Species composition of fish eggs in the northwest Pacific

Abstract

In order to study on the spawning ecology of fish in the northwest Pacific, we collected fish eggs from 326 stations in June, 2012. And also we simultaneously measured temperature and salinity at the 3m depth. The range of temperature and salinity were 20.4~30.4 ℃ and 31.53~34.69 psu, respectively. The 16SrDNA sequences were obtained from 444 single specimens out of 548 specimens collected. Based on the 16SrDNA sequences, the specimens were identified into 38 species including four unidentified species in fish, two species in squid, and three species in euphausiid. The temperature and salinity were more than 20.8℃ and 32.25 psu in the sea area where fish eggs appeared. In major species including dominant species, Encrasicholina punctifer, the environmental feature was different according to the species in the sea area where they distributed. E. punctifer and Acanthocybium solandri were sampled in the places temperature and salinity were higher (> 29.1℃ and > 34.06 psu), of which both variations were very narrow. Four species such as Katsuwonus pelamis, Thunnus sp., and two unidentified species were found in the range of salinity (34.06~34.69 psu) in contrast to wide range of temperature (24.3~30.4℃). Two species, Auxis rochei and Coryphaena hippurus, were distributed in the wide range of temperature (20.8~29.7℃) and salinity (32.25~34.56 psu). Engraulis japonicus was collected in the lowest temperature (20.8~20.alinity were 20.4~30.4 ℃ and 31.53~34.69 psu, respectively. The 16SrDNA sequences were obtained from 444 single specimens out of 548 specimens collected. Based on the 16SrDNA sequences, the specimens were identified into 38 species including four unidentified species in fish, two species in squid, and three species in euphausiid. The temperature and salinity were more than 20.8℃ and 32.25 psu in the sea area where fish eggs appeared. In major species including dominant species, Encrasicholina punctifer, the environmental feature was different according to the species in the sea area where they distributed. E. punctifer and Acanthocybium solandri were sampled in the places temperature and salinity were higher (> 29.1℃ and > 34.06 psu), of which both variations were very narrow. Four species such as Katsuwonus pelamis, Thunnus sp., and two unidentified species were found in the range of salinity (34.06~34.69 psu) in contrast to wide range of temperature (24.3~30.4℃). Two species, Auxis rochei and Coryphaena hippurus, were distributed in the wide range of temperature (20.8~29.7℃) and salinity (32.25~34.56 psu). Engraulis japonicus was collected in the lowest temperature (20.8~20.