Zoological Studies

Vol. 58, 2019

(update: 2019.07.23)

Habitat Partition and its Possible Genetic Background Between Two Sympatrically Distributed Eel Species in Taiwan

Hsiang-Yi Hsu1,, Hsiao-Wei Chen1,, and Yu-San Han1,*


1Institute of Fisheries Science, College of Life Science, National Taiwan University, 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan. *Correspondence: E-mail: yshan@ntu.edu.tw. Tel: 886-2-3366-3726. Fax: 886-2-3366-9449
Hsiang-Yi Hsu and Hsiao-Wei Chen contributed equally to this work.

Received 19 April 2019 / Accepted 19 July 2019
Communicated by Yasuyuki Hashiguchi

The geographical distributions of Japanese eel (Anguilla japonica) and Giant-mottled eel (A. marmorata) overlapped at many regions in East Asia, therefore, they would suffer from an interspecific competition in the same rivers. After a long period of adaption, Japanese eel and Giant-mottled eel may have habitat partitioning in the rivers, to diminish the interspecific competition between them. In this study, we conducted a field investigation in the Fengshan River in Taiwan to survey the habitat distributions of Japanese eel and Giant-mottled eel across a river. Moreover, we would like to know whether their habitat distributions are related to their swimming and upstream migration. Thus, the mRNA expression levels of several candidate genes that may be associated with the swimming and upstream migration of eel were examined in the glass eels of Japanese eel and Giant-mottled eel. Field investigation indicated that the Japanese eel mainly inhabited the lower and middle reaches of the Fengshan River, but the Giant-mottled eel was distributed over the middle to upper reaches. The mRNA expression levels of fMYH, dio2, gria3, and neurod1 were higher in the Giant-mottled eel than in the Japanese eel, implying that Giant-mottled eel might have better swimming bursts and more active upstream migration than Japanese eel. These results suggested that there is a habitat partition when these two eel species coexist in a river, and the habitat distributions of them may link with their swimming bursts and upstream migration. To find out the habitat distributions of freshwater eels is important for developing applicable plans for eel conservation and resource management.

Key words: Giant-mottled eel, Habitat partitioning, Interspecific competition, Japanese eel and upstream migration.

Citation: Hsu HY Chen HW, Han YS. 2019. Habitat partition and its possible genetic background between two sympatrically distributed eel species in Taiwan. Zool Stud 58:0z. doi:-.

Supplementary Materials: Table S1 | Table S2 | Table S3