The maturity at length of females was studied during the main spawning season. IGS monthly variation and the frequency of macroscopic states of maturity reached maximum values each year, between September and October, and minimum from January to June. In addition, the histological analysis of the ovaries confirmed that S. fueguensis is a partial spawner whose reproductive activity although tends to concentrate between September and October can be extended to December. The mean length at maturity of females during the reproductive season was 13.5 cm, indicating that they spawned at longer lengths in comparison with the same species from other localities. It is discussed that the increase of the reproductive activity in spring and larger maturity sizes could be part of a reproductive strategy of the species to enhance the survival during early stages in the inland seawater of Chiloé.
By mans of the fisheries activity records and the information of tralws sampling carried out in surveys of common hake the batimetric and latitudinal distributions of cardinal fish (Epigonus crassicaudus) in the Chilean coast were studied. Aditionality, information on feeding habits of cardinal fish through analysis of the gastric content on samples collected in the central zone from Chile are reported. According to fishery data the cardinal fish would concentrate their distribution between Valparaíso (33º04'S) and Puerto Montt (41º46'S). However, the acustic surveys register positive captures from north limit of their operation (29°00'S). Deep distribution showed coincidence from the two sources information so much in the throw positives frequency like in capture, indicating that the resource would concentrate their distributon in depth range of 300 to 400 m. Regarding the feeding, although some bentics components were registered in their diet, the preys more consumed by E. crassicaudus were planctonics organisms represented by eufausids and stomatopods. The result of present study suggest that E. crassicaudus would present migratory habits from the pelagics to the bentics environmental determined by the offer of food, concentrating their distribution on the talud and continental shelf. A wider latitudinal distribution acquaintance through the fisheries activity data was also confirmed.
RESUMEN.La reineta (Brama australis) adquiere cada vez mayor importancia en los desembarques de la pesca artesanal, no obstante, es escasa la información que existe acerca de su biología básica, particularmente sobre su dinámica reproductiva. En este trabajo se determina la época principal de desove de B. australis en la costa central de Chile y la talla de madurez (TM), para lo cual se analizó un total de 1061 individuos capturados frente a Lebu (37º37'S-73º40'W), entre enero y septiembre de 2001. El análisis macroscópico de los ovarios, mostró ejemplares sexualmente maduros durante todo el período de muestreo. El Indice Gonadosomático (IGS) presentó fluctuaciones que indican un extenso período de desove, con un máximo invernal (junio-agosto). La TM se calculó a partir del método de longitud del 50% de hembras maduras a los 36,9 cm longitud horquilla (LH), con intervalo de confianza entre 35,3 y 37,8 cm y en 39 cm LH mediante el método del Incremento Relativo del IGS (IR.IGS). Debido a que las capturas ocurrieron principalmente en ejemplares sobre 39 cm LH, la flota estaría extrayendo mayoritariamente peces maduros.Palabras claves: reineta, talla de madurez, desove, Brama, Chile. Maturity size and spawning time of the Pacific pomfret (Brama australis Valenciennes, 1836) in the central coast of ChileABSTRACT. Landings of Pacific pomfret (Brama australis) is acquiring an increasing importance to the Chilean artisanal fishery. However, lack of information regarding its basic biology, in particular, reproductive dynamics, still persists. In this work we determine the spawning season of B. australis in the central coast of Chile and the length of maturity (LM). A total of 1061 individuals captured in the coastal zone of Lebu (37°37'S-73°40'W), Chile, between January and September 2001, were analyzed. Macroscopic analysis of ovaries, showed sexually mature individuals throughout the sampling period. Gonadosomatic Index (IGS) showed fluctuations indicative of extensive spawning periods, with a maximum in the austral winter season (June-August). LM of females was estimated with the length at 50% maturity method, in 36.9 cm fork length (LH), with a confidence interval between 35.3 and 37.8 cm LH, and 39 cm LH using the Relative Increment of IGS method (IR.IGS). Since the catch comprises principally individuals over 39 cm LH, the fishing fleet extracts mainly mature fish.
In the central north of Chile (25°00'S-32°10'S) an anchoveta fishery (Engraulis ringens) operates on a small scale. In spite of being controlled by total allowed catches, the life history parameters used to estimate its abundance remain unknown. We estimated the basic biological parameters as growth, maturity and natural mortality for anchovy inhabiting the Chilean central north. The von Bertalanffy parameters were an annual growth rate (k) of 0.91 year-1 , asymptotic length (L ∞) at 18.72 cm, and age at zero length (t o) of-0.01 year. The maximum value of the gonadosomatic index in September and the high frequency of mature stages between July and December, support that the main spawning period of anchoveta in the area would occur from August to October of each year. The mean maturity length (L m50%) was estimated at 12.5 cm and the natural mortality (M) was 1.30 year-1. The biological parameters of E. ringens located in central north of Chile are in concordance with the life history characteristics of small pelagic fish.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.