Take a deep dive with this month’s creature feature – looking at the weird and wonderful Roughsharks. There are five species of Roughshark – all unmistakable due to their unusually large dorsal fins. The Roughshark family is known as the Oxynotidae.  

Roughsharks are small sharks, with two large sail-like dorsal fins which give them an unusual appearance. They also have broad, slightly flattened heads, with small thick lips. They have large to enormous spiracles close behind their eyes. 

Roughsharks are not targeted by fisheries, but being deep-sea sharks, they are sometimes caught as bycatch in deep-sea bottom fisheries. There is limited research into Roughsharks, due to their scattered distribution and their deep-sea habitat. Very little is known about their behaviour or biology. 

Caribbean Roughshark 

The Caribbean Roughshark, as the name suggests, live in the Caribbean. Its first dorsal fin leans forward. And it is light grey or brown in colour. With dark bands and blotches. The pectoral and pelvic fins are noticeably lighter in colour pattern.   

It isn’t targeted by fisheries but can be caught as bycatch by deep-sea fisheries. The species isn’t usually consumed by humans. Although it can be made fit for consumption. It is sometimes used as bait.

Roughsharks have unusual teeth. Their top jaws have spear-like upper teeth, forming a triangular pad. The bottom teeth are very compressed, with a saw-like cutting edge, of around 9-18 rows. The Caribbean Roughshark's feeding behaviours have not been observed. But it’s expected that they feed on bottom invertebrates and small fishes. Like the other Roughsharks, very little is known about their behaviour or ecology.

SCIENTIFIC NAME: Oxynotus caribbaeus 

FAMILY: Oxynotidae 

MAXIMUM SIZE: 150cm 

DIET:   Unknown – likely small fishes and invertebrate 

DISTRIBUTION:   West-Central Atlantic: Gulf of Mexico, Caribbean coast of Central America & Venezuela.

HABITAT:  218m – 579m. Over muddy and rocky outcrops and bottoms.  

CONSERVATION STATUS: 

Banner Image - Sailfin Roughshark © Citron / CC BY-SA 3.0 via Wikimedia Commons

Image - Caribbean Roughshark ©Nakedape13 via Wikimedia Commons