The Oxyrhynchus fish is a Nile perch that looks like a regular perch. Representations of the Oxyrhynchus fish typically have a dramatic horn that is not found in nature. The origins of this horn appear to be via indirect associations with Vishnu in the form of his second avatar (re-incarnation) as matsya, a horned fish. In Egypt, the Oxyrhynchus was associated with the Nile, the god Hapi and with the constellation Piscis Austrinus in astronomy. As a species of the Mormyrus fish it was associated with Set in his fish form in the town of Oxyrhnchus at Nome 19 in Upper Egypt. http://www.egyptsites.co.uk/middle/minya/bahnasa.html cf. http://www.ancientegyptonline.co.uk/nomesupper.html Shortfin Mako Isurus oxyrinchus newenglandsharks.com/shortfin.htm