Interspecies differences in food sources for the tropical callichirid shrimp Neocallichirus spp. on San Salvador Island, Bahamas

Abstract

At least 4 species of callichirid shrimp coexist in the shallow marine settings of San Salvador Island, an isolated, small platform of the all-carbonates Bahama Archipelago, implying that interspecific competition or trophic niche segregation occurs between these shrimp species. Carbon and nitrogen stable isotope analyses were conducted on soft tissues of 3 callichirid species, Neocallichirus cacahuate, N. grandimana, and N. maryae, to determine the food sources for each species. These analyses revealed that the isotopic trophic niches for these 3 species do not overlap. The most important food source for all 3 species was manatee grass Syringodium filiforme. The second most important food source for N. cacahuate and N. grandimana was drifting seaweed Sargassum sp., whereas that for N. maryae was turtle grass Thalassia testudium. These food-source adaptations likely contribute to the high species diversity of callichirid shrimp in tropical settings such as those found on San Salvador Island.