Beyond Jaws: rediscovering the ‘lost sharks’ of southern Africa

Abstract

Southern Africa has one of the richest and most diverse chondrichthyan faunas in the world, comprising all 13 orders, 49 families, 111 genera and approximately 204 species. This represents nearly 20% of all known chondrichthyans, and includes 117 shark, 79 batoid and 8 chimaera species. A greater diversity of chondrichthyan species is seen on the east coast (n = 175) compared to the west coast (n = 96), especially among the families Carcharhinidae and Dasyatidae. The cumulative number of species added to the fauna has increased over the past 112 years from 28 to 204. A golden age of southern African chondrichthyan research occurred between 1967 and 1976 when 46 species were added to the fauna, 16 of which were newly described. A total of 5 families, 23 genera and 130 species have been described from southern Africa. Three families, 17 genera and 75 species are still considered valid. In all, 59 researchers have authored new species descriptions of southern African chondrichthyans, with 95 of 130 species being described by just 14 authors. The most new species described were by JLB Smith with 18, followed by J Müller and FGJ Henle, who collaborated to author 12 new species descriptions. A review of the conservation status of 189 chondrichthyan species indicates that 29% have been assessed as Vulnerable or higher (more threatened), a much higher percentage than the 17.4% of chondrichthyans globally. Of particular concern is that 13% are species endemic to southern Africa. Despite increased chondrichthyan awareness and popularity, most research and conservation efforts centre on a few charismatic species, while the future of little-known species remains ‘lost’ from the public and scientific consciousness.

Keywords: biodiversity, chondrichthyans, conservation, history, taxonomy