Kaji, T., Yamaoya, K., Isshiki, T., Yamada, T.-1995
Bulletin of Marine Sciences and Fisheries, Kochi University,15: 117-120
Abstract:
The development of mucous cells on the body surface in larval stages of the red-spotted grouper, Epinephelus akaara (Temminck et Schlegel), was examined to get the basic information for understanding the mechanism of a "floating death". In larvae of ca. 2 mm TL (0-1 day old), small and round mucous cells were developed mainly on the whole dorsal part of the body, especially from the snout to post-orbital region. The mucous cells were close with each other and developed in a single layer in cross sections. In larvae of ca. 2.2-2.3 mm TL (2-4 day old) when the mouth was opened, they developed well, each mucous cell being larger, and its density became higher. Especially on dorsal parts of the snout, well-developed mucous cells could be observed. In larvae of ca. 2.5 mm TL (6 day old), the well-developed mucous cells showed a tendency of reduction. In larvae of ca. 3.6 mm TL (10 day old), they disappeared. The relation between mucous cell development and high mortality rate observed around mouth opening stage was discussed.
(Laboratory of Aquatic Ecology, Faculty of Agriculture, Kochi University, Nankoku, Kochi 783, Japan)
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