Demersal fish assemblages off São Sebastião, southeastern Brazil: structure and environmental conditioning factors (summer 1994)

Abstract

The demersal fish community of the Channel and shelf of São Sebastião (SP), on the southeastern Brazilian coast, was investigated during the summer of 1994. The sampling was carried out usinga bottom otter trawl at 26 stations located between 8 m and 65 m in depth. Ninety-three species of 40 families were identified in the area. Sciaenids were the most prominent in number of species, abundance, and weight. Ctenosciaena gracilicirrhus, Paralonchurus, brasiliensis, and Cynoscion jamaicensis dominated in the catches. Cluster analysis showed three major groups of species and three groups of sites. The first group was composed of species found in the Channel and shallower areas of the inner shelf, the second of species associated with the inner shelf «50 m depth), and the third group of species fTom the outer shelf (> 50 m depth). Environrnental variables considered in Canonical Correspondence Analysis (CCA) explained 51 % of the variation in the species data. Bottom water temperature was the most important variable selected by CCA, accounting for 21% of the explainable variance. The results revealed that structure of the ichthyofauna was associated with water mass distribution. During the period studied, the area was occupied by the warm Coastal Water (CW), but cold South Atlantic Central Water (SACW) was detected over the bottom or the outer shelf, influencing the distribution and abundance ofthe main species.

Checklist of the fish fauna of the Araçá Bay, São Sebastião Channel, northern coast of São Paulo, Brazil

“…A bottom trawl survey carried out 20 years ago in the outer sublittoral of the Araçá Bay recorded the following species not recorded in the present study: (Muto et al 2000). The absence of these species in our samples may be due to sampling effort but also potential differences in fish community between 1994 and 2016.…”

“…Several studies of the benthic fauna have been carried out at Araçá Bay (Migotto et al 1993;Arruda and Amaral 2003;Petracco et al 2013;Corte et al 2014;Gorman et al 2015), but the fish fauna of this bay is still largely unknown, despite its high importance for local fishermen. Available information of the fish fauna is restricted to bottom-trawl surveys (Muto et al 2000;Rossi-Wongtschowski et al 2008) and diving surveys (Gibran and Moura 2012) conducted in São Sebastião Channel and on the adjacent continental shelf.…”

Identifying key habitat and spatial patterns of fish biodiversity in the tropical Brazilian continental shelf

“…In addition, some of the dominant species also share the same food resource (sessile and mobile invertebrates) (Bowen et al, 1995;Rangel et al, 2007). The dominance of the demersal assemblage by few families (7 out of 49) has also been registered in other studies in Brazil (Azevedo et al, 2007;Muto et al, 2000) and elsewhere (Jaureguizar et al, 2006;Johannesen et al, 2012;Prista et al, 2003), seeming to be an ecological pattern of demersal assemblages (Gibson et al, 2007).…”

Ichthyofauna in the Inner Continental Shelf Next to the Paranaguá Estuarine Complex, Southern Brazil

“…Key species are those that make up the community base and, when absent, result in a substantially different community (Mahon and Smith, 1989). The concept of key species can be applied in this study, where 37.2% of the total catch of individuals was from the family Sciaenidae; the high 9/13 representativeness of this family seems to be a common pattern in the sand-muddy bottom areas of the brazilian coast (Muto et al, 2000;Moraes et al, 2009;Silva Junior et al, 2013;Nóbrega et al, 2019). This predominance is common in other estuaries of the world and is due to the fact that this transition between marine/ euryhaline environments occurred several times throughout the evolutionary history of the family.…”