Filling gaps in the knowledge of grouper, especially Comb grouper (Mycteroperca acutirostris) (2013-2020) (Copacabana fishery, Rio de Janeiro, Brazil)

Abstract

There are gaps in our knowledge of important fish consumed by people in tropical countries. Small-scale fisheries are difficult to regulate, especially in countries with no species monitoring. At Copacabana (Rio de Janeiro), we observed 490 individuals of badejo (Comb grouper) (Mycteropeca acutirostris in 2013-2014 and in 2018-2020. The average catch was 1.36 kg (n=466 individuals). A pattern of decreasing catches was observed for Comb grouper.  Therefore, provided that the fishing gear and the number of fish have remained the same, the apparent decrease in Comb grouper needs to be further investigated. The results provide information about the major spawning season, around spring (September-December) with additional spawning during April. Genetic analyses in samples from 96 grouper obtained along the coast of Brazil were conducted. The Single Nucleotide Polymorphism (SNP) loci obtained for grouper species enabled us to determine the relative genetic proximity of M. acutirostris and Mycteroperca bonaci, information that can be useful for aquaculture and conservation. The objectives of this study were: a) to obtain data about the fishing activity (catch landings) of Comb groupers at Copacabana, Posto 6; b) to verify the reproductive period of Comb grouper, throughout the year, through the catches from the fishery; c) to develop a large numbers of SNP markers, which can be useful to studies about grouper populations (Mycteroperca and Epinephelus); and, d) to obtain data on the price of the Comb grouper. This study contributes data on the fishery and on the biology and ecology of groupers, and further contributes to conservation efforts.

Keywords: comb grouper, fisheries, genetics, Mycteroperca.