The complete mitochondrial genome of the Japanese seahorse, Hipppocampus mohnikei (Syngnathiformes: Syngnathidae) and its phylogenetic implications

Diversity of Seahorse Species (Hippocampus spp.) in the International Aquarium Trade

Seahorses (Hippocampus spp.) are threatened as a result of habitat degradation and overfishing. They have commercial value as traditional medicine, curio objects, and pets in the aquarium industry. There are 48 valid species, 27 of which are represented in the international aquarium trade. Most species in the aquarium industry are relatively large and were described early in the history of seahorse taxonomy. In 2002, seahorses became the first marine fishes for which the international trade became regulated by CITES (Convention for the International Trade in Endangered Species of Wild Fauna and Flora), with implementation in 2004. Since then, aquaculture has been developed to improve the sustainability of the seahorse trade. This review provides analyses of the roles of wild-caught and cultured individuals in the international aquarium trade of various Hippocampus species for the period 1997–2018. For all species, trade numbers declined after 2011. The proportion of cultured seahorses in the aquarium trade increased rapidly after their listing in CITES, although the industry is still struggling to produce large numbers of young in a cost-effective way, and its economic viability is technically challenging in terms of diet and disease. Whether seahorse aquaculture can benefit wild populations will largely depend on its capacity to provide an alternative livelihood for subsistence fishers in the source countries. For most species, CITES trade records of live animals in the aquarium industry started a few years earlier than those of dead bodies in the traditional medicine trade, despite the latter being 15 times higher in number. The use of DNA analysis in the species identification of seahorses has predominantly been applied to animals in the traditional medicine market, but not to the aquarium trade. Genetic tools have already been used in the description of new species and will also help to discover new species and in various other kinds of applications.

Complete mitochondrial genome of nearly threatened freshwater ornamental fish, Microphis deocata and its phylogenetic relationship within Syngnathidae

Microphis deocata (deocata pipefish), belonging to family Syngnathidae, is one of the important indigenous ornamental fish species listed as near threatened in the IUCN red list. Here, we first report the complete mitochondrial genome of deocata pipefish using Illumina next-generation sequencing platform. The total length of the mitogenome is 16,526 bp. It encompasses 13 protein coding genes, 2 ribosomal rRNAs, and 22 tRNAs. The WANCY region (a cluster of five tRNA genes) contains the 50 bp O_L light strand origin of replication. Phylogenetic analysis of Syngnathidae revealed M. deocata to cluster with Oostethus manadensis, forming a sister group with Doryrhamphus japonicas and Dunckerocampus dactyliophorus. The mitochondrial genome sequence data generated in the present study will play an important role in population genetic analysis and developing conservation strategies for this species.

Characterization and phylogenetic analysis of the complete mitochondrial genome of Glossogobius giuris (Perciformes: Gobiidae)

The species tank goby (Glossogobius giuris) is assessed as Least Concern on the IUCN Red List of Threatened Species. In the present study, we first determined and described the complete mitochondrial genome of G. giuris. The circular genome is 16,595 bp in length. It has the typical vertebrate mitochondrial gene arrangement and consists of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one non-coding control region. The overall base composition is 29.1% for A, 24.6% for T, 29.4% for C, and 17.0% for G. Phylogenetic analysis of 21 species in the family Gobiidae showed that G. giuris was clustered into the genus Glossogobius, subfamily Gobiinae. This information will contribute to future phylogenetic studies of Gobiidae and conservation strategies for G. giuris.