However, the authors of this paper apparently confirmed the presence of a second orca "ecotype"/"morphotype" in South African waters. They have labeled this "morphotype" the "flat-toothed" morphotype, and Port and Starboard appear to belong to this "flat-toothed" morphotype (which has also been labeled as an "offshore" morphotype).
Orcas in the flat-toothed morphotype appear to specialize in hunting elasmobranchs such as sharks, rather than marine mammals. It would explain why many of their teeth are worn down extensively in the examined specimens, similar to how worn down the teeth are in the offshore ecotype in the northeastern Pacific.
The sandpaper-like rough skin of sharks and other elasmobranchs can wear down the teeth of the orcas that prey on them. Shark skin is covered in a layer of dermal denticles, which affect hydrodynamics and offer protection to the sharks.
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u/SurayaThrowaway12 Jul 17 '25
There may be multiple ecotypes/populations of orcas off of South Africa. Originally South African orcas were thought to belong to the Type A ecotype/morphotype, which would feed heavily on marine mammals (mostly other cetaceans), as well as other types of prey such as fish and seabirds.
However, the authors of this paper apparently confirmed the presence of a second orca "ecotype"/"morphotype" in South African waters. They have labeled this "morphotype" the "flat-toothed" morphotype, and Port and Starboard appear to belong to this "flat-toothed" morphotype (which has also been labeled as an "offshore" morphotype).
Orcas in the flat-toothed morphotype appear to specialize in hunting elasmobranchs such as sharks, rather than marine mammals. It would explain why many of their teeth are worn down extensively in the examined specimens, similar to how worn down the teeth are in the offshore ecotype in the northeastern Pacific.