Habitat selection by anchovies (Clupeiformes: Engraulidae) in a tropical bay at Southeastern Brazil

Abstract

Distribution of anchovies (Clupeiformes, Engraulidae) was described in the Sepetiba Bay, a coastal area of Southeastern Brazil, to assess eventual mechanisms of habitat selection. Two fish sampling programmes were accomplished; one using beach seine (1998/2000) to catch juveniles in sandy beaches, and the other, using seines (1999/2000) to catch adults in deeper bay areas. Six species representing 4 genera were recorded: Anchoa tricolor, Anchoa januaria, Anchoa lyolepis, Cetengraulis edentulus, Engraulis anchoita and Lycengraulis grossidens. Anchoa tricolor and A. januaria were the most abundant species, with the former peaking in the outer bay, while the latter peaking in the inner bay. Adults A. tricolor are target of heavy commercial fisheries in the bay during Spring-Summer, while E. anchoita, an abundant species in the continental shelf, was occasionally caught in large numbers during the Autumn. The habitat selection, by using two different bay areas, was developed by the two most abundant species, a probable mechanism to enable their coexistence.<br>A distribuição de manjubas (Clupeiformes, Engraulidae) foi descrita na Baía de Sepetiba, uma área costeira do Sudeste do Brasil, para determinar eventuais mecanismos de seleção de habitat. Dois programas de amostragem foram realizados; um usando arrasto de praia (1998/2000) para captura de juvenis, e outro, usando arrasto de fundo (1999/2000) para captura de adultos. Seis espécies representadas por quatro gêneros foram capturadas: Anchoa tricolor, Anchoa januaria, Anchoa lyolepis, Cetengraulis edentulus, Engraulis anchoita e Lycengraulis grossidens. Anchoa tricolor e A. januaria foram as espécies mais abundantes, com a primeira ocorrendo principalmente na zona externa da baía, enquanto a segunda com maior abundância na zona interna. Adultos A. tricolor são alvo de intensas pescarias comercial na baía durante a Primavera-Verão, enquanto E. anchoita, uma abundante espécie na plataforma continental, foi ocasionalmente capturada em grande numero durante o Outono. A seleção de hábitat, através do uso de diferentes áreas da baía, foi desenvolvida pelas duas espécies mais abundantes, um provável mecanismo para permitir a coexistência

Phylogeography from South-Western Atlantic Ocean: Challenges for the Southern Hemisphere

“…Recruitment occurs in protected, shallow areas that offer food and shelter against predators. Adults move during seasons between open coastal areas and bays, where they form large aggregations that are targeted by important fisheries (Araújo et al, 2008). Present phylogeographic analysis based on mitochondrial cyt-b sequences in E. anchoita from three different collecting regions in the Río de la Plata and the border of continental shelf revealed unexpected large values for haplotype and nucleotide diversity in this taxon.…”

Reproductive biology of Cetengraulis edentulus (Cuvier, 1829), the major fishery resource in Guanabara Bay, Brazil

“…Surprisingly, our results partially contrasted with those of Souza-Conceição et al (2005) for Cetengraulis edentulus in a bay at Southern Brazil, which spawned in late spring and summer. These variations suggest a plasticity of C. edentulus to adjust their reproductive period in accordance with the local environmental characteristics, of which temperature, photoperiod and food availability have been suggested as determinants for engraulids reproduction in coastal bays (Silva et al, 2003;Araújo et al, 2008aAraújo et al, , 2008b. Comparing our results with those obtained for other C. edentulus or C. mysticetus populations, rising water temperatures seems to be the crucial factor for the spawning season of these species, which seems to start earlier (winter) for populations at lower latitudes (Beltrán-Leon, 2002; this study), and latter (spring) for those at higher latitudes (Souza-Conceição et al, 2005).…”

“…This planktivorous species is well tolerant to changes in environmental conditions, being often found at inner zones of coastal bays, where salinity is generally low, temperatures are high, and phytoplankton biomass is high due to the great input of organic waste (Sergipense et al, 1999;Silva et al, 2003;Araújo et al, 2008a). Although the great importance of C. edentulus as fishery resource in coastal bays of Southeastern Brazil, especially on Guanabara Bay where accounted for 69% (ca.13,000 ton) of total landings in 2004, (Jablonski et al, 2006;Araújo et al, 2008a), the ecology of this species is barely known, especially on its reproductive biology (Souza-Conceição et al, 2005). The present study aimed to broaden the knowledge on C. edentulus reproduction in Guanabara Bay and test whether reproductive activity, gonadosomatic index and fecundity varied among seasons.…”

Variaciones a gran escala (2002-2011) de las pesquerías de Cetengraulis edentulus (Clupeiformes: Engraulidae) en la bahía de Guanabara, Brasil

“…C. edentulus first matures at 118mm total length (L 50 for both sexes), reaching 200mm at maximum (Silva et al, 2003;Souza-Conceição, Rodrigues-Ribeiro, & Castro-Silva, 2005). This species feeds mainly on phytoplankton and is widely tolerant to changes in environmental conditions (Krumme, Keuthen, Barletta, Saint-Paul, & Villwock, 2008;Giarrizzo & Krumme, 2009).It is often associated with muddy substrates of inner bay zones, where salinity is low, temperatures are high, and phytoplankton biomass is high due to the great input of organic waste (Sergipense, Caramaschi, & Sazima, 1999;Gay, Sergipense, & Rocha, 2000;Silva et al, 2003;SouzaConceição et al, 2005;Araújo, Silva, Santos, & Vasconcellos, 2008).…”

“…edentulus began to be used as human food and fish meal since early 1980s, in part due to declining stocks of other traditionally exploited species, such as Sardinella brasiliensis (Whitehead et al, 1988;Jablonski et al, 2006), currently accounting for the major fishery resource in coastal bays of Rio de Janeiro, Southeastern Brazil (Araújo et al, 2008). Overall, commercial vessels operating at Guanabara Bay use purse seines (35-40m length; 12mm mesh) to catch preferentially C. edentulus but also other small pelagic fish species (i.e.…”