Related Experiment Video
Updated: Feb 14, 2026

Necropsy-based Wild Fish Health Assessment
Published on: September 11, 2018
Genetic diversity and population structure of penis fish (Urechis unicinctus) based on mitochondrial and nuclear gene
Jie Gong1, Ruoping Zhao2, Jiaheng Deng1
1a School of Life Sciences , Ludong University , Yantai , Shandong , P. R. China.
Abstract:
Urechis unicinctus is distributed only in Bohai Gulf of China and Korean and Japanese coast. The wild populations of this species have sharply declined in China and Japan. We collected 105 samples from six localities of Bohai Gulf and Korea coast, and investigated genetic diversity and population structure with mitochondrial COI, 16S-rRNA and nuclear 28S-rRNA gene fragments. Genetic diversity of U. unicinctus based on COI sequences was still high (Hd: 0.9595, π: 0.0101), however, 28S-rRNA gene sequences showed low level of genetic diversity (Hd: 0.4084, π: 0.0007). Based on COI sequences, FST values between populations ranged from -0.00204 to 0.05210, and 99.12% genetic diversity was contributed by different individuals within population. Both phylogenetic trees and median-joining network did not show clear geographic cluster, haplotypes from different populations were mixed. Our results indicated low level of genetic divergence among different localities of U. unicinctus, and this species should be treated as a whole population among China, Japan and Korea coast during species conservation.
Related Concept Videos
Animal Mitochondrial Genetics
What is Population Genetics?
Export of Mitochondrial and Chloroplast Genes
Mutation, Gene Flow, and Genetic Drift
Conservation of Small Populations
Penis
Anatomy of the Penis
The glans penis, or the head, is the terminal part of the penis and houses the external urethral orifice, the exit point for urine and semen. Covered by the prepuce, or foreskin, the glans is noted for its sensitivity and plays a key role in sexual pleasure. The body of the...

