Spawning season, recruitment and early life distribution of Anchoa tricolor (Spix and Agassiz, 1829) in a tropical bay in southeastern Brazil

Abstract

The pattern of the use of the Sepetiba Bay, a semi-closed 450 km 2 area in southeastern Brazil, by Anchoa tricolor was investigated to assess spawning period, recruitment and to detect spatial-temporal patterns of this major fishery resource. Fishes were sampled by seine nets, from spring, 1998 to winter, 1999 and by beach seine, from spring, 1998 to winter, 2000. Reproductive season, measured in terms of GSI, gonad development and appearance of recruits, indicate that reproduction occurs from August to March, when they reach the best condition. Recruitment peaks in winter/ spring at sandy beaches where they stay until late summer, moving toward deeper bay areas during autumn. After that, they join adults and perform movements between the bay and the adjacent continental shelf to reproduce.Keywords: reproduction, condition, anchovies, Engraulidae, recruitment. Período de reprodução, recrutamento e distribuição de jovens de Anchoa tricolor (Spix and Agassiz, 1829) em uma baía tropical do sudeste do BrasilResumo O padrão de uso da Baía de Sepetiba, uma área semifechada no Sudeste do Brasil, por Anchoa tricolor foi estudado visando determinar o período reprodutivo, recrutamento e detectar padrões de distribuição espacial e temporal. As amostras foram realizadas por rede de cerco, entre a primavera de 1998 e o inverno de 1999, e por arrasto de praia, da primavera de 1998 ao inverno de 2000. O período reprodutivo, estimado com base no índice gonadossomático, desenvolvimento gonadal e aparecimento de recrutas, ocorre de agosto a março, quando é atingida a melhor condição dos adultos. O recrutamento ocorre principalmente no inverno/primavera nas praias arenosas onde eles permanecem até fins do verão, movendo-se para áreas mais fundas da baia durante o outono. Depois disto eles se juntam aos adultos e fazem movimentos entre a baia e a plataforma costeira adjacente para reproduzir.Palavras-chave: reprodução, condição, manjubas, Engraulidae, recrutamento.

Ontogenetic development of the sagittal otolith of the anchovy, <em>Anchoa tricolor</em>, in a subtropical estuary

“…In this second growth phase, most of the morphological attributes are attained. Also during this stage, the species moves up to the inner continental shelf (Araújo et al 2008), where it forms large shoals (Rossi-Wongtschowski et al 2014). The third growth phase is related to the first maturation in the anchovy, close to 61-70 mm TL, both quoted in Whitehead et al (1988) and diagnosed from analysis of the current data, still unpublished.…”

“…The species inhabits the estuary at this stage (Araújo et al 2008) and still has more rounded otoliths with a small rostrum, which corresponds to fish with low swimming ability Echeverría 2003, Volpedo et al 2008). The circular shape is inherited from the larval phase (Joh et al 2015), which will be progressively reduced.…”

“…Classified as a euryhaline species (Araújo et al 2008, Vilar et al 2011, it grows up to 118 mm long, with a life span of 2.3 years (Whitehead et al 1988). It has an isometric growth pattern RossiWongtschowski 2013, Franco et al 2013) and spawns between September and February (Araújo et al 2008).…”

“…Classified as a euryhaline species (Araújo et al 2008, Vilar et al 2011, it grows up to 118 mm long, with a life span of 2.3 years (Whitehead et al 1988). It has an isometric growth pattern RossiWongtschowski 2013, Franco et al 2013) and spawns between September and February (Araújo et al 2008). Very few studies on the relationship between the species and estuaries are extant: the exclusive presence of juveniles and young fish of the year have been reported in Sepetiba Bay and in the Paranaguá Estuarine Complex (PEC), Brazil, with the occurrence of adults in open beaches outside these ecosystems (Araújo et al 2008, Contente et al 2011).…”

“…It occupies a key position in the food web (Araújo et al 2008), constituting an important prey for marine mammals, seabirds and other fish (Santos et al 2002, Bugoni and Vooren 2004, Bornatowski et al 2014. Some of these piscivorous species are top predators in the southwestern Atlantic and have different levels of conservation risk (IUCN 2014).…”