Off the Reef
Go off the beaten path with Umeed Mistry as he brings you on an eye-opening exploration of all the quirky and interesting creatures that live on the sand flats, silt beds and seagrass meadows of the Indian Ocean
A quick online search for scuba diving in India brings up the Andaman and Lakshadweep Islands as the top scuba holiday destinations in the country, with Netrani, Goa and Pondicherry also attracting some of the diving fraternity to these less clear, but no less interesting waters. And from these destinations, the top-rated dive sites tend to be coral reefs and a few artificial reefs (including shipwrecks) that are teeming with a variety of different fish and crustacean species, and with varying amounts of coral growth.
In my time spent photographing India’s waters, I have had the good fortune of being able to dive in some places where most recreational divers wouldn’t think to go. A cursory glance over these dive sites reveals very little. And with a few exceptional individuals whom I am grateful to, most dive operators aren’t interested enough to visit these sites and aren’t knowledgeable enough to make these sites interesting for their diving guests.
But the truth is that there is always something to see – as many of the guides from the meccas of muck diving will testify to. And if you’ve become familiar with reef creatures from around the world, then you are likely to find some very alien and very surprising life off the reef. Some of these habitats include seagrass beds, sand flats, silt beds adjacent to mangrove forests and a variety of jetties that range from being somewhat clean to completely overrun with trash.
Many creatures choose to live off the reef. One reason for this may be that there is less competition for territory and food in these other, seemingly desolate habitats. However, the “decision” to live off the reef comes with its own set of challenges, for which many creatures have evolved certain adaptations and have fostered certain relationships that allow them to thrive in what might otherwise be considered comparatively inhospitable spaces.
For example, sand flats and silt beds provide little or no solid substrate upon which to settle. On a reef, sessile creatures like many anemones, feather stars and sponges attach themselves to rocks or coral without a problem. This, however, proves an almost insurmountable obstacle on constantly shifting sand and silt beds. Enter the hermit crab. It is quite common to find hermit crabs with small anemones fixed to their shells. In this instance, the relationship is mutually beneficial. The anemone finds a hard surface upon which to settle, while also getting carried about to different places on the sandy ocean floor. The hermit crab benefits from the stinging tentacles of the anemone, which help to ward off would-be predators. A less common sight is a feather star hitching a ride on the back of a hermit crab.
Another creature that invariably attracts other animals is the sea pen. These invertebrates live in vertical burrows in the sand, with a feather-like part of their bodies sticking out into the
One reason for living off the reef may be that there is less competition for territory and food in these other,
seemingly desolate habitats
water. They resemble the feather quills of old. On an ocean bottom devoid of any features, sea pens form anchors that many other creatures have come to rely on. Barnacles cling to them while picking plankton out of the water Some tiny crustaceans hide within their feathery structures, even laying eggs on these animals.
Another challenge of living on flat, featureless muck bottoms is the difficulty of remaining unseen – whether to hunt prey or elude predators. Some pipefish have evolved to look like sticks, floating along on the current. Many fish have evolved colours and patterns that allow them to blend perfectly into the sand. Many creatures make burrows, and some of them emerge only under cover of darkness. And some have developed the ingenious use of tools, which allows them to traverse these underwater deserts with relative impunity.
One such remarkable animal is the octopus. In many parts of India, I have observed octopus inhabiting sand flats and using discarded shells for their protection. Some of them employ the relatively straightforward method of ducking into a larger, empty snail shell, which they sometimes claim as their home. But there are others that need the freedom to roam the sand flats and not be bound to one snail shell refuge. These intrepid cephalopods drag clam shells, coconut shells and even discarded food cans around with them. When a potential threat approaches, they stop their dragging shuffle, climb into their portable refuges and use their many tentacles to close their shelters around them, often with just an eye peeping out.
In seagrass meadows, where there is little to hide beneath, sponge crabs have taken to carrying large pieces of sponges above their bodies. They seem to upturn the third leg on either side of their bodies, and use these legs to support the sponge above them – not unlike the luggage porters at Indian train stations! The sponges themselves are often alive, and sometimes large enough to have other smaller crustaceans, brittle stars and a mini-ecosystem of invertebrates being ferried here and there by the enterprising crab. A diver who has never encountered a sponge crab might, from a distance, wonder at the piece of sponge skittering about on the sea floor.
All these varied inhabitants on muck, sand, silt and seagrass bottoms invariably attract predators. In these open habitats, camouflage becomes crucial to successful hunting. One of the absolute masters of this game of subterfuge is the frogfish. These fish come in all sorts of colours, sizes and textures and many of them have a variety of growths on their skin, thereby inspiring names like hairy frogfish, warty frogfish, painted frogfish and freckled frogfish. These fish, also known as anglerfish, shuffle imperceptibly towards other fish and then sit in wait. They sometimes use a “lure” at the end of a fishing-rod like appendage at the top of their heads to attract a fish’s attention. When suitable prey is within striking distance, the frogfish lunges, opening its very distensible mouth so quickly that the prey is swallowed in the suction of water created by the movement.
Another successful predator but with a different strategy for hunting is the flounder. These flat fish are often exactly the colour of the sand. They have a pair of eyes located at the top of their heads that allows them to watch their sandy world while the rest of their bodies remains beneath the sand. Swimming with a gentle undulating movement of their flattened bodies, these fish sneak up on shrimp, small crabs and other prey. When they finally strike, all that’s left is a cloud of sand where their hapless victim stood.
India’s waters haven’t made it to muck diving headlines in the international diving community.
The denizens of these types of habitats may not be as charismatic as the brightly coloured fish, curious turtles or large sharks and rays that one may encounter on the reef. But their lives are no less interesting. Many of these creatures have evolved extraordinary adaptations and comparatively eccentric behaviours to survive in these special places.
So, the next time you get an opportunity to dive off the reef in India, take it! Chances are you’ll have some unexpected encounters with some memorable critters.
Many of these creatures have evolved extraordinary adaptations and comparatively eccentric behaviours to survive in
these special places
TOP LEFT: Hermit crab and feather starTOP RIGHT: Sea pen and brittle star MIDDLE: Trachyrhamphus pipefish,RIGHT: DragonetIMAGES: Umeed Mistry
OPPOSITE PAGE TOP: Octopuses OPPOSITE PAGE BOTTOM: Sponge crab LEFT: A frogfish attempts to attract a fish’s attentionBELOW: Painted frogfishBOTTOM: FlounderIMAGES: Umeed Mistry