There is a bully full of bristle lurking among the rocks of the inshore. Fiercely territorial and utterly fearless, the tompot blenny will dash from cover to confront any interloper – even divers.
With a mouthful of needle-sharp teeth and antler-like growths on top of the head, the tompot is quite the adversary; perhaps it’s no bad thing that it grows no more than 30cm in length.
- 10 weird and spectacular sea creatures found in British waters
- "Fierce fight": diver films dramatic animal battle in Falmouth waters
Are there tompot blennies in the UK?
Worldwide, there are some 900 species in the sub-order Blennioidei, with around 10 that might be found in British waters. The largest, the tompot, is also one of the most common, particularly around the south and western coastline.
Familiar in the Mediterranean Sea, and the Atlantic coasts of Morrocco, Spain, France and Ireland, this is a species likely to increase around the eastern and northern coasts of Britain as the seas steadily warm.
What's unique about tompot blennies?
Tompot blennies lack an air bladder, which means they are unable to swim in open water. Instead, they live a life without buoyancy, tucked among rock and weed close to the shoreline.
The larger specimens tend to be found at greater depth, although rarely beyond 30 metres, and will find a crevice or overhang which they will defend against other blennies.
How do tompot blennies mate?
In spring, the males create a ‘nest’ in their chosen sanctuary, clearing mud and other debris, before attempting to attract a mate. They have glands near their anal fins which enlarge, producing pheromones to attract a female, who they then try to impress by waving the small, antler-like growths above the eyes.
If successful, the female will lay her eggs within the crevice before they are fertilised by the male. He will guard them for up to a month, fanning them with his scallop-shaped fins to keep them cool and keeping them clean from algae or detritus.
When hatched, the larvae drift in open water before returning to the sea floor.
How long do tompot blennies live for?
The tompot blenny is fast growing but short-lived, reaching around 4 years old in the wild and up to 9 years in captivity.
What do they look like?
The head is large and jowly in appearance, with rounded, slightly bulbous eyes positioned at the top of the head. The top lip has a slight, downward curve which gives the blenny a rather grumpy expression, softened, perhaps, by those frilly antlers.
The skin is loose and mottled in appearance, with dark stripes along the taper of the body. The tompot blenny does not have scales but instead produces a mucus that covers the body in a protective slime.
The name ‘blenny’ is derived from the Ancient Greek word blennos, which means slime or mucus, while ‘tompot’ likely relates to the fish’s appearance.
What do tompot blennies eat?
The sharp teeth enable the tompot blenny to scrape crustaceans from the surface of rocks. They are unfussy eaters, with a diet including sea anemones, prawns and crustaceans, while their territorial nature means the same individual will often be found in the same spot. This allows to divers to recognise and even hand-feed individual fish, providing the blenny doesn’t charge at them first.
