Variaciones en la historia de vida de Anadara tuberculosa (Mollusca: Bivalvia) en el ecosistema de manglar de la costa Sur de Ecuador

Abstract

Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these lifehistory traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L ∞ and 0.22 to 0.80/year for k. The growth indices (Φ') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t max ), size and age at maturity (L 50% and t 50% ) were estimated in 7.71±2.53years, 39.13±2.24mm and 1.46±0.56years for PB; 9.51±2.85years, 37.78±1.95mm and 1.37±0.41years for PJ and 5.81±2.11years, 39.73±3.31mm and 0.94±0.41years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in Φ' and OGP indices as well as L 50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery. Rev. Biol. Trop. 62 (2): 473-482. Epub 2014 June 01.

Estimation of Growth and Size at First Maturity under a Multimodel Approach of Anadara tuberculosa (Sowerby, 1833) on the Southeast Coast of the Gulf of California

“…The growth of A. tuberculosa in Estero Las Lajitas was constant, reaching an estimated maximum asymptotic length similar to that estimated by Félix-Pico et al [15] on Mexican coasts; however, this value was lower than those found in studies carried out in areas influenced by the tropical-equatorial zone, where sizes of L∞ between 63 and 93 mm have been reported [12,27,29,39,40]. However, the growth estimates made in the aforementioned area were derived using the VBGM via statistical programs such as ELEFAN I [41] and FiSAT [42], and this is not the best model for describing the information generated in the present research.…”

“…In this context, Panta-Vélez et al [14] mentioned that the protandry hermaphroditism of the species may be associated with the imbalance in sexual proportion, since the reproductive activity of A. tuberculosa as regards sexual maturity is not coherent with that measured in other areas of the Ecuadorian Pacific. In addition, the emergence of protandry hermaphroditism and changes in sex ratio indicate that the population may respond to anthropogenic and environmental pressures [5,12]. The numerical superiority between females and males may also be caused by the physicochemical properties of the water, which favor the development of females or interfere with the development of males, as mentioned by Guilbert [36].…”

“…Multimodel inference (MMI) is frequently used to choose the model that best describes the individual growth of the species, highlighting the Akaike Information Criterion (AIC) [10]. One of the main topics addressed regarding the black clam (A. tuberculosa) found along the coasts of the south-central Pacific is reproductive biology and the estimation of maturity size (L 50% ) [11][12][13][14]. In Mexico, few studies have been carried out in relation to A. tuberculosa on issues related to growth and maturity; among these, Félix-Pico et al [15] estimated a maximum asymptotic length (L∞) of 81 mm and a growth rate (k) of 1.85 years −1 , while [6,16] estimated an L 50% of 38 and 36.5 mm, respectively, on the coasts of Baja California Sur.…”

Vii Foro Iberoamericano De Los Recursos Marinos Y La Acuicultura

“…En el Ecuador su reproducción parece tener un período de máxima actividad gonadal durante el período noviembre-febrero (Ayala et al, 2013;Flores et al, 2014). En el presente trabajo se realiza un análisis macroscópico y microscópico de las gónadas de hembras de Anadara tuberculosa de la localidad de Bajo Alto, Provincia de El Oro.…”

“…Los resultados obtenidos en este estudio preliminar, demuestran que los organismos analizados se encuentran en actividad reproductiva, particularmente en los procesos vitelogenicos y madurez final de los ovocitos tal como se evidencia en los cortes histológicos (Figura 1), donde se visualiza los folículos con ovocitos maduros y núcleo bien definidos y en menor grado, algunos aún no tan desarrollados. Estos resultados concuerdan con los períodos reproductivos señalados para esta especie en las costas del Ecuador (Ayala et al, 2013;Flores et al, 2014). Pudiendo suponer que estos meses se corresponden con un período de máxima maduración.…”