Fecal pellet production

Feeding and growth rates, egg production and hatching success, and fecal pellet production are affected by both quantity and quality of food supply (Abou Debs, 1984 Besiktepe and Dam, 2002 Frost, 1972 Tang and Taal, 2005). Changes in food quality can create a mismatch in stoichiometry between predator and prey (Sterner and Hessen, 1994) and effect all of the above parameters, as well as body N content, and ultimately zooplankton production and biomass. In fact the nutritional status of phytoplankton (N cell quotas), not the phytoplankton biomass, may be the major bottom-up determinant of zooplankton biomass (Hessen, 1992 Sterner and Hessen, 1994) except in periods of low food availability (Jonasdottir et al., 2002). 

Honjo, S. Roman, M. R. Marine Copepod Fecal Pellets Production,... 

In this chapter, mechanisms of particle removal are limited to coagulation and sedimentation. Predictions of size distributions are obtained that are in reasonable agreement with measured size distributions from oceanic waters and digested sewage sludge. Sensitivity of the predictions to fluid turbulence and fluid density presents a plausible explanation for zones of higher particle concentration observed in the oceanic water column. The analysis does not include zooplankton fecal pellet production, particle breakup, or dissolution, nor does it directly incorporate biological productivity. 

Collumb, C.J. and Buskey, E.J. Effects of the toxic red tide dinoflagellate Karenia brevis) on survival fecal pellet production and fecundity of the copepod Acartia tonsa, in Harmful Algae 2002, Steidinger, K.A., Landsberg, J.H., Tomas, C.R. and Vargo, G.A. Eds., I.O.C. of UNESCO, 2004, pp. 44-45. 

Clearly, for some terrestrial species, deposition of fecal pellets can be considered as marking behavior. Mathis (1990) found that females of Plethodon cinereus deposited fecal pellets at a faster rate when exposed to their own chemical cues than when exposed to chemical cues of males or other females, suggesting the hypothesis that the primary function of fecal markers for females is advertisement of their own areas. Therefore, if an experiment is to last for several days, the rate of fecal pellet production can be easily quantified. 

The nematode, Nematospiroides dubius, was selected for the assay. Infected mice were fed for six days with milled Purina Lab Chow which had been mixed with the fermentation product to be tested. The mice were then fed a normal diet and, at 14 days postinfection, fecal pellets were examined for the presence of eggs. If eggs were absent on three successive days, the mice were sacrificed and their small intestines examined for the presence of worms. 

Since insect fecal pellets contain both undigested food and nitrogenous waste products, Bhattacharya and Waldbauer (58) subtracted the urine content of the feces from the total weight of the fecal pellet. This provided better estimates of assimilation and conversion of assimilated food. Schmidt and Reese (57) noted that BCW larvae will feed upon their fecal pellets if no other food is available. Growth on fecal pellets is nearly as rapid as growth on diet, suggesting that much of the nutrient content of the diet is not assimilated. The result of fecal feeding on nutritional parameters is an overestimation of the AD and ECI and an underestimation of the ECD. 

Madin, L.P., The production, composition and sedimentation of salp fecal pellets in oceanic waters, Mar. Biol., 67, 39, 1982. 

Fecal pellets can contain unabsorbed digestive products that then leak into the surrounding water, providing a potentially important source of DOM (Jumars et al., 1989 Lampitt et al., 1990). Fecal pellets may leach relatively more DOM when they... 

Buder, M., and Dam, H. G. (1994). Production rates and characteristics of fecal pellets of the copepod Acartia tonsa under simulated phytoplankton hloom conditions Imphcations for vertical flux. Mar. Ecol. Prog. Ser. 114, 81-91. 

M0Uer, E. F., Thor, P., and Neilsen, T. G. (2003). Production of DOC by Calanus fmmarchicus, C. glacialis and C. hyperboreus through sloppy feeding and leakage from fecal pellets. Mar. Ecol. Prog. Ser. 262, 185-191. 

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