The Influence of Diet Composition on Fitness of the Blue Crab, Callinectes sapidus

Abstract

The physiological condition and fecundity of an organism is frequently controlled by diet. As changes in environmental conditions often cause organisms to alter their foraging behavior, a comprehensive understanding of how diet influences the fitness of an individual is central to predicting the effect of environmental change on population dynamics. We experimentally manipulated the diet of the economically and ecologically important blue crab, Callinectes sapidus, to approximate the effects of a dietary shift from primarily animal to plant tissue, a phenomenon commonly documented in crabs. Crabs whose diet consisted exclusively of animal tissue had markedly lower mortality and consumed substantially more food than crabs whose diet consisted exclusively of seaweed. The quantity of food consumed had a significant positive influence on reproductive effort and long-term energy stores. Additionally, seaweed diets produced a three-fold decrease in hepatopancreas lipid content and a simultaneous two-fold increase in crab aggression when compared to an animal diet. Our results reveal that the consumption of animal tissue substantially enhanced C. sapidus fitness, and suggest that a dietary shift to plant tissue may reduce crab population growth by decreasing fecundity as well as increasing mortality. This study has implications for C. sapidus fisheries.

Fecundity Assessment of Stone Crabs in the Eastern Gulf of Mexico

“…; Hjelset et al. ; Griffen ; Belgrad and Griffen ). Although seafloor habitat differences among the sampled sites were not documented in this study, habitat within and among locations is likely to have varied.…”

“…In addition to the inability to consume bivalves and other hard-shelled prey, the availability of food likely varies within and among locations along Florida's coast. Habitat type, which varies throughout the west coast of Florida (Continental Shelf Associates 1991; Hine et al 2003;Kingon 2013), influences the quality and quantity of benthic food sources, carrying capacity, population density, and stresses from predators, all of which influence the health of spawning females and, in turn, the quality and quantity of the eggs produced (Annala and Bycroft 1987;Dugan et al 1991;Lardies and Castilla 2001;Lardies and Wehrtmann 2001;Bas et al 2007;Hjelset et al 2012;Griffen 2014;Belgrad and Griffen 2016). Although seafloor habitat differences among the sampled sites were not documented in this study, habitat within and among locations is likely to have varied.…”

The timing of energy allocation to reproduction in an important group of marine consumers

“…None of these studies addressed income breeding, as each focused on other topics. These include experiments on two crabs of the family Portunidae, the European green crab Carcinus maenas [ 51 ] and the blue crab Callinectes sapidus [ 56 ], on Cancer irroratus within the family Cancridae [ 57 ], on Panopeus herbstii of the family Panopeidae [ 17 ], and on Aratus pisonii of the family Sesarmidae [ 58 ]. Each of these studies used a similar experimental design where crabs were fed for several weeks on a specific diet that varied the total amount of food offered to each crab and the proportion of food that was animal or algal tissue, and the precise amount consumed was quantified throughout.…”

Maternal Trophic Status and Offpsring Phenotype in a Marine Invertebrate

“…Variations associated to environmental factors may be driven by either changes in diet or changes in allocation of reserves at the time of oogenesis. Maternal diet can affect important traits such as gonadosomatic index 12 and offspring size 2 , 13 . The maternal diet, in particular, is a major contributor towards chemical composition of eggs 14 , 15 .…”