Mitochondrial DNA reveals low population differentiation in elongate loach, Leptobotia elongata (Bleeker): implications for conservation

• Published in: Environmental biology of fishes Vol. 93; no. 3; pp. 393 - 402
• Main Authors: Liu, Guangxun, Zhou, Jian, Zhou, Dinggang
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2012; Springer; Springer Nature B.V
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal populations; Animal Systematics/Taxonomy/Biogeography; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Comparative studies; Endemic animals; Endemic species; Environment; Fish; Freshwater; Freshwater & Marine Ecology; Freshwater fish; Fundamental and applied biological sciences. Psychology; Genetic diversity; Haplotypes; Larvae; Life Sciences; Mitochondrial DNA; Nature Conservation; Population differentiation; Population genetics; Population growth; Population structure; Rivers; Vertebrata; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Wildlife conservation; Zoology; China, People's Rep., Changjiang R; Population structure; Mitochondrial DNA; Genetic diversity; Bleeker; Conservation strategy; Vertebrata; Pisces; Conservation; Strategy; Differentiation; Leptobotia elongata (Bleeker)
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-011-9927-7

Elongate loach (
Leptobotia elongata
(Bleeker)), an endemic fish species to China, is a famous ornamental freshwater fish. Here, a comparative study of mtDNA control region (D-loop) (835 bp) sequences was performed to analyze its wild population structure and evaluate the genetic diversity for 110 individuals from five locations in the upper reaches of the Yangtze River, China. A total of 49 polymorphic sites and 45 haplotypes yielded high haplotype diversity (
h
 = 0.952), but low nucleotide diversity (
π
 = 0.00454) as that of many fish species. Sequence divergences between haplotypes ranged from 0.0033 ± 0.0011 to 0.0050 ± 0.0012 in intra-groups, and from 0.0037 ± 0.0.0011 to 0.0050 ± 0.0012 between groups. Significant values of Tajima’s
D
(−1.86383,
P
 < 0.01) and Fu’s
F
S
(−25.93,
P
 < 0.01), together with uni-modal mismatch distribution, indicated a recent genetic bottleneck or population expansion of the species. Analysis of molecular variance (AMOVA) indicated a small amount of differentiation among groups (1.7%); most of the total variation occurred within groups (98.3%). Also, there was no significant population structure (
F
ST
 = 0.017,
P
 > 0.05), and estimates of gene flows among groups were extremely high (
Nm
 = 28.88), suggesting low genetic divergence between populations in the species. The lack of genetic differentiation among groups is most likely due to the combined gene flow from the downstream movement of eggs and larvae with currents and the upstream or downstream migration of adults throughout the distribution. These groups of
L
.
elongata
distributed in upper reaches of the Yangtze River should be considered as a single management unit.