Estudo das variações da relação peso total/comprimento total em função do ciclo reprodutivo e comportamento, de Sardinella brasiliensis (Steindachner, 1879) da costa do Brasil entre 23ºS e 28ºS

Abstract

SYNOPSISThis paper analyses some aspects on the length/weight relationship of Sardinella brasiliensis and its variations as a function of their reproductive cycle and displacements along the Brazilian coast between 23 0 S and 28°S. The area surveyed was divided into five subareas, each one covering one degree of latitude. The relationship and its variations between shoals were studied for each sub-area at different seasons and for the sub-are as at the same season. The absence of a variation pattern for the length/weight relationship has shown to be the result of seasonal changes in the physiological aspects of fish (as a function of their reproductive cycle) as well as result of behaviour of individuaIs in two main areas: 23 0 S-25 0 S and 26 0 S-28 0 S, which are spawning areas, spawning occuring during spring and summer at the first and only during spring at the latter. After spawning the young (from both areas) more at different times to a common trophic area where they find suitable conditions (25 0 S-26°S), returning to their original sub-areas at different occasions, following their first sexual maturation. Although spawning takes place at different times and sites, with the convergence of young to a common nursery, mixing might occur. Further studies on meristics and body proportions are being developed regarding the existence of different populations.

Morphometry and relative growth of the Brazilian sardine, Sardinella brasiliensis (Steindachner, 1879) in the southeastern Brazilian bight

“…Our results also show that there is an increase in individual weight resulting from gonad maturation (Braga, 1997), also documented for Sardinella brasiliensis by several authors (Vazzoler & RossiWongtschowski, 1976;Rossi-Wongtschowski, 1977;Isaac-Nahum et al, 1983Matsuura et al, 1992, Matsuura, 1998. The coefficient "a" can be identified as the allometric condition factor (Braga, TABLE 1: Sardinella brasiliensis: regression analyses ("a" and "b" regression coefficients of allometric model, r² = coefficient of determination) and relative growth analysis ("t" = t-test statistic, P = probability value of t-test, n = number of observations) by year and season (Su = Summer, Au = Autumn, Wi = Winter, Sp = Spring).…”

Iheringichthys labrosus (Siluriformes: Pimelodidae) in the Piquiri River, Paraná, Brazil: population structure and some aspects of its reproductive biology

“…This indicates an accumulation of reserves to accomplish reproduction, and by decreasing drastically during that period, caused by the expenditure of energy in such activity. Similar behavior was observed by Le Cren (1951), Rossi-Wongtschowski (1977), Isaac-Nahum & Vazzoler (1983); Barbieri (1992Barbieri ( , 1995 and Silva et al (2005;2007) in other fish species. The analysis of gonadal maturation confirm the above findings, indicating that the reproductive period of the species begins in September and extends to the end of December, with a peak in November.…”

“…The present study corroborates those results; however, statistical differences were not observed between the sexes regarding this coefficient. According to Rossi-Wongtschowski (1977), the length/weight relationship in fish may or may not show sexual dimorphism.…”

Estudo da diversidade de Sardinella brasiliensis (Steindachner, 1879), na área entre Macaé (22º23'S) e Ilha de Santa Catarina (27º35'S): 1. Crescimento de dimensões corporais

“…pescadores; as regiões II e IV constituem respectivamente dois locais de desova (Rossi-Wongtschowski, 1977); e a região III abrange ambientes costeirós abrigados: com condições ambientais distintas das de mar aberto.…”

“…tores sugeriram a existência de grupos distintos de S. brasiliensis ao longo da costa, entre Cabo Frio e Florianópolis (Besnard, 1950;Richardson et aI., 1959;Vazzoler & Ngan, 1976;Rossi-Wongtschowski, 1977). Tal heterogeneidade deve ocorrer tendo em vista as variações das condições oceanográficas e geográficas existentes na área.…”