Starry Smooth-hound (Mustelus asterias)

• Colour; grey or grey-brown above, light below.

• White spots usually present on dorsal side and along lateral line.

• Second dorsal fin slightly smaller than first

• Flattened crushing type teeth

Common Smooth-hound (Mustelus mustelus)

• Colour; uniform grey or grey-brown above, light below

• No white spots

• Second dorsal fin slightly smaller that first

• Flattened crushing type teeth

Smooth Hound Identification

The ‘Stars’

The differences between starry and common smooth-hounds are sometimes difficult to interpret because

the ‘stars’ of starry smooth-hounds vary greatly in appearance and may be vivid and definite, faint and

sometimes even absent. This results in the misidentification of starry smooth-hounds as common

smooth-hounds which lack any of these white spot.

The variation of white spots on starry smooth-

hounds. (A) vivid spots (B) faint spots (C) no

spots.

A B

C

How to determine the sex of a smooth-hound

Smooth-hounds like all sharks occur as either male or female. Female sharks have no obvious external

reproductive structures, whilst males have two extensions of the pelvic fin known as claspers. These

claspers are used by males during reproduction to internally fertilise the female sharks.

In juvenile sharks the claspers are small, soft and flexible and do not usually extend beyond the end of

the pelvic fin. As the male matures the claspers grow longer and become more rigid as they are hardened

with calcium. The end of the clasper also develops a distinct ‘bump’, which is due to the development of

the internal cartilage structure. At certain times of the year when males are in an active mating state the

claspers may appear reddened and sperm may flow when the area around the clasper is pressed.

Left: The pelvic fins of a

female smooth-hound.

Right: The pelvic fins and

claspers of a mature adult

male smooth-hound.

Male

Female

Above: Smooth-hounds have small overlapping crushing teeth. Above: Tope have sharp, well developed teeth for eating fish.

Below: A smooth-hound tail has a shallow notch and a small lower lobe Below: A tope tail has a deep well-developed notch and a large lower lobe

Sometimes small pup tope may be confused for smooth-hounds. The following pictures illustrate two key features that may be

used to accurately distinguish these species.