Age determination, validation, and growth of Brazilian flathead (Percophis brasiliensis) from the southwest Atlantic coastal waters (34º 41ºS)

Abstract

ABSTRACT. The age and growth parameters of Brazilian flathead, Percophis brasiliensis, from the southwest Atlantic coastal waters (34º-41ºS) were determined for samples collected in spring (n = 853; years 1998 and 2000) and winter (n = 596; year 2004), whereas age was validated through the edge analysis of otoliths collected in 2007 (n = 1367 otoliths). The indices of precision APE, V, and D were used to test the reproducibility, between agers, of the ages determined from 845 otoliths. Maximum determined ages were 19 years for males and 15 years for females. One opaque and one translucent band are laid down per year, in the sagittal otolith. According to the APE (0.668%), V (1.121%), and D (0.647%) indices, the age determination was consistent. Von Bertalanffy's growth parameters [males: spring (L ∞ = 58.1 cm, k = 0.26 year -1 , t 0 = -2.02 years), winter (L ∞ = 58.7 cm, k = 0.21 year -1 , t 0 = -2.90 years); females: spring (L ∞ = 65.2 cm, k = 0.29 year -1 , t 0 = -1.15 years), winter (L ∞ = 63.5 cm, k = 0.26 year -1 , t 0 = -2.01 years)] were significantly different between sexes and seasons. From the first year of life, females grow faster and reach greater lengths than males of the same age due, probably, to an asynchronism in the sexual maturity. Keywords: Brazilian flathead, Percophis brasiliensis, age determination, otolith, validation, growth, southwest Atlantic. Determinación de edad, validación y crecimiento del pez palo (Percophis brasiliensis) de aguas costeras del Atlántico sudoccidental (34º-41ºS)RESUMEN. Se determinó la edad y los parámetros de crecimiento del pez palo, Percophis brasiliensis, de aguas costeras del Atlántico sudoccidental (34º-41ºS) en muestras obtenidas durante primavera (n = 853; años 1998 y 2000) e invierno (n = 596; año 2004), mientras que la edad fue validada mediante análisis del tipo de borde de otolitos colectados durante 2007 (n = 1367 otoliths). Los índices de precisión APE, V, y D fueron usados para probar la reproducibilidad, entre lectores, de las edades determinadas a partir de 845 otolitos. Las edades máximas determinadas fueron 19 años para machos y 15 años para hembras. Una banda opaca y una translúcida se depositan anualmente en el otolito sagitta. Los índices APE (0,668%), V (1,121%) y D (0,647%) indican que la determinación de la edad fue consistente. Los parámetros de crecimiento de Von Bertalanffy [machos: primavera (L ∞ = 58,1 cm, k = 0,26 año -1 , t 0 = -2,02 años); invierno (L ∞ = 58,7 cm, k = 0,21 año -1 , t 0 = -2,90 años). hembras: primavera (L ∞ = 65,2 cm, k = 0,29 año -1 , t 0 = -1,15 años); invierno (L ∞ = 63,5 cm, k = 0,26 año -1 , t 0 = -2,01 años)] fueron significativamente diferentes entre sexos y estaciones. A partir del primer año de vida, las hembras crecen más rápido y alcanzan mayores longitudes que los machos de la misma edad debido, probablemente, a un asincronismo en la madurez sexual. Palabras clave: pez palo, Percophis brasiliensis, determinación de edad, otolito, validación, crecimiento, Atlántico sudoccidental.

Assessing the role of host traits as drivers of the abundance of long‐lived parasites in fish‐stock assessment studies

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“…If the two independent readings differed, then the otolith was discarded. The validation of the periodical occurrence of opaque bands was established from a previous study performed by Barretto et al (2011); hence, age determination of the specimens was precise and acceptable.…”

Reproductive potential of Pagrus pagrus (Perciformes: Sparidae) in coastal waters of Buenos Aires Province (Argentina) and Uruguay (34º-39ºS)

“…However, it was similar to estimates from the southeastern US (Harris, McGovern, 1997) and the Gulf of Mexico (Hood, Johnson, 2000;DeVries, 2006). A 50 estimated for red porgy, was lower than that of other species in the BCE, such as whitemouth croaker (Micropogonias furnieri) (2.5 years, Arena, Hertl, 1983), striped weakfish (Cynoscion guatucupa) (4 years, Vieira, Haimovici, 1997) and Brazilian flathead (Percophis brasiliensis) (2 years, Barretto et al, 2011).…”