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Otolith microstructure of Japanese sea bass larvae and juveniles: interpretation and utility for ageing
Author(s) -
Islam Md. S.,
Ueno M.,
Yamashita Y.
Publication year - 2009
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.2009.01251.x
Subject(s) - sagitta , otolith , biology , juvenile , larva , metamorphosis , sea bass , bass (fish) , fishery , zoology , serranidae , hatching , ecology , fish <actinopterygii>
Summary This paper interprets and discusses the usefulness of otolith microstructure for ageing Japanese sea bass ( Lateolabrax japonicus ) larvae and juveniles. Samples were collected from the Tango Sea along the Japan Sea coast, January–March 2007. Known‐age (0‐day and 10‐day‐old) larvae were obtained from the Ibaragi Prefectural Hatchery, Japan. Sagittal and lapillar otolith were processed and read using an otolith reading system. Clearly discernible hatch‐ and first‐feeding marks were evident on sagitta, and development of accessory premordia (AP) appeared to be associated with larva‐juvenile transition; however, no other marks indicating metamorphosis or settlement were evident. In lapillus, no discernible check mark was found. Known‐age larvae showed that deposition of the first daily increment (DI) corresponded to first‐feeding, which occurred at day‐4 post‐hatch. However, mean increment counts were significantly lower in lapillus than in sagitta, caused by poorly expressed increments around the centrum as well as relatively unclear centrum of the lapillus. The authors suggest that the use of lapillus can cause significant underestimation of age. Therefore, the sagitta is recommended for age and growth estimations of larvae and juveniles, although the presence of numerous subdaily increments warrants careful preparation and interpretation of the microstructure. A test for asymmetry showed the right and left otoliths to be quite symmetrical and their DI counts not significantly different, suggesting that either otolith can be used for studying age and growth of Japanese sea bass larvae and juveniles.