Week 3: B. Classes of Fishes Lamprey Chondrichthyes Osteichthyes

Chondrichthyes ~1000 species sharks rays chimaeras Holocephali Elasmobranchii

shark body shape pectoral fin gill placement anal fin ray Elasmobranchs

Sharks ~400 species

5th superorder

Sharks Galea (with anal fin) ~280 species Squalea (mostly no anal fin) ~120 species

Week 3 sharks... Orectolobiformes ~33 sp with terminal mouth Lamniformes ~15 sp. with subterminal mouth Carcharhiniformes ~ 225 sp with subterminal mouth and nictitating eyelid

Lamniformes subterminal mouth

sand tiger shark Lamniformes Odontaspidae Carcharias taurus ~10 ft

sand tiger shark replaces teeth ~2 days

swallows air for buoyancy

cannabalistic viviparity predatory embryo 9-12 mo gestation alt. years, 1/uterus

social schooling migratory

South Korean Aquarium

white shark aka great white shark > 20 ft, ~2 tons Lamniformes Lamnidae Carcharodon carcharius

large range endothermic

ovoviviparity embryo feeds on eggs 12 mo gestation 2-3 yr intervals

largest teeth >2 in

Rodney Fox, 1963, Australia

anti-shark device

seals sea lions

protected in California waters since countries in 2010 no ESA coverage depleted

up to 33 ft (10 m) basking shark Lamniformes Cetorhinidae Cetorhinus maximus

filtering plates=modified placoid scales replaced annually ovoviviparous 3.5 y gestation

5 m long with mouth > 1 m wide bioluminescent First captured 1976, described 1983, 24 specimens by 2004 commonly attacked by Isistius, cookie-cutter shark megamouth shark Lamniformes Megachasmidae Megachasma pelagios

goblin sharks bubblegum color deep sea to 1300m Atlantic, Pacific electrosensory snout highly protrusible jaws ~4 m Lamniformes Mitsukurinidae Mitsukurina owstoni

Lamniformes subterminal mouth

Week 3 sharks... Orectolobiformes ~33 sp with terminal mouth Lamniformes ~ 15 sp. with subterminal mouth Carcharhiniformes ~ 225 sp with subterminal mouth and nictitating eyelid