Ginglymostomatidae
The Ginglymostomatidae is a family of sharks in the order Orectolobiformes. They are commonly known as nurse sharks, a name derived from their habit of resting on the seafloor, seemingly “nursing” their young. Ginglymostomatidae sharks are found in tropical and subtropical waters around the world, inhabiting shallow coastal areas, coral reefs, and seagrass beds. They are characterized by their robust, streamlined bodies, flattened heads, and large, prominent spiracles.
Characteristics
Ginglymostomatidae sharks possess a unique combination of features that distinguish them from other shark families:
- Large, prominent spiracles: These openings behind the eyes allow the sharks to breathe while resting on the bottom.
- Two dorsal fins: The first dorsal fin is positioned far back on the body, and the second dorsal fin is smaller and placed close to the tail fin.
- Small, widely spaced eyes: The eyes are positioned on the top of the head, allowing for a wide field of vision.
- Long, whip-like tail: The tail provides power for swimming and maneuvering.
- Five gill slits: These slits are located on the sides of the head and allow for efficient respiration.
- Small, tooth-like scales: These scales provide protection and reduce drag in the water.
Environments
Ginglymostomatidae sharks are primarily bottom-dwelling fish that prefer shallow, coastal waters. They are often found in:
- Coral reefs: The intricate structures of coral reefs provide a variety of habitats for nurse sharks, offering shelter, food, and breeding grounds.
- Seagrass beds: Seagrass meadows provide a rich source of food and camouflage for nurse sharks, allowing them to ambush prey.
- Mangrove forests: These coastal ecosystems provide a nursery habitat for young nurse sharks, offering protection and access to food.
Diet
Ginglymostomatidae sharks are primarily nocturnal predators, feeding mainly on invertebrates, including crabs, lobsters, and shrimp. They also feed on fish and other small marine animals. They have a unique feeding strategy, using their strong jaws and teeth to crush prey.
Reproduction
Ginglymostomatidae sharks are ovoviviparous, meaning they give birth to live young after an extended gestation period. The embryos develop inside eggs that are retained within the mother's body. Once born, the young nurse sharks are relatively independent and capable of hunting their own food.
References
FishBase: Family Ginglymostomatidae