Phylogenetic position of rasborin cyprinids and monophyly of major lineages among the Danioninae, based on morphological characters (Cypriniformes: Cyprinidae)

Abstract

The cyprinid subfamily Danioninae is one of the most important fish groups due to its inclusion of the model fish, Danio rerio. Molecular investigations have shown that species traditionally placed in the Danioninae are non-monophyletic, divided into two groups corresponding to the Danioninae and Opsariichthyinae. The Danioninae are further divided into three lineages, i.e. chedrins, danionins and rasborins. However, morphological characters determining the foregoing groups are unknown. To investigate the interrelationships among major lineages within the Danioninae, a phylogenetic analysis based on 43 morphological characters from 34 taxa was conducted. Parsimony analysis recovers the Danioninae and Opsariichthyinae to be distinguished by the Y-shaped ligament, absent in the Danioninae while present in the Opsariichthyinae. The Danioninae are divided into two tribes, Danionini and Rasborini. The Rasborini, including Boraras, Brevibora, Horadandia, Kottelatia, Rasbora, Rasboroides, Rasbosoma, Trigonopoma and Trigonostigma, are diagnosed by presence of dark supra-anal pigment and subpeduncular streak as well as presence of the rasborin process on epibranchial 4. The Danionini are composed of two subtribes, Danionina and Chedrina, the Danionina including Chela, Danio, Devario, Microdevario and Microrasbora, and the Chedrina comprising Chelaethiops, Esomus, Luciosoma, Megarasbora, Mesobola, Nematabramis, Opsarius, Raiamas and Salmophasia. The Danionina are diagnosed by the unossified interhyal and presence of the danionin foramen in the horizontal limb of the cleithrum while the Chedrina are characterized by the postcleithrum absent or greatly reduced and approximately normal to abdominal ribs when present.

Resolving Cypriniformes relationships using an anchored enrichment approach

“…We obtain three major groups that have previously been resolved in the Danionidae based on both morphological and molecular evidence: Danioninae, Chedrinae, and Rasborinae [11, 19, 31, 34, 66, 67] Fig. 5.…”

“…The placement of Esomus has been contentious [67]. Esomus has been placed as closely related to Danionella or Sundadanio within Danioninae with poor support [19, 31, 66].…”

“…Because of poorly supported nodes, molecular phylogenies are ambiguous on the placement of Esomus among the clades of Danionidae. Liao et al [67] remark that Esomus has a long branch in molecular phylogenetic analyses, and this may attract this branch towards other long branches such as Danionella and Sundadanio . Using morphological characters, Liao et al [67] establish Esomus as sister to all other members of Chedrinae based on four characters, including two acquired states and two homoplasious states.…”

“…Liao et al [67] remark that Esomus has a long branch in molecular phylogenetic analyses, and this may attract this branch towards other long branches such as Danionella and Sundadanio . Using morphological characters, Liao et al [67] establish Esomus as sister to all other members of Chedrinae based on four characters, including two acquired states and two homoplasious states. In a subsequent paper, they admit this topology is never recovered in molecular analysis [68].…”

Evolution of the connection patterns of the cephalic lateral line canal system and its use to diagnose opsariichthyin cyprinid fishes (Teleostei, Cyprinidae)

“…The cyprinid tribe Opsariichthyini, of the subfamily Xenocypridinae (Liao et al 2011; Kottelat 2013), comprises the East Asian genera Opsariichthys Bleeker, 1863, Zacco Jordan & Evermann, 1902, Candidia Jordan & Richardson, 1909, Parazacco Chen, 1982, and Nipponocypris Chen, Wu & Hsu, 2008 (Wang et al 2007, Chen et al 2008, Kottelat 2013). The opsariichthyins comprise approximately 19 species (Kim et al 2005, Huynh and Chen 2013, Ito and Hosoya 2016).…”