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

Carcharhiniformes subterminal mouth nictitating membrane

cat sharks NEAq 2010: coral, chain Carcharhiniformes Scyliorhinidae ~160 sp.

oviparous keratin egg case

1-2 m >20 y captivity large interspecific schools along Calif. coast ovoviviparous ~30 pups/litter Carcharhiniformes Triakidae ~40 sp. hound sharks Triakis semifasciata leopard shark

requiem sharks Carcharhiniformes Carcharhinidae Carcharhinus ~30 sp. ~no spiracles ~ram ventilators ~viviparity

black-tip reef Carcharhinus melanopterus 1.5 m interspecific schooling elaborate displays hierarchies

oceanic whitetip Carcharhinus longimanus pelagic scavenger at ship and plane wrecks

silky shark Carcharhinus falciformes with pilot jacks aggressive schools with tuna bycatch

grey reef shark Carcharhinus amblyrhynchoides ~25 years

black tip reef shark Carcharhinus melanopterus

blacktip shark Carcharhinus tilsoni inshore spinner

bull shark Carcharhinus leucas freshwater spinner 2-3 m length

also Mississippi, NA Zambezi, Africa Lake Nicaragua, CA Amazon River Valley freshwater ~2000 mile migration

lemon shark Negaprion brevirostris color vision mature 24 y life-span 30 y replace teeth ~ 8 days 3 m long Carcharhinidae low oxygen, salinity

fast-growing matures 4-6 y lives~12 y

long labial furrows

nocturnal solitary only ovoviviparous carcharhinid pups/litter

blue shark Prionace glauca widest ranging migratory > 6000 km/yr, 60 km/day speeds 30 km/h Carcharhinidae

no spiracles mating wounds female skin 3x thicker than male skin and teeth segregated schools aggressive ~13 ft ~20 y

threatened most heavily fished ~bycatch finned, discarded 50,000/yr off Hawaii 6 M/yr global

from Costa Rica

Traditional Chinese Medicine (TCM) IUU illegal, unregulated, unreported to Singapore

Carcharhiniformes Sphyrnidae hammerheads

stereoscopic detection triangulation manueverability

acute vision, chemical and electrical detection

~8 species winghead scoophead scalloped great hammerhead mallethead small eye bonnethead smooth

large schools near magnetic mounts bycatch high mortality

viviparity placental viviparity ~4 month gestation ~parthenogenesis

Carcharhiniformes subterminal mouth nictitating membrane

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