Phylogenetic analysis and genetic structure of the seahorse, Hippocampus fuscus from the Arabian and Red Sea based on mitochondrial DNA sequences

Abstract

The unique body morphology and specialized life history traits make seahorses excellent flagship species for many issues in marine conservation and biological evolution. In this study, the complete mitochondrial genome of Hippocampus fuscus was determined. Phylogenetic analyses showed that H. fuscus had a close genetic relationship to Hippocampus reidi, which give us a new insight into the speciation and dispersal among seahorse genus. A total of 843 base pairs of cytochrome b (Cytb) gene and a 646 base pairs of cytochrome oxidase I (COI) gene were obtained from 36 H. fuscus and 26 H. reidi from three populations. Population genetic analysis revealed a relatively high genetic diversity across the populations of H. fuscus compared with H. reidi. Neighbour-joining (NJ) tree of COI and Cytb gene sequences showed that H. fuscus haplotypes formed one cluster. The result of median-joining network of haplotypes based on COI and Cytb indicated a lack of structure in populations of H. fuscus. This study addressed the information about the evolution history and genetic structure of an Arabian seahorse H. fuscus, which provides insight into the genetic conservation and sustainable management for this species.

Complete mitochondrial genomes of eight seahorses and pipefishes (Syngnathiformes: Syngnathidae): insight into the adaptive radiation of syngnathid fishes

“…The mitochondrial genome organization of syngnathid fishes was quite conserved, as identified for other bony fishes [22, 31–33]. The differences in length among the Syngnathidae mitochondrial genome sequences are mainly due to length variation of the control region and random insertions in the intergenic regions.…”

“…Degenerate primers for fragment amplification were designed based on conserved nucleotide sequences from the mitochondrial genomes of Hippocampus kuda (AP005985) and Microphis brachyurus (AP005986) using DNAssist 2.2 and Primer Premier 5.0 software [55]. The PCR amplifications, sequence assemble, and genome annotation were performed according to a slightly modified method described by Wang et al [31].…”

Mitogenome reconstruction of an endangered African seahorse from a Traditional Chinese Medicine market was based on a misidentification

“…These results confirm that the Chinese specimen was misidentified. The portion of the mitochondrial control region of this specimen is identical to one of the sequences of H. casscsio, from Beibu Bay, South China Sea (Zhang et al 2016), whereas its partial cytochrome b sequence is identical to that of a specimen of H. fuscus from Safaga on the Red Sea coast of Egypt (Wang et al 2019a). All Chinese seahorses clustered randomly among sequences of H. fuscus, a species name that was considered to be a synonym of H. kuda in a recent taxonomic revision of seahorses (Lourie et al 2016).…”

Morphological and molecular evidence for first records and range extension of the Japanese seahorse, Hippocampus mohnikei (Bleeker 1853) in a bay-estuarine system of Goa, central west coast of India

“…Food availability has been considered as one of the factors influencing the abundance and distribution of seahorses [20]. Zooplankton such as Oithona davisae, Calanoida and Penilia avirostris have been identified as the main prey organisms for juvenile and young H. mohnikei in Tokyo Bay [39], whereas the adults have been reported to prey upon mainly larger organisms such as gammarid and caprellid amphipods [63].…”

“…pelvic and caudal fins), and have high variability in body proportion, color (camouflage) and skin filaments, fin-ray and trunk-ring numbers; any of these traits might overlap between species [3,17]. On the other hand, molecular methods have proved helpful in resolving morphologically challenging seahorse taxonomy [16,18], phylogenetic relationships within the genus Hippocampus [19,20], natural species boundaries [21][22][23] and genetic variability [22,24] of many seahorse species. An integrated approach combining morphological and genetic analyses [25] would aid in the management of demographically separate populations as independent units and allow international legal mechanisms and international agreements such as the Convention on International Trade in Endangered Species (CITES) to work effectively [26].…”