Geographical Variations in Morphological Characters of the Fluvial Eight-Barbel Loach, Nagare-Hotoke-Dojo (Cobitidae: Nemacheilinae)
Biogeography 17. 43–52. Sep. 20, 2015 Geographical variations in morphological characters of the fluvial eight-barbel loach, Nagare-hotoke-dojo (Cobitidae: Nemacheilinae) Taiki Ito*, Kazuhiro Tanaka and Kazumi Hosoya Program in Environmental Management, Graduate School of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan Abstract. The morphological and color variations of Lefua sp. 1 Nagare-hotoke-dojo individuals from 13 river systems were examined. Analysis of variance revealed highly significant variations in Lefua sp. 1 mor- phology and coloration among the 13 populations examined, across all 19 measurements and counts. The 13 populations of Lefua sp. 1 were classified into two major clusters (I and II) by using UPGMA cluster analy- sis. Cluster I comprised fish from the Maruyama, Yura, Muko, Mihara, Yoshino, Hidaka, Kumano, Yoshii, Chikusa, and Ibo river systems. Cluster II comprised fish from the Yoshida, Saita, and Sumoto river systems. Cluster I was further subdivided into sub-clusters: I-i (the Maruyama, Yura, Muko, Mihara, Yoshino, Hidaka, Kumano, and Yoshii river systems) and I-ii (the Chikusa and Ibo river systems). Principal component analysis revealed that populations within cluster II clearly possessed longer caudal peduncles, while populations within cluster I possessed a longer anterior body on average and a deeper body. Populations within sub-cluster I-ii possessed a higher average dorsal fin and a longer average dorsal fin base than those of populations within sub-cluster I-i. A strong correlation was noted between the PC3 score and population latitude (r = 0.621). Observations of body color patterns revealed that individuals from the Yoshino, Mihara, Sumoto, and Hidaka river systems had dark brown mottling on both sides and the dorsal regions of their bodies and many small dark brown spots on the dorsal and caudal fins, while those from the Yura, Muko, and Kumano river systems possessed neither.
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