Food Consumption and Growth of Aplysia dactylomela Rang (Gastropoda: Opisthobranchia)

Abstract

The consumption of two macrophytic algae, namely Ulva pertusa and Enteromorpha linza, by the adult gastropoda Aplysia dactylomela was studied for a period of 36 days under laboratory conditions. Animals were fed three times a day to satiation. Both algae species were well consumed and promoted increase in the body weight, body length as well as the egg production of the gastropoda. The consumption of Ulva by Aplysia was 22.5% of mean body weight eaten per day, and was independent of temperature, but Enteromorpha consumption was 15.0% and increased with increasing temperatures. Nevertheless, animals fed on Enteromorpha had a better growth rate and egg production than those fed on Ulva. The gross assimilation efficiency was highest on the algae giving the better growth (29% for Enteromorpha and 14% for Ulva) . The study found that the detrimental thalli of Ulva pertusa and also that of Enteromorpha may eventually be controlled by the introduction of gastropods in fish or shrimp ponds.