Wrap Up on Sharks

Classification of Sharks

Spiny Dogfish

Spiny Dogfish Shark, Squalus acanthias Other Names: cape dogfish, spring dogfish, spiked dogfish, spur dog Life History Average lifespan: years Maturity: Males, 6 years Females, 11 years They have the longest gestation period of any vertebrate, which is about months Females have between 2-12 eggs and an average of six pups, per spawning season Females are larger in body size than males  sexual dimorphism

Dogfish cont’d. Feeding Opportunistic feeders: crustaceans, jellyfish, squid, schooling fish (such as mackerel and herring) Preyed upon by cod, red hake, goosefish, other dogfish, larger sharks, seals, and orcas Habitat/Range Distributed throughout the North Atlantic and North Pacific, occurring from Cape Hatteras (Maine) and can be found as far south as Florida Migrate north in the spring and summer, and south in fall and winter Travel in schools

More Dogfish Facts: Most common and frequently studied shark in the world Can migrate more than 5,000 miles  Equivalent to flying from NY to CA round trip!

Other Species of Sharks We Should Know About Great White Shark, Carcharodon carcharias

Life History: Average lifespan is unknown  predicted to be up to 100 yrs. however, this is not yet proven 5,000+ lbs. and ft. long  7,000 lbs. and 23 ft. long (largest on record) Pups can be over 5 ft. long at birth  aplacental viviparity Population status is vulnerable No reliable data on these sharks Great White Shark cont’d.

Feeding: Largest predatory fish on Earth  up to 3,000 teeth at once Feed on seals, sea lions, small toothed whales, and sometimes sea turtles  apex predators on the food web Don’t chew their food  meals can sustain them for 2 months long Habitat/Range: Cosmopolitan range distribution  temperate coastlines around the world, but are also pelagic Can swim up to 15 miles per hr  very migratory Solitary but occasionally travel in pairs Protected on coasts of US, Australia, and South Africa

Other Shark Species, cont’d. Hammerhead Shark, Sphyrna mokarran

Hammerhead Shark cont’d. Life History Average life span: years 500-1,000 lbs. and ft. long Viviparity  one litter can range from about 6-50 pups Mother immediately separates from young  good percentage survive

Feeding: Mostly stingrays, but also bony fishes, crabs, lobsters, and squid Solitary hunters  may be seen in groups in the daytime, but not at night Uses its head shape to pin down stingrays Predators: great whites, tiger sharks, orcas Habitat/Range: Cosmopolitan Distribution Warm, temperate waters  coastal and along continental shelf Population status: Vulnerable

Other Shark Species, cont’d. Whale Shark, Rhincodon typus

Whale Shark cont’d. Life History: Estimated lifespan: years Largest fish in the ocean  20.6 tons and ft long (40 ft. is the largest on record) Females larger than males Viviparity  up to hundreds of pups, each about 2 ft. long Sexual maturity is 30 years old

Feeding: Have 3,000 teeth but are filter feeders  plankton, krill small fish, squid They have gill rakers  similar to baleen that some whales have Can process over 1,500 gallons of water per hour Habitat/Range: Found worldwide along the warm waters of the equator Coastal and pelagic  spend most time near the surface Average speed is 3 miles per hr Solitary

What’s With the Remora?

The remora is a symbiotic “sucker fish” that attaches itself to sharks with a disc that was modified from the dorsal fin. They are harmless to sharks, and may attach to whales and marine mammals. They eat parasites off the shark and any leftover food from the shark Keeps the sharks clean, while they can travel, coexist, and feed all at the same time!