Perkinsus Marinus en Crassostrea Gigas Y Chione Fluctifraga De Bahía De Kino, Sonora, México

Abstract

At present, the Pacific oyster Crassostrea gigas is the most cultivated shellfish in northwest Mexico. Nonetheless, other mollusks species such as the black clam Chione fluctifraga, which can be found along with cultured C. gigas in Sonora, represents a profitable emerging fishery resource. Since 1997, the oyster industry along the Gulf of California has been affected by severe mortality episodes disturbing almost all the farming areas. In order to evaluate the prevalence of Perkinsus marinus, a monthly sampling of 30 oysters and 30 clams was carried out during a one-year period. A total of 360 oysters and 360 clams were analyzed by Ray's fluid thyoglicolate medium (RFTM) and PCR. The RFTM assay showed prevalence ranging from 3.3 to 60% for both oysters and clams through the study period, with infection levels from light to moderate, according to the Mackin scale. The PCR analysis was positive to P. marinus in the only one C. gigas with moderate infection in the RFTM analysis. The resulting sequence revealed 100% identity with the ITS region of P. marinus. To our knowledge, this is the first indication of Perkinsus sp. in the C. fluctifraga clam.

Perkinsus marinus in the pleasure oyster Crassostrea corteziensis cultivated on the southeast coast of the Gulf of California, Mexico

“…While they are adults, their growth rate decreases, and the parasite can reach higher infection intensity, which is consistent with this work, because bigger oysters (>50 mm shell height) presented the highest prevalence and infection intensity of P. marinus. Contrary findings for other cultivated oyster species are reported by Enríquez-Espinoza et al (2015) and da Silva et al (2016), who found that infection rates were independent of oysters' size. According to Paytner et al (2010) and Ehrich & Harris (2015), larger oysters have a larger gill area that consequently leads to a higher filtration rate favoring infection through the increased ingestion of parasite cells, which could explain our results.…”

“…Different Perkinsus-like parasites have been reported in wild and cultivated bivalve species in and around the Gulf of California using different techniques given their presence, detection, confirmation, and infection degree. For instance, P. marinus was found in natural populations of C. corteziensis on the central coast of the Mexican Pacific (Cáceres-Martínez et al, 2008) and the mangrove oyster Saccostrea palmula along the Sinaloa coast (Cáceres-Martínez et al, 2012), as well as in the wild population of the black clam Chione fluctifraga in Kino Bay, Sonora (Enríquez-Espinoza et al, 2015). Perkinsus sp.…”

Relación del crecimiento, condición y supervivencia del ostión del Pacífico Crassostrea gigas y las variables ambientales, cultivado en suspensión en el sistema lagunar Navachiste-Macapule, Sinaloa, México

“…Algunas teorías basadas en la combinación e interacción de factores extrínsecos (bióticos y abióticos) e intrínsecos (genéticos, inmunológicos y fisiológicos), son usadas frecuentemente para explicar la drástica reducción de bivalvos en cultivo (Royer et al 2007, Enríquez-Espinoza et al 2010. Derivado de esfuerzos coordinados del gobierno con los productores y centros de investigación para tratar de conocer las causas de mortalidad en C. gigas, se ha concluido que la presencia de patógenos (Enríquez-Espinoza et al 2010, Vázquez-Yeomans et al 2010, Enríquez-Espinoza et al 2015 y/o la combinación de parámetros ambientales (Chávez-Villalba et al 2007, Castillo-Durán et al 2010 pueden estar asociados a la reducción del cultivo. No obstante, la erradicación de los patógenos y el control de las condiciones del medio ambiente son tareas imposibles, por lo que la única opción para los productores parece ser el seguimiento de buenas prácticas de cultivo para minimizar el impacto de las mortalidades (Enríquez-Espinoza et al 2010).…”

OsHV 1 and notifiable protozoa in healthy Crassostrea corteziensis cultured in two distant areas of the Gulf of California

“…In the Gulf of California, reported this protozoan in C. corteziensis, and Enríquez-Espinoza et al (2010) in C. gigas. Enríquez-Espinoza et al (2015) mention that this pathogen was found throughout the year in cultures of C. gigas and wild black clam Chionista fluctifraga with fluctuating prevalence and without mortality events. This pathogen has proven to be the most prevalent one in the south area where the higher temperature was presented compared to the north.…”