Friday, April 28, 2017

[Entomology • 2017] Preliminary Molecular Phylogeny and Biogeography of the Monobasic Subfamily Calinaginae (Lepidoptera, Nymphalidae)

Figure 2. Bayesian phylogeny of Calinaga estimated in BEAST using concatenated data. Purple squares are calibration points (root: 75 ± 3; Satyrinae + Charaxinae 70 ± 3.5, Charaxes + Euxanthe 22 ± 1). Monophyly was enforced on nodes marked with orange squares. The inset map shows the biogeographic regions used in DIVA analysis: A) Southwestern China ecozone, B) Himalaya-Tibetan plateau region, C) Northern Sino-Himalaya, D) Southern Sino-Himalaya, E) Indochina. Colored dots correspond to haplogroups on the tree.

Calinaga (Moore 1857) is a rare and enigmatic Asian butterfly genus whose phylogenetic placement within Nymphalidae has only recently been established. The evolutionary history of Calinaga species however remains unknown. Here we explore the phylogeography of Calinaga using 1310 bp of sequence data from two molecular (mtDNA barcode and ribosomal protein S5 nuclear gene) and two morphological traits (genitalia and wing pattern). Within the proposed phylogenetic framework, we estimate the ages of divergence within the genus and reconstruct their historical biogeography. We found strong support for monophyly of Calinaga and support for the most recent accepted species in the genus. Our results indicate that the common ancestor of Calinaga first split in the Eocene (~43 million years ago) in southern China, probably as a consequence of geological and environmental impacts of the collision of the Indian and Asian subcontinents. In the Oligocene/Miocene, the extrusion of Indochina from the continent caused further dramatic orogenetic changes that promoted isolation and speciation events within the genus while Pleistocene climatic changes also influenced the distribution and further speciation. A dispersal–vicariance analysis suggests that vicariance events have played a far more important role than dispersal in the distribution of extant species.

Key Words: Calinaga, Calinaginae, Nymphalidae, mtDNA, butterfly, Indochina, Oligocene

Figure 1. (A) Approximate geographic distributions (Shirôzu 1960, Lang 2012) and sampling localities (circles) for the species of Calinaga included in this study (with the exception of the sample CBUD-INDIN for which we do not have an exact locality). Species as initially identified are highlighted and shown in different colours. Note that many of these initially attributed names subsequently proved erroneous. The map was obtained using Quantum GIS 2.8.2 based on a map from Natural Earth (
(B) Median-Joining Network of mtDNA. Circle size proportional to haplotype frequency; number of nucleotide substitutions indicated along connections, except for single or double substitutions. In both figures the species are highlighted and shown in different colours as initially identified. 

The genus Calinaga probably originated in the South-East Tibet in Eocene following the immense geological and environmental impact caused by the collision between Indian and Asian subcontinents. The extrusion of Indochina from the continent during the Oligocene/Miocene further prompted dramatic orogenetic changes that promoted isolation and speciation events in the genus. More recently, in the Pleistocene, climatic changes further modified the distribution of species and probably facilitated vicariant speciation events.

Since we did not sample or sequence specimens from all of the available names under Calinaga, we cannot make any definitive statements about the number of valid species warranted to be recognized as such, although the existence of many superfluous names is evident. From the names of the genus and the species coined by early British lepidopterists including F. Moore, it is apparent that they drew inspiration from Hindu mythological characters. In Sanskrit, Nāga refers to mythical reptilian creatures found in Indian religions (Hinduism, Buddhism and Janism) who were often worshipped as deities. Among them, “Kaliya” (or Kalya, “Kalia-Naga”, Calinaga) was a particularly notorious and poisonous one living in Yamuna river in Vrindavan (Uttar Pradesh). After an encounter with Krishna, Kaliya surrendered and was sent to exile (Bhagavata Purana, 16:10). It seems that the modern taxonomy of Calinaga is in need of a Krishna to conquer these superfluous names and cleanse its taxonomy albeit after careful examination of the types and sequencing of additional material.

 Valentina Todisco, Vazrick Nazari and Paul D.N. Hebert. 2017. Preliminary Molecular Phylogeny and Biogeography of the Monobasic Subfamily Calinaginae (Lepidoptera, Nymphalidae). Zoosystematics and Evolution. 93(2); 255-264. DOI: 10.3897/zse.93.10744

Origins of an enigmatic genus of Asian butterflies carrying mythological names decoded

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