Morphometric and genetic identification of a newly record pygmy seahorse Hippocampus denise in the Kepulauan Seribu reefs, Indonesia

The study was conducted to describe the seahorse species based on morphological and molecular characters. The pygmy seahorse in Panggang Island in Kepualuan Seribu was discovered in October 2011. The species was allegedly identified as Hippocampus denise (Family: Syngnathidae) described by Lourie and Randall which published in 2003. The high similarity is based on small morphometric, orange-like color and its association with sea fan Annella sp . Their habitat is fairly shallow at a depth between 13-24 meters compared with their sister species observed in Bali, Nusa Tenggara, and Sulawesi. The phylogenetic analysis constructed with several sequence data of Hippocampus spp. from Genbank shows that sample collected from Panggang Island is in the same clade with Hippocampus denise with 100% bootstrap value. BLAST analysis result also showed a high maximum similar identity (>99%) with the species Hippocampus denise . The seahorse specimen described in this study has a common typology of habitat with Hippocampus denise . This study shows that genetic analysis to determine the Hippocampus denise can be carried out to support species recognition, especially for cryptic species such as Hippocampus spp. There are variations in morphometric and habitat depth levels, indicating local adaptation of pygmy seahorses to the Kepulauan Seribu reefs.