Diving over sand

At some point during many of your dives here in Thailand you will find yourself swimming over the sandy seabed. Many divers just consider this a transit from one beautiful coral bommie to the next but it’s worth taking your time to see what’s lurking in these sandy areas. Here are a few critters that you could bump in to.

Bluespotted stingray. Or Kuhl’s stingray can be seen on the sandy bottom at the outer edges of reefs. Their upper is sandy coloured with bright blue spots which warn of their venomous spines. Often the first thing a diver will see is the two eyes poking up out of the sand. Approach too close and they will swim off a short distance before settling back in the sand and using their wing like pectoral fins to bury themselves.

Stonefish. Another fish that likes to bury itself in the sand, the stonefish is a highly venomous, potentially deadly member of the scorpion fish family. Normally they stay still on the seabed, disguised as a rock or lump of coral. If disturbed they raise there dorsal fins as a warning. They are slow, clumsy swimmers, hindered by the algae and hydroids that they allow to grow on their body to improve their camouflage. Stonefish are less commonly seen than the abundant tassled scorpionfish.

Flounder. Another master of disguise, the flounder spends all it’s life hiding on the sandy bottom. Look for an oval shape in the sand about 15-20cm long. An adult flounder has both it’s eyes on the upper side of it’s body. Their pectoral and anal fins run almost the whole length of their body. Flounder prey on small fish and crustaceans that swim too close.

Garden eels. Related to the conger eel, garden eels get their name from the fact that they live in groups on the sea floor and spend their time with most of their body in their own individual burrow, heads poking up to feed on plankton. They are constantly swaying about in the current and as you swim closer they retreat into their burrows. As you swim away they pop out again like a garden growing. This makes garden eels very hard to photograph close up because as soon as you approach they duck back down. Even when spawning garden eels keep their tails anchored in their burrow, a mate must be close enough to stretch across to.

Garden eel colonies are found on sandy bottoms close to reefs where there is current but no waves. The spotted garden eel found in Thailand is grey coloured with large dark spots behind the head. They are about 1cm in diameter and poke out of the sand about 10-12cm.

Bent stick pipefish. You can see all sorts of pipefish on dives in Thailand. Divers get excited about the Ornate ghostpipefish or Harlequin ghostpipefish which can be found hiding in the coral. The poor bentstick pipefish causes less excitement because it just looks like a bent stick. But because of this they are very hard to spot so if you see one you should pat yourself on the back for being so eagle eyed. Look on sandy bottoms around marine debris for something stick like but with a head off the ground. Their long snout resembles that of the seahorse, to which pipefish are related.

Cuttlefish. Part of the cephalopod family that includes octopus and squid the cuttlefish isn’t actully classed as a fish but as a mollusc. They have eight arms and two tentacles and a unique internal structure called a cuttlebone which they use to regulate their buoyancy. Cuttlefish can often be approached quite closely by divers. If you see one cuttlefish while finning over the sand have a look around for another because they are often found in pairs, either two males fighting for territory or a male and a female mating.

Cuttlefish have the ability to change their skin colour rapidly and can put on an amazing display for divers. They also change their shape and skin texture to camouflage themselves.
Some interesting cuttlefish facts are that they are colour blind, they have three hearts and their blood is green. Like octopus and squid, cuttlefish can squirt ink if threatened by predators.

Gobies are small bottom dwellers. There are more than 2,000 species of goby and most are just a few cm’s long. Gobies live in male-female pairs and make burrows for dwelling and spawning. If you are patient you can sit on the sandy seabed and watch gobies making a burrow then protecting it with small pieces of rubble.

Some gobies also form symbiotic relationships with other marine creatures. They share burrows with shrimps where the shrimp will dig the burrow and the goby will act as sentry. Gobies also provide cleaning stations for bigger fish such as grouper or snapper who choose to be cleaned rather than make a meal of the gobies.