Resumen del producto

Background: The fat horsemussel Modiolus capax is a commercially important resource in northwest Mexico;however, few studies evaluate its reproduction. Goals: Compare the reproductive cycle of M. capax intwo beds at different depths in Ensenada de La Paz, B.C.S., Mexico, and its relationships with the environmentalvariables. Methods: Approximately 25 (±4.5) specimens were collected between October 2008 andDecember 2010, in a shallow bed in the intertidal zone (Bed A), and 23 (±4) at a five meters deep bed (BedB), in Ensenada de La Paz, B.C.S., Mexico. Monthly assessments of individual biological information werecomplemented by histological analyses of the gonads at different moments of the reproductive cycle, takingin environmental changes. The size at the first sexual maturity (L50) was estimated using a logistic model toobtain the size at 50% maturity. The relationship between gonad development stages and the gonadosomaticindex was estimated, as well as the relationship between these stages with temperature and chlorophyll.Results: A peak spawning occurred in March in Bed A and in January in Bed B. In both beds, mature andpost-spawning females showed follicular atresia, up to 82% in Bed B. The estimated L50 was 74.12 mmfor Bed A and 71.74 mm for Bed B. The gonadosomatic index differed between beds, and was positively correlatedwith the increase in chlorophyll-a (Bed A). A significant negative correlation was observed betweentemperature and the frequency of the maturing stage (Bed A). Conclusions: The reproduction of M. capaxrevealed that the beds have a different reproductive periodicity and that environmental changes affect theactivity and favor the development of follicular atresia.

Palabras clave: gonadosomatic index; mussel reproduction; reproductive activity

Para obtener una copia del documento contacta la personal de la biblioteca a través del correo bibliocicimar{a}ipn.mx