Histological evidence of Bluefin tuna (Thunnus thynnus Linnaeus, 1758) spawning in waters within the Mexican Exclusive Economic Zone in the Gulf of Mexico

ABSTRACT

Ovaries of bluefin tuna, Thunnus thynnus, from organisms measuring 247.62 ± 3.54 cm fork length collected within the Mexican Exclusive Economic Zone in the Gulf of Mexico, were examined. The highest gonadosomatic index was recorded in April (1.6 ± 0.28), coinciding with the presence of oocytes with a migratory nucleus (oocyte diameter 439 ± 32.84 µm); fully developed gonads were also observed in two females and two males (ovaries or testes, respectively) caught in late April when sea surface waters exceeded 26 °C. The microscopic examination of the gonads sampled showed structures that evidenced spawning in females measuring 280 cm FL.

KEYWORDS:

• Atlantic bluefin tuna
• reproduction
• gonadosomatic index
• histology

Acknowledgements

To FIDEMAR and the Scientific Observer Program for tuna in the Gulf of Mexico, particularly the regional office located in Tuxpan, Veracruz, Mexico for all the support to collect the samples. SOG is a scholar of EDI and COFAA of IPN. Thanks to Jorge Jimenez for his invaluable help in the logistics to carry out the sampling; Maria Elena Sánchez Salazar and Diana Fischer who contributed to the English edition of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was developed in the projects: SIP20150861 and SIP20170615 supported by Instituto Politécnico Nacional (IPN).