Gayana (Jan 2005)
PARAMETROS BIOLOGICO-PESQUEROS DE LA JIBIA, DOSIDICUS GIGAS (ORBIGNY, 1835) (CEPHALOPODA: OMMASTREPHIDAE), FRENTE A LA COSTA DE CHILE CENTRAL (29ºS-40ºS) DURANTE 1993-1994 FISHERY BIOLOGY PARAMETERS OF JUMBO SQUID, DOSIDICUS GIGAS (ORBIGNY, 1835) (CEPHALOPODA: OMMASTREPHIDAE), IN CENTRAL CHILE COAST (29ºS-40ºS) DURING 1993-1994
Abstract
Se presentan los resultados de dos cruceros de pesca de investigación de la jibia, Dosidicus gigas (Orbigny 1835) realizados entre julio de 1993 y enero de 1994 en la Zona Económica Exclusiva de Chile comprendida entre los 29º S y 40º S. En cada lance se registró el día, hora, duración del lance, así como el volumen de la captura por lance y máquina potera, para efectuar estimaciones de abundancia relativa. A los ejemplares capturados se les determinó la longitud dorsal del manto (LDM), peso total, peso eviscerado, peso manto, sexo y se les extrajo el tracto digestivo, para un análisis del contenido estomacal. Las jibias sólo fueron capturadas entre los 29º S y los 30º S. En el primer crucero (invierno) se registraron ejemplares grandes (71 a 98 cm LDM) y chicos (The results of two fishing research cruises of the jumbo squid, Dosidicus gigas, between July 1993 and January 1994 in the Chilean economic exclusive zone between 29º S to 40º S, are described. For each trawling, date, hour, trawling duration and volume of squids by catch and jigging machines, were registered to estimate the relative abundance. The squid mantle length, total weight, eviscerated weight, mantle weight, and sexes, were measured in each collected specimen. Then, the digestive tracts were extracted for stomach content analysis. The captures of jumbo squid occurred only from the 29ºS to the 30º S. In the first cruise (winter) specimens of large (71 to 98 cm MDL) and small size (< 44 cm MDL) in both sexes, were collected; while in the second cruise (spring) medium size squids were captured (26 to 60 cm MDL). Size frequency distribution analysis in the both cruises shows two cohorts of D. gigas in the same fishing zone. The diet does not change among seasons and was compound mainly for pelagic and demersal fish and secondarily by cephalopods and occasionally pelagic crustaceans; furthermore, cannibalism may also occurs among squids. Length-weight relationships were similar in both sexes and it corroborates that jumbo squid registered in Chile, reaches bigger weight to the same length that the populations from Mexico and Peru
