Biodiversity

Sunday, April 08, 2007

INTERACTIVE DELTA KEY ON THE SKATES (CHONDRICHTHYES)






Key 5a. Confirmatory characters

Characters: 20 in data, 12 included, 9 in key.
Items: 11
in data, 11 included, 11 in key.
Parameters: Rbase = 1.40 Abase =
2.00 Reuse = 1.01 Varywt = .80
Characters included: 1–2 4
7–10 14–15 17 19–20
Character reliabilities:
1–20,5.0

1(0).
  • Maximum number of
    interdorsal thorns 0 ... 2
  • Maximum number of
    interdorsal thorns 1... Bathyraja smithii

  • Maximum number of interdorsal thorns 8... Cruriraja
    parcomaculata

  • Maximum number of interdorsal thorns unknown... 3
  • Maximum number of interdorsal thorns 2... 4
  • Maximum number of interdorsal thorns 1... Raja
    lanceorostrata

  • Maximum number of interdorsal thorns 4... Cruriraja
    triangularis

2(1).

  • Snout shape obtuse; Scapular thorns 3 on each side; Ventral disc surface
    smooth; Thorns on tail present ... Raja radiata

  • Snout shape unknown; Scapular thorns unknown; Ventral disc surface with
    spinules; Thorns on tail unknown... Raja
    wallacei

3(1).

  • Snout shape rounded; Scapular thorns 1 on each side; Ventral disc surface
    smooth; First dorsal fin Continuous ... Neoraja stehmanni

  • Snout shape pointed; Scapular thorns unknown; Ventral disc surface with
    spinules; First dorsal fin Separate... Raja
    miraletus

4(1).

  • Maximum disc width:length ratio 1.4 times as broad as long; ventral base
    colour grey; IUCN status Data deficient ... Raja pullopunctata

  • Maximum disc width:length ratio 1.5 times as broad as long; ventral base
    colour white; IUCN status Endangered... Raja alba

  • Maximum disc width:length ratio 1.2 times as broad as long; ventral base
    colour brown; IUCN status Not on IUCN Red data list... Raja
    doutrei





























Cite this publication as:
‘My_Authors (2000 onwards). ‘My_Title: Descriptions, Illustrations,
Identification, and Information Retrieval. Version: 21st September 2000. http://My_URL’. Dallwitz (1980) and Dallwitz,
Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).

Index

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