Zoological Studies

Vol. 37 No. 4, 1998

Use of Otolith Microchemistry to Investigate the Life History Pattern of Gobies in a Taiwanese Stream

Kang-Ning Shen1, Ying-Chou Lee1 and Wann-Nian Tzeng2,*

1lnstitute of Fisheries Science, College of Science, National Taiwan University, Taipei, Taiwan 106
2Department of Zoology, College of Science, National Taiwan University, Taipei, Taiwan 106

Kang-Ning Shen, Ying-Chou Lee and Wann-Nian Tzeng (1998) To understand the migratory history of stream gobies in Taiwan, otolith microchemistry of 11 species of gobies collected in Longlong Brook, northeastern Taiwan from 26 Sept. 1995 through 4 Nov. 1996 was examined by use of an electron probe microanalyzer. According to the time-series changes in strontium (Sr) to calcium (Ca) ratios from the primordium to the edge of the otolith, the 11 species are divisible into 3 life history patterns. Rhinogobius brunneus is a freshwater species, its otolith Sr/Ca ratios being less than 10‰. Glossogobius biocellatus and Favonigobius reichei are estuarine species, with Sr/Ca ratios of around 10‰, Awaous melanocephalus, Eleotris acanthopoma, Glossogobius celebius, Oligolepis acutipennis, Redigobius bikolanus, Rhinogobius nagoyae formosanus, Sicyopterus japonicus, and Stenogobius genivittatus are amphidromous species migrating between seawater and fresh water, Sr/Ca ratios being higher in inner layers (approximately 10‰-17‰) than outer layers of the otolith (less than 10‰). This indicates that the 8 amphidromous species migrate to a marine environment during early life and back to fresh water at a later stage. The marine phase of post larval duration in the amphidromous fishes lasts from approximately 1 mo in O. acutipennis to 6 mo in Sicyopterus japonicus. This study reveals that Sr/Ca ratios in otoliths can be used as indicators of a fish's past life history.

Key words: Gobioidei, Amphidromy, Otolith, Microchemistry, Larval duration.

*Correspondence: Fax: 886-2-23636837, E-mail: wnt@ccms.ntu.edu.tw