title: Molecular phylogeny of elasmobranchs inferred from mitochondrial and nuclear markers.
abstract: The elasmobranchs (sharks, rays and skates) being the extant survivors of one of the earliest offshoots of the vertebrate evolutionary tree are good model organisms to study the primitive vertebrate conditions. They play a significant role in maintaining the ecological balance and have high economic value. Due to over-exploitation and illegal fishing worldwide, the elasmobranch stocks are being decimated at an alarming rate. Appropriate management measures are necessary for restoring depleted elasmobranch stocks. One approach for restoring stocks is implementation of conservation measures and these measures can be formulated effectively by knowing the evolutionary relationship among the elasmobranchs. In this study, a total of 30 species were chosen for molecular phylogeny studies using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA gene and nuclear Internal Transcribed Spacer 2. Among different genes, the combined dataset of COI and 12S rRNA resulted in a well resolved tree topology with significant bootstrap/posterior probabilities values. The results supported the reciprocal monophyly of sharks and batoids. Within Galeomorphii, Heterodontiformes (bullhead sharks) formed as a sister group to Lamniformes (mackerel sharks): Orectolobiformes (carpet sharks) and to Carcharhiniformes (ground sharks). Within batoids, the Myliobatiformes formed a monophyly group while Pristiformes (sawfishes) and Rhinobatiformes (guitar fishes) formed a sister group to all other batoids.
authors.affiliation: Division of Fish Genetics and Biotechnology, Central Institute of Fisheries Education, Versova, Andheri West, Mumbai, 400061, India, pavanannam@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Pavan-Kumar
authors.forename: P
authors.initials: P
authors.lastname: Gireesh-Babu
authors.forename: P P Suresh
authors.initials: PP
authors.lastname: Babu
authors.forename: A K
authors.initials: AK
authors.lastname: Jaiswar
authors.forename: V
authors.initials: V
authors.lastname: Hari Krishna
authors.forename: K Pani
authors.initials: KP
authors.lastname: Prasasd
authors.forename: Aparna
authors.initials: A
authors.lastname: Chaudhari
authors.forename: S G
authors.initials: SG
authors.lastname: Raje
authors.forename: S K
authors.initials: SK
authors.lastname: Chakraborty
authors.forename: Gopal
authors.initials: G
authors.lastname: Krishna
authors.forename: W S
authors.initials: WS
authors.lastname: Lakra
mesh_terms: D000818:Animals; D001482:Base Composition; D001499:Bayes Theorem; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D018940:Elasmobranchii / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics; D050259:Genes, Mitochondrial; D005819:Genetic Markers; D016013:Likelihood Functions; D008957:Models, Genetic; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D021903:DNA, Ribosomal Spacer; D029941:Fish Proteins; D005819:Genetic Markers; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D003576:Electron Transport Complex IV