The von Bertalanffy (vB) growth parameters for pink cusk-eel (Genypterus blacodes) were estimated for the Chilean australzone (41°28¢-57°00¢S) by gender and management fishing zones. A total of 47 026 samples were collected between March 1982 and May 2004, with total length ranging from 19 to 154 cm. Age determinations, based on the reading of saggital otoliths, were between 1 and 14 years in males and between 1 and 16 years in females. Statistical differences in growth were found between the sexes and management fishing zones. For the combined sexes the vB growth parameters for the northern-austral zone (41°28¢-47°00¢S) were: l ¥ ¼ 111.452 cm, k ¼ 0.186 year )1 , t 0 ¼ )0.912 year; and for the southern-austral zone (47°00¢-57°00¢S): l ¥ ¼ 123.447 cm, k ¼ 0.147 year )1 , t 0 ¼ )1.779 year.

Abstract.-The cardinalfish Epigonus crassicaudus is a deep-demersal fish with commercial importance for the trawl fishery operating off central Chile. Previous analysis in age assignment, based on the whole otolith, determined the maximum age to be 15 years old. Although scarce data is available for the genus, other congeneric species might live up to 100 years. Using sagitta otolith transversal sections, we determined age to 1277 fish collected in central Chile between January and December 2008. Longevity was determined in 54 years old.

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Age and growth parameters were estimated for the deep-sea cardinalfish (Epigonus crassicaudus) from sagittal otoliths collected between 2012 and 2015 onboard commercial fishing vessels from the South-east Pacific off Chile between 33°04′S and 41°46′S. Von Bertalanffy growth parameters (VBGP) were estimated from assumed annual otolith growth zone counts. The verification of the first annulus of sagittal otoliths was determined by examining in detail daily micro-increments. These data helped inform the interpretation of the annual growth zones from transverse otolith sections. The von Bertalanffy growth model estimated to length-at-age data were asymptotic length (L∞) of 34.1 cm fork length (FL), a growth coefficient (k) of 0.1 cm/year and a t-zero (t0) of −0.85. The maximum ages observed were 67 and 65 years for female and male fish, respectively.

Reproductive traits and natural mortality rate of cardinalfish females (Epigonus crassicaudus) were studied from samples collected onboard commercial fishing vessels, from 2012 to 2015, on the Chilean coast. The reproductive cycles of females analyzed thought gonadosomatic index (GSI) showed a maximum reproductive activity in austral fall, between March and May. Length (L50%) and age (A50%) at maturity, estimated using a macroscopic scale of the developed ovary, was 22.3 cm fork length (FL) and 9.3 years, respectively. Natural mortality (M) was estimated by two age-related methods. Using maximum age (tmax) M was estimated in 0.063 yr-1 and through age-at-maturity (A50%) in 0.15 yr-1. A potential bias in the reproductive study is discussed when a macroscopic maturity scale is used. Nevertheless, its usefulness is validated when funding is scarce, and time is limited. Although M uncertainty was not evaluated, the estimated range appears to be into the expected values to long-lived species. The life history parameters estimated in the present study can be used to evaluate possible time variability in maturity and M rates. Also, these results could be used in stock assessment analysis and to apply effective management measures in the fishery.

RESUMEN.El congrio dorado (Genypterus blacodes) es un pez demersal de gran importancia económica en la pesquería multiespecífica y multiflota que opera en la zona sur-austral de Chile (41°28'-57°00'S). Desde principio de los años noventas se consideró para efectos de la evaluación poblacional la existencia de un único stock. Sin embargo, varios antecedentes relacionados con la historia de vida y demografía han conducido a que, desde el año 2005, la evaluación de esta especie se realice bajo dos stocks administrativos, uno en la zona norte (41°28'-47°00'S) y otro en la zona sur (47°00'-57°00'S). La separación de stocks produce una demanda por actualización de parámetros de historia de vida, entre éstos la mortalidad natural (M). En este trabajo se estimó M para el congrio dorado mediante métodos empíricos aplicados por zona y sexo. La incertidumbre en M fue incorporada a través de remuestreo de Monte Carlo considerando dos fuentes de error, una proveniente de los parámetros de historia de vida que alimentan los modelos empíricos y otra, proveniente de los coeficientes que los definen. El promedio de M mediante los diferentes métodos mostró, para una determinada zona, importantes diferencias entre sexos, como también para sexos conjuntos entre zonas de pesca. Los individuos de la zona norte presentaron mayor M que aquellos provenientes de la zona sur y los coeficientes de variación por método son altamente dependientes del tipo de error incorporado. El método de Pauly (1980) parece ser el más adecuado para el congrio dorado entregando valores de M para sexos conjuntos de 0,27 año -1 (IC: 0,13-0,47) en la zona norte y 0,23 año -1 (IC: 0,11-0,40) en la zona sur.Palabras clave: Genypterus blacodes, mortalidad natural, pesquería demersal, historias de vida, demografía, sur de Chile. Estimation of natural mortality and uncertainty in pink cusk-eel (Genypterus blacodes Schneider, 1801) in southern ChileABSTRACT. Pink cusk-eel (Genypterus blacodes) is a demersal fish of high economic importance for the multi-species and multi-fleet fishery operating off far-southern Chile (41°28'-57°00'S). Since the early 1990s, the existence of a single stock was assumed for purposes of stock assessments. However, several attributes related with life history and demography led to the designation, as of 2005, of two administrative stocks of this species, a northern-austral stock stock (41°28'-47°00S) and a southern-austral stock (47°00-57°00S). The division of these stocks has produced a demand for updating life history parameters, including natural mortality (M). In the present work, we used empirical methods to estimate M for pink cusk-eel by zone and sex. The uncertainty in M was incorporated through Monte Carlo resampling considering two sources of error: one from the life history parameters that feed the empirical models and the other from the coefficients that define them. The average M obtained by the different methods showed important differences between sexes for a given zone and between combined sexes between the different fish...

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