Crescimento da pescada-foguete (Macrodon ancylodon): aspecto quantitativo

Abstract

SYNOPSISWe determined the age of the commercial marine fish "pescada-foguete" (Macrodon ancylodon, Bloch 1801) caught by trawls along the southern coast of Brazil (28°S-34°S), from 1961 to 1963, by means of the annuli in otoliths (CHUGU-NOVA, 1959).We correlated the mean total length (L) in centimetres with the age (t) in years by means of the BERTALANFFY expression adjusted by FORD-WALFORD method (BEVERTON & HOLT, 1957).The mean total length was correlated with the mean weight (W) in grams, by means of the expression W = a Lb adjusted by least square method, after a logarithmic transformation.Results :

Age and changes in growth of the king weakfish Macrodon atricauda (Günther, 1880) between 1977 and 2009 in southern Brazil

“…Depending on its size and shape, the entire otolith can be read, but it can also be cut through the nucleus or in thin sections (Chilton and Beamish, 1982) The king weakfish otolith is laterally compressed and relatively large; on its outer surface, opaque and translucent bands can be distinguished. These bands have been interpreted to be annuli in previous age and growth studies of the king weakfish in southern Brazil (Yamaguti and dos Santos, 1966;Haimovici, 1988). Although ageing has been validated through marginal increment analysis, it is difficult to identify the translucent bands on the outer edge of otoliths.…”

“…It has also been fished in Uruguay and Argentina (Cousseau and Perrota, 1998). Because of its importance as a fishing resource, several aspects of its biology and population dynamics have been studied, including reproduction (Yamaguti, 1967;Juras and Yamaguti, 1989;Militelli and Macchi, 2004), feeding (Juras and Yamaguti, 1985), migration (Santos and Yamaguti, 1965), mortality (Yamaguti, 1968) and the age and growth of sub-adults and adults (Yamaguti and dos Santos, 1966;Haimovici, 1988).…”

A mathematical model for growth in weight of silver catfish (Rhamdia quelen) (Heptapteridae, Siluriformes, Teleostei)

“…ANGELESCU et al (1958) did not find differences in the relationship between males and females of the Argentinean merluza, Merluccius merluccius hubbsi. BAXTER (1960) did not observe significant differences on size between sexes in Seriola dorsalis, nor did YAMAGUTI & SANTOS (1966) for Macrodom ancylodon. However, males from piava, Leporinus friderici, collected in Lobo reservoir and Moji-Guaçu river presented higher growth rate than females (BARBIERI & SANTOS, 1988).…”

Long-term changes in the age structure, mortality and biomass of the king weakfish Macrodon atricauda (Günther, 1880) in southern Brazil: Is it resilient enough to avoid collapse?

“…These changes need to be considered in the context of the life-history theory (Hutchings, 2002;Roff, 2002). The apparent stability from the 1970s to the 1990s might be the result of a combination of life-history traits that favor resilience and recovery (Reynolds, 2003;Reynolds et al, 2001), such as high fecundity (Militelli and Macchi, 2004), low age at maturity (Cardoso and Haimovici, 2014;Yamaguti, 1967), rapid individual growth and a relatively short lifespan (Cardoso and Haimovici, 2011;Haimovici, 1998;Yamaguti and Santos, 1966). However, resilience has a limit, since there are genetically determined boundaries to the plasticity of life-history traits (Dieckmann and Heino, 2007;Houston and McNamara, 1992).…”