Food availability effects on reproductive strategy: the case of Acartia tonsa (Copepoda: Calanoida)

Abstract

Food availability has been linked to changes in the biochemical composition of zooplankton eggs. However, a number of species are capable of resource storage and are thereby able to use accumulated reserves for reproduction during periods of poor food conditions. Conversely, in species such as Acartia tonsa with limited storage capacities, there can be a strong dependence of egg composition on ambient food conditions. The aim of this study was to determine the effect of food availability on the carbohydrate, protein and fatty acid composition of A. tonsa females and their eggs after being fed with different concentrations of the cryptophyte Rhodomonas baltica. During the experiments, no significant differences in the biochemical composition of females were observed, although egg protein composition was higher in food-limited females. We propose that the production of protein-rich eggs by food-limited copepods is a reproductive strategy for ensuring the survival of offspring during poor feeding conditions. In terms of their relative biochemical makeup, there were no significant differences between both adults and eggs of A. tonsa and their prey R. baltica. However, these biochemical similarities did not influence egg production. Rather, higher biochemical similarities were observed between R. baltica and eggs when females were food limited. These findings suggest that food-limited females may moderate the cost of reproduction by producing eggs without much modification to the substrates they ingest.

Seasonal variations in larval biomass and biochemical composition of brown shrimp, Crangon crangon (Decapoda, Caridea), at hatching

“…In this way, our study confirms the hypotheses proposed by Paschke et al (2004) and provides a chemical basis explaining the previously observed seasonal patterns in larval starvation resistance. Similar seasonal variations in offspring quality and environmental conditions prevailing at hatching have also been described in other aquatic crustacean species, for example in porcelain crab (Gebauer et al 2010), marine copepods (Acheampong et al 2011) and limnic cladocerans (Boersma 1997).…”

Resting eggs in free living marine and estuarine copepods

“…Laboratory experiments have demonstrated that resting egg production can be induced by both food and temperature, as well as by photoperiod, abrupt salinity changes, crowding and oxygen deficiency (Uye et al, 1979;Sullivan and McManus, 1986;Ban and Minoda, 1994;Chinnery and Williams, 2003;Holmstrup et al, 2006;Holste and Peck, 2006;Drillet et al, 2011). It has also been suggested that the higher protein content of resting eggs from A. tonsa produced under starvation is an indication of resting eggs being an adaption to cope with low food availability (Acheampong et al, 2011). In the present study resting eggs are viewed as an adaption to seasonality, which is why seasonal range and not actual values of chlorophyll a concentrations or SST is related to their production.…”

Forage fish quality: seasonal lipid dynamics of herring (Clupea harengus L.) and sprat (Sprattus sprattus L.) in the Baltic Sea

“…These changes have most likely reduced the lipid content in zooplankton available for clupeids as Pseudocalanus sp. is characterized by lipid storage in large oil sacs, while species such as Acartia tonsa have limited storage capacity (Acheampong et al, 2011). Furthermore, mysids, an alternative prey for herring, occur in low abundance in the central Baltic possibly due to inaccessibility of the oxygen-deficient bottom layer (Barz and Hirche, 2009).…”