Phylogeny and speciation of the eastern Asian cyprinid genus Sarcocheilichthys

Abstract

The genus Sarcocheilichthys is a group of small cyprinid fishes comprising 10 species/sub‐species widely distributed in East Asia, which represents a valuable model for understanding the speciation of freshwater fishes in East Asia. In the present study, the molecular phylogenetic relationship of the genus Sarcocheilichthys was investigated using a 1140 bp section of the mitochondrial cytochrome b gene. Two different tree‐building methods, maximum parsimony (MP) and Bayesian methods, yielded trees with almost the same topology, yielding high bootstrap values or posterior probabilities. The results showed that the genus Sarcocheilichthys consists of two large clades, clades I and II. Clade I contains Sarcocheilichthys lacustris, Sarcocheilichthys sinensis and Sarcocheilichthys parvus, with S. parvus at a basal position. In clade II, Sarcocheilichthys variegatus microoculus is at a basal position; samples of the widespread species, Sarcocheilichthys nigripinnis, form a large subclade containing another valid species Sarcocheilichthys czerskii. Sarcocheilichthys kiangsiensis is retained at an intermediate position. Since S. czerskii is a valid species in the S. nigripinnis clade, remaining samples of S. nigripinnis form a paraphyly. This speciation process is attributed to geographical isolation and special environmental conditions experienced by S. czerskii and stable environments experienced by the other S. nigripinnis populations. This type of speciation process was suggested to be very common. Samples of Sarcocheilichthys sinensis sinensis and Sarcocheilichthys sinensis fukiensis that did not form their own monophyletic groups suggest an early stage of speciation and support their sub‐species status. Molecular clock analysis indicates that the two major lineages of the genus Sarcocheilichthys, clades I and II diverged c. 8·89 million years ago (mya). Sarcocheilichthys v. microoculus from Japan probably diverged 4·78 mya from the Chinese group. The northern–southern clades of S. nigripinnis began to diverge c. 2·12 mya, while one lineage of S. nigripinnis evolved into a new species, S. czerski, c. 0·34 mya.

Phylogeny of the gudgeons (Teleostei: Cyprinidae: Gobioninae)

“…Without examining Rhinogobio nasutus (type species of Megagobio), we are unable to comment on its status as a distinct genus as proposed by Naseka (1996), a decision that later workers reversed, returning Megagobio to the synonymy of Rhinogobio (Bȃnȃrescu, 1997;Yue et al, 1998). The relationships within Sarcocheilichthys match the pattern of relationships found by Zhang et al (2008), in the areas where this study and that one overlapped in taxon sampling.…”

Estimated evolutionary tempo of East Asian gobionid fishes (Teleostei: Cyprinidae) from mitochondrial DNA sequence data

“…Two other cyprinid fishes, Leuciscus leuciscus and L. waleckii, were used as outgroups. The analyzed sequences were downloaded from GenBank, were published our previous studies [24,25], or were newly sequenced. Detailed sample information is shown in Table 1.…”

“…This test rejected the null hypothesis of rate constancy (χ 2 = 343.6028, df = 59, P <0.01). a) Sequence downloaded from GenBank; b) sequence cited from Yang et al [24]; c) sequence cited from Zhang et al [25], and other sequences are original to this study.…”

Molecular phylogenetic relationships of pangasiid and schilbid catfishes in Thailand

“…was discovered at Ban Nong Pla in Phetchabun Province (Roberts & Jumnongthai, 1999). The molecular clock estimates in accordance with vicariant events should provide further information on the causes of diversification in these catfishes (Zhang et al , 2008). As revealed by several studies, the estimation of divergence times of fish families such as Cichlidae (Martin & Bermingham, 1998), Cyprinidae (He & Chen, 2006), Channidae (Li et al , 2006) and Siluridae (Peng et al , 2006) offers the potential to provide a link between the geological evolution and the evolutionary history of taxa for the appreciation of their patterns of diversification and distributions.…”