MEPS 333:303-308 (2007)  -  doi:10.3354/meps333303

Oceanic larval life of La Réunion ‘bichiques’, amphidromous gobiid post-larvae

Thierry B. Hoareau1,2,3,*, Raymonde Lecomte-Finiger4, Henri-Paul Grondin2, Chantal Conand1, Patrick Berrebi3,5

1Laboratoire d’Ecologie Marine, Université de La Réunion, 97715 Saint-Denis mes. Cedex 9, La Réunion, France
2Association Réunionnaise pour le Développement de l’Aquaculture—Centre des Eaux Douces, BP 16, Z.I. Les Sables, 97427 Etang-Salé, La Réunion, France
3Laboratoire Ecosystèmes Lagunaires, UMR 5119, cc093, and 5Institut des Sciences de l’Evolution, UMR 5554, cc065, Université de Montpellier 2, place Bataillon, 34095 Montpellier Cedex 05, France
4Laboratoire Ecosystèmes Aquatiques Tropicaux et Méditerranéens, UMR 8046 EPHE-CNRS, Université de Perpignan, 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France
*Address for correspondence: Montpellier. Email: thoareau@

ABSTRACT: The 2 amphidromous gobiids Sicyopterus lagocephalus and Cotylopus acutipinnis from La Réunion Island (Mascarene archipelago, south-western Indian Ocean) are heavily exploited by traditional fisheries during their river colonisation. Traits of their oceanic larval life were investigated to better understand the complex life cycle of these fishes. Age estimates were established using otolith increment counts and an alizarin complexon validation method. Larval duration was longer for the widespread S. lagocephalus (133 to 266 d; mean 199 ± 33 d) than for the endemic C. acutipinnis (78 to 150 d; mean 101 ± 14 d), which reflects their distributional ranges. For both species, no correlation was established between age and size, suggesting a decrease in growth during the larval phase. From the back-calculated birth dates, all S. lagocephalus of a major colonisation episode (December 2002) were hatched during the cool season. All results are discussed in terms of the recruitment origins of S. lagocephalus and C. acutipinnis within the Mascarenes. Recognition of the differences in larval life traits is essential for proposing both management and conservation measures for each species.

KEY WORDS: Sicyopterus lagocephalus · Cotylopus acutipinnis · Goby-fry · Otolith micro-increment · Age validation · Hatching date

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