REPRODUCTIVE CYCLE OF MARINE ORNAMENTAL SHRIMP Stenopus hispidus IN LONG-TERM MAINTENANCE: CONSTANT SUPPLY FOR LARVICULTURE

RAFAEL A. GREGATI; VIVIAN FRANSOZO; MARIA LUCIA NEGREIROS-FRANSOZO; LAURA LÓPEZ GRECO*

VERACRUZ, MEXICO

Congreso; WAS AQUACULTURE 2009; 2009

World AQUACULTURE SOCIETY

Reproductive cycle of marine ornamental shrimp Stenopus hispidus in long-term maintenance: constant supply for larviculture   Rafael A. Gregati; Vivian Fransozo; Maria Lucia Negreiros-Fransozo; Laura López Greco* *Dept. of Biodiversity and Experimental Biology, FCEyN, University of Buenos Aires Ciudad Univ. C1428EHA, Buenos Aires, Argentina. laura@bg.fcen.uba.ar In contrast to freshwater ornamental fishes, the most marine species for aquarism are collected from the environment. Stenopus hispidus (Decapoda, Stenopodidae), commonly known as “banded coral shrimp” or “cleaner shrimp”, is the most popular shrimp for aquarists due to its body coloration and because they are easily kept in aquaria. This marine shrimp is collected around the world and it has a high value in Brazilian market. A number of attempts have been carried out to close its complete life cycle on commercial scale, but none has succeeded yet. Since the knowledge of reproductive cycle can provide basic information for culture of ornamental shrimps and preserve their natural stocks, this work focused on understanding the reproductive cycle of S. hispidus in long-term controlled conditions aimed to obtain constant supply of larvae. Adults of S. hispidus were obtained from Fortaleza, Ceará State, Brazil and kept as 12 mating pairs in interconnected aquaria (0.45 m x 0.20 m x 0.30 m), photoperiod 12:12, salinity 35‰ and 26 ± 1°C. Daily, the shrimps were fed with ornamental fish food and pieces of shrimp, squid or shellfish. The occurrence of ecdysis, mating, spawning and larvae hatching were recorded during eight months. Some hatched larvae were counted in the end of the first, fifth and eight month to evaluate the fertility over time. The survival was 100%. Time of egg development was 22.8 ± 2.1 days. After egg hatching, and up 72 hours, the female molted and within the next 12 hours, mating occurred (Figure). Egg spawning was almost immediate, but in few cases this process delay nearly six hours. The intermolt periods were 25.5 ± 2.3 days for females and 26 ± 4.1 days for males. Males always molted 8.7 ± 2.6 days after the female ecdysis. The number of hatched larvae was 815 ± 252, 855 ± 130 and 801 ± 48 for the first, fifth and last month, respectively. This means that each of the 12 mating pairs performed one reproductive cycle almost monthly, without apparent decrease in the number of larvae. Unlike the specimens from the wild, under controlled conditions we can achieve continuous reproductive cycles and, as a consequence, constant larvae supply with a few adult shrimps. These larvae would be sufficient to test technologies of larviculture since the main problems for the production in commercial scale are related to the long period of larval development and high mortality, as well as problems on settlement and metamorphosis to juvenile stage. Financial support: CAPES (fellowship to the first author), CNPq (international cooperation) and FAPESP (installations and vehicles). All the experiments were conducted at the NEBECC (Núcleo de Estudos em Biologia, Ecologia e Cultivo de Crustáceos), UNESP, Botucatu, Brasil.