NEW BIOGEOGRAPHIC DATA AND DNA BARCODES FOR THE INDIAN SWELLSHARK , CEPHALOSCYLLIUM SILASI ( TALWAR , 1974 ) ( ELASMOBRANCHII : CARCHARHINIFORMES : SCYLIORHINIDAE ) , FROM ANDAMAN WATERS

Abstract. Indian swellshark, Cephaloscyllium silasi (Talwar, 1974), is reported for the fi rst time in Andaman waters, India which is a considerable extension of its known distribution range with more than 1000 km toward eastern Indian EEZ. This is the fi rst confi rmed geographic distributional record of poorly known deep-water Indian swellshark, C. silasi, in the Andaman waters and fi rst outside its type locality. A detailed morphological description of C. silasi collected from Andaman waters and comparison with other known materials along with the molecular barcodes are provided.

The fi sh fauna of Indo-Pacifi c is one of the most diverse due to the zoogeographical importance of region (Randall 1998, Kimura et al. 2009, Hubert et al. 2012).Andaman Islands and surrounding waters in the Indian EEZ have a rich marine biodiversity that is largely unexplored.Rajan et al. (2012) reported 39 sharks from the waters around Andaman and Nicobar Islands of India.
Swellsharks of the genus Cephaloscyllium are very small to medium sized sharks, most of them having no commercial signifi cance due to its small size and abundance.They are known as swellsharks or balloon sharks because of their characteristic ability to infl ate/swell body by swallowing air or seawater to deter predation or when out of the water (Inoue andNakaya 2006, Schaaf-Da Silva andEbert 2008).Genus Cephaloscyllium Gill, 1862 currently contains 17 valid species (Weigmann 2016) of which the Indian swellshark, Cephaloscyllium silasi (Talwar, 1974), originally described from southeastern Arabian Sea as "Scyliorhinus (Halaelurus) silasi" is the only valid species of genus in Indian EEZ (Akhilesh et al. 2014a).
The knowledge on the elasmobranch diversity in the Indian EEZ is rather scarce.In a recent checklist Akhilesh et al. (2014b) suggested that approximately 160 species are known from Indian waters with several species requiring confi rmation of their taxonomic status.Bineesh et al. (2016) revealed the species composition of sharks and rays in the Indian commercial fi shery using DNA barcoding and 11 elasmobranch species were confi rmed fi rst records for Indian waters.
The present report of Cephaloscyllium silasi from the region is a new addition to shark fauna of Andaman waters.This paper present the fi rst report of Cephaloscyllium silasi with molecular confi rmation based on DNA barcoding of recently collected specimens from deep waters in Andaman waters which is a considerable extension from its known distribution range east coast of Indian EEZ.
Three specimens of Cephaloscyllium silasi were collected from the deep-sea shrimp trawler bycatch landings from Junglighat fi sh landing centre, Port Blair, Andamans, India.The deep-sea shrimp trawler operated off North Sentinel Island of Andaman and Nicobar Islands (Fig. 1) at a depth range of 150-300 m.Morphometric measurements were recorded following Compagno (2001).The specimens were identifi ed following (Talwar 1974, Compagno et al. 2005, Akhilesh et al. 2014a).Tissue samples collected were preserved in 95% ethanol and DNA was extracted by standard protocols (Miller et al. 1988).Partial sequence information of mitochondrial gene, Cytochrome c oxidase subunit I (COI) was generated (Ward et al. 2005) by bidirectional sequencing using ABI 3730 sequencer.The edited sequences of Cephaloscyllium silasi were submitted to the NCBI database (KU841524 and KU841525).Additional sequences of Cephaloscyllium spp.were downloaded from the NCBI database for analysis, which are follows EU398669-EU398676, HM909795, DQ108322, and GU440268.
Family SCYLIORHINIDAE Genus Cephaloscyllium Gill, 1862 Cephaloscyllium silasi (Talwar, 1974) Description of material from Andaman waters.Stout body and expanded belly (Figs.2-3).No labial furrows, anterior nasal fl aps broadly triangular.Head depressed, fl attened and broad, rounded in dorsal and ventrally, mouth large and arched.Proportional measurements in percentage of total length presented in Table 1.Colour.Seven dark brown bands dorsally over body, two comparatively small bands near pectoral fi ns; remaining dorsal part of body pale brown.Ventral portion pale.Caudal tip end with small dark brown band.Geographical distribution.Gulf of Aden (Manilo 1993) to Andaman waters.Many species from Andaman waters are recently been reported from southwest coast of India and vice versa suggesting a similar deep habitat in the region or a change in the current pattern.DNA barcoding results.The partial sequence of mitochondria COI gene produced a mean value of 655 nucleotide base pairs.Pair-wise genetic distance values (K2P) based on COI sequences using MEGA 6.1.Neighbour Joining (NJ) trees of Kimura two parameter (K2P) distances were created to provide a graphic representation of the patterning of divergences (Fig. 4).A comparison of the DNA barcode of present Andaman specimens shows a 99.2% match with Cephaloscyllium silasi from India (GenBank: KF899707-KF899711).Remarks.A detailed redescription with morphological data was presented from Arabian Sea, off Kollam (Kerala) south-west coast of India at a depth range of 250-500 m Akhilesh et al. (2014 a).Morphometric measurements of presently collected Cephaloscyllium silasi has been compared with that of Akhilesh et al. (2014a) for the species confi rmation and its comparison with earlier reports.Compagno et al. (2005) and Ebert et al. (2013) suggested a Cephaloscyllium similar to C. silasi occurs in Andaman waters, with the present morphometric comparisons and genetic results we suggest it is a considerable range extension of Cephaloscyllium silasi.the earlier version of manuscript.The Pondicherry University is acknowledged for providing the facilities.Thanks are also due to Rajiv Gandhi National fellowship (RGNF) for Ravi Ranjan Kumar.We also thanks to Mr. Balakrishna, Department of Disaster Management for designing the map.Thanks to fi shermen and merchants at Junglighat fi sh landing center, Andaman Islands for their kind support and cooperation.Pelvic fi n length 5 11.9 11.8 11.2 11.8 3.0 Pelvic fi n-anterior margin length 6.6 6.2 6.0 5.5 7.0 0.5 Pelvic fi n base length 5 8.9 8.0 7.5 9.1 1.6 Pelvic fi n height 5.6 5.4 6.0 3.6 4.2 1.0 Pelvic fi n-inner margin length -3.2 3.3 2.4 3.8 1.5 Pelvic fi n-posterior margin length 7.4 7.2 8.5 5.9 9.7 1.4 First dorsal fi n length 9.3 9.5 8.5 9.1 9.1 0.4 First dorsal fi n-anterior margin 10 10.3 9.3 9.5 10.0 0.4 First dorsal fi n base length 7.1 6.9 6.6 5.9 6.4 0.5 First dorsal fi n height 6 6.0 6.0 5.1 6.7 0.5 First dorsal fi n-inner margin 2.7 2.8 3.0 4.1 3.3 0.5 First dorsal fi n-posterior margin 4.8 4.8 4.1 5.5 4.8 0.5 Second dorsal fi n length 6.8 7.4 7.4 6.3 7.3 0.5 Second dorsal fi n-anterior margin 6.4 6.6 5.8 5.5 6.7 0.5 Second dorsal fi n base length 5.1 4.8 3.0 4.3 4.2 0.8 Second dorsal fi n height 3.7 3.4 2.7 3.2 3.6 0.4 Second dorsal fi n-inner margin 2.5 2.7 2.2 2.8 2.7 0.2 Second dorsal fi n-posterior margin 3.3 3.4 2.5 2.4 3.3 0.5 Anal fi n length 9.2 8.9 8.8 8.7 7.3 0.8 Anal fi n-anterior margin length 7.9 7.4 5.8 6.7 7.0 0.8 Anal fi n base length 6.7 5.8 6.3 6.3 5.8 0.4 Anal fi n height 3.8 3.8 2.5 2.8 3.3 0.6 Anal fi n-inner margin length 2.8 2.9 2.6 2.4 2.6 0.2 Anal fi n-posterior margin length 4.3 3.9 3.5 3. Caudal fi n-terminal lobe length 6.3 6.5 5.2 5.9 6.1 0.5

Table 1
Morphometric measurements (% TL) of Cephaloscyllium silasi from Andaman waters compared with known materials