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SPINY DOGFISH
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The spiny dogfish shark is the most abundant shark. This small shark is also
known as the piked dogfish, skittledog, spotted dogfish, white-spotted dogfish,
codshark, and thorndog. Its dorsal fin has spines that are mildly poisonous.
More is known about it than any other species of shark; it is often studied in
scientific laboratories. It is used extensively by people as food, fertilizer,
hide, pet food, and liver oil.
GENERAL DESCRIPTION
The spiny dogfish shark is a small shark that is deep gray with some white
spots; the belly is off-white. It had two dorsal fins, each preceded by a mildly
poisonous spin. It has a short snout, large eyes and no anal fin.
TEETH
The smooth teeth are located in rows which rotate into use as needed. The first
two rows are used in obtaining prey, the other rows rotate into place as they
are needed. As teeth are lost, broken, or worn down, they are replaced by new
teeth that rotate into place.
SIZE
Spiny dogfish sharks average
3-4 feet (0.9-1.2 m) long.
DIET AND FEEDING HABITS
It eats mostly fish (including other sharks), but also eats squid and octopus.
SPINY DOGFISH SHARK ATTACKS
Dogfish are not considered to be dangerous, but some damage could be done by
their teeth and their slightly poisonous dorsal fin spines.
SOCIAL GROUPS
Spiny dogfish sharks are gregarious (social) and travel in schools of hundreds
to thousands of individuals. These schools are sometimes segregated by sex and
age. They are called dogfish because they travel and hunt in packs. They also
migrate in schools, following cool waters.
HABITAT
The spiny dogfish shark stays in water that is between 45°F - 59°F (7°C - 15°C).
It will venture into brackish waters. Dogfish are mostly bottom-dwellers,
dwelling in depths from the surface down to 400 fathoms (2,400 feet).
DISTRIBUTION
The spiny dogfish shark is found worldwide in temperate and subarctic waters, in
the temperate and subarctic latitudes of the North Atlantic and North Pacific
oceans. These sharks have even been found in the Black sea and Mediterranean
sea.
REPRODUCTION
The spiny dogfish shark reproduces via aplacental viviparity and bears live
young. About 2-11 pups are in each litter, these pups are between 8-12 inches
(20-30 cm) long. The gestation period is the longest of any vertebrate, about
18-24 months after a winter mating. This is longer than elephants or whales.
Male dogfish reach maturity at 11 years old; female dogfish reach maturity at
19-20 years old.
MIGRATION
Migrates to stay in water between 45°F - 59°F (7°C - 15°F).
LIFE SPAN
Estimates of the dogfish's life span range from 25-100 years.
POPULATION COUNT
The spiny dogfish shark is very abundant, the most common shark alive.
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