Where is the spine on a dogfish?
Two large, sharp, mildly poisonous dorsal spines are located in front of each dorsal fin. The spiny dogfish uses its spines defensively by curling up its body and striking at an enemy.
How do you position your shark once you remove the dorsal spines?
How did you position your shark once you remove the dorsal spines? Once I removed the dorsal spines, I kept the shark in its original position (ventral side down, dorsal side up). In step 2, you made an incision from where to where? I made a mid-ventral incision from the cloaca cranially to just below the jaw.
Do dogfish have poisonous spines?
As their name suggests, spiny dogfish sharks sport sharp, venomous (poisonous) spines in front of each dorsal fin. Their bodies are dark gray above and white below, often with white spotting on the sides.
Where is the gallbladder located in a dogfish shark?
liver
The gall bladder is on the liver near the duodenum. The hepatic ducts and bile duct empties into the duodenum as in the shark, but may be difficult to see. The irregular pinkish mass of the pancreas lies on the hepato-duodenal ligament and is fused into one.
What common feature is absent in the dogfish shark?
There is no notch on the upper caudal lobe and the lower caudal lobe is not well-developed. There is no anal fin on the spiny dogfish.
Where are the dorsal spines located?
Thoracic spine is the central part of the spine, also called as dorsal spine, which runs from the base of the neck to the bottom of your rib cage.
What does the lateral line do on a dogfish shark?
The lateral line is responsible for alerting a shark to potential prey and predators. It’s made up of a row of small pores that run all the way from the snout to the tail. Surrounding water flows through these pores and special sensory cells sense any pressure changes.
Can dogfish harm you?
In general, the spiny dogfish poses little if any threat to humans. As the English common name “spiny dogfish” alludes to, this species has spines on the dorsal fins that can result in nasty wounds if not handled carefully.
Do sharks have a rectum?
The spiral valve intestine is an internally coiled organ that increases the surface area across which nutrients can be absorbed. The spiral valve intestine empties into the rectum and anus which in turn empties into the cloaca.
What is the largest internal organ in the dogfish?
Liver – The largest organ lying within the pleuroperitoneal cavity is the liver. Its two main lobes, the right and left lobes extend from the pectoral girdle posteriorly most of the length of the pleuroperitoneal cavity.
What is the fin on a shark’s back called?
caudal fin
The tail of a shark consists of the caudal peduncle and the caudal fin, which provide the main source of thrust for the shark. Most sharks have heterocercal caudal fins, meaning that the backbone extends into the (usually longer) upper lobe.
Do dogfish have bones?
Like all sharks, dogfish are elasmobranchs, which means they have cartilage instead of bone for a skeleton.
What does dogfish look like?
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.
Why are they called dogfish?
The common name “dogfish” originated from fishermen who described these fish as chasing smaller fish in large dog-like “packs”.
What does the pectoral fin do on a shark?
Pectoral fins originate behind the head and extend outwards. These fins are used for steering during swimming and help to provide the shark with lift. Pelvic fins are found near the claoca and are also stabilizers.