Thursday, October 6, 2016

[Ichthyology • 2016] Scomber indicus • A New Species of Mackerel (Scombridae: Scombrini) from Eastern Arabian Sea


Scomber indicus 
   Abdussamad, Sandhya & Arun, 2016
Indian Chub Mackerel  |  DOI: 10.21077/ijf.2016.63.3.59184-01 

ABSTRACT
Scomber indicus, a new species of mackerel is described based on the specimens collected from the eastern Arabian Sea. The species is differentiated from its nearest congener Scomber australasicus, in having 29-32 gill rakers on lower limb of first gill arch, posteriormost part of hypohyal blunt, with presence of a pit between the hypohyal and the ceratohyal and also in having a posteriorly directed haemal spine which is deeply curved in the basal region. Genetic differentiation and divergence between the newly described species and the 4 valid species of the genus Scomber viz., S. scombrus, S. japonicus, S. australasicus and S. colias were compared using cytochrome c oxidase 1 and cytochrome b gene sequences. The new species was found closest to S. colias followed by S. japonicus with Kimura 2 parameter (K2P) values of 1.4 and 1.8% respectively. In the phylogenetic tree, sequences of Scomber indicus sp. nov. formed a distinct well separated clade with significant bootstrap values as compared to the sequences of S. scombrus, S. japonicus, S. australasicus and S. colias indicating their distinctiveness and separate species status.

Keywords: Arabian Sea, Indian chub mackerel, New species, Scomber indicus




E. M. Abdussamad, Sandhya Sukumaran, Arun K. O. Ratheesh, K. Mohamed Koya, K. P. S. Koya, Prathibha Rohit, Sally Reader, K. V. Akhilesh and A. Gopalakrishnan. 2016. Scomber indicus, A New Species of Mackerel (Scombridae: Scombrini) from Eastern Arabian Sea. Indian J. Fish. 63(3); 1-10. DOI: 10.21077/ijf.2016.63.3.59184-01