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. The smooth teeth are located in rows which rotate into use as needed.
What are the characteristics of a dogfish shark?
Appearance
- Spiny dogfish are slim, with a narrow, pointed snout and characteristic white spots.
- They are gray above and white below.
- They have two dorsal fins with ungrooved large spines.
- Males grow up to 3.3 feet, and females grow up to 4 feet.
What is unique about the dogfish shark?
The spiny dogfish may go by many names, including piked dogfish, rock salmon and spiky dog, but only one truly represents this shark’s unique defense strategy. Using sharp, venomous spines in the front of each dorsal fin, the spiny dogfish is a small but mighty predator that isn’t afraid to take a jab at passing fish.
Why is the dogfish a good choice for study and dissection?
Look no further than the dogfish. Students enjoy dogfish dissection, and they remember and refer to the activity long after they perform it. The specimen’s many conspicuous and specialized organs make it ideal for studying structure and function.
What type of body shape does a dogfish have?
Biology. The spiny dogfish has a slender, elongate body and a moderately flattened head. The snout is narrow, tapering to a pointed tip. The eyes of this dogfish are moderately large.
How do you identify dogfish?
Distinguishing Characteristics
- Grayish-brown color on top, fading to lighter below.
- Small, slender shark with two spineless dorsal fins, the second slightly smaller than the first.
- Spiracles present.
- Caudal fin lower lobe rounded and much shorter than upper lobe.
- Upper lobe of caudal fin with deep notch at end.
What common feature is absent in the dogfish shark?
The anal fin is absent, as in all dogfish. The caudal fin is narrowly lobed and moderately long with a long ventral lobe.
Why dogfish is called true fish?
Dogfish belongs to class Chondrichthyes (super class Pisces). It’s important that True fishes are considered as members of super class Pisces and have a streamlined body with scales. Dogfish possess a cartilaginous skeleton. Dogfish is referred to as true fish, amongst Dogfish, Jellyfish, Starfish, and Silverfish.
How do dogfish sharks differ from other sharks?
This small, slender shark has elongated cat-like eyes, triangular fins, and an asymmetrical, notched caudal (tail) fin. Unlike most sharks, this dogfish has rows of flat grinding teeth rather than sharp blades, which are ideal for crushing and chewing the crustaceans and mollusks that it hunts.
Do dogfish have sharp teeth?
Their teeth are pavement-like, but with an extra set of small, very strong and very sharp teeth (often difficult to see).
What type of food would you guess the dogfish shark is best adapted to eating?
Dogfish are carnivorous or meat eaters. Their teeth are sharp and are inclined laterally in order to cut through their prey. The Pacific dogfish usually eat mollusks or crustaceans such as squid, krill, and shrimp.
Why is the dogfish important?
Their light, white meat found a strong market abroad, and today spiny dogfish is still one of the primary species used in British “fish and chips” and other European dishes. As a result, they are the top shark species caught in U.S. waters by volume and make up a major proportion of U.S. seafood exports.
Why is it important to study sharks?
Understanding sharks is crucial, and their importance to the health of our oceans is a major driving force for various conservation policies. Often persecuted for their false identity of ‘man-eating monsters’, they need us now more than ever to protect them and educate each other about their true nature.
What sensory organs do dogfish sharks have and what are their functions?
eyes, snout, and nostrils are the openings of the ampullae of Lorenzini. These sense organs are sensitive to changes in temperature, water pressure, electrical fields, and salinity.
Do dogfish sharks have brains?
The brain in encased in membranes called meninges. In dogfish there is only a single meninx, which holds cerebrospinal fluid between it and the brain. The cerebrospinal fluid also circulates within the cavities of the brain and spinal cord. In mudpuppies, there is an outer dura matter and an inner secondary meninx.
Do dogfish have bones?
Like all sharks, dogfish are elasmobranchs, which means they have cartilage instead of bone for a skeleton.
What does a dogfish shark feel like?
Spiny dogfish skin is rough and covered by a tooth-like, scaled surface called dermal denticles. The skin feels smooth when rubbed with the grain of the denticles, but feels rough when rubbed against the grain. Spiny dogfish are the most abundant and most commonly seen of all sharks in Narragansett Bay.
What is a dogfish called?
dogfish, (order Squaliformes), any of several small sharks making up an order of chondrichthyian fishes composed of the families Centrophoridae (gulper sharks), Dalatiidae, Echinorhinidae, Etmopteridae, Oxynotidae, Somniosidae, and Squalidae. In North America the name is also used for a freshwater fish, the bowfin.
How long can a dogfish live out of water?
They can survive out of water for 2-3 days. Their diet consists of anything that looks edible, but is mainly other fish. They prefer water bodies with heavy vegetation, but do inhabit clear water lakes.
What are the characteristics of a shark and what makes them unique?
Sharks do not have bones.
Sharks use their gills to filter oxygen from the water. They are a special type of fish known as “elasmobranchs”, which translates into fish made of cartilaginous tissues—the clear gristly stuff that your ears and nose tip are made of. This category also includes rays, sawfish, and skates.
What are the unique features of the sharks?
Most sharks have a muscular, asymmetrical, upturned tail; pointed fins; a pointed snout; and sharp triangular teeth. Sharks have no swim bladder and must swim perpetually to keep from sinking. Most species bear living young.