Biodiversity

Thursday, March 22, 2007

SOUTH AFRICA SHARKBASE: INTERACTIVE KEY

Key to the 12 common sharks found around the South African Coast

Characters: 41 in data, 23 included, 11 in key.
Items: 12 in data, 12 included, 12 in key.
Parameters: Rbase = 1.40 Abase = 2.00 Reuse = 1.01 Varywt = .80
Characters included: 3 8–12 17–26 29–31 36–38 41
Character reliabilities: 1–41,5.0

1(0).
  • Tooth shape Large triangular, serrated on both sides ... 2
  • Tooth shape Triangular, slanted and smooth... 3
  • Tooth shape Backward pointing, curved saw-edged... Galeocerdo cuvieri
  • Tooth shape Sharp, cusped and oblique... Triaenodon obesus
  • Tooth shape Small, pointed and tricuspid... 4
  • Tooth shape Numerous rows of fang-like teeth... Carcharias taurus
  • Tooth shape Narrow pointed cusps... 5
  • Tooth shape Plate-like... Callorhinchus capensis

2(1).
  • Colour Grey; Southern African distribution Port Elizabeth to Zambezi River; Freshwater tolerance Freshwater tolerate; Reproduction Live bearer (approximately eight to ten) ... Carcharhinus leucas
  • Colour Grey-blue; Southern African distribution Entire Southern African Coast; Freshwater tolerance Freshwater intolerant; Reproduction Live bearer (one to five)... Carcharodon carcharias

3(1).
  • Colour Dusky grey; Reproduction Live bearer (approximately eight to ten); Activity Both nocturnal and diurnal; Attack humans Rare incidents ... Carcharhinus obscurus
  • Colour Grey; Reproduction Live bearer (approximately 30); Activity Diurnal; Attack humans No, but can be traumatogenic... Sphyrna lewini

4(1).
  • Attack humans No, but can be traumatogenic; Snout Pointed; Population Status Fairly common; Capitivy Captive - poor breeding ... Poroderma africanum
  • Attack humans Harmless; Snout Rounded; Population Status Uncommon; Capitivy Captive breeding... Poroderma pantherinum

5(1).
  • Biogeography Temperate waters ... Haploblepharus edwardsii
  • Biogeography Cold waters... Haploblepharus pictus


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