Resources of Tunas and Related Species and Their Fisheries in the Indian Ocean

Collette, Bruce B.; Silas, E G; Pillai, P P

doi:10.2307/1444419

Cited by 8 publications

(1 citation statement)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Τα ψάρια αναγνωρίστηκαν από εξωτερικά μορφολογικά χαρακτηριστικά, όπου αυτό ήταν εφικτό, και από σκληρά σκελετικά μέρη που δεν πέπτονται. Η αναγνώρισή τους έγινε με βάση τις κλείδες των Whitehead (1985) και Collette (1983). Τα Καρκινοειδή αναγνωρίστηκαν από εξωτερικά μορφολογικά χαρακτηριστικά όπου αυτό ήταν εφικτό.…”

Section: διαδικασία μελέτης των δειγμάτων στο εργαστήριοunclassified

Συμβολή στη μελέτη της βιολογίας και της βιοχημικής σύστασης της παλαμίδας Sarda sarda (Bloch 1793) σε ελληνικές θαλάσσιες περιοχές

Ζαμπούκας¹

View full text Add to dashboard Cite

show abstract

Section: διαδικασία μελέτης των δειγμάτων στο εργαστήριοunclassified

Συμβολή στη μελέτη της βιολογίας και της βιοχημικής σύστασης της παλαμίδας Sarda sarda (Bloch 1793) σε ελληνικές θαλάσσιες περιοχές

Ζαμπούκας¹

View full text Add to dashboard Cite

show abstract

Geographic variation of body morphology of the Atlantic bluefin tuna, (Thunnus thynnus, Linnaeus, 1758)

et al. 2014

View full text Add to dashboard Cite

Geometric morphometric methods were used to explore body shape morphology in 260 Atlantic bluefin tuna, Thunnus thynnus, collected in Sardinia (Western Mediterranean) during the breeding phase and in the Bay of Biscay (North Eastern Atlantic) during the feeding phase. The shape of each specimen was captured by high resolution digital images and recording the 2-D coordinates of seven morphological landmarks. A general procruste analysis (GPA) was applied in order to eliminate any morphological variations resulting from size, position or orientation of specimens. A thin plate-spline (TPS) method was then used to provide a graphical representation of the shape conformation between two sets of data. Results of the regression model between the direct and indirect measurements accounted for a R2 = 0.98. The Principal Components Analysis shows differences linked to the two sampling areas, accounting for 37% and 19.97% of the body shape variation in the first (PC1) and second (PC2) principal component, respectively. Specifically, the deformation grid projection highlights the major differences regarding the anterior-ventral part of the body (landmark 5-6-7). These differences might not necessarily be linked to an actual population substructure. Instead, it was hypothesized that such body shape differences were due to the diverse life phases during which specimens were collected, since the reproductive specimens show a 'potbellied' shape, which was larger than for the feeding specimens that showed a 'slimmer' shape. Analyses of likely sexual dimorphism conducted on Sardinian specimens did not reveal any significant differences; whereas body shape differences related to the pre- and post-reproductive sizes were detected

show abstract

Reproductive biology of female bigeye tunaThunnus obesusin the western Pacific Ocean

Sun

Yeh

Chang

et al. 2013

Journal of Fish Biology

View full text Add to dashboard Cite

The reproductive biology of female bigeye tuna Thunnus obesus was assessed by examining 888 fish (ranging from 84·9 to 174·4 cm fork length, LF ) caught by Taiwanese offshore longliners in the western Pacific Ocean from November 1997 to November 1998 and November to December 1999 and 258 gonad samples from these fish. The overall sex ratio of the catch during the sampling differed significantly from 0·5, but males were predominant in sizes >140 cm LF . Reproductive activity (assessed by histology), a gonado-somatic index, and the size-frequency distributions of whole oocytes indicated that spawning occurred throughout the year and the major spawning season appeared to be from February to September. The estimated sizes at 50% maturity (LF50 ) of females was 102·85 cm (95% c.i.: 90·79-110·21 cm) and the smallest mature female was 99·7 cm LF . They are multiple spawners and oocytes develop asynchronously. The proportion of mature (0·63) and reproductively active (0·70) females with ovaries containing postovulatory follicles indicated that they spawn almost daily. Batch fecundity for 15 females with the most advanced oocytes (>730 µm) ranged from 0·84 to 8·56 million eggs (mean ± s.d. = 3·06 ± 2·09). The relationships between batch fecundity (FB , in millions of eggs) and LF (cm) and round mass (MR , kg) were FB=9·91×10-14LF6·38 (r(2) = 0·84) and FB=8·89×10-4MR2·05 (r(2) = 0·80), respectively. The parameters estimated in this study are key information for stock assessments of T. obesus in the western Pacific Ocean and will contribute to the conservation and sustainable yield of this species.

show abstract

Resources of Tunas and Related Species and Their Fisheries in the Indian Ocean

Cited by 8 publications

References 16 publications

Συμβολή στη μελέτη της βιολογίας και της βιοχημικής σύστασης της παλαμίδας Sarda sarda (Bloch 1793) σε ελληνικές θαλάσσιες περιοχές

Συμβολή στη μελέτη της βιολογίας και της βιοχημικής σύστασης της παλαμίδας Sarda sarda (Bloch 1793) σε ελληνικές θαλάσσιες περιοχές

Geographic variation of body morphology of the Atlantic bluefin tuna, (Thunnus thynnus, Linnaeus, 1758)

Reproductive biology of female bigeye tunaThunnus obesusin the western Pacific Ocean

Contact Info

Product

Resources

About