Reproductive aspects of Acanthurus chirurgus (Perciformes: Acanthuridae) captured by the artisanal fleet operating in Itamaracá Island, Pernambuco, Brazil

Abstract

This study examined the reproductive biology of Acanthurus chirurgus through monthly collections from May 2016 to May 2018. A total of 505 specimens (317 males, 188 females) were analysed, with males having a larger total length than females (32.0 cm vs. 30.8 cm). The highest frequency of individuals was in the 23-25 cm size range. Reproduction occurred from January to July, with peak spawning in February, March and June. The first (L50) and maximum (L99) maturation sizes were 18.0 and 22.1 cm, respectively. Spawning was synchronous, occurring in batches and following an indeterminate fecundity pattern. Spawning frequency was estimated at every 4.2 days (hydrated oocytes) and 3.5 days (post-ovulatory follicles). Batch fecundity ranged from 15403.9 to 48030.9 oocytes, and relative batch fecundity from 2710628.5 to 16842518.6 oocytes. Due to the long reproductive period, recommendations include catch quotas, a closed season (February, March and June) and an 18 cm minimum size.