Early Summer Composition and Diversity of Fish Larvae in the Coastal Waters of Hualien, Eastern Taiwan

Abstract

This study investigated the composition and diversity of fish larvae with the hydrological environment in the coastal waters of Hualien on June 26, 2009. The range of surface water temperature and salinity varied from 25.56 °C to 26.05 °C and from 33.77 to 34.69, respectively. A total of 140 larvae representing 20 families and 25 species were collected using a bongo net from 9 stations during this survey. The abundance and species composition varied by station. The first 5 dominant species of Benthosema pterotum, Callionymidae spp., Auxis spp., Diaphus A group, and Decapterus spp. occupied 69.61%, 8.9%, 3.44%, 2.95%, and 1.58% of the total catch, respectively. According to the dendrogram from a cluster analysis of the fish larvae, the larval assemblages of 9 sampling stations were divided into 3 groups. Group A comprised only Station 9, with a total abundance of 3220.4 ind./1000 m3 and the dominant species was B. pterotum (69.12%). The larval abundance in Group B, comprising Stations 3, 5, and 6, was the lowest among the groups, with approximately 2387.2 ind./1000 m3 and an average diversity index of 2.21. The 4 most dominant species were B. pterotum (19.03%), Auxis spp. (14.13%), Decapterus spp. (8.98%), and Leiognathus spp. (8.67%). Group C exhibited the highest larval abundance, with 15590.8 ind./1000 m3 and the an average diversity index of 1.4. The 3 most dominant species were B. pterotum (66.31%), Callionymidae spp. (8.96%), and Diaphus A group (3.54%). Possible interpretations of fish larvae assemblages and diversity are provided.