A Preliminary Study of the Feeding Habits of the Japanese Oyster Drill, Ocinebra japonica

1958 ◽  
Vol 15 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Kenneth K. Chew ◽  
Ronald Eisler
Keyword(s):  
Experimental Evidence ◽  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Feeding Habits ◽  
The Body ◽  
Pacific Oysters ◽  
Oyster Drill ◽  
Japanese Oyster ◽  
Preliminary Study ◽  
Olympia Oysters

Individually marked Japanese oyster drills, Ocinebra japonica, were presented with a choice of four different food organisms: mussels (Mytilus edulis); clams (Venerupis japonica); and oysters (Crassostrea gigas and Ostrea lurida). During the course of the 65-day experiment mussels constituted 42.6 per cent of the food organisms attacked by drills; clams, 36.5 per cent; and oysters, 20.9 per cent. The average time that an Ocinebra took to drill though a shell and finish feeding on the body mass are: mussels, 4.98 days; clams, 6.31 days; Olympia oysters, 5.70 days; and Pacific oysters, 14.0 days (on the basis of one Pacific oyster). Experimental evidence suggests that a drill will continue to attack the same species of food organism that it had attacked previously, rather than moving to an easily accessible organism of a different species.

scholarly journals Distribution, Condition and Gonad Maturity of the Invasive Pacific Oysters (Crassostrea Gigas, Thunberg 1793) in Cimanuk Delta, Indramayu, West Java, Indonesia

Omni-Akuatika ◽  
2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Selia Hermawati ◽  
Sulistiono Sulistiono ◽  
Agustinus M Samosir
Keyword(s):  
Distribution Pattern ◽  
Crassostrea Gigas ◽  
Brackish Water ◽  
Pacific Oyster ◽  
Condition Factor ◽  
Maturity Stage ◽  
West Java ◽  
Gonad Maturity ◽  
Pacific Oysters ◽  
The Pacific

Pacific oyster (Crassostrea gigas) is an invasive species which is able to adapt a wide range of environmental conditions. The study was conducted from August to October 2014. Objective of this study was to asses the distribution pattern, condition and gonad maturity length (Lm 50%) of the Pacific oysters in mangrove ecosystem of Cimanuk Delta, Indramayu, West Java, Indonesia.  This study was conducted in two adjacent areas:  Pabean Ilir and Pagirikan subdeltas. The oysters were collected from the estuary, brackish water ponds and the coastal flat, and  observed for their abundance, total length (mm) and weight (g). Morphological and histological methods were used to estimate the gonad maturity stage. Analysis were carried out to estimate distribution pattern and condition factor. According to the study, the Pacific oyster distribution pattern was clumped. The condition factor of the oyster was higher in the brackish water pond and estuary than in the coastal flat.  The Pacific oyster was found in gonad maturity stage (GMS) I – IV. The oyster was hermaprodit protandry and had length maturity (Lm 50%) of 47,46-48,43 mm (male) and 75,27-75,50  mm (female). 

Spatial Distribution of Pacific Oyster (Crassostrea gigas) Population Related Environment Factor in Coastal Water of Pabean Ilir, Indramayu

2020 ◽  
Vol 4 (1) ◽  
pp. 38-47
Author(s):  
Risma Qurani ◽  
Fredinan Yulianda ◽  
Agustinus Mangaratua Samosir
Keyword(s):  
Spatial Distribution ◽  
Coastal Water ◽  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Oyster Population ◽  
Pacific Oysters ◽  
The Pacific ◽  
Arc Gis ◽  
Environment Factor ◽  
Spatial Condition

Pacific oysters (Crassostrea gigas, Thunberg, 1793) is a benthic organisme that tend to live and settle in the bottom. One of the pacific oyster habitat is Coastal Water of Pabean Ilir, Indramayu. The purpose of this study was to map spatial condition of the population related habitat of the oyster (Crassostrea gigas). The mapping were done with laptop, using Arc GIS. There were 15 points of sampling. The oyster population in Pabean Ilir can be categorized into three categories: low, medium, and high density. Based on the similarity of environmental characteristics the habitat were divided into four groups. Condition Coastal Water of Pabean Ilir such as temperature, salinity, pH, BOD, TSS, TDS, COD, and composition of substrate indicated Coastal Water of Pabean Ilir have compatibility optimum sufficient habitat to support the growth of pacific oyster

Limitations of the A-IM Method for Fecal Coliform Enumeration in the Pacific Oyster (Crassostrea gigas)

1987 ◽  
Vol 70 (3) ◽  
pp. 535-537
Author(s):  
Charles A Kaysner ◽  
Stephen D Weagant
Keyword(s):  
Escherichia Coli ◽  
Positive Reaction ◽  
Crassostrea Gigas ◽  
Water Samples ◽  
Fecal Coliform ◽  
Pacific Oyster ◽  
Food Products ◽  
Fecal Coliforms ◽  
Pacific Oysters ◽  
The Pacific

Abstract Use of the A-IM method, which was originally devised for testing water samples, has recently been extended for enumeration of fecal coliforms and Escherichia coli in shellfish and other food products. Results of our study indicate that while this method is reliable for analysis of growing waters, the use of the A-IM method for testing Pacific oysters may be less reliable because bacteria not belonging to the coliform group but which are sometimes present in these animals also give a positive reaction.

scholarly journals Autotetraploid Pacific oysters (Crassostrea gigas) obtained using normal diploid eggs: induction and impact on cytogenetic stability

Genome ◽  
2015 ◽  
Vol 58 (7) ◽  
pp. 333-348 ◽  
Author(s):  
Abdellah Benabdelmouna ◽  
Christophe Ledu
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
High Variability ◽  
Limiting Factor ◽  
Oocyte Size ◽  
Induction Method ◽  
Genetic Progress ◽  
Pacific Oysters ◽  
Important Impact

We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploid lines to tetraploids used as broodstock, avoiding a triploid step with the risk of transferring undesirable traits from highly fecund triploids. High variability in the level of cytogenetic stability was found among the different tetraploid oysters tested, showing that induction method has an important impact on the long-term cytogenetic stability of the tetraploids. It appears that induction method based on the use of triploid females induces a greater cytogenetic instability among tetraploids so obtained, and this compared to tetraploids originating from the two methods described in our present study. As the aneuploidies and reversions observed in tetraploids can have serious consequences for the sustainability of tetraploid broodstock itself, as well as their triploid offspring, the two tetraploid induction methods described in the present work offer means to produce tetraploids with optimal cytogenetic, genetic, and zootechnical performances.

Refrigerated Seawater Depuration for Reducing Vibrio parahaemolyticus Contamination in Pacific Oyster (Crassostrea gigas)

2010 ◽  
Vol 73 (6) ◽  
pp. 1111-1115 ◽  
Author(s):  
YI-CHENG SU ◽  
QIANRU YANG ◽  
CLAUDIA HÄSE
Keyword(s):  
Crassostrea Gigas ◽  
Vibrio Parahaemolyticus ◽  
Pacific Oyster ◽  
Most Probable Number ◽  
Probable Number ◽  
Log Reduction ◽  
Pacific Oysters ◽  
The Pacific ◽  
Postharvest Treatment ◽  
Depuration Process

The efficacy of refrigerated-seawater depuration for reducing Vibrio parahaemolyticus levels in Pacific oyster (Crassostrea gigas) was investigated. Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (105 to 106 most probable number [MPN] per g) and depurated with refrigerated seawater (5°C) in a laboratory-scale recirculation system equipped with a 15-W gamma UV sterilizer. Depuration with refrigerated seawater for 96 h reduced V. parahaemolyticus populations by >3.0 log MPN/g in oysters harvested in the winter. However, 144 h of depuration at 5°C was required to achieve a 3-log reduction in oysters harvested in the summer. Depuration with refrigerated seawater at 5°C for up to 144 h caused no significant fatality in the Pacific oyster and could be applied as a postharvest treatment to reduce V. parahaemolyticus contamination in Pacific oysters. Further studies are needed to validate the efficacy of the depuration process for reducing naturally accumulated V. parahaemolyticus in oysters.

scholarly journals Ostreid Herpesvirus 1 Infection among Pacific Oyster (Crassostrea gigas) Spat: Relevance of Water Temperature to Virus Replication and Circulation Prior to the Onset of Mortality

2014 ◽  
Vol 80 (17) ◽  
pp. 5419-5426 ◽  
Author(s):  
Tristan Renault ◽  
Anne Lise Bouquet ◽  
Julien-Thomas Maurice ◽  
Coralie Lupo ◽  
Philippe Blachier
Keyword(s):  
Water Temperature ◽  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Mortality Rates ◽  
Mass Mortality ◽  
Content Type ◽  
Pacific Oysters ◽  
The Pacific ◽  
Herpesvirus 1 ◽  
Ostreid Herpesvirus 1

ABSTRACTA number of bivalve species worldwide, including the Pacific oyster,Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified asOstreid herpesvirus 1(OsHV-1) within the familyMalacoherpesviridae. Since 2008, mass mortality outbreaks amongC. gigasin Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond (“claire”), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C.

A Preliminary Study of Chromosomes of Two Species of Oysters (Ostrea lurida and Crassostrea gigas)

1967 ◽  
Vol 24 (10) ◽  
pp. 2155-2159 ◽  
Author(s):  
Muzammil Ahmed ◽  
Albert K. Sparks
Keyword(s):  
Chromosome Number ◽  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Diploid Chromosome Number ◽  
Ostrea Lurida ◽  
Lampbrush Chromosomes ◽  
Somatic Metaphase ◽  
The Pacific ◽  
Preliminary Study ◽  
Native Oyster

A diploid chromosome number of 20 (n = 10) was found for each of the native oyster Ostrea lurida, and the Pacific oyster Crassostrea gigas. The diploid complements of the native oyster were normal but in the Pacific oyster atypical numbers, polyploid nuclei, and abnormal cleavage was observed in some somatic metaphase plates. The diplotene meiotic bivalents of the native oyster resembled lampbrush chromosomes.

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