Spawning rhythms of common snook in Florida

Abstract

Common snook Centropomus undecimaliswere sampled monthly from the Jupiter–Lake Worth area of Florida's Atlantic coast during 1989 and 1991 (1452 fish) and from Tampa Bay on Florida's Gulf of Mexico coast during 1988 and 1989 (2090 fish). Group‐synchronous oocyte development was demonstrated. Ovarian maturation began during March or April on both coasts. Spawning was first detected histologically in April during 1989 and 1991 on the Atlantic coast and during May in 1988 and in April in 1989 on the Gulf coast. In each year, spawning ended during October on the Atlantic coast and during September on the Gulf coast. Ovarian histological evidence suggested that individual females may spawn every 1·1–2·5 days between 1400 and about 2000 hours. Final oocyte maturation occurred independently of either tidal cycle or lunar phase, and some common snook were observed in prespawning or spawning condition on every day sampled. Spawning occurred in or near major inlets to the Atlantic Ocean and the Gulf of Mexico, in secondary passes to larger inland bays and bayous, and around nearshore islands.

Reproductive variability of the common snook, Centropomus undecimalis, in environments of contrasting salinities interconnected by the Grijalva–Usumacinta fluvial system

“…The actively spawning subphase was observed only in MA. This coincides with reports supporting spawning of C. undecimalis at sea (Grier 1985, Tucker 1987, Taylor et al 1998, Perera-García et al 2011, Andrade et al 2013. According to our data, spawning frequently occurs during the months of higher salinity and temperature.…”

“…Estos autores no mencionan la condición gonádica de los peces residentes o no-migrantes, por lo cual no es posible definir la condición gonádica al momento que ocurre. La maduración gonádica en el AD sin posibilidad de desove supone un desperdicio en el presupuesto energético y apoya la idea de que los robalos capaces de desovar migran hacia el AM para desovar (Grier 1985, Taylor et al 1998, Perera-García et al 2011. Esto requiere evaluarse estudiando las migraciones entre los ambientes en el sistema Grijalva-Usumacinta.…”

“…Esto coincide con los registros que indican que el desove de C. undecimalis ocurre en el mar (Grier 1985, Tucker 1987, Taylor et al 1998, Perera-García et al 2011, Andrade et al 2013. De acuerdo con nuestros datos, el desove ocurre con mayor frecuencia en los meses de alta salinidad y temperatura.…”

“…Snooks are protandric hermaphrodites that spawn from April to September in the coastal marine environment, estuaries, and lagoons with salinities of 28 to 35 (Grier 1985;Tucker 1987;Taylor et al 1998;Perera-García et al 2008. Larvae and fry migrate into estuaries and rivers, where part of their development as juveniles and adults takes place.…”

Reproductive activity and recruitment of the yellow-mandi Pimelodus maculatus (Teleostei: Pimelodidae) in the Igarapava Reservoir, Grande River, Southeast Brazil

“…The classification was based on gross aspects of the ovaries, on the gonadosomatic index (GSI), in the most advanced phase of oocyte development and in the presence of postovulatory follicles in the ovarian tissue (Wallace & Selman, 1981;Bazzoli & Godinho, 1991;Taylor et al, 1998). The following oocyte development phases were described based on histological characteristics common to teleosts (Wallace & Selman, 1981): i) chromatin nucleolar, in which the scanty cytoplasm is homogeneously basophilic and the centrally located nucleus contains a single, large basophilic nucleolus, ii) perinucleolar, indicated by nucleus enlargement, multiple nucleoli appearance and presence of basophilic, dense material (Balbiani body) in the perinuclear cytoplasm, iii) yolk vesicle, characterized by the appearance of clear cytoplasmic vesicles which increase in size as they move towards the peripheral ooplasm, iv) vitellogenesis, oocytes with central nucleus and whose ooplasm is filled with yolk granules.…”