No abstract

Se estableció el ciclo reproductivo del pargo lunarejo Lutjanus guttatus, un pez de gran importancia comercial. Los organismos se recolectaron mensualmente desde febrero de 1993 a diciembre de 1994. La proporción de sexos poblacional fue de 1M:0.96H y no se encontró una diferencia significativa (P≤0,05) de la proporción esperada de 1:1. Las gónadas se analizaron histológicamente y se describieron las fases de desarrollo gonadal. L. guttatus presenta un desarrollo asincrónico de las gónadas y es un desovador parcial. La actividad reproductiva estuvo presente todo el año aunque con dos períodos reproductivos principales (marzo-abril y agosto-noviembre) representados por altos porcentajes de gónadas categorizadas como maduras y en desove. Estos períodos coinciden con valores elevados del índice gonadosomático (IGS) y valores bajos del índice hepatosomático (IH). El factor de condición (FC) presentó una tendencia similar a la del IGS con los máximos valores durante la época de reproducción y disminuyendo hacia las épocas de reposo. Se considera que el IGS representa adecuadamente la actividad reproductiva y que puede haber una relación inversa entre la actividad reproductiva y el IH.

The reproductive cycle of Anadara tuberculosa (Sowerby, 1833) and its relationship with temperature and food availability in Magdalena Bay, Mexico was studied. Twenty five adult specimens were collected, on a monthly basis, between January 1998 and February 1999. Gonads were processed by routinary histology. The reproductive cycle was divided in five stages: resting, developing, ripe, spawning and spent. The developing stage was found within the interval

The reproductive cycle of the scallop Argopecten circularis, an important resource of the fisheries in Baja California Sur, was studied in relation to exogenous factors such as temperature and photoperiod in Bahía Concepción. Monthly samples of adult specimens were used, and biometric data for the shell and soft body parts were recorded. The gonads were analysed histologically and five phases of gonadal maturation were described. This species was confirmed to be functionally hermaphroditic, with a reproductive pattern characterized by a period of maximum activity from December to March, when the dominant phases are maturity and spawning. The prevailing conditions during the main spawning peak were: water temperature between 16 and 22ºC, and photoperiod between 630 and 760 minutes of daily average illumination per month. The first maturation of the gonads, determined histologically, occurred when the organisms had an anteroposterior length of 35 mm. Spawning can occur at 47 mm. The minimum size for maturity and spawning in the general population was 58 mm. We determined that maximum reproductive potential starts at this size, and coincides with the lowest water temperature in the annual cycle. The annual variations in the spawning periods of this species, in different parts of Baja California Sur, suggest flexibility in the influence of exogenous factors and endogenous controls on the reproductive event.

Reproductive aspects (spawning season, size and weight at maturity, and fecundity) of Octopus hubbsorum are reported for Espíritu Santo Island, southern Gulf of California (Mexico). A total of 230 octopuses were captured (46% females and 54% males) between June 2006 and June 2007. The sex ratio was not significantly different from 1:1 (P > 0.05) except in November, when more males were captured than females. Four sexual maturity stages were established for both sexes: immature, maturing, mature, and prespawning (for females) or spawning (for males). The principal spawning season of O. hubbsorum occurred in autumn, when sea surface temperature ranged from 24 to 29 ºC. The size and weight at maturity were 390 mm and 445 g, respectively, for males and 490 mm and 680 g, respectively, for females. The mean potential fecundity was 205,144 oocytes per female and the mean relative fecundity was 309 oocytes per gram of female body weight. Maturing females apparently use substances stored in the digestive gland.