Effect of heterotrophic versus autotrophic food on feeding and reproduction of the calanoid copepod Acartia tonsa: relationship with prey fatty acid composition (original) (raw)
Related papers
Influence of algal diet on feeding and egg-production of the calanoid copepod Acartia tonsa Dana
Journal of Experimental Marine Biology and Ecology, 1990
Threshold concentration, retention efficiency and egg-production in the calanoid copepod Acartia tonsa Dana were examined using the algal species Isochtysis galbana clone T-ho, Dunaliella tertiolecta Butcher, Rhodomonas baltica Karsten, Ditylum brzghtwellii Grunow and Thalassiosira weissflogii Grun. Feeding and egg-production in A. tonsa was shown to be influenced by the size, quantity and quality of the food particles. The small I. ga~ana (4.8 am) were inetkiently retained by A. tonsa and ma~mum ingestion rates on this species were first obtained at algal concentrations > 1 pg C*ml-'. However, the highest maximum rate of egg-production was obtained when feeding on this algal species with gross efficiencies of 22 and 38 % in terms of carbon and nitrogen, respectively. Egg-production in A. tonsa ceased entirely within 4 days of feeding on a sole diet of D. tertiolecta. D. tertiolecta is similar in size to R. baltica but contained only trace amounts of fatty acids higher than C-18 fatty acids. The diatoms D. brightwellii and T.fluviatilis were retained with maximal effkiency but daily egg-production and gross growth efficiency was lower for these species than for 1. gaibana and R. baltica.
Different phytoplankton diets were tested on Acartia clausi and A. lilljeborgii from Bahía de La Paz to determine their effect on survival, egg production, and ingestion rate. Female copepods were fed diatom strains (Chaetoceros sp., Cylindrotheca closterium, Odontella longicruris, and Dytilum brightwelli), dinoflagellate strains (Scrippsiella sp., Gyrodinium sp., Prorocentrum micans, and P. rhathymum), and one Raphidophyceae (Chattonella sp.). After 24 h of incubation in darkness at 24 °C, survival with various phytoplankton diets was above 91%. Gyrodinium sp. produced the lowest survival in both copepod species (44.5% in A. clausi and 89.6% in A. lilljeborgii). Dinoflagellate diets provided the highest egg production. A. clausi had higher egg production when fed with P. rhathymum, P. micans, Gyrodinium sp., Scrippsiella sp., and Chattonella sp. A. lilljeborgii had a higher egg production with Scrippsiella sp., P. micans, Gyrodinium sp., and Chaetoceros sp. Ingestion rates were higher in both Acartia species with two diatom diets (O. longicruris and Chaetoceros sp.), P. rhathymum and Chattonella sp. These results suggest that both Acartia species respond to nutritional quality of phytoplankton in a short time. Higher ingestion rates did not necessarily result in higher egg production, suggesting that the link between ingestion and egg production may be in what is eaten, rather than in how much. The response in egg production seems to be species specific, but in general was higher with dinoflagellate diets, suggesting a higher food quality compared with diatoms (excepting Chaetoceros sp.).
Marine Ecology Progress Series, 2012
To understand the role of food quality in planktonic trophic interactions and marine copepod reproduction, we conducted laboratory experiments to investigate the effect of different prey with specific fatty acid profiles on the reproduction of Acartia erythraea. Copepod egg production rates and hatching success were assessed using a mixed diet combining Dunaliella sp. (containing no long-chain polyunsaturated fatty acids, PUFAs) with the diatom Thalassiosira weissflogii (high eicosapentaenoic acid, EPA), the dinoflagellate Prorocentrum dentatum (high docosahexaenoic acid, DHA), the cryptophyte Rhodomonas sp. (moderate EPA and DHA) or the ciliate Strombidium sulcatum (high nitrogen), respectively. Copepods fed a mono-diet of Dunaliella sp. were used as controls. The results showed that a food mixture with dinoflagellates provided the highest egg production rate and hatching success. The bacterivorous ciliate was not a good prey for copepod reproduction because of the deficit in fatty acid composition, despite its low C:N ratio. Generalized additive models indicated that food quality (ingested PUFAs) was important for egg production in addition to food quantity. Among PUFAs, DHA was the most important specific fatty acid based on its high partial correlation coefficient for egg production rate. Egg hatching success was significantly correlated with the percentage of the 3 major ω3 unsaturated fatty acids (alpha-linolenic acid ALA, EPA and DHA) in diets.
Journal of experimental marine biology and ecology, 2005
Recent literature suggests that heterotrophic protists could improve the biochemical constituents of poor quality algae for subsequent use by higher trophic levels, a phenomenon dubbed btrophic upgradingQ. We conducted experiments to test trophic upgrading effects on the omnivorous calanoid copepod Acartia tonsa. Two heterotrophic protists, Oxyrrhis marina and Gymnodinium dominans, were grown on three algal species of different nutritional qualities: Dunaliella tertiolecta, Isochrysis galbana and Rhodomonas salina. In parallel incubations, the copepods were fed the heterotrophic protists or the algae that the protists grew on. We measured the ingestion rate, egg production rate and egg hatching success of the copepods in each treatment. Comparison of the egg production efficiency (EPE; egg carbon production/carbon ingestionÂ100%) between parallel diet treatments allowed us to calculate the trophic upgrading index (TUI; ratio of EPE-heterotrophic protist to EPE-alga). The copepods ingested similar amount, or 20-30% more algae than heterotrophic protists. Daily rations ranged 50-122% of body C per day. Copepods feeding on O. marina that grew on D. tertiolecta had higher egg production rate and egg hatching success than copepods feeding on D. tertiolecta directly, and the resultant TUI between the two treatments was 19.7. Similarly, the copepod egg production was improved by G. dominans that grew on D. tertiolecta and the resultant TUI was 23.3. TUI was near 1 between I. galbana treatment and the parallel heterotrophic protist treatments, indicating no or little trophic upgrading effects on the copepod's egg production. However, egg hatching success was significantly lower with G. dominans growing on I. galbana. O. marina that grew on R. salina induced a lower EPE relative to the alga itself, yielding a TUI of less than 1. Biochemical data showed that the heterotrophic protists contained eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) even when they fed on alga that lacked these essential fatty acids, which may explain some of the observed trophic upgrading effects and species-specific differences in our experiments. However, our data also suggested that dietary EPA and DHA could not be the sole factors regulating the 0022-0981/$ -see front matter D
Different phytoplankton diets were tested on Acartia clausi and A. lilljeborgii from Bahía de La Paz to determine their effect on survival, egg production, and ingestion rate. Female copepods were fed diatom strains (Chaetoceros sp., Cylindrotheca closterium, Odontella longicruris, and Dytilum brightwelli), dinoflagellate strains (Scrippsiella sp., Gyrodinium sp., Prorocentrum micans, and P. rhathymum), and one Raphidophyceae (Chattonella sp.). After 24 h of incubation in darkness at 24 °C, survival with various phytoplankton diets was above 91%. Gyrodinium sp. produced the lowest survival in both copepod species (44.5% in A. clausi and 89.6% in A. lilljeborgii). Dinoflagellate diets provided the highest egg production. A. clausi had higher egg production when fed with P. rhathymum, P. micans, Gyrodinium sp., Scrippsiella sp., and Chattonella sp. A. lilljeborgii had a higher egg production with Scrippsiella sp., P. micans, Gyrodinium sp., and Chaetoceros sp. Ingestion rates were higher in both Acartia species with two diatom diets (O. longicruris and Chaetoceros sp.), P. rhathymum and Chattonella sp. These results suggest that both Acartia species respond to nutritional quality of phytoplankton in a short time. Higher ingestion rates did not necessarily result in higher egg production, suggesting that the link between ingestion and egg production may be in what is eaten, rather than in how much. The response in egg production seems to be species specific, but in general was higher with dinoflagellate diets, suggesting a higher food quality compared with diatoms (excepting Chaetoceros sp.).
CICIMAR Oceánides, 2009
This study experimentally determined the role of local diatom and dinoflagellate diets and theirfatty acid composition on the survival, ingestion, and egg production rates of the copepod Centropages furcatus from Bahía de La Paz. The fatty acid profiles of the diatoms Odontella longicruris and Chaetoceros sp., and of the dinoflagellates Scrippsiella sp., Gyrodinium sp., and Prorocentrum micans were determined. After incubating at 24 °C in darkness during 24 h, survival within all phytoplankton diets was > 90%. Dinoflagellate diets provided higher egg production (>25 eggs female-1 day-1) than diatom diets (<10 eggsfemale-1 day-1). No significant differences were observed in the ingestion rates when fed dinoflagellates or diatoms, which varied between 400 and 900 ng C copepod-1 h-1. Higher egg production with dinoflagellate diets suggests better food quality, which may be attributed to higher proportions of the fatty acids 18:4 (n-3) and 22:6 (n-3). These results suggest that...
Marine Ecology Progress Series, 2001
The effects of different types of food on the growth, development, reproduction, egestion and grazing of the copepod Centropages typicus Krøyer was studied in the laboratory at 15°C. The copepods were reared from eggs to NVI using Isochrysis galbana as food, and from NVI onwards with a range of diets: a single food source consisting of 1 of 2 algae (the haptophyceaen Hymenomonas elongata and the diatom Thalassiosira weissflogii), a single food source consisting of the ciliate Strombidium sulcatum, and a mixture consisting of each type of algae and the ciliate. The results, based on daily sampling, show that growth, development rate and egg production were dependent on food type. The food types that induced the shortest development times (H. elongata, S. sulcatum) did not necessarily result in the highest production rates. The daily specific growth rate for copepodid stages was significantly lower with T. weissflogii (0.045 d-1) than with the other diets (0.09 to 0.15 d-1). The combination of variable development and variable growth rates with the different diets induced a high variability in mean weight within developmental stages. The weights recorded are amongst the highest observed for this species. Length did not differ significantly within the same development stage between different diets. Mixed food sources were more efficient than a single food source in terms of egg production and viability. No relationship was established between hatching success, female age or copepodid mortality rate and food type. A pure diet of T. weissflogii resulted in a sex ratio skewed towards males, whereas the other diets produced a balanced sex ratio. The present results indicate the mixture phytoplankton/ciliate to be the most favourable for development, growth and egg production, suggesting that omnivory is the best feeding strategy for C. typicus.
Hidrobiológica, 2008
Different phytoplankton diets were tested on Acartia clausi and A. lilljeborgii from Bahía de La Paz to determine their effect on survival, egg production, and ingestion rate. Female copepods were fed diatom strains (Chaetoceros sp., Cylindrotheca closterium, Odontella longicruris, and Dytilum brightwelli), dinoflagellate strains (Scrippsiella sp., Gyrodinium sp., Prorocentrum micans, and P. rhathymum), and one Raphidophyceae (Chattonella sp.). After 24 h of incubation in darkness at 24 °C, survival with various phytoplankton diets was above 91%. Gyrodinium sp. produced the lowest survival in both copepod species (44.5% in A. clausi and 89.6% in A. lilljeborgii). Dinoflagellate diets provided the highest egg production. A. clausi had higher egg production when fed with P. rhathymum, P. micans, Gyrodinium sp., Scrippsiella sp., and Chattonella sp. A. lilljeborgii had a higher egg production with Scrippsiella sp., P. micans, Gyrodinium sp., and Chaetoceros sp. Ingestion rates were higher in both Acartia species with two diatom diets (O. longicruris and Chaetoceros sp.), P. rhathymum and Chattonella sp. These results suggest that both Acartia species respond to nutritional quality of phytoplankton in a short time. Higher ingestion rates did not necessarily result in higher egg production, suggesting that the link between ingestion and egg production may be in what is eaten, rather than in how much. The response in egg production seems to be species specific, but in general was higher with dinoflagellate diets, suggesting a higher food quality compared with diatoms (excepting Chaetoceros sp.).
Marine Ecology-progress Series, 2001
Experiments were conducted over 10 to 20 d periods to study the grazing and reproductive success of the copepod Temora stylifera fed on unialgal cultures of the diatom Thalassiosira rotula (THA) or the dinoflagellate Prorocentrum minimum (PRO), as well as mixtures of THA and PRO (MIX experiments) and alternating diets of THA and PRO switched daily (SWITCH experiments). Adult females ate both THA and PRO, and while rates of feeding on the 2 diets were similar in terms of carbon ingestion, egg production was generally higher on the diatom diet. In contrast, copepod egg-hatching success was low on the diatom diet, declining rapidly after 2 d from > 80 to 0% by Day 17. The diminution in hatching success was slower when females were fed MIX or SWITCH diets, but nonetheless diminished to 0 and < 25% by the end of the experiment, depending on the incubation method. Only in the case of the PRO diet was egg viability high and stable with time (87 to 96%), regardless of whether female and male couples were incubated as individual couples in crystallizing dishes or as triplicate couples in rotating bottles. However, in most other cases, the incubation method (crystallizing dishes vs rotating bottles) had very strong effects on egg and fecal pellet production, and hatching success. Higher egg production rates were generally obtained when females were incubated in crystallizing dishes, whatever the diet, although fecal pellet production rates were significantly higher in the rotating bottle experiments in most cases. Egg-hatching success was also strongly affected by incubation method, with generally higher hatching rates in the rotating bottles. This was probably due to the fragility of non-viable eggs, which were more easily destroyed by mechanical disturbance in rotating bottle experiments. The results support the recent discovery that reproductive failure in copepods can be due to deleterious antimitotic compounds present in some diatoms that arrest normal embryonic division. Reduction in egg viability was not only visible when females were fed unialgal diatom diets, but also when they were fed mixed diets. However, on mixed diets there was a 'dilution effect' in that hatching was reduced by approximately half, and this took about twice as long to occur. The evolutionary advantages for diatoms in producing antimitotic compounds are discussed, as well as questions of why copepods feed on diatoms with impunity, even though some diatoms are detrimental to copepod reproductive success.
Diet influence on egg production of the copepod Acartia tonsa (Dana, 1896)
Anais da Academia Brasileira de Ciências, 2010
Egg production in the copepod Acartia tonsa was evaluated using different densities of the microalgae Thalassiosira weissflogii, Chaetoceros muelleri and Isochrysis galbana. Male and female were kept under controlled conditions (salinity 30, 20°C, photoperiod 12L:12D), acclimated to the experimental conditions and left over a period of 24 h to allow copulation. Algal densities tested were equivalent in biovolume and corresponded to 0, 2.5, 5, 10, 20, 40 and 60.10³ cells.mL-1 of T weissflogii. Ten acclimated female were separated, transferred to glass bottles and exposed for further 24 h to the corresponding experimental medium. After this period, the eggs were fixed and counted. Copepod egg production reached a threshold value when T weissflogii, C. muelleri and I. galbana were supplied at 10.10³, 140.10³ and 640.10³ cells.mL-1, respectively. Mean egg production corresponded to 28.0 ± 0.5, 20.1 ± 1.0 and 22.0 ± 3.5 eggs.female-1 .day-1, respectively. Copepods fed T weissflogii showe...