In this installment of tales from the Tropical seas, Umeed Mistry introduces us to eels, an inhabitant of the Indian Ocean, often spotted by divers not far offshore from some of our favorite beach side destinations.
Divers in India’s waters often come across eels on reefs and in shallow inter tidal areas. These long,slender creatures are generally observed poking their heads out of crevices in rocks or coral close to the sea floor. Their elongated shape and undulated movement when observed swimming out in the open, is reminiscent of snakes. This appearance, coupled with the fact that many of them have very obvious sharp teeth, generally leads to a feeling of wariness when in the presence of eels. But the truth is that most of these animals are not aggressive by nature and are quite harmless if unprovoked. In fact, in many places where divers feed marine life, habituated eels will leave the shelter of the reef floor and swim out when they sense their arrival. And so, short of a feeding mishap or blindly sticking ones hand into holes and crevices, the chances of being bitten by an eel are pretty slim.
Eels are elongated fish, belonging to the order Anguilliformes. They do not have pelvic fins and many species also lace pectoral fins. The dorsal fin is fused with the anal and caudal fins to form a long, single fin running along almost the entire length of the animal. Their scale-less bodies are coated with a transparent, protective mucous layer.
Eels range from five centimeters to four meters in length and most of them are predators in their habitat. Some species,like members of the genus Gymnothorax have long, sharp teeth for hunting fish and octopus. In addition to the teeth along the upper and lower jaw line, these species also have two teeth in the middle of the palate. Other species, like those in the genus Echidna, have blunt teeth used for crushing crabs and other crustaceans.
Many eels are nocturnal and are therefore rarely seen. During the day, they are reclusive and rest in burrows and crevices along the seabed. Snorkelers and divers generally encounter eels in shallow lagoons and on reef slopes – their bodies hidden in burrows or holes and heads poking out. Some species can be observed out in the open at night, hunting for food along the reef.
Snake eels and garden eels also use burrows on the sea floor, but tend to stick to sand and mud flats instead of reefs. Snake eels have pointed snouts and bony tails which allow them to burrow forward or backward beneath the sediment. They are less common than moray eels and in almost two decades of diving in the Andamans and Lakshadweep, I have only encountered a few individuals. They are shy animals that should be approached very slowly. Often, only the tops of their heads show above the sand with their eyes, nostrils and mouth exposed.
Many eels open and close their mouths when resting. This movement, often perceived as a threat, is simply to push water over their gills for respiration. For divers observing these animals, an eel that continues to open and close its mouth in as low, regular manner, is one that is okay with and unthreatened by the presence of the diver. These are the ones to try and inch a little closer to for a photograph. But it is worthwhile to note that although unaggressive by nature, a threatened eel can give a careless or over-friendly diver a nasty bite.
This article first appeared in the March 2015 issue of Saevus magazine.