Abstract

BARBA MACIAS, Everardo; SANCHEZ MARTINEZ, Alberto J.; RAZ-GUZMAN, Andrea  and  GALLEGOS, Margarita E.. Dieta natural y tasa de forrajeo del camarón carideo Hippolyte zostericola Smith sobre epífitas de Thalassia testudinum Banks et Solander ex König. Hidrobiológica [online]. 2000, vol.10, n.2, pp.139-146. ISSN 0188-8897.

Diet of caridean shrimp Hippolyte zostericola was studied analizing stomach contents of specimens collected in Thalassia testudinum meadows. Experimental diets included seagrass leaves with epiphytes as food and were conducted in light and dark conditions (12:12) in 3 hours periods along 24 hours. In both cases, more than 55% of dietary components were plant material constituted by filamentous algae and diatoms. The composition of the natural diet had a seasonal variation, whereas in the rainy season the caridean shrimp prefered filamentous algae and unidentifiable organic matter. In experimental conditions, the grazing rate was higher during the 15:00 hours in dark conditions with an average value of 1.16 ± 0.36 mg of epiphytes afdw/individual/hour. The grazing rate in dark was 1.9 times higher than in light condition. The average grazing rate in darkness was 0.64 ± 0.29 mg of epiphytes afdw/individual/hour, while in light condition it was 0.33 ± 0.26 mg of epiphytes afdw/individual/hour. Fecal pellets was 1.7 times larger in darkness with 89.03 ± 67.71 fecal pellets. The number of fecal pellets with respect to time had a similar behavior to the grazing rate, with maximum values in dark condition at 15:00 and 18:00 hours. H. zostericola is a link between primacy producers and higher trophic levels. This caridean is a numerically important component of seagrass habitats and represents an available food item for fish and other higher invertebrates via biomasa.

Keywords : Diet; grazing rate; Hippolyte zostericola; epiphytes; Thalassia testudinum.