Spiny dogfish (Squalus acanthias)

IUCN Red List Status: Vulnerable

Small bodied sharks, reaching sizes up to about 3.5 feet, but reported up to 5 feet

Spiny dogfish have a spine on the leading edge of each dorsal fin, and white spots along their flank

Often found associated with the bottom of the ocean and swimming in large schools, segregated by size and sex

There is little mixing between different populations, but it does occur

Spinys are ovoviviparous, which means the pups develop in the mother’s uterus, and are nourished from egg sacks

These sharks don't have typical shark teeth, they have flat tooth pallets that facilitate crunching through invertebrate shells when feeding

Pups develop throughout a gestation period of 18-22 months, which is among the longest for any animal

Spiny dogfish eat various small fishes and invertebrates

This species reaches maturity late in life, produces few young, and often many pregnant females can be caught in fishing gear at the same time due to aggregating behavior; taken together, these characteristics make this species particularly vulnerable to overfishing