Genetic diversity and population structure of Hyporhamphus sajori (Beloniformes: Hemiramphidae) inferred from mtDNA control region and msDNA markers

Abstract

This paper presents preliminary data on the genetic diversity and population structure of Hyporhamphus sajori by analysing a 510 bp sequence in the mitochondrial DNA (mtDNA) control region and eight polymorphic microsatellite DNA loci. The H. sajori individuals from different locations were indistinguishable from one another based on mtDNA variation, as demonstrated with a neighbour-joining tree and minimum spanning network analysis. Low level of genetic diversity and the absence of population structure in H. sajori from the north-west Pacific Ocean, combined with negative indices for neutral evolution in these populations, suggest that H. sajori underwent a population expansion after a recent bottleneck. The Structure analysis, discriminant analysis of principal components (DAPC) and the pair-wise Φ values after Bonferroni correction using eight microsatellite loci provided no clear inference on the genetic differentiation and thus no evidence of population structure of H. sajori. The genetic connectivity among locations might be due to fairly high gene flow via transport of eggs and larvae by the Kuroshio and Tsushima warm current. This study revealed low levels of genetic diversity and suggested high level of contemporary gene flow among populations of H. sajori in the East (Japan) Sea and the Pacific Ocean.

Upwelling and eddies affect connectivity among local populations of the goldeye rockfish,Sebastes thompsoni(Pisces, Scorpaenoidei)

“…thompsoni ; for example, the flat top of the Wangdolcho Reef may now be located closer to the sea surface than during the glacial period. A similar result was reported for the Japanese halfbeak Hyporhamphus sajori (Yu et al., ). Yu et al.…”

“…Yu et al. () suggested that the decline of surface seawater temperatures in the East Sea might have been caused by the blockage of the Tsushima Warm Current during the last glacial maximum, resulting in the local extinction of East Sea species and a subsequent substantial drop in genetic diversity, which is currently observed. S .…”

“…Some larvae released near the Jejudo and Chujado Islands might have been spread to the Yellow Sea with the help of the Tsushima or the Yellow Sea Warm Currents. Likewise, Japanese halfbeak ( Hyporhamphus sajori ; Yu et al., ) and Korean rockfish ( Sebastes schlegelii ; Gao et al., ; Zhang, Yanagimoto, Zhang, Song, & Gao, ), associated with drifting seaweed during early lifetime like S. tompsoni , in the similar geographic area showed no population structure based on mtDNA control region and ms loci, which may be attributable to the passive dispersal of the eggs and larvae through the Yellow Sea Warm Current. Extensive drifting seaweed, identified as Sargassum horneri , originated from the East China Sea during spring also flows into the Yellow Sea due to the effects of the Yellow Sea Warm Current and the northwestern monsoon (Hwang, Lee, Ha, & Park, ).…”

“…The reproductive strategy of associating with drifting seaweed predisposes marine fishes to disperse larvae and juveniles via drifting seaweed transported by tidal, wind‐driven, and ocean currents, provides opportunities to exchange genetic material among geographically distant populations (Helmuth, Veit, & Holberton, ; Highsmith, ). Japanese halfbeak ( Hyporhamphus sajori ) and Korean rockfish ( Sebastes schlegelii ) are good examples to demonstrate this; both species spend their early life stages in drifting seaweed, showing very high genetic homogeneity despite the geographic distance between populations (Gao et al., ; Uchida & Shojima, ; Yu, Kai, & Kim, ).…”

Multiple surveys employing a new sample‐processing protocol reveal the genetic diversity of placozoans in Japan

“…In the Sea of Japan, the Tsushima Current, a branch of the Kuroshio Current, flows along the Japanese coast from the south through the Tsushima Strait (Figure ). It has been reported that the Kuroshio and the Tsushima Currents impact the distribution of various animals, including sponges, clams, mantis shrimp, sunfish, and halfbeaks (Cheng & Sha, ; Hoshino, Saito, & Fujita, ; Yamada, Ishibashi, Toyoda, Kawamura, & Komaru, ; Yoshita et al., ; Yu, Kai, & Kim, ). H2 placozoans have been reported from Okinawa and Hong Kong (Eitel & Schierwater, ; Pearse & Voigt, ) and were collected on the coasts of both the Pacific and the Sea of Japan during this study (Figure ).…”