Bigeye sand tiger

It can be distinguished from the similar smalltooth sand tiger (O. ferox) by its teeth, which have only one lateral cusplet on each side, and by its uniformly dark brown color.

Inhabiting continental margins and oceanic waters at depths of 60–1,000 m (200–3,280 ft), the bigeye sand tiger may make vertical and horizontal migratory movements.

It feeds on bony fishes and squid, and its sizable eyes and dark coloration suggest that it may spend most of its time in the mesopelagic zone.

The first known bigeye sand tiger was a female 1.7 m (5.6 ft) long caught off Madeira in April 1941, on a longline set for black scabbardfish (Aphanopus carbo).

The specimen was mounted and later formed the basis for a scientific description authored by German ichthyologist Günther Maul in a 1955 article for Notulae Naturae.

[2] A 2012 molecular phylogenetic analysis, based on mitochondrial DNA, supported a sister species relationship between O. noronhai and O. ferox but not a clade consisting of Odontaspis and Carcharias.

[9] Though extremely rare, the bigeye sand tiger has been reported from scattered locations around the world, suggesting a wide and possibly disjunct global distribution in tropical and warm-temperate oceanic waters.

[4] The existence of this species in the Pacific Ocean was first suspected in 1970 from teeth recovered from bottom sediments, which was confirmed over a decade later by captures from the Marshall Islands and Hawaii.

In Brazilian waters, bigeye sand tigers are only captured in spring, hinting at some type of seasonal migratory movement.

[2] One account of a bigeye sand tiger that had been caught alive noted that it behaved very aggressively, thrashing and snapping violently in and out of the water.

[6] It is caught incidentally on longlines and in gillnets and purse seines, though the paucity of captures suggest that it mostly lives in waters too deep for commercial fisheries.

Head
The teeth differ in shape in the bigeye sand tiger and in other, similar species.
Lateral teeth
Central teeth