Sharks and Fish

 

Waleshark

Sharks have a lightweight skeleton made of cartilage.
This makes them different from most other fish in the sea.
Which other animals belong, like sharks, to the cartilaginous animals?

 Rays
 Jellyfish
 Giant kraken

Sharks were around long before dinosaurs, true or false?

 True!
 False!

How many types of sharks are currently (in 2010) known to science?

 350 types
 530 types
 620 types


 

SYSTEMATIC

The old conception

In all previous books, shark systematics have 530 shark species that can be classified in 8 orders and 34 families. The order of carcharhiniformes (ground sharks) with 8 families, 48 genera and about 260 species is the largest by far. Rays are classified as a separate sister system.





The families

  • Hexanchiformes (grey sharks)
    • Chlamydoselachidae (frilled sharks)
    • Hexanchidae (grey sharks, cow sharks)


  • Squatiniformes (angel sharks)
    • Squatinidae (angel sharks)


  • Pristiophoriformes (saw sharks)
    • Pristiophoridae (saw sharks)


  • Squaliformes (sleeper sharks)
    • Echinorhinidae (bramble sharks)
    • Squalidae (spiny dogfish)
    • Centrophoridae (gulper sharks)
    • Etmopteridae (lantern sharks)
    • Somniosidae (sleeper sharks)
    • Oxynotinae (rough sharks)
    • Dalatiidae (kitefin sharks)


  • Lamniformes (mackerel sharks)
    • Odontaspididae (raggedtooths)
    • Pseudocarchariidae (crocodile sharks)
    • Mitsukurinidae (goblin sharks)
    • Megachasmidae (megamouth sharks)
    • Alopiidae (thresher sharks)
    • Cetorhinidae
    • Lamnidae (mackerel sharks)


  • Carcharhiniformes (ground sharks)
    • Scyliorhinidae (cat sharks)
    • Proscylliidae (finback cat sharks)
    • Pseudotriakidae (false cat sharks)
    • Leptochariidae (barbeled houndshark)
    • Triakidae (hound sharks)
    • Hemigaleidae (weasel sharks)
    • Carcharhinidae (requiem sharks)
    • Sphyrnidae (hammerhead sharks)


  • Orectolobiformes (nurse sharks)
    • Parascyllidae (collared carpet sharks)
    • Brachaeluridae (blind sharks)
    • Orectolobidae (carpet sharks)
    • Hemiscylliidae (bamboo sharks)
    • Ginglymostomatidae (nurse sharks)
    • Stegostomatidae (zebra sharks)
    • Rhincodontidae (whale sharks)


  • Heterodontiformes (bullhead sharks)
    • Heterodontidae (bullhead sharks)


  • Hexanchiformes (grey sharks)
    • Chlamydoselachidae (frilled sharks)
    • Hexanchidae (grey sharks, cow sharks)




Die Tabelle macht deutlich, wie man mit etwas Übung und Erfahrung die Artbestimmung aber auch durch reine anatomische Vergleiche vornehmen kann. Zur Klärung der Verwandtschaft werden die anatomischen Ähnlichkeiten durch genetische Proben ergänzt.


Graphic: Ch.Staacks