Atherinella blackburni (Schultz, 1949) at Itamambuca Beach, Ubatuba, SP: ecological characterization and distribution on the Brazilian coast (Teleostei: Atheriniformes: Atherinopsidae)

Abstract

Atherinella blackburni is a silverside species whose occurrence on the Brazilian coast was not properly registered until recently. So far, records of its distribution along the Brazilian shore were limited to Itaparica Island, Bahia State, and Porto Inhaúma, Rio de Janeiro State. In a recent survey of the ichthyofauna of Itamambuca Beach, Ubatuba, São Paulo State, 100 specimens of this species were collected, yielding a considerable source of information regarding its ecology and a new southern limit of its distribution. A detailed survey of an ichthyological collection revealed lots of this species from regions of the Brazilian Northeast, resulting in a northward expansion of the occurrence of A. blackburni in Brazilian waters. Besides the populations found on the Brazilian coast, the species also occurs discontinuously in the Atlantic coasts of Costa Rica, Panama and Venezuela. Meristic and morphometric analysis showed overlapped values between Brazilian populations and the ones closer to the Caribbean. An ecological study of A. blackburni at Itamambuca Beach revealed that it is a predominantly diurnal species with preference for warm and salty waters, often occurring in sandy-bottom environments. It was more abundant in Summer and Winter, when individuals with smaller values of length and weight also occurred.Keywords: ecology, marine fish, new occurrence, silverside, West Atlantic.Atherinella blackburni (Schultz, 1949) na praia de Itamambuca, Ubatuba, SP: caracterização ecológica e distribuição na costa brasileira (Teleostei: Atheriniformes: Atherinopsidae) ResumoAtherinella blackburni é uma espécie de peixe-rei cuja ocorrência na costa brasileira não havia sido precisamente registrada até recentemente. Ainda assim, sua distribuição no litoral brasileiro estava restrita à Ilha de Itaparica, Bahia e Porto Inhaúma, Rio de Janeiro. Em um recente levantamento da ictiofauna da Praia de Itamambuca, Ubatuba, São Paulo, foram coletados 100 espécimes desta espécie, originando uma fonte considerável de informações no tocante à sua ecologia e a um novo limite sul de sua distribuição. Um estudo detalhado revelou lotes desta espécie em regiões do nordeste brasileiro em coleção ictiológica, resultando na expansão para o norte da ocorrência de A. blackburni em águas brasileiras. Além das populações encontradas na costa brasileira, a espécie também ocorre descontinuamente na costa Atlântica da Costa Rica, Panamá e Venezuela. Análise merística e morfométrica revelou valores sobrepostos entre populações brasileiras e aquelas mais próximas ao Caribe. O estudo ecológico de A. blackburni na Praia de Itamambuca evidenciou que é uma espécie predominantemente diurna com preferência por águas quentes e salgadas, freqüente em ambientes com fundo arenoso. Foi mais abundante no verão e inverno, quando indivíduos com menores valores de comprimento e peso também ocorreram.Palavras-chave: Atlântico ocidental, ecologia, nova ocorrência, peixe marinho, peixe-rei.

Feeding ecology of the beach silverside Atherinella blackburni (Atherinopsidae) in a tropical sandy beach, Southeastern Brazil

“…Furthermore, seasonality has been an important factor for the population structure throughout the year, with smaller fish captured during the dry season, particularly during the autumn and winter. This result differs in part from a previous study by MATTOX et al (2008), who suggest that the recruitment of A. blackburni occurs during summer and autumn, when there is a higher incidence of small individuals. Although not conclusive since there is a low number of studies, the recruitment period of A. blackburni appears to occur during autumn.…”

“…Unlike other Atherinopsids commonly found in Brazilian waters (e.g. Atherinella brasiliensis and Odontesthes bonariensis), A. blackburni prefers high water temperature and salinity (MATTOX et al, 2008), with a sparse distribution limited to the West Atlantic and occurrence throughout Central and South America. Specimens were found in Honduras (MATAMOROS et al, 2009), Costa Rica (GILBERT;CALDWELL, 1967), Venezuela (SCHULTZ, 1949;GASPAR;ÁVILA, 2009) and Brazil (GILBERT;CALDWELL, 1967;OLIVEIRA-SILVA, 2001;MAZZEI et al, 2011;PESSANHA, 2014;GARCIA-JÚNIOR et al, 2015).…”

“…The collected fish were properly conditioned in ice for posterior laboratory analysis. The identification of species was based on the diagnosis proposed by MATTOX et al (2008), which lists characteristics to differentiate A. blackburni from other Atherinopsids regularly found in Brazilian waters.…”

“…blackburni is a small fish of the Atherinopsidae family that inhabits the surf zone of beach environments and measures up to 130 mm and 12.67 g (MATTOX et al, 2008). Unlike other Atherinopsids commonly found in Brazilian waters (e.g.…”

“…MATTOX et al, 2008) due to their discontinuous distribution and low occurrence, and none assessing the feeding ecology of this species. Moreover, since the life cycle of A. blackburni is restricted to shallow areas of beach environments (LOPES; OLIVEIRA-SILVA, 2001;MATTOX et al, 2008), this species might be an important model for elucidating how the surf zone influences the fish species at different life stages.…”