Triakidae

Triakidae is a family of sharks belonging to the order Carcharhiniformes. Commonly known as houndsharks, these sharks are characterized by their slender bodies, two dorsal fins with spines, and a distinctive anal fin. They are widely distributed in coastal waters worldwide, inhabiting a variety of habitats including reefs, sand flats, and seagrass beds. Triakidae is a diverse family comprising over 40 species, ranging in size from the diminutive dwarf smooth-hound (Triakis megalopterus) at just 60 cm in length to the impressive 3-meter-long smooth-hound (Mustelus mustelus).

Common Names

The family Triakidae is commonly referred to as houndsharks, although individual species may have other vernacular names. For example, the genus Mustelus is sometimes called "smooth-hounds" or "dogfish sharks", while the genus Triakis is often referred to as "leopard sharks" or "catsharks" due to their spotted patterns.

Characteristics

Triakidae sharks share several key characteristics:

  • Slender body: They have a streamlined, elongated body shape.
  • Two dorsal fins with spines: Their first dorsal fin has a sharp spine, while the second dorsal fin is smaller and lacks a spine.
  • Anal fin: They possess a well-developed anal fin located between the second dorsal fin and the caudal fin.
  • Five gill slits: Their gill slits are located on the sides of the head, behind the eyes.
  • Two nostrils: Their nostrils are located on the snout, below the eyes.
  • Teeth: Their teeth are small, numerous, and often serrated, designed for crushing and tearing prey.
  • Coloration: Their color patterns vary by species, ranging from brown and grey to yellow and white, with many species exhibiting spots or stripes.

Environments

Houndsharks are found in coastal waters around the globe, inhabiting a wide range of environments:

  • Reefs: Some species, such as the leopard shark (Triakis semifasciata), prefer rocky reefs and coral reefs.
  • Sand flats: Others, like the smooth-hound (Mustelus mustelus), are more common on sandy bottoms and mudflats.
  • Seagrass beds: Many species inhabit seagrass beds, where they feed on small invertebrates and fish.

References

For further information on Triakidae, refer to the following reliable sources: