[en] A new Western North Atlantic Ocean species of kitefin shark, Mollisquama mississippiensis sp.
nov., was captured during a NOAA/NMFS midwater trawling survey to assess predator/prey
trophodynamics for sperm whales (Physeter microcephalus). The new species designation is based
on five diagnostic features not found on the only other known pocket shark specimen -
Mollisquama parini Dolganov that was captured in the eastern South Pacific Ocean. Diagnostic
features include a putative pit organ, photophores irregularly distributed along many areas of the
body, 16 distinct ventral-abdominal photophore aggregations, and two differences associated with
the dentition. Other potential diagnostic features are 10 fewer vertebrae than Mollisquama parini
and six morphometric proportional differences that exceeded +/- 20%. The unique pocket gland
that produces and expels luminous fluid was examined with high-resolution synchrotron scans and
by histological analysis.
