Sex Ratio and Sex Reversal in Two-year-old Class of Oyster, Crassostrea gigas (Bivalvia: Ostreidae)
نویسندگان
چکیده
The sex ratio (F:M) in the same population of oyster, Crassostrea gigas at the commencement of the study (2007) was 1:1.0, but changed to 1:2.8 by the end of the study (2008). The sex reversal rate in two-year-old oysters was 40.2%. Specifically, female to male sex reversal rate was 66.1%, which is higher than the male to female sex reversal rate of 21.1%. The sex reversal pattern of C. gigas appears to go from male⇒female⇒male, and as such is determined to be rhythmical hermaphroditism.
منابع مشابه
Crassostrea gigas
Scientific names: Crassostrea gigas (Thunberg 1793), Ostreidae, Bivalvia Synonyms: Gryphaea angulata Lamarck 1819; Ostrea gigas Thunberg 1793; Ostrea laperousii Schrenk 1861; Ostrea talienwhanensis Crosse 1862. Note: The Portuguese oyster Crassostrea angulata is a name often used for this species. According to genetic studies it was shown that Crassostrea angulata is likely a strain of Crassost...
متن کاملMorphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae).
In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning El...
متن کاملThe estimation of Dynamic Energy Budget (DEB) parameters for Crassostrea gigas larvae Rico-Villa, Benjamin and Pouvreau, Stéphane Département de Physiologie Fonctionnelle des Organismes Marins, Station IFREMER
The major commercial marine bivalve in French aquaculture is the Pacific oyster, Crassostrea gigas. Traditionally, bivalve culture relies on juvenile collection from the natural environment but due to the high year-to-year variation in spatfall recruitment the spat production in hatcheries is increasing recently. In this context, a better understanding of the biology of C. gigas larvae is requi...
متن کاملLinkage maps of microsatellite DNA markers for the Pacific oyster Crassostrea gigas.
We constructed male and female consensus linkage maps for the Pacific oyster Crassostrea gigas, using a total of 102 microsatellite DNA markers typed in 11-day-old larvae from three families. We identified 11 and 12 linkage groups in the male and female consensus maps, respectively. Alignment of these separate maps, however, suggests 10 linkage groups, which agrees with the haploid chromosome n...
متن کاملImpact of the copepod Mytilicola orientalis on the Pacific oyster Crassostrea gigas in Ireland.
Infections of a population of Crassostrea gigas by the copepod Mytilicola orientalis were examined at an oyster growing site at Dungarvan, County Waterford, Ireland. Twenty-one samples, each consisting of 20 to 30 oysters have been examined over 2 yr. Condition, sex, reproductive stage, length, weight, glycogen content and other parasite burdens of the oysters were examined in relation to the d...
متن کامل