Reproduction of Cortez oyster, Crassostrea corteziensis (Hertlein, 1951) in a growing area in the central Mexican Pacific coast

Abstract

ABSTRACT. The state of Nayarit is the main oyster producer in the Mexican Pacific, this derived from artisanal crops of Crassostrea corteziensis and collecting of wild seeds. Despite its importance, there are no studies on the reproduction of this species in Boca de Camichín, Nayarit, Mexico, which is the area with the highest production (around 90%). The aim of this study was to evaluate sex ratio, condition index (CI), reproductive cycle, and recruitment size for reproduction and its relationship with environmental factors. Sixty oysters were sampled monthly at La Palicienta Lagoon for one year. The organisms were weighed and measured, then fixed with 10% formalin for histological analyses. Subsequently, the gonads were processed by histology. Sex ratio was different from 1:1, with a predominance of females. The condition index (CI) was higher from March to July. Oyster spawning was most prevalent in May, August, and October. The temperature had a positive relationship with reproduction. Recruitment size at reproduction was 57.1 mm. The results of this study could supply useful information about reproduction of the species at La Palicienta and seed collection in Boca de Camichín, Nayarit.

Gonadal maturity of Crassostrea corteziensis cultivated in the Gulf of California

“…It is characteristic of some species of mollusks that before spawning, organisms store food reserve components that are used in gonadal growth and development (Rodríguez-Astudillo et al, 2005;Dridi et al, 2007;Aldana-Aranda et al, 2014), which is a distinguishing characteristic of bivalves with a conservative and seasonal reproductive strategy. In our study, C. corteziensis spawning evaluated from 2014 to 2017 was detected between six to nine months per year and no correlated with the Chl-a, indicating an opportunistic breeding strategy; this coincides with observations made by Rodríguez-Jaramillo et al (2008) and Mena-Alcántar et al (2017) for the same species.…”

“…The sex change has been reported for several oyster species (Mann, 1979;Gosling, 2004), including C. corteziensis (Chávez-Villalba et al, 2008). The sex ratios observed in our four cultivation cycles showed a higher proportion of males than females, coinciding with results published by Mazón-Suástegui et al (2011), but differ from those of Chávez-Villalba et al (2008), Rodríguez-Jaramillo et al (2008) and Mena-Alcántar et al (2017) for the same oyster species. Baqueiro-Cárdenas (1991) described C. corteziensis as a hermaphroditic protandric species, being the first males when they are small and females when they grow larger, which also was observed in our study.…”

“…Lango-Reynoso et al (2006) mention that the appearance of hermaphrodites coincides with the stage of sexual transition in C. gigas, that is, when they are young or small. The proportion of hermaphrodites in our rearing cycles were greater than those reported for other species of oysters such as C. rhizophorae (0.8-1.3%) (Lenz & Boehs, 2011) and C. virginica (0.83%) (George-Zamora et al, 2003); indeed, the proportion of hermaphroditic C. corteziensis in our study exceeded that reported by other researchers for the same species (1.5%) (Chávez-Villalba et al, 2008;Mena-Alcántar et al, 2017). These distinct results may be due to differences in age , species (Kasaynov, 2001), genetics (Gutiérrez et al, 2018), and the specific environmental conditions (Yusa, 2007) at each locality.…”

“…Endemic to this region, C. corteziensis is highly valued for consumption and represents an important resource for the oyster industry. Its reproduc-tive cycle has been reported for natural (Rodríguez-Jaramillo et al, 2008;Mena-Alcántar et al, 2017) and cultivated populations (Chávez-Villalba et al, 2008;Mazón-Suástegui et al, 2011) from different sites along the northwestern coast of the Mexican Pacific, including the Gulf of California. C. corteziensis has an opportunistic reproductive strategy; they focus on nutrient-rich sites where they acquire energy through nutrient consumption, particularly lipids and carbohydrates (Racotta et al, 2008).…”

Biología reproductiva del ostión de roca Striostrea prismatica en el sureste del Golfo de California

“…Se ajustó una curva logística a los datos para estimar la longitud a la que el 50% de los individuos eran sexualmente maduros. Para obtener la talla de madurez, se consideraron solo los organismos que se encontraban en etapa de maduración y desove (Mena-Alcántar et al 2017). Se calculó la frecuencia relativa y la longitud acumulada del intervalo de frecuencia (5 mm).…”