Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal

Freshwater fishes in the river and lake systems in the Himalayas and Tibetan Plateau are morphologically diverged but the evolutionary relationship of putative subspecies separated in these freshwater systems has not been explored. Snowtrout (Schizothorax spp.) are minnows (Cyprinidae) broadly distr...

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Main Authors: B Regmi, MR Douglas, DR Edds, ME Douglas
Format: Article
Language:English
Published: Inter-Research 2021-01-01
Series:Aquatic Biology
Online Access:https://www.int-res.com/abstracts/ab/v30/p19-31/
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author B Regmi
MR Douglas
DR Edds
ME Douglas
author_facet B Regmi
MR Douglas
DR Edds
ME Douglas
author_sort B Regmi
collection DOAJ
description Freshwater fishes in the river and lake systems in the Himalayas and Tibetan Plateau are morphologically diverged but the evolutionary relationship of putative subspecies separated in these freshwater systems has not been explored. Snowtrout (Schizothorax spp.) are minnows (Cyprinidae) broadly distributed in Asia. Body shapes of 3 Lake Rara (northwest Nepal) endemics (S. macrophthalmus, S. nepalensis, S. raraensis) and 2 widely distributed riverine species (S. progastus, S. richardsonii) across 3 drainages in Nepal (i.e. Karnali, Gandaki, and Koshi Rivers) were studied using geometric morphometry. Data were derived from museum voucher specimens/tissues collected in 1984-1986 and 1996 (Lake Rara). Cartesian coordinates of 18 anatomical points (Type I landmarks) from 528 individuals were digitized; shape variation was then quantified with principal component analysis and visualized with thin-plate splines derived from a Procrustes analysis. Models of shape variation (i.e. taxonomy versus geography) were tested with a multivariate analysis of variance and a morphological distance matrix. Phylogeographic relationships were examined with a haplotype network (N = 115) derived from 1140 base pairs of the mitochondrial DNA cytochrome b gene, and selected GenBank sequences (N = 5). Koshi River snowtrout diverged morphologically from conspecifics, consistent with the phylogeographic data. In contrast, Gandaki and Karnali River snowtrout grouped by morphotype (up- versus downstream) irrespective of geographic origin, yet clustered separately within the haplotype network. Lake Rara snowtrout were morphologically but not genetically distinct, due to incomplete lineage sorting. Morphological and genetic variability in Schizothorax from Nepal represent a mosaic driven by isolation (= vicariance) and specialization (= adaptation), with taxonomy insufficiently reflecting diversity. Additional data are required to appropriately derive management and effective conservation plans.
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spelling doaj.art-ec746bac125849be9030d080d0a6b1d52022-12-21T20:14:49ZengInter-ResearchAquatic Biology1864-77821864-77902021-01-0130193110.3354/ab00737Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in NepalB Regmi0MR Douglas1DR Edds2ME Douglas3Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USADepartment of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USADepartment of Biological Sciences, Emporia State University, Emporia, KS 66801, USADepartment of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USAFreshwater fishes in the river and lake systems in the Himalayas and Tibetan Plateau are morphologically diverged but the evolutionary relationship of putative subspecies separated in these freshwater systems has not been explored. Snowtrout (Schizothorax spp.) are minnows (Cyprinidae) broadly distributed in Asia. Body shapes of 3 Lake Rara (northwest Nepal) endemics (S. macrophthalmus, S. nepalensis, S. raraensis) and 2 widely distributed riverine species (S. progastus, S. richardsonii) across 3 drainages in Nepal (i.e. Karnali, Gandaki, and Koshi Rivers) were studied using geometric morphometry. Data were derived from museum voucher specimens/tissues collected in 1984-1986 and 1996 (Lake Rara). Cartesian coordinates of 18 anatomical points (Type I landmarks) from 528 individuals were digitized; shape variation was then quantified with principal component analysis and visualized with thin-plate splines derived from a Procrustes analysis. Models of shape variation (i.e. taxonomy versus geography) were tested with a multivariate analysis of variance and a morphological distance matrix. Phylogeographic relationships were examined with a haplotype network (N = 115) derived from 1140 base pairs of the mitochondrial DNA cytochrome b gene, and selected GenBank sequences (N = 5). Koshi River snowtrout diverged morphologically from conspecifics, consistent with the phylogeographic data. In contrast, Gandaki and Karnali River snowtrout grouped by morphotype (up- versus downstream) irrespective of geographic origin, yet clustered separately within the haplotype network. Lake Rara snowtrout were morphologically but not genetically distinct, due to incomplete lineage sorting. Morphological and genetic variability in Schizothorax from Nepal represent a mosaic driven by isolation (= vicariance) and specialization (= adaptation), with taxonomy insufficiently reflecting diversity. Additional data are required to appropriately derive management and effective conservation plans.https://www.int-res.com/abstracts/ab/v30/p19-31/
spellingShingle B Regmi
MR Douglas
DR Edds
ME Douglas
Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
Aquatic Biology
title Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
title_full Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
title_fullStr Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
title_full_unstemmed Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
title_short Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal
title_sort geometric morphometric analyses define riverine and lacustrine species flocks of himalayan snowtrout cyprinidae schizothorax in nepal
url https://www.int-res.com/abstracts/ab/v30/p19-31/
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