Dinâmica populacional, biologia reprodutiva e o ictioplâncton de Cetengraulis edentulus Cuvier (Pisces, Clupeiformes, Engraulidae) na enseada do Saco dos Limões, Florianópolis, Santa Catarina, Brasil

Abstract

Os dados utilizados neste estudo são originários de um monitoramento ambiental realizado na enseada do Saco dos Limões, Florianópolis, Santa Catarina, Brasil. Neste monitoramento foram coletadas amostras da ictiofauna, sendo separados para análise um total de 3820 exemplares de Cetengraulis edentulus Cuvier, 1828, capturados em 17 coletas, no período compreendido entre julho de 1999 e abril de 2001. A análise dos dados permitiu estimar parâmetros populacionais e reprodutivos importantes como o comprimento de primeira maturação (118 mm para sexos grupados, 112 e 118 mm para machos e fêmeas, respectivamente), as distribuições de freqüências de comprimento, a relação peso-comprimento (Pt = 0,0000003 x Ct 3,67º8), a proporção sexual ao longo do tempo, a variação sazonal dos estádios de maturação gonadal, o índice gonadossomático, o fator de condição e o fator de condição somático, o ciclo reprodutivo e o período de desova, sendo também determinada a participação da espécie no ictioplâncton. Foram determinadas as correlações entre os parâmetros biológicos e os ambientais de temperatura e salinidade da água, superficial e de fundo. Constatou-se que a espécie utiliza o ambiente de estudo ao longo de todo seu ciclo de vida, tanto para reprodução quanto para a alimentação e o crescimento, e está estrategicamente adaptada às condições ambientais e biológicas da área de estudo.

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

“…This pattern agrees with its congener Cetengraulis mysticetus (Günther, 1867) in the Gulf of Panama, which shares many morphological and ecological similarities (Beltrán-Leon, 2002), and also for Anchoa tricolor (Spix & Agassiz, 1829) in Sepetiba Bay (Araújo et al, 2008b). 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.…”

“…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).…”

“…All individuals were measured for total length (mm; TL) and total weight (g), of which 754 gonads were weighed and preserved in 10% buffered formalin. Individuals were classified into adults or juveniles according to the stage of the gonad development and the length at first maturity (L 50 ) of 118 mm TL found by Souza-Conceição et al (2005) for a population of C. edentulus at a Southern Brazilian estuary.…”

“…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.…”

The influence of the 1992-1993 el niño on the reproductive biology of Scomber japonicus peruanus (Jordán & Hubb, 1925)

“…The condition factor is one of the principal parameters for the evaluation of the general conditions of fish, frequently being associated with their reproductive cycle (VAZZOLER, 1996;SOUZA-CONCEIÇÃO et al, 2005). According to Claereboudt et al (2005) and Plaza et al (2007), the condition factor and the gonadosomatic index are quantitative indicators utilized in the evaluation of the reproductive biology of pelagic species.…”