EVOLUTIONARY ICHTHYOLOGY Explorations in Systematic Biology 2003

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					Batoidea – Sawfishes, Skates and Rays: 4 suborders, 12 families, 62
       genera, 456 species (Figures 4, 5)
       A. Pavement-like crushing teeth
       B. Pectoral fins fused to head and trunk
       C. Eyes and spiracles on dorsal surface
       D. Dorso-ventrally flattened
       E. Anal fin absent
       F. Four subgroups within Batoidea:
               Pristoidei - Sawfishes
               Topedinoidei - Torpedos and electric rays
               Rajoidei - Skates and guitarfishes
               Myliobatoidei - Stingrays and allies
Pristioidei – Sawfish: 1 family, 2 genera, 6 species
        A. Pristidae – Sawfishes
                (1) blade-like snout with equal sized teeth
                (2) Pristis – 2 species in Western North Atlantic; to 18 ft.
Topedinoidei – Torpedos: 2 families, 11 genera, 38 species
      A. Generate electricity using modified gill muscles: electroplax
      B. Used to stun prey
      C. Sluggish, flabby fishes
      D. Torpedinidae – Electric Rays
              (1) Torpedo nobiliana – Atlantic Torpedo: to 1.8m TL
      E. Narcinidae – Lesser Electric Rays
              (1) Narcine brasiliensis – Lesser Electric Ray
Fig. 10.23
Fig. 10.22
Rajoidei –Skates and Guitarfishes: 3 families, 22 genera, 209 species
       A. Rajidae – Skates: 18++ genera, 200+ species
              (1) extremely flattened, disk-like fishes
              (2) 7 species of skates in our area, we treat three
              (3) Raja eglanteria – Clearnose Skate
              (4) Dipturus laevis – Barndoor Skate
              (5) Leucoraja erinacea – Little Skate
       B. Rhinobatidae – Guitarfishes: 7 genera, 45 species
              (1) triangular ray-like head, shark like trunk and tail
              (2) swim like sharks
              (3) sub-terminal mouth
              (4) Rhinobatos – 2 species in Western North Atlantic
       C. Rhinidae – Bowmouth Guitarfish: 1 genus
              (1) Rhina
Fig. 3.7
Myliobatoidei – Stingrays and allies
      A. Presence of a “sting” composed of one or two modified dorsal
              fin spines, serrated and barbed, with venom gland at base
      B. Viviparous
      C. Three subgroups within Myliobatoidei
               (1) Plesiobatoidea – Deepwater & six-gill stingrays
               (2) Dasyatoidea – Stingrays
               (3) Myliobatoidea – Eagle, cownose, devil & manta rays
Plesiobatoidea – Deepwater & six-gill stingrays
       A. Plesiobatis daviesi – Deepwater stingray
       B. Hexatrygon yangi – Six gill stingray
Dasyatoidea – Stingrays
       A. Dasyatidae – Stingrays: 9 genera, 70 species
               (1) Dasyatis americana – Southern Stingray, to 6 ft. diam.
                       Cayman Islands and Stingray City
               (2) Dasyatis say – Bluntnose Stingray
       B. Urolophididae – Round stingrays
               (1) Urobatis jamaicensis – Yellow Stingray
       B. Potamotrygonidae – Freshwater stingrays, South America
               (1) Potamotrygon motoro
       D. †Heliobatidae Freshwater Stingrays, Green River Formation
               (1) †Heliobatis radians
Myliobatoidea – Stingrays
      A. Gymnuridae – ButterflyRays
              (1) Gymnura altavela
      B. Myliobatidae – Eagle, cownose, devil & manta rays
              (1) Myliobatinae – Eagle Rays
                      a) Aetobatus narina – Spotted Eagle Ray
              (2) Rhinopterinae - Cownose Rays
                      a) Rhinoptera bonasus – Cownose Ray
              (3) Mobulinae - Devil and Manta Rays
                      a) Mobula mobular – Devil Ray
                      a) Manta birostris – Manta Ray
Fig. Focus 14.1

				
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