The Japanese oyster Crassostrea gigas forms the mainstay of the South African oyster farming industry. Despite having been cultured along the South African coast for 30 years, this is the first record of naturalized populations of this well known global invader from the region. DNA sequence data confirmed the presence of C. gigas in the Breede and Goukou estuaries. Populations of 184,206 ± 21 0...

The occurrence of OsHV-1, a herpes virus causing mass mortality in the Pacific oyster Crassostrea gigas was investigated with the aim to select individuals with different susceptibility to the infection. Naïve spat transferred to infected areas and juveniles currently being grown at those sites were analyzed using molecular and histology approaches. The survey period distinguishes itself by ver...

Since 1991, numerous herpesvirus infections associated with high mortality have been reported around the world in various marine bivalve species. In order to determine whether these infections are due to ostreid herpesvirus-1 (OsHV1), a previously characterized pathogen of the Japanese oyster (Crassostrea gigas), PCR analysis was carried out on 30 samples of larvae collected from four bivalve s...

A recombinant metallothionein CgMT1, from the Pacific oyster Crassostrea gigas, was synthesized and used as antigen in the development of antibodies and a specific enzyme-linked immunosorbent assay (ELISA). The ELISA showed that rabbit anti-CgMT1 IgG reacted with purified CgMT1 and MTs from other marine bivalves, indicating its suitability as a reagent to quantify MTs and for monitoring of meta...

Microplastics are present throughout the marine environment and ingestion of these plastic particles (<1 mm) has been demonstrated in a laboratory setting for a wide array of marine organisms. Here, we investigate the presence of microplastics in two species of commercially grown bivalves: Mytilus edulis and Crassostrea gigas. Microplastics were recovered from the soft tissues of both species. ...

The purpose of this study is to investigate summer mortality of the cupped oyster, Crassostrea gigas, in relation to culture practices in the traditional oyster production region of Marennes-Oléron (France). Four oyster rearing conditions, varying culture location (“on-“ or “off-bottom”), and site depth (65% to 80% daily immersion termed “deep” or 45% to 65%, termed “shallow”) were studied to c...

Light-sensitivity is important for mollusc survival, as it plays a vital role in reproduction and predator avoidance. Light-sensitivity has been demonstrated in the adult Pacific oyster Crassostrea gigas, but the genes associated with light-sensitivity remain unclear. In the present study, we designed experiments to identify the genes associated with light-sensitivity in adult oysters. First, w...

SUMMARY We studied the prevalence and intensity of the parasitic copepod Myicola ostreae in 2 closely related oysters Crassostrea angulata and C. gigas and their F1 hybrids. The effects on host and host reaction were also analysed to better understand host-parasite relationships between copepods and bivalve molluscs. Full reciprocal crosses were carried out between C. angulata and C. gigas and ...

This paper reports a comparative study of two cupped oysters, Crassostrea gigas and C. angulata, and their hybrids reared in the Marennes-Oléron Sound (France) under usual farming conditions. The relative proficiency of these species was characterized in terms of growth, survival and reproduction, three major concerns for oyster farming. Four populations of each taxon were sampled (C. gigas: Ja...