Gelatinous zooplankton

However, recently there has been evidence that the production of chemical defenses by benthic marine amphipods is indeed possible, as Norton and Stallings155 report on the distribution and abundance of three aposematic, chemically defended gammarid amphipods in the northwest Pacific Ocean. There is no reason to suspect that planktonic amphipods cannot similarly evolve their own chemical defenses. Hyperiid amphipods, which are known to associate extensively with gelatinous zooplankton, are perhaps uniquely situated to exploit the chemical defenses of other planktonic organisms. 

Harbison, G.R., Biggs, D.C., and Madin, L.P., The association of amphipoda Hyperiida with gelatinous zooplankton. II. Associations with cnidaria, ctenophora and radiolaria, Deep Sea Res., 24, 465, 1977. 

Laval, P, Hyperiid amphipods as crustacean parasitoids associated with gelatinous zooplankton, Oceanogr. Mar. Biol. Anna. Rev., 18, 11, 1980. 

Western N. Atlantic Mixed gelatinous zooplankton 39-63 Biggs (1977)... 

Big, D. C. (1977). Respiration and ammonium excretion by open ocean gelatinous zooplankton. Limnol. Oceanogr. 22(1), 108—117. 

Nemazie, D. A., PurceU, J. E., and Glibert, P. M. (1993). Ammonium excretion by gelatinous zooplankton and their contribution to the ammonium requirements of microplankton in Chesapeake Bay. Mar. Biol. 116, 451-458. 

Table 26.1 Biochemical composition of some crustacean and gelatinous zooplankton... 

Gelatinous Zooplankton Ctenophores Beroe cucumis 29.7 1.1 Curl, 1962... 

Although zooplankton tend to maintain a rather rigid biochemistry, intra- and interspecific differences may arise due to physical characteristics (e.g., water content, body size), developmental stage, as weU as location (e.g., latitude) and season. Increased water content, and thus decreased muscle tissue, leads to a decrease in protein and N content in zooplankton (ChUdress and Nygaard, 1974 Morris and Hopkins, 1983). This may explain the lower N and protein content in gelatinous zooplankton relative to crustaceans as described above. The effect of water content on proteins can also be seen within taxonomic groups. For example, Calanus paciftcus... 

Excretion rates in Biggs (1977) are given in mg body protein this was converted to dry weight assuming body protein = 23% DW (for gelatinous zooplankton Table 26.1). 

Bailey, T. G., Youngbluth, M. J., and Owen, G. P. (1995). Chemical composition and metabolic rates of gelatinous zooplankton from midwater and benthic boundary layer environments off Cape Hatteras, North Carolina, USA. Mar. Ecol. Prog. Ser. 122, 121—134. 

Clarke, A., Holmes, L. J., and Gore, D.J. (1992). Proximate and elemental composition of gelatinous zooplankton from the Southern Ocean. J. Exp. Mar. Biol. Ecol. 155, 55—68. 

---