Influence of gonadal development on metal accumulation in the Portuguese oyster,Crassostrea angulata,in subtropical areas

Abstract

Metal enrichment makes oyster considered to be an appropriate food source for trace elements, but excessive accumulation can threaten human health. Reproduction is an important biotic factor that affects the metal accumulation in oysters. However, the influence of continuous gonad development model on metal accumulation in some subtropical oysters is still unclear. The present study addresses the concentrations of trace metals and glycogen associated with the gonadal and somatic tissues throughout the reproductive cycle of diploid and triploid Crassostrea angulata cultured in Fujian, China. Cu, Zn and Pb contents of gonads were negatively correlated (p < 0.05) with gonadosomatic index (GSI). The correlation between Cd content and GSI was not significant. There was a positive correlation (p < 0.05) between GSI and Mn content in female gonads while the correlation was negative (p < 0.05) in males, indicating Mn plays an important role in gametogenesis of females. The effects of gonadal maturity and gender on metal accumulation in somatic tissue were not significant (p > 0.05). The concentrations of all metals in sterile triploids were not significantly different from those of the somatic tissue of diploids. Gonadal glycogen content showed a negative correlation with the GSI. However, somatic glycogen content was not affected by gonadal development, indicating that the energy consumed during gametogenesis comes mainly from recently ingested food rather than from energy stored in somatic tissue. The effects of the gonadal development on the metal accumulation in oysters varied according to the metal and tissue type.

Effect of environmental factors on the fatty acid profiles and physicochemical composition of oysters ( Crassostrea gasar ) in Amazon estuarine farming

“…Oysters store energy in the form of glycogen instead of fat (Berthelin, Kellner, & Mathieu, 2000;Dridi, Romdhane, & Elcafsi, 2007;Gabbott, 1983;Thompson & Macdonald, 1990). Therefore, we can infer that the nutritional condition of oyster meat observed in the present study was related to increased food availability in the environment, which occurred during the rainy season (Sousa et al, 2013;Vilhena et al, 2014), favouring the uptake of nutrients necessary for the synthesis of glycogen, proteins and lipids related to oocyte growth and maturation in bivalves (Ojea et al, 2004;Oliveira et al, 2018;Paixão et al, 2013;Rodríguez-Jaramillo et al, 2008;Lagade, Taware, & Muley, 2015, Shi, Wu, Zhou, You, &Ke, 2019.…”

Identification of Main Oyster Species and Comparison of Their Genetic Diversity in Zhejiang Coast, South of Yangtze River Estuary

“…Portuguese oysters have been reported to be distributed as far as the Okinawa (Ryukyu Archipelago) and Shikoku Islands in southern Japan, although the authors were unsure whether the oysters were indigenous (Sekino and Yamashita, 2012;Sekino et al, 2016). The latitude of Zhejiang Province is similar to that of the above locations, and Portuguese oysters prefer high salinity and high-temperature environments (Shi et al, 2019); therefore, we cannot exclude the natural distribution of Portuguese oysters here.…”

NanoSIMS Imaging of Bioaccumulation and Subcellular Distribution of Manganese During Oyster Gametogenesis

“…Marine bivalves are the keystone benthic species in estuarine environments, and their filter-feeding and sedentary characteristics facilitate their exposure to different metal pollutants including Mn. Unlike other metals, Mn is remarkably accumulated in female gonads of marine bivalves such as oysters, − scallops, and clams, when compared to that in male gonads. For instance, the Mn concentration in the mature gonads of female oyster Crassostrea hongkongensis was more than 10-fold higher than that in male gonads .…”