ABSTRACT
Spondylus limbatus es una especie bajo protección especial en México, de la que existe poca información biológica y nada sobre estudios histológicos o de ultraestructura del ovario. El objetivo de esta investigación fue caracterizar la morfología ultraestructural de los gametos femeninos maduros y en degeneración. La gónada femenina de S. limbatus en estado de madurez presentó ovocitos postvitelogénicos de 60-70 µm de diámetro, que presentan el aspecto característico de células metabólicamente activas y altamente sintetizadoras. La membrana citoplasmática posee especializaciones destinadas a aumentar la superficie de absorción de la célula, las microvellosidades; el citoplasma presenta numerosos sistemas membranosos relacionados con la síntesis de material de reserva y secreción; y el patrón de organización nuclear altamente lobulado, y por consiguiente con una gran superficie que asegura el intercambio núcleo-citoplasma, se incorpora de forma estructural al proceso de vitelogénesis. Finalmente, se describen los cambios ultraestructurales resultantes de la lisis de los ovocitos: colapso de las membranas nuclear y citoplásmica, y presencia de células hemocíticas macrófagas.
Spondylus limbatus is a species under special protection in Mexico, of which there is little or no information in the literature of biological, histological or ultrastructural studies of the ovary. The objective of this research was to characterize the ultrastructural morphology of mature and degenerating female gametes. The female gonad of S. limbatus in mature state presented post-vitellogenic oocytes 60-70 µm in diameter, which have characteristics of metabolically active and highly synthesizing cells. The cytoplasmic membrane has specializations designed to increase the absorption surface of the cell, the microvilli; the cytoplasm presents numerous membranous systems related to synthesis of reserve and secretion material as well as the highly lobed nuclear organization pattern; a large surface that ensures core-cytoplasm exchange, is structurally incorporated into the vitellogenesis process. Finally, ultrastructural changes resulting from the lysis of the oocytes are described: collapse of nuclear and cytoplasmic membranes, and the presence of macrophage hemocytic cells.
Subject(s)
Animals , Female , Oocytes/ultrastructure , Bivalvia , Gonads/ultrastructure , Reproduction , Microscopy, ElectronABSTRACT
In this paper, aspects of the reproductive biology of Lutjanus peru that can be used for the fishery management are described. Samples were taken monthly in 1993 and 1994, from commercial catches in the southern coast of Guerrero, Mexico. A global sex ratio of 1:1.37 (M:F) was found, but the sex ratio was highly variable each month. The condition factor, gonadosomatic, hepatosomatic and stomach fullness indexes were analyzed. None of the morphophysiological indexes showed any clear tendency. From 377 gonads, both male and female, five developmental stages were characterized for each sex. L. peru shows asynchronous gonad development and multiple spawning. Two spawning period were observed in 1993 (March, and August-September) and three in 1994 (April-May, July-August, and November), with a maximum in August of both years. Length at first maturity for the females of L. peru was estimated at 295 mm fork length.
Subject(s)
Animals , Male , Female , Fishes , Gonads , Sexual Maturation , Fishes , Gonads , Mexico , Reproduction , SeasonsABSTRACT
In this paper, aspects of the reproductive biology of Lutjanus peru that can be used for the fishery management are described. Samples were taken monthly in 1993 and 1994, from commercial catches in the southern coast of Guerrero, Mexico. A global sex ratio of 1:1.37 (M:F) was found, but the sex ratio was highly variable each month. The condition factor, gonadosomatic, hepatosomatic and stomach fullness indexes were analyzed. None of the morphophysiological indexes showed any clear tendency. From 377 gonads, both male and female, five developmental stages were characterized for each sex. L. peru shows asynchronous gonad development and multiple spawning. Two spawning period were observed in 1993 (March, and August-September) and three in 1994 (April-May, July-August, and November), with a maximum in August of both years. Length at first maturity for the females of L. peru was estimated at 295 mm fork length.
Subject(s)
Fishes/growth & development , Gonads/growth & development , Sexual Maturation/physiology , Animals , Female , Fishes/anatomy & histology , Gonads/anatomy & histology , Male , Mexico , Reproduction/physiology , SeasonsABSTRACT
Durante 1994 se recolectaron especímenes de S. leucacanthus en Isla Danzante, Golfo de California, se registró la temperatura superficial y del agua del fondo, se tomaron muestras del contenido estomacal y del fitoplancton en el medio, la época de reproducción se estimó a través del índice gonádico. Se encontró una temporada fría de diciembre a mayo y una cálida de junio a noviembre. El contenido estomacal estuvo compuesto por detritus (60%), células fitoplanctónicas (30%) y restos de espículas de esponjas y material no identificado (10%). La mayor frecuencia de células del fitoplancton en el contenido estomacal y en el medio ocurrió de marzo a mayo. La población tiene un patrón reproductivo anual, la actividad gametogénica y la madurez de la población coinciden con los picos de abundancia del fitoplancton.