Asymbolus

Asymbolus is a genus of catsharks in the family Scyliorhinidae, commonly known as swellsharks. These sharks are characterized by their plump bodies, relatively short snouts, and distinctive dermal denticles. They are distributed throughout the temperate and tropical waters of the Indo-Pacific region.

Grey spotted catshark – Asymbolus analis

Characteristics

Asymbolus species typically have a robust, fusiform body shape, with a blunt snout and small, widely spaced eyes. Their coloration ranges from pale brown to dark gray, often with darker blotches or saddles. They possess two dorsal fins, both of which are located well back on the body. The first dorsal fin is typically larger than the second, and both are often rounded. The anal fin is positioned close to the caudal fin, which has a distinct lower lobe.

One of the most notable features of Asymbolus is the presence of dermal denticles, which are small, tooth-like scales that cover the body. These denticles are often arranged in rows and can be quite sharp, providing some protection against predators. Another interesting adaptation is the ability of some species to inflate themselves with water, making them appear larger and more intimidating to potential threats.

Environment

Swellsharks are predominantly found in shallow, coastal waters, typically inhabiting rocky reefs, seagrass beds, and sandy bottoms. They are generally nocturnal, spending the day resting in crevices or under ledges. At night, they emerge to hunt for prey, primarily crustaceans, mollusks, and small fish. They are solitary animals and rarely form aggregations.

Species

There are currently 12 recognized species within the genus Asymbolus, each with its own unique characteristics and distribution:

  • Asymbolus analis
  • Asymbolus anguineus
  • Asymbolus bucculentus
  • Asymbolus coatesi
  • Asymbolus crassispinus
  • Asymbolus dentatus
  • Asymbolus earskinae
  • Asymbolus flavus
  • Asymbolus macleayi
  • Asymbolus micropunctatus
  • Asymbolus pallidus
  • Asymbolus vincenti

References

For further information on Asymbolus, consult these reputable sources: