I TOOK THESE PHOTOGRAPHS in Vaavu Atoll in the Maldives when, snorkelling by night, I watched the unusual behaviour of a male and female tawny nurse shark for more than 20 minutes.
These carpet sharks are found in shallow coastal areas of the tropical Indian and Pacific Oceans, no deeper than about 70m. Their reddish-brown colour is reflected in a Latin name suggestive of rust, Nebrius ferrugineus.
At 2.5 to 3m long they are certainly big enough for those “heroic” photographs but are not intimidating. Faces are characterised by that “moustache”, the photogenic tail accounts for a quarter of their body-length, and their disposition is peaceful, phlegmatic even, although any diver showing excessive familiarity is likely to be vigorously repelled.
Many Indian Ocean dive-centres offer nurse-shark night-dives. That’s because these predators rest during the daylight hours, stretched out at the bottom of gullies or under a reef canopy, sometimes in quite large groups.
They hunt nocturnally, feeding on reef fish, crustaceans, cephalopods and even sea urchins. If they can’t get their heads into the reef cavities in which their prey lurks, it doesn’t matter – using a strong sucking action they can draw it into their mouth on a stream of water.
This produces a characteristic smacking sound – a sort of goodnight kiss from the nurse.