2000 年 47 巻 2 号 p. 139-143
Intraspecific genetic differences in the seahorse, Hippocampus corona-tus (Syngnathiformes: Syngnathidae), collected from Sagami Bay (Shizuoka and Kanagawa Prefectures, Japan), were surveyed by molecular phylogenetic analyses using a portion of the mitochondrially-encoded 12S ribosomal RNA (12S rRNA) gene. The results indicated that the species comprised two genetically-divergent clades, one characterized by a low coronet and short snout and the other by a tall coronet and long snout. Although the sequence divergences within each clade were very low (0-0.1%), that between the two clades was relatively high (4.4-4.6%), close to values recorded for interspecific genetic divergences in this genus (5.5-7.5%). This suggests that H. coronatus includes at least two taxonomic units.