 1959, Mordukhai-Boltovskaja 1958).
There are vsrious reports of an increase in filtering rate with an increase in the temperature (Fuller 1937, Nauwerck 1959, Monakov 1959, Marshall & Orr 1955a, Main 1962, Mullin and Brooks 1970). However, the response is not always a direct linear relationship. For the cladoceran Ceriodaphnia reticulata
Gophen (1976) found that the food intake increased 142% when the temperature increased frora 15-20 C but the food intake increased only 6% as the tempera-ture increased from 22-27 C. The most suitable teraperatempera-ture for survival was found to be 22°C.
Sorae investigators have observed an increase in filtering rate with an in-crease in temperature to a peak teraperature after which additional temperature increase results in a decrease in filtering rate. This has been observed with Paphnia middendorffiana (Chisholm et al. 1975), Daphnia rosea (Burns & Rigler
1967), Daphnia magna (McMahon 1965) and Daphnia schodleri (Hayward & Gallup 1976).
In experiments with several species of Daphnia Burns (1969b) found two types of response in filtering rate with an incraase in temperature over 15 C. Daphnia schodleri and Daphnia pulex increased filtering rate from 15-20 C after which there was a decrease in the filtering rate. In another type of response found in Daphnia magna and Daphnia galeata there was an increase in filtering rate over the entire temperature range used (15-25°C) and at 25°C the rate was 2-3 times higher than at J5°C.
Problems are encountered in attempting to interpret responses to temperature change as Kibby (1971) has demonstrated with Daphnia rosea that the effects of temperature are effected by the state of acclimation. Burns and Rigler
(1967) reported the temperature of maximum filtering rate for Daphnia rosea to be 20°C, however when Kibby cultured D. rosea at 12°C he found the maximum filtering rate to occur at 14 C after which the filtering rate decreased. This effect of temperature and maximum filtering rate being rslated to acclimation can also be found in nature. Most Daphnia frora lakes have a temperature
optimum at 20-22 C, however, Daphnia middendorffiana, an arctic species, has its maximum filtering rate at 12°C (Chisholm et al. 1975).
The effect of temperature on filtering rate of Daphnia was found by Burns (1976b) to be related to body size. At 15°C filtering rate was approximately proportional to the square of body length but at 20°C it was proportional to the cube of the body length.
15
-The first detailed attempt to study the effect of pH was that of Ivanova (1969) who studied the response of seven species of cladocerans to different pH
values. The animals exhibited a maximum feeding rate in a narrow range with lower rates at pH values higher and lower. A close correspondance was found between the pH of maximum feeding response and the pH at which the animal is found in nature. Similar results were observed with Simocephalus vetulus (Ivanova & Klekowski 1972) and Daphnia pulex (Kring & 0'Brian 1976a). The maximum feeding rate of Daphnia pulex has been found to occur near the pH value which the animal was accustomed to during growth and development (Kring & 0'Brian 1976a). This species was found to be able to acclimate to an altered pH in a period of 6-8 weeks. In view of these results acclimation to pH must be taken into consideration when feeding experiments are conducted.
The results of Kring & 0'Brian (1976a) as well as those of Tezuka (1971) and 0'Brian and deNoyelles (1972) suggest that the severe inhibition of zoöplankton filtering rate after blooms of blue-green algae is likely due to a physiologi-cal response of the zoöplankton tó high pH caused by increased photosynthesis and not the result of secreted toxins as is most commonly suggested.
9 Oxygen concentration
Very little attention has been paid to the feeding rate of zoöplankton orga-nisms as effected by the oxygen concentration. It has been known for some time that with the exception of Leptodora cladocerans can produce hemoglobin
(Fox 1948, Fox 1953). It has also been reported that hemoglobin never occurs in lake daphnia but only in species found in ponds and ditches (Fox 1948). It has been demonstrated by Fox and co-workers (1951) that the feeding rate Daphnia obtusa without hemoglobin was depressed at low oxygen concentrations but that it increased as the amount of hemoglobin in the animals blood in-creased.
More recently Kring & 0'Brian (1976b) working with Daphnia pulex have clearly shown that hemoglobin allows Daphnia to feed at low oxygen concentrations and a high hemoglobin level allows the animal to feed at 2-2.5 times faster than an animal without hemoglobin. When exposed to decreasing oxygen concentrations Daphnia pulex continues to filter at a high rate until it reaches a critical concentration where the filtering rate drops rapidly. This critical
concen 16 concen
-tration has been found to be 3 rag 02/liter for Daphnia pulex (Kring & O'Brian
1976b) and Daphnia magna (Heisey & Porter 1977) and 3.6 rag 00/L for
Siraoeepha-lus vetuSiraoeepha-lus (Hoshi 1957). It was found (Kring & O'Brian 1976b) that is the period of exposure to the low oxygen concentration was longer than 8-10 hours
that Daphnia pulex was able to resumé and exceed its initial high filtering rate. It is proposed that this is due to a stimulus for hemoglobin production at low oxygen concentration.
Similar response to low oxygen concentration has been found in Daphnia magna (Heisey & Porter 1977) but they found that Daphnia galeata mendotae responded somewhat differently vith a steady decline in filtering rate with decreasing oxygen concentrations.
Table 1 Filtering axtd iogestion rates vf some planktonic zoöplankton
zoöplankton species
life stage1
method
used2 type of food
f i l t e r i n g rate nu. animal""1. day
rate cell s. animal—1 .day~1
funiess othenn.se noted)
oonments reference FHOTOZOA Loxodes m g m i s BOTIFEEA Brachïonus calyciflorne Bracfaicmua calycifloras Brachionua ealyciflorae Brachiomis calycifluniB Braohionus calyciflpniB Braebionua p l i c a t i l i s BraehlcmiB p l i c a t i l i s nuB p l i c s t i l i s A A A A A A A A 5 5 Rnodotorula Ghlorella. pyrenoxdosa. mxxei algae Laugerheimia Ep. ihigleia, s p . , Hhodutorula sp. Euglena eracilis Rhodotorula gl-gtinis tertiolecta Dnnaleilla aalïTia 24 0.016-0.027 .031 .024 48—134.4 tnn 0.263 0.336 0.026 0.024 O.008 0.008 0.240 0.144 0.201 0.086 0.073 0.023 0.016 0.027 0.029 0.018 0.015 0.036 1.08-1.2 1 10 2.4 1 103 1.2-2.4 1 03 13.57 I 10 4.32 x 106 26.8 x 104 3.25 ï 10 2-3 1 104 2 . 1 x TO4 2.2 x 104 1.7 x 104 1.4 1 104 2.1 x 104 0-5 1 TO cel I s . ml 1 0-5 1 106 2-6 1.0 1.0 jfg. 1 10.0 10.0 50.0 50.0 T food, food, dark food, l i ^ l t food, dark food, ligi+ food, dark o 0.1 Mg-nu" food >100 ug-ml~ food 1.03 1.03 x 10 10 cells.ml" 1440 x 10* cells.ml"1 1440 x 10* cells.Bl"1 775 x 10* c«lls.Bl'1 970 1 10* cells.ml"1 970 10* cells.ml"1 590 x 103 cells-mT1 GcnJ-der, 1973 Starioreather * ( K l i e r t , 1977» Halback £ Ealbacfc-Erap, 1374 Bfelkovskay», 1963 Ernsan, 1962a
Starkneather & Oilbert, 1977b Deirey, 1976 Chotiyapputta A Hïrayama, 1978 Eirayama ft Ogana, 1972 Ito, 1955 Doohan, 1973
Hbl« 1 (otaitünud) zoöplankton apocies Brachic-ng rnbene -EuchlaniB dilatata Ktllicottia sn. I«r*tella coehleariB C0RFODS-CALA1DII1A Acarti* claati Acartia clansi Acartia clansi Aoartia clauai Aortia danai Aoartia tonea Acartia t e n t Aortia rtona» Acartia. tonaa Acartia tonea Acartia tcnsa Acartia tonsa. l i f e f etage A A A A Ig A A A
i
Aï
A~ï
A A A X c A A A A MtDOd UBed^ 1 4C CC 3 2P X s 5 32p X V X X X X X ^c ai.» cc type of food CIÜDPella 'vnlflaris Ankiatrodesnnis falcatusChlorella vul garis Cblorélla liiteovirides Soenedeaims ol.iI.ruuB ScenedeBDOB scuninatis Chlaiipdomonas elejsans AftrobacxcT aspo^dscs ndxed algae nixed algae daaardOBanaB st>. Êxuüena eraoilis Euelena eeaiculata 33 f disaster partieles >10 ^ flagellates >10 ii diatoioB ïïialassiosjra fJux±a.tUie ülialaBBioBin' fXuviatili.s Katural plankton Ba-tnral plankton B^toral pil «wVtnw Katural plankton iatural plankton (a-taral plankton filtering pate Bl.aniinal—1. day^1 0.002-0.027 0.192 0.187 ü.254 0.153 0.153 0.007-.168 9-0 2-7 10.4 8 . 6 23-0 £5-1 105-0 ï-10 4-19 19-75 36-106 2-11 1.44-3-36 2.68-4-08 1.2-2.88 ingestlon rate oell8.aniaBl-1.day~1
{nnlesB otherwise noted) 0.209 MS C,animal~ -isj 0.201 0.170 0.046 0.015 0-004 0.082 1.771 "g C.animal~1.aay~1 1.776 1-997 1-574 0.175 2,7 26.6 1 103 1.6-125-3 1 103
5-29 «g dry wt.anin«a~1-day"1
5,S tig dij- wt.ani!Bal~ .day" 20-1 lig diy vt.anisal~ . day"~ 42.7 tv diy irt. aninal . dajr"
comaents 2°C Be0 15°C 22.5°C in situ in si~tu referonco Pïlarska, 1977a, 1977b King, 1967 Haney, 1973 Glinioa, 1970 KarBball ft OTT, 1962 Ar.Taku, 1964a Conover, 1956 Marahall * Orr, 1962 tnraiu, 1963 Conover, 1955 Anrafca, 1963 Anralni, 1963 Anrufca, 1964 a Eargrave & Geen, 1970 Hargrave <i Qeen, 1970
Table 1 [contimieö) zoöplankton species
Jatideus diverggiB
Calanua f innexchimiB
C&ISTTUS •fiTi»mi*cJliCïlB
CalanuB finttaïchicïus Calonus f inm&rchïdis Ca/ïamiw ^TkiBnt^chi.cns CsQasus •fÏTi—Tfthigofl Cftlwus ^••«•fcifshirwiH Calanu» rimmrchicoB C. helffolmdicuB stage1 A A C-V A
*ï
C-V 1 A A A A?
JUf A A A C-V C-V C-IV c-m B - m J^.IV B-V S-VI C-I c-n c-m A used2 CC 1! H 32p H CA V 3f •g K H K K K 5 S ff ff F ff 9 ï H X ff s ff ff ff type of f ood Thalassiosira f l a v i a t i l i s Coscïnodigcus a n ^ s i i Coscinodiscus aziglsii Hatural plankton Thalasaiosira fluvitalia Jitylixmi sp+ Htylinm sp. Sitzechia ap. Bïtaschla sp. Camdue jarticlee CÏLlaiitfdomonas BD. >TO IL a l ^ e > 1 0 » f l a g e l l a t e s >10 *• diatcns a l . animal~T.day 240 101 84 1200 36 4275 200 76 74 34 172 108 85 108 60 54 7-92 0.192 4.56 2.88 10.8 5-52 1,544.6 1,704-7 879.6 533.8 1.0 1 . 2 1.7 2 . 0 2.8 Ë.4 9.2 84 43 o e l l s . animal"~1. cLsy~ (anless otherwise noted)4.0 lig C.aEïmal" .day~ 9-4 Ag C.animal" .day~ 21.0 j*g C.anioal~1.day~1 31,8-132.7 x 103 comments in sitti 2°C 8 ° C -15° C -8°C 15°C 12,5°C 17°C 17°C 17°C 31.5%° 29-5%° 27.5°/oo 31-5°/o0 29-5°Ao 27.5°/oo 31.5%o 29-5°A° £7.5%o sal mity salimty salinity salinity Ealinity salinity salinity salinity T eference BoTjei-tson i Proet, 1977 Harv^y, 1937 Gauld, 1951 Marshall & Orr, Cushing, 1959i Corner, 1961 Cushing, 1964 Anraku, I96J AnTnlcu 1 ^ É ^ Aaratu, 1963 Anrafcu, 1963 Ar.raku, 1964B Eaymon-t k Gross, Barvey, 1937 PulIer, 1937 P u l l e r 4 Clarke Gauld, 1951
Marshall & Orr,
Jfershall * Orr, 1955b 1942 1936 1956 195?aftb
Tabel 1 (cmtinaed)
zoöplankton species Calamis heleolandicus
CalaEUB helgol&ndicuB
Calanus hypertOT eus
Calanus sp. : Calanus sp* Centrowwes hawttus Centrotwxes hamatus CeirtroKMïes hanstuB DiaotoüBAS —racilïs Diaptoflus cracilis Diapto-us firsciljs Siaptoous teracilis l i f e stage1 A A C-V A C-T A A An A A U A A method used^ CC H V s 14c K 14c type of food Thsi assiosira f l u v i a t l l l s Katural plankton Satural plankton Kialassiosira f l u v i a t i l i s Lauderia l o r e a l i s Kityliam briörtuell 2 mixed plankton Thalassiosira sp. Chlaimrdompnas sp. >10 f flagellstes >10 p diatoms Chloj-ella sp. Scenedes—as sp. Diplosph&eria sp. AnkistTodesmus SP. Carter ia sp* yitzgcfaxa. sp. Fediagtrunt sp* Haematöcoccus Bacteria Uatural pbytoplahkton Kelosiia sp. & Asterionella sp. Asterionella forsnosa filtering rat« mL.aniaal-1.day-1 1-100 4- >100 16-50, ï = 30 10-75, ï = 50 48-96 16S-240 128-7,018 8-39 311-76 15.0 2-7 0.61 1-51 2.40 0.94 1.32 1.76 3-54 1.61 2.45 0.87 1.96 0.02 2.16 0.19 1.92-1*96 U* DO 1-57 1.17 0.53 0*48 0.37 0.16 ingeartion r a t e cells.aniasl— 1. d a y ~1
funless otheTwise noted)
137-2,100 246-2,435 187-2,420 0.05-390.335 tiody wt.day"1 2.5 Bg C.animal" -day~ 7.87 1 103 11.71 1 103 13.25 1 103 24-00 x 103 36.96 1 1C3 32.16 2 1C3 comnents 10°C 15°C winter siiinmer 13-395ÏAE 19-5O5ÊAE 13.4-30^ AE 10°C 5°o 12°C 20°C 12°C 20°C 12°C 20°C 12°C 20°C 20°C 20°C 20°C 20°C 20°C 40-50* AE 24~?2 1 10^ c e l l s . t t l "1 198 1 103 o e l l s . m l ~1 0*5 1 104 c e l l s . B l ^1 1.0 1 104 c e l l s . m l "1 2-5 1 104 c e l l s - m T1 5-0 x W4 cells-ml""1 10.0 1 104 c e l l s - m l "1 20.0 1 104 c e l l E . m l "1 refeyence Jfcllin 4 Brooks, 1970 Cow^y i Coraer, 1962 Conover, 1962 Harvey, 1937 Cushing, 1964 Anraku 4 Osmora, 1963 Gauld, 1951 Karshall 4 Orr, 1562 Kibby, 1971 O u l a t i , 1978 Ifalovitskaya 4 SorDkin, 1961 ï n f a n t e , 1973
Table 1 (oontinued) zaoplanktoc species UlaptomiE R r a c i l i s * U. Kraciloideg Diautonus «raeiloides Eiaptoimis w a c i l o i d e s Diaptonnis ^raciloides Diaptomus eraeiloides Eiaptomis «raciloides Diaptoszus Kraeiloides Biaptosus mirmtus Siaptomus oreeonensis Diaptontis oreeonensis Hiaptorais ore^nensis l i f e stage1 & A A A A A M.T, A A A A A method used2 » n *% X '4G If % type of food KLcrocystis SD. Oocygtis ap. fil&katothrn sp. Gloeocystis BTI* Ar.abaesa sp. Tritonema s p . Cloelastrmn s e . O s c i l l a t o r i a sp. Asterionella sp. Ankistrodesmug sp. ^ryptomonas sp. Chlorococcus sp+ Hatural nannoplankton Scenedesmus SD. Natural phytonlaiïlrtor 1^ diameter p a r t i c l e s Batural phytoplankton ÏTatural nanncplanlrtoTi Tfatiiral net plankton Chroarolina s c h e r f e l l n Chlorella p^frenoidDsa Ochromonas STJ. Chlaflffdonionas reiTihardti Cryptomonas sp. ifavlca2s sp. Net plankton Chlamrdomanas reinhardti Chlorella vul gans Chlorella sp. Hatural plaritton-*bloo!D of "Chlorella" type filtering rate ml. aniiDal— *, day~1 4 . 1 1.92 1.96 0.6-. 35 4 . 1 .024^2.64 35-04 0.3-2-? 1.92-2.36 0.4Ö-1.2 1-5 1.33 1.63 1.43 1.D7 0.2S-2.C7 1.91-12-9 2-5 2.5-1-4 1.4-0.3 COS-C. 1 0.12-0.067 ingestion r a t e c e l l s . s m a a l " ' ' . Sajr~1 (imless otheruise uerted) 28.08 Hg dry irt.animal .day 101.76 49-92 37.44 8.16 47.04 61.92 36.4 171.84 40.8 46-56 0.6-2.2 mg dry v r t . l i i e ' 1. day 1
3.84 ug wet w-t.ajiimal . daj 15.61 iig wet w-t.anima! .day 30.41 ug wet wt-animal" . daff 89.98 mg wet wt.animal" . day~ 210.47 «g wet Bt.animal .day 0.404-11.123 1 103 1.3-25.25 1 103 comnents 45.3% AE 13. T% AE 11.3% ÈB iA.2% SE 73-5/E AS 1 9 - 9 * AE 29.15ê AE 2 9 . 7 ^ AE 20.1# AE 49-4% AE 100 % SS 13.6 1 103 cells.ml~1 24.S i 10 cells.naT''' 52.0 1 103 cells.nü~1 198.0 x 103 cellE.tü^1 13-É x 103 cells-nü"1
June — hagjsest va]ues TOT 30 M diameter p a r t i c l e s 2.1 1 103 c e l l s . m l "1 20.7 1 103 c e l l s . m l "1 20.0 ï. 10 oells.BÜ 1 23-0 1 103 cells.ml"1 19.7 1 10J cells.ml"1 247-17,644 c e l l s . m l "1 175-7,461 cells.ml"1 1.5-25.0 1 10^ cells.ml" 25-52 1 103 celJs.ml^1 52-198 x 103 cells.snl"1 200-^00 1 105 cells.ml 1 'efeTenoe Schindler, 1971 Kalovitskaya 4 Sorokin, 1964 Belyatskaya, 1959 Gliwioa k HillDricht-injcowska, 1972 Malovitskaya & Sorokin,
1964 Cliwioa, 1977
C l i m e z , 1970 Sautferecfc, 1959 Bogdan & McKau^it. 1975
Mcftueen, 1?70
Eichman, 196É
T&ble 1 ( coni imied) zoöplankton species Siaptotaua oreficnensie Biaptonus oreKonensiB BiaptomiB pallidus Diaptomus siciloides Diaotomig spp. Piaptonnis Bpp. Epischura l s c u s t r i s LiBmocalamis macrums Xetndia Ineens Pseudocalanus minuies Fseudocalaxms «inutiiB Pseudocalanus misutue pseudocalanus «imrtus Fseudocalaxrua mnutUB pFf'^tfvyil «TMIÖ imjn^tiiQ Pseudocalanus minutüE Pseudocalanus ffiinutus t Tenors lonelcornis PsenHocal ftnua nimïtua & Tenora lonKicorais life A A AJ AO A A A A k 40. A A A AO. k A l i C mettaod used2 ^7 3 2P N I4C wc 3 2P V N H 32p S H F S N type of food Bhodotorala sp.. natural plankton Hhodotonü^ sp*, natural plankton Bhodotonila sp. Bhodotorula sp.
Pandorina. monnum, GhlaE^rdo-nonas sp. Hahnopl ankt on Set plankton Hhodotorula sp-Naimoplankton Bet plankton Scenedesmus sp-ScenedesflME sp.t bacteria Chlamvdomonas sp. >10i" flagellatea >10 f diatoms Thalassiosira f l u v i a t i l i s ChlaoDrdosLonas sp. >10 ji flagellates Hatural plankton Hatural plankton Filtering rate ml. animal" . day~1 2.1-2.2 0.48 0.75-1.8 0.6-1.8 0.5-1-35 0.75-5-5 2.0 18.0-40.0 3.4-36.0 4. T 11.2S-12.0 18.96-26.0 3.05 2.45 2.04 2.14 1.02 1.24 1-3 0 . 4 14-22 21-40 15-32 6-10 6 . 8 9.1 40.0 102.72 9.0 4-12,5 tngestiem rate
cell s. animal" ^. day~^ (xinless otherwise noted)
7.B-42.8 i 10J
3.5-25 v-g dr-y wt. aniraal . day~ 40.6 >ig diy wt.animal . day
comments in situ noon midnigïit noon icidm^t animal laüoratory in situ 1aboratrry in situ laborat orj ^n situ 8°C i5°c 22.5°C 1O°C reference Haney, 1973 Haney, 1973 Haney £ Hall, 1975 Comita, 1964 Lane, 1975 Haney fc Hall, 1975 Lane, 1975
Eibby & Rigler, 1973
Harshall & Crr, 1962
Anj-akn, 1963
Anraku, 1964A Gauld, 1951
Harshall & Or- , 1962 Anraiu, 1963
Gauld, 1951
Karshall &. Orr, 1962 Harg-ave &. Geen, 1970
Table 1 (coirtinued) zoqplanktos s p e c i e s Hhiscttlanus n a s a t u s T&BOTS. l o t u n c o D i ï s Temora l o n g i c o r a t i s Teraora l o n g i c o r a i e COFEPODS-CTCIOPOrD Crcloos scatifer Grclops streauus Oithona s i n i l i s Oithona similis Thermocjrclops hyalinus COÏEPODS-HAHPACTICOinA Bacrosetella jflracilis -)osmir.a coregoni ^ ^ c o ^ g o n . 3O3E -• -or-eRpni life etage A A A£ *2 A A AO. C A C s A A A A aetbod nsed? CC V N K N UC type of food Bitylium ï r i A t w e l l i ThalasaiosiTa fluviatilis Chlaspdoinonas sp. >10 M flaeellates >10 y- diatoms Skeletonema costatum Xergtelia sp., uauplii Jfatural plaiürton Melpsira sp.
Scenedesious se. (decavedl JtiCï^cystis sp. Oocystis sp. Ulakatotfcrii sp. Gloeocystis sp. Triboneaia sp. Coelastrmn sp. Oscillatoria sp. Asterionella. sp. Ankistrodesinus sp. > 10 it flagellates >10 K diaioira mturzl plarfrton Tj*3.CilOÖ.es'ILÏ^i3l SÏJ» ITataral plarJrtor. Ifi diaaeter pa: - ïcïes
filtering rate 2.^-100 8.0- >100 2.5- >100 2-5- >100 193-S 1É-0 -JB.O 5.5 0.O2 0 . 0 10 0.04B-0.96J 40.08 ingesticm r a t e c e l l s , a n i r a a l " ' . d a y -1
(unleos otherviae notad)
0.06 body «t.aniiiial ,day 0.06 body wt.aninal .day
, , . . . . . - 1 . - 1 0 .c1 tody wt.animal .day
0.42 tody wt.animal .day 323-28 Mg Sry w t . a n i m a l ' ^ d a y "1
640.08 Mg 3ry wt.aninsal" .day~ 32.88 Mg djy wt.animal~1.day~1
253.80 ng dry wt.ajiijial~1.day~1
12.9é Mg dry srt.animal" -day~ 127.2 Mg dry wt.aniiKtl~1.day~1
64.8 Mg dry wt.animal" .day~ 206.4 ug dry wt.animal" .day~ 48.0 Mg dry vt.animal .day
—1 —1 86.4 Mg dry v t . a n i n a l .day 68.88 Mg d i ? wt.aninal 1.day 1 10.3 Mg dry v t . a n i n a l " ,day~ 0.33 UB C.animal" .day~ 0. ' 8 Mg C.animal .day 0. 38 Mg C animal .day 1-Do f±Q C.Ëniioal . d a y coments 10°C 15°C 10°C 15°C 10°C 8 . fjL AE 8.056 AE 19.O?SAE 18.236 AE 25.95tAB 6.2SÈAS 3 - 7 * AE 38.056 AE 11.456 AE I8.3f£ AE
values May to 0c±ofcert
10-30 M diaBHt ™-r part i - l e s reference R i l l i n * Brooks, 1970 Gaald, 1951 Karehall * Or*, 1962 Bei-ner, 1962 Manakov e t a l , 1972 Schinder, 1971 Harshall * Orr, 1962 Hargrave 4 Geen, 1970 Koriarity et a l , 1973 Homan, 1978 Kanailova, 1958 DlizKicz, J977 CllBWlCI, 197C
Tabl* 1 (oaatinMd) zoöplankton species Bo—in* eorwecmi Borttoa loncirostris Boaaln» Iweirortris Bo—la». Icndrortri»
Ho—In» Icpgiro atria Ba—la», Imurirogtria T « — H ™ l o n e i r o s t r i .
Cafiedsshnia, r e t i c u l a t a
Cariodaohni» auadranjwla
rffHfHmphn1a aamdr*TiPn'tl&
CtrwA « o h u r i ChjnioruB snhuricua dtrdoru» anhaericufl Itoimla «•biroa, •^r*"1** oaxiaata Datatal» e»t<afba •n-T*"<- oac!ill*t* Barfaai% oiciiUttai Baalmi» oucnllata n_pw-4» mtcaillaAa. Daphnia cucallat* llf« st^se1 A A A A A A A A A A A A A A A A A 1.44 • • A A A A A A •rtbod used? X I ; 32j, 1 40 1 40 ^ P 32p 1 40 32p 32j, 32p 1
t
14e 32p type of food ïwmoplantton Bacteria ' Katural lake plankton LvfistiFa SB. . Sc«Bsdesausffo-Sannoplaiittoji Set plankton Bwmoplantton ï e t plankton
Chlorella. wrenoidoBa Hhodotonüa ap., Satural Ehodotorula SB-, Batural plankton
Chlorella TralgariB
Hatural lake plankton I^ntfpa s p . , ScenedegBnia sp. Rhodotonila sp», Satural 3-3^- diameter part i e l es Bstural plankton 0.18-0.42, ï - .18 Batural lake plankton l^BgtlTa ap., Scenedeaoua SD.
ïlmrotocteriuB so. SamMplwkto* Set plankton Bacteri» HaturaJ plankton Bacteria partïclesljt «üaaeter /
mi. a»i<—i—T. day 1 10 0 . 8 0 . 4 2 . 6 0.37-1.7 0.34- -70 1.2-2.1 0-78-4-2 2 . 6 0.009-0.9, 5 = 0.44 0.45-0-46 5-7 1.1 0.4-7.7, ï = 4.6 9-84 O.012-0-30 8 . 2 2 - 5 19-2-21.6 12.5-19.2 13.44 12.00 14 .30.8 0.12-1.008 14 42.96 ingsstion ratte 1 cellB.aninal~1.day~
funlesB othervise noted)
-1 - 1 0.7-1.7 ^g C.Bnlmal .day
397 ïög alga-gm body wt *^ay 1 —1 96o mg alga-gm body wt -day 1026 mg alga.gn tody wt~ .dsjT 19-6 1 106 19-2 1 106 0,9 Mg C-aninal~ .day coments 30-5Ojf JE D.44—O.46 UlE WTTÏrfw"[ 0.31-0.35 mn aninal Heart lake Bog lake 15°C, 1 . 0 I 1 05 cellB.al"1 28°C, 1 . 0 i 1 05 celle ml"1 27°C, 1 . 0 * 105 « l l s . M l -1 Jiuie-October, 10-30 *" diameter particlea 850 1 103 eella.ml Jtay to OctobeT, 10-30^ diameter partioleB Teferenue Haiwerok, 1959 Xuntilova, 1958 Webster A Peters, 1978 Bulati, 197Ö Suscheny*, 1958 Lane, 1975 Siiechenya, 1958 Baney, 1^73 Haney, 1973 Gophen, 1976
Webster & Petere, 1978 Haney, 1973 Clizvjcz, 1970 Glizwicz, 1977 Haney, 1973 Vebstei- 4b Peters, 1978 Tesuka, 1971 lane, 1975 Oulati, 1978 Ifainiilova, 1958 Belyatekaya, 1959 Olizwicz, 19T7 Manuilova, 195? Glxzwi.CE. 1970
Txble 1 (costisiied) zoöplankton species Japhnia galaat» Jtg&nia galaat» Daphjia galeata. Daühnla «aleat Daxdmia galeala ttffihni* galeata Dscihnia «slesta Bapimi» fcwaj» Baömia lonöroina IJgDhnia lomtiBPÏna Dftphnia lcmffi.BP.ua DBuhnia lonaiBDina life stag*1 A A 1 - > 1.7 «m J A A l l J A A l l J A A l l A A 1 . 4 2 umi 1 . 5 6 mm A A A A A method used* 3 2P 1 4C 32p 14C 3^> 1 40 14C 14C T4C 32p 1 4C 1 4C type of food Ifatuxal plankton IFannoplaaktoB Set pliamon Hhodotonüa SD. Rïiodotorula ^Lutmas iriVi sftrodesmus s p . 1.9-20.8, ï = 6.4 Harmoplfflürton Het plankton Sannoplac^on Set plankton Batural plankton Teast baateri* Chlorella sp* Katural plankton Astericmella sp. AnJcistrodesnus sp. Cnrptomjnas sp. Astericmella formoaa filtering rate ml.animal"'.day~1 1.1-6.2, ï = 3-64 ,.84-10.08 3.12-11.04 4.7
254-4 •"! (mgdiy wt BaphniaJ" -day 153.6 204.0 398.4 595-2 518.4 612.0 540.0 571.0 3.6 3 . 6 14-4 26.4 34.8 40.S 15.6 3T.2 26.4 0.12O-1.32 42.48 16.32 20.16 15-74 21.0 7.94 6.26 3-45 1.61 l u g e a t i o n i-ate o e l l s . a n i m a l "1. d a y ~ f u n l e s a otiierwise noted) 2 . 4 pg C.animal -day 1 1 . 6 - 1 8 . 2 8 8 ^g C.aniinal~1.day~1 8*352—14.112 t*gG-»aniinal .day 12. 384—15- 33É tig C. anima!" . day
7.87 x 104 2.1 1 105 1.99 1 105 3.13 x 105 3-46 x 105 3.22 x 105 coaments
average nigit value
15°Cw = 0.014 L?"5 4 • 20°C 25°C 1 mg.L"1 DO 2 mg.lT1 DO 4 rng-L"1 3» 6 tng.lT DO 9 mg.L"1 DO 5 6 . 1 - 5 6 . 7 % AE 5 0 . 2 - 5 5 - 1 £ AE 39- 9 - 4 1 - 295 AE June-October, 10-30M diameter p a r t i o l e s 38.4% AE 100JS AE 91.6)CAE 0-5 x 104 cells.oü"1 1.0 x 104 cells.ml"1 2.5 x 104 oells-ml"1 5.0 x 104 c e l l s . n l -1 10.0 x 104 cells.ml~1 20.0 x 104 cells.ml~1 reference Buras k Higlei-, 1967 Bogdan & KeKsu^rt, 1975 Haney t Hall, 1975 Buras, 1969 Heisey * Porter, 1977 Baney, 1973 Lane, 1975 Gulati, 1978 Pedorov 4 Sorokm, 1967 Gliwioz, 1977 Scïiindler, 1971 Infante, 1973
TaMe 1 (ccurtraned) zoöplankton species Saohni» lomÖBDin» Desnhnia lomtteoina f PH^fthH^ 11 1 ftl^ A ^ ^n^T TUT Jfctrtinia lonaisDina Daotmia lonsisDim Tfttrihnï& lomrJBDina l l f e atage1 A A A A A A A A A uethod 1 4C 1 40 1 4C 14c 14c sr S type of fooö Oryptomonas ovata ScenedesflMs acuroinates Stsurastrum 5t ichococcuE minutissiTnus
ïi-tzschia act loaatronies
Chloroooocan st>. Hized bacteria filtÊTine rat». iil.aiiiiiBil~~.day 9-04 É-34 3-02 3-39 2.12 0.92 15.93 11.51 5.41 3.11 1.63 0-71 0-35 0.10 0-10 0.06 0.06 0.02 20.64 15-39 10-74 8.31 6.33 0.61 4-09 1.61 0.81 0.52 0.21 0.14 16.7 17-2 7.05 3-7 2 3 4.8 1.68-1.92 i^gestïoQ r&xe c e l l s . animal^i. day-1 (uiüess otheivise noted) 2.26 x 104 3- H I 104 2.25 x 104 3-39 x 104 5.28 i 104 4.56 i 104 1.59 i 105 2.87 1 105 2-71 x 10^ 3-1 x 105 4.08 x 105 9-6 1 105 336 240 480 384 480 600 1.03 x 106 1.54 1 10É 2.Ê9 1 106 4. 75 1 ra 6.31 x 10é 6.02 x 106 4.08 x 105 4.02 - 104 4-08 1 104 5.04 x 104 5-4 x 104 7.2 1 104 1.92 - 106 3 0.25 1 104 oells-nü~1 0.5 1 104 c e l l s . ml~1 0.75 1 104 cellB.al~1 1.0 I 104 cells-ifl"1 2.5 1 104 cells-ial"1 5-0 x TO4 cells.ml"1 1.0 x 104 cells.ml" 2.5 1 104 cells.ül 1 5.O1 104 cells.ml~1 25.0 1 1O4 cells.ml~1 50.0 x 104 cell3.aa~1 0.1 1 104 cells.aü"1 0.1 x 104 cells-sil"1 0.25 x 104 c e l l s . eü."1 . 4 -1 0-5 x 10 c e l l s . n l 0.75 x 104 c e l l s . ml~1 1.0 x 104 o e l l s . n l '1 2.5 ï IQ4 cells.ml"1 5 1 104 oells.nl""1 10 1 104 c e l l s . nl~1 25 x 104 cells.ml"1 50 x 104 e e l l s . - l "1 10 1 105 eells.nl'"1 10 z 106 o e l l s . - l "1 1.0 x 104 cells.«LT1 2.5 x 104 cellE-nl"1 5.0 x 104 cellB.nl~1 10.0 x 104 cells.ml"1 25.0 1 104 cells.jil"1 50.0 1 104 c e l l s . Bi"1 5-5 1 103 c e l l s . # ~1 10.8 x 103 cellB.ml~1 22.5 x 103 c e l l s . «1~1 42.1 1 103 cells.»1~1 reference Infante, 1973 Infarrte, 1973 Infante, 1973 I r f a n t e , 1973 Monafcov éb Sorofciis, 19É1 ManuilovB., 1958 Shushkina t Peien, 1964 Teautai, 1971
Table 1 (ccmtinued) zoöplankton species
Daphnia loneispina
Itohnia loneiSDiaa
Daphnia lorotiapina
Barfmia lonsrispina hyalina Baofania nagna Japhnia nagna Ds-ptmia mama Üttohnia aaffna Daphnia «mi» jwf.>«n» aagns ÜBphnia »»gna Daphnia nagna Dftpfattia ***??"* life stage1 A A A k A A A A A A J A A l l J A A l l J A A l l A A nethod 1 4C 14C 1 4C ir H 32p K V H 3 2P 32p ^ ? 14C 1 4 ( 3 type of food Kicrocystis BP. Oogystis sp. Slakatothrir sp. Gloeoeystis sp. Anabaem EP-Tribonena sp. Cloelastrom sp. Oscillatoria sp. bacteria Chlorococcus sp. HyflxoeenBonaE flav? Wiled bacteria Hatural plankton Chlorella sp. Sacchronjrces cervisiae Chlorella vulgaris-log Chlorella vulearis—sen Chlorella vnlgaris Scenedesimi3 onaiipicaujd£
Ohlorella log phase
Shodotorula sp. AnkistroaeaiaiS sp. Batural planirton phase ïscent i fil-te ml.anis» 23 2.88-14.0 3.7-1É.7 0.2-5.4 5-4 4 . 0 2 . 8 0 . 2 0.2-4.5 3-3-7.2 62.4 7 . 0 240.0 EüOngdiyi 271.2 256.8 741.6 444.0 53D.4 744-0 501.6 609- 6 52 24 26.4 26.4 26.4 1.92-43.92 ring rate il-1.day-1 T-1 - 1 ïBgeeitian rat e c e l l s . animal-1. day"1
{unless otiierni3e noted) 9-36 ng dry nt.animal" .day~ 20.6 3.12 26.4 15.2 12.24 40.32 52-8 . A.8-28.8 1 10É 1.68-3-36 x 106 5.28-6.48 1 106 5.28-6.24 1 106 9.84-31.2 ng Canimal-I day"1 comoents 17.9JS AE 10.5*iE 100JE AE 13-65É AE 5O.8JÉ AE 68.656 J E 2O.8J5 AE 25.Ê5& AE 8.5-92.0 1 103 cells.ml 5.5-22.5 1 103 cells. ml 2.2-79.0 1 10 cellE.ml 2.4 X 10 cells.ml"1 4.8 X 106 cells. mT1 9.6 1 106 oells.ml"1 79-0 x 10 cellE.na"1 0 - 105 cells.nl"1 0.05-0.60 1 10 cells.ml 0.O5-O.6Ox106 cells.ml 1.59-8.0 1 105 cells.ml 1.69-1.83* 105 cells.nl 15°C v = 0.009 1^* 15°C 15°C 20°C 20°C 20°C 25°C 25°C 25°C 1 mg.L~1 DO 2 ttg.lT1 TX> 2.5 Bg.L~1 BO 5 me.L~1 SQ 8 mg.lT1 DO - 1 - f - 1 - 1 1 - 1 - 1 refei-ence Schindler, 1971 «anuilova, 1958 Xajiakov 4 Sorokln, 1961 Monakova S Sorokin, 1961 Navmerck, 1959 StischenyB, ?958 R i g l e r , 1961 Rhyther, 1954 Rfyther, 1954 Suschensra, 1958 Burns, 1969a BUTDE, 1969b
Heisey & Port er, ,yll
Tafcle 1 (continued) zoöplankton species Daphnia magpa D&plüÜa mnpnw Dap}mz4 ms£P£ Ifepïmïa ^iajp^ P&phuia w>pn Dsphnia naena Imuhnia n&pna Dapïmia. stagna Baphnia aagna Daphnia nafiüa Daphnia nagna DaDhnia adddenclorffiana Daphnia panrala Baphnia pil ei life stage' A A A 1 . 2 5 OM 3.54MB A A A A A A A 2. 3 mm 2.6 au A A oethqd used CC CC 5 3 2P 3^ 3 2P B ^ P t j p e of food Ohlorella v a l p a r i s Chlorella vul^aris Chlorella pjn-enoidosa Chlorella s p . Jhlorella 3p* Sacohroaiyces s p . Sacchromyces s p . Saccïrom/ces s p . Esc&erichia c o l i (0.9 f ) Chlorella v u l ^ r i s log piiase ser.escerrt Sacciiroinyoes sp. Tetrahymena pyrif ormes Chlorella vulfpris Sacchroatyces ceruisiae Eschericiua coli Cklamriomcm^s reinhard-ti ïïhodotorula sp-^ Natural plantton
Rhodot orula sp- 9 Natural
plankton Scenedesmtis
si>-filtering rat e Bi. aniaal~~. day~1
JJ.6-124.8 76.8 112.8 8.0 11.04 100.6 83.28 78.78 74-4 96.72 62.88 73-2 20.4 19.44 18.48 2Ï-52 24-24 28.08 52.8-7Ê.6 61.6 64.8-81.6 16. S 52. e 72.0 7.5-12-4 2.5-5.2, ï = 3.8 0.3-O.8 ingestlon r a t e cells.animal~^. day (unless otherwiae nortéd)
1.2 1 106 1.2 1 106 9.6 1 105 8.16 1 10É 8.4 1 105 1. 34 1 108 1.2 1 l o7 6.48 1 106 6.0 1 ia6 .067
.024—9-6 ram .animal . 3ay .024-2-4 ™ .aiiimal . day 1.32 1 10^ 3.8-6.3 1 106 S. 8-26.8 1 105 18°C 22°C 24°C >25°C dark,o.5 1 1Q6 cells.ml~1 100 ft cd 500 ft cd 1000 ft cd 3000 ft cd 10000 ft cd darli,0.2i 106 eells.ml"1 100 ft cd 500 ft cd 1000 ft cd 3000 ft cd 10000 ft cd
in aitu Drowned Boe Laie in satu, Heart Lake
reference Kersting, 1978 EerfftiTiff ét Leesw, 1976 LeFwrre, 1962 HeMahon, 1965 Mclbhon, 1965 HcUahDii, 1965 «cMahon, 1965 HeMahon, 1962 KoMahon * E i g l e r , 1965
«cMahon & Eigler, 1963
Loedolffi, 1964 Chi-xsholm et a l , 1975
ïaney, 1?73 Han^y, 1973
Taïile 1 (contiuued) zooplanüion species Daühnia pul ex Daphnia ~pulex ^apiïrii.a piilst Öaphnia pul e i Dapïmia pul ex Daphnia pul ex Daphnia. pul ex DaphJiia pul e r Ustphnia pul e i l i f e stage1 A A k A A A J A A l l J A AU J k A l l A A method used^ 32p N 14a 14o 1 4C 32p 14c 1 J )C type of food Bhodotorula s l u t i n i s ChlastTÜomonas reinharctti Katural plankton JfatBTal plankton • Chlorella sp. Sceïiede suflis sp. Alïkistrodesmus £alcatTis Ctlorella vul^aris Anacvstis tuciulans SyDechoooocus elongata Merasmooedia sp. SvnechocüCcus cedorum Anataena flos-aguae ^ynechocustis sp. Gloeocapsa alpioola Bhodotorula ^ l u t i u i s Asterionella formosa filtering rate1
EÜ . animal""'. day 1Ê,48
12.26
5-96 5-36
10,7
316.8 ml [mgdry vt J^phnaaJ" ,d^y
345-6 326.4 360.0 424.8 37é.3 453-6 249-6 309.6 72.66 57.79 23,7S fi.05 3-71 1.38 16.34 13.66 6.88 5.55 2.47 1.43 c e l l s. anïmal . day" ' {ïmless otïierwise noted^
216 mg C.(g body C)~ .day~ 2-37-5-35 MS C. smaal' .day*" 211.2 mg C,(g -body C)~1.day~1 52.8 Ï ioÊ 26.4 ï 10 39.6 ï 106 31-92 n 106 21.24 1 106 26.88 T 106 8.16 1 106 24.24 1 106 31-92 1 106 3-6 1 106 5-7 x 106 5-94 i 10£ 3.02 1 106 3-72 1 106 2.78 1 10Ê 4.08 1 10' 6.8 1 105 5.1 i 105 5-54 1 105 6.16 1 105 7.0? 1 105 commertts 1 Baplïnia/20 ml 1 Baphnaa/10 ml 1 Daphma/5 ml lli s l t u sujmner 1005E ss 15.65É ÜT, poor survival
4 repi oduct ion 67.25Ê AE
8^. 3^ AE, IOH survival, no reproduction 8 1 . 3 ^ AE
1005È AE
77.8^ AE, poor grOMth -no repT oduction 70.6^£ AE t Door survival t no reproduction 1<fc « = 0.012 L ? '6 3 20°C 2f°C 0.1 1 104 c e l l s . ml*"1 1.0 x 104 cella.111 1 25 1 104 cells.rol~1 5.0 1 104 c e l l s . m l " 10.0 1 104 c e l l s . m l " 20.0 1 10 c e l l s . m l " 0.25 x 104 c e l l s . m l "1 0.5 1 104 oells.ml 1 0.75 1 1D4 c e l l s - n l "1 1.0 % 104 c e l l s . m l "1 ?.^ 1 TO4 c i l i s . m : "1 1.0 1 104 cells.Hil"' refer&Tiee Cl-ovley, 1973 Buikema, 1973 B e l l & Mard, 1970 Bourne, 1959 Stadovsiy, 1941 Arnold, 1971 a ^ s , 1969 Infante, 1973 Infante, 1973
