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Gametogenic cycle of Crassostrea gigas in contrasting Mediterranean habitats: marine (Gulf of Tunis) and continental (Bizert lagoon) culture sites.

Dridi S, Romdhane MS, Elcafsi M - J Biol Res (Thessalon) (2014)

Bottom Line: The applied techniques gave similar results.The obtained results are probably related with the different environmental conditions of the studied habitats, temperature and food supply, in particular.The sexual cycle of the species was successfully completed in the marine area, stressing the invasive character of C. gigas.

View Article: PubMed Central - PubMed

Affiliation: Institut Supérieur de Pêche et d'Aquaculture de Bizerte, ISPA -BP 15, ERRIMEL, 7080 Bizerte, Tunisia.

ABSTRACT

Background: The gametogenic cycle of Crassostrea gigas, a species imported into the Mediterranean for aquaculture, has been studied (May 2005 to July 2006) in two contrasting habitats of Tunisia: the Bizert lagoon, where oyster farms have been developed since 1970, and the Gulf of Tunis, where oysters have been experimentally farmed during this study, to assess the potential of this latter marine area for sustaining oyster-culture.

Results: The sexual cycle of the species was described through the histological examination of the gonads, the estimation of oocytes diameter, and the assessment of its condition and gonadal condition indices. The applied techniques gave similar results. The gametogenic cycle of C. gigas was precocious and more intense in oysters farmed within the lagoon than in the marine area, considering as well gonadal growth, maturation stages and gametes release.

Conclusions: The obtained results are probably related with the different environmental conditions of the studied habitats, temperature and food supply, in particular. The sexual cycle of the species was successfully completed in the marine area, stressing the invasive character of C. gigas.

No MeSH data available.


Related in: MedlinePlus

Simultaneous hermaphroditism inCrassostrea gigas. (A): Hermaphrodism (G = 10 × 10); (B): Hermaphrodism (G = 10 × 40) [SPZ = Spermatozoides; Oo = oocyte.
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Fig3: Simultaneous hermaphroditism inCrassostrea gigas. (A): Hermaphrodism (G = 10 × 10); (B): Hermaphrodism (G = 10 × 40) [SPZ = Spermatozoides; Oo = oocyte.

Mentions: Sex ratio (males/females) ranged from 1.00 to 5.67 in PP and from 1.00 to 4.00 in FMB (Table 1), with an overall mean at 2.23 and 1.6, respectively. According to χ2 test results non-significant deviation from 1:1 ratio was detected to the overall population at both sites at 95% confidence level (χ2 = 2.96 in PP and χ2 = 3.3 in FMB). Three cases of simultaneous hermaphroditism (one at PP and two at FMB), which is rare for C. gigas, were detected from the histological examination of the gonads (Figure 3).Table 1


Gametogenic cycle of Crassostrea gigas in contrasting Mediterranean habitats: marine (Gulf of Tunis) and continental (Bizert lagoon) culture sites.

Dridi S, Romdhane MS, Elcafsi M - J Biol Res (Thessalon) (2014)

Simultaneous hermaphroditism inCrassostrea gigas. (A): Hermaphrodism (G = 10 × 10); (B): Hermaphrodism (G = 10 × 40) [SPZ = Spermatozoides; Oo = oocyte.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4390001&req=5

Fig3: Simultaneous hermaphroditism inCrassostrea gigas. (A): Hermaphrodism (G = 10 × 10); (B): Hermaphrodism (G = 10 × 40) [SPZ = Spermatozoides; Oo = oocyte.
Mentions: Sex ratio (males/females) ranged from 1.00 to 5.67 in PP and from 1.00 to 4.00 in FMB (Table 1), with an overall mean at 2.23 and 1.6, respectively. According to χ2 test results non-significant deviation from 1:1 ratio was detected to the overall population at both sites at 95% confidence level (χ2 = 2.96 in PP and χ2 = 3.3 in FMB). Three cases of simultaneous hermaphroditism (one at PP and two at FMB), which is rare for C. gigas, were detected from the histological examination of the gonads (Figure 3).Table 1

Bottom Line: The applied techniques gave similar results.The obtained results are probably related with the different environmental conditions of the studied habitats, temperature and food supply, in particular.The sexual cycle of the species was successfully completed in the marine area, stressing the invasive character of C. gigas.

View Article: PubMed Central - PubMed

Affiliation: Institut Supérieur de Pêche et d'Aquaculture de Bizerte, ISPA -BP 15, ERRIMEL, 7080 Bizerte, Tunisia.

ABSTRACT

Background: The gametogenic cycle of Crassostrea gigas, a species imported into the Mediterranean for aquaculture, has been studied (May 2005 to July 2006) in two contrasting habitats of Tunisia: the Bizert lagoon, where oyster farms have been developed since 1970, and the Gulf of Tunis, where oysters have been experimentally farmed during this study, to assess the potential of this latter marine area for sustaining oyster-culture.

Results: The sexual cycle of the species was described through the histological examination of the gonads, the estimation of oocytes diameter, and the assessment of its condition and gonadal condition indices. The applied techniques gave similar results. The gametogenic cycle of C. gigas was precocious and more intense in oysters farmed within the lagoon than in the marine area, considering as well gonadal growth, maturation stages and gametes release.

Conclusions: The obtained results are probably related with the different environmental conditions of the studied habitats, temperature and food supply, in particular. The sexual cycle of the species was successfully completed in the marine area, stressing the invasive character of C. gigas.

No MeSH data available.


Related in: MedlinePlus