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Vol. 54, 2015
Population structure of Hirundichthys
oxycephalus in the
northwestern Pacific inferred from mitochondrial cytochrome oxidase I
gene
Chang-En Chou1,†,
Te-Yu Liao2,†,
Hsueh-Wen Chang1,*,
and Shui-Kai Chang3,*
1Department
of Biological Sciences, National Sun Yat-sen University, 70, Lien-hai
Road, Kaohsiung 804, Taiwan
2Department
of Oceanography, National Sun Yat-sen University, 70, Lien-hai Road,
Kaohsiung 804, Taiwan
3Institute
of Marine Affairs, National Sun Yat-sen University, 70, Lien-hai Road,
Kaohsiung 804, Taiwan
Abstract
Background: Hirundichthys oxycephalus
is an important flyingfish resource in eastern Taiwan and northwestern
Japan. A substantial catch decline in Taiwan has caused serious
concerns on stock status of the fish, prompting the government to
impose a set of regulations on flyingfish egg fishery since 2008.
However, the regulations were set in a precautionary manner, without
considering the fundamental understanding of the population genetic
structure. This study aims to investigate the population genetic
structure of H. oxycephalus
in the region based on mtDNA cytochrome oxidase I (COI) gene and to
thus provide scientific information for sustainable management of the
resource.
Results: Tissue
samples (156) from six localities of eastern Taiwan and western Japan
were collected, and 616 bp of mtDNA COI gene were sequenced. Seventy
haplotypes were determined, and the haplotype diversity and nucleotide
diversity were estimated as 0.93% and 0.57%, respectively. Results of
various statistical analyses suggested that the genetic
differentiations among the six localities were small and most variation
occurred within populations, indicating a high gene flow in the region
with undergoing population expansion. Although the study showed that
the fishes were genetically divided into two groups, the support was
low and the separation was not geologically evident.
Conclusions: The study revealed two groups of H. oxycephalus
in the northwestern Pacific Ocean. However, due to high gene flow, an
association of either group to a spatial distribution was not observed,
and so the two groups may be considered as one population. Thus, the
results favored the conclusion that H. oxycephalus
from eastern Taiwan and western Japan belong to the same population
and, consequently, that the management unit of the current regulations
only covering eastern Taiwan does not match the spatial structure of
the population. Rather, the results suggest that joint efforts from
countries within the population boundary are necessary to maintain a
sustainable exploitation.
Key words: Ecological population; Flyingfish; Taiwan; Northwestern Pacific; COI.
*Correspondence: E-mail: hwchang@mail.nsysu.edu.tw;
skchang@faculty.nsysu.edu.tw
†Equal contributors
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