Introduction
The Arabian Sea with its unique ecological
features such as position between two land masses,
presence of islands, features like oxygen minimum
zone (OMZ), circulation pattern, currents, influence
of monsoon and high saline water intrusion from
Persian Gulf and Red Sea etc. supports a very diverse
ichthyofauna. Reports on the diversity of deep-sea
fish fauna especially that on deep-sea
chondrichthyans from Indian waters are very few.
Raje et al. (2007) listed 47 species of sharks in
commercial landings along the Indian coast mainly
from catches made within 100 m depths. However
elasmobranchs are also known from deeper waters
and probably many species, which are not yet
recorded, occur in the unexploited/underexploited
deep waters of the Indian EEZ.
The targeted deep-sea shark fishery in Indian
waters, especially along the southwest and southeast
coasts of India started lately after 2002 by the
multiday shark fishermen of Thoothoor (Tamilnadu).
The fishery targets gulper sharks (Centrophoridae)
but many other deep-sea chondrichthyans occur as
by catch, which were dominated by bramble shark,
Echinorhinus brucus and chimaera, Neoharriotta
pinnata besides several small sized deep-sea sharks,
skates and rays which are often discarded. Cochin