Recruitment Age of Litopenaeus vannamei (Boone, 1931) (Decapoda: Penaeidae) in the Cabeza De Toro-La Joya Buenavista Lagoon System, Oaxaca-Chiapas, Mexico

Abstract

At present, the fishery of Litopenaeus vannamei continues overexploited in the Gulf of Tehuantepec (GT), Mexico. From the available literature it was demonstrated that marine closure systems implemented in GT have not worked adequately since 1993, because these are completely protecting marine recruitment seasons, and reproductive seasons were only partially considered to protect. Due to these problems, new marine closure systems were proposed in the literature, but they were not accepted by fishermen from GT because they did not include marine and lagoon recruitment information. For this reason, in this study both recruitment types were analyzed with estimations on the recruitment age ( RA ), and its relationship with total length and weight. To the Cabeza de Toro la Joya Buenavista lagoon system (CTJB-LS), it was concluded that young recruits migration toward outside CTJB-LS elapsed between 3 and 5-m-olds, with the highest recruit flow in 4-m-olds. Thus, this last age was called the RA of L . vannamei (at 106 mm). Maximum marine recruitment ranked from June to July, and maximum reproductive seasons were in October. In both recruitment seasons it was observed that biomass production was different. In marine season RA recorded 8.4 g more than lagoon season at the same size. Results were used in order to discus about atarraya nets uses, and to propose the implementation of a lagoon closure during July inside lagoon systems located in GT. With this proposal artisanal fishermen will be allowed to use atarraya nets with mesh opening of 25.4 mm during June, and they will obtain a good biomass production level as economic support.Additionally, with new marine closure systems shrimp reproductive seasons will be protected (from July to November).