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Menoud, Mathilde; Van Wynsberge, Simon; Le Moullac, Gilles; Levy, Peva; Andrefouet, Serge; Remoissenet, Georges; Gaertner-mazouni, Nabila. |
Monitoring gonadmaturation for protandrous and functional hermaphrodite species such as the giant clamTridacna maxima is difficult due to the juxtaposition and relative proportion ofmale and female tissues in the gonad [gonadal sex ratio (GSR)]. Here, the relevance of the widely used gonadosomatic index (GSI) as proxy of giant clam gonad maturation is tested with a large dataset (n = 265). Gonadosomatic index is compared with other indices, namely the proportion of the male part harboring spermatozoids, the proportion of empty oocyte follicles, the mean oocyte diameter, and the oocyte elongation. At gonad scale, high index variability highlighted partial spawning. At individual scale, male and female maturation proxies were contrasted, showing either... |
Tipo: Text |
Palavras-chave: Giant clam; Marine bivalve; Reproduction; Spawn; Tatakoto atoll; Histology; Tridacna maxima. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44441/44111.pdf |
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Van Wynsberge, Simon; Andrefouet, Serge; Gaertner-mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges. |
Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48214/48335.pdf |
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