Sri Lanka, surrounded by the sea, has a rich diversity of marine habitats, each with its own community of sea creatures. Although the oceans are vast and many seem infinite, we are now causing enough damage for its effects to be felt. Sri Lanka has 1700km of coastline, which provides a little-explored but extensive series of habitats – from sandy beaches to rock pools.
Whales are the world’s largest warm-blooded marine mammals, which are of the order Cetacea. They breathe air, give birth to live offspring and are found in all oceans of the world, making whale watching holidays possible! Whales are divided into two classes, the Odontoceti (toothed whales) and Mysticeti (baleen whales). A sieve-like structure called baleen is observed in the mouths of Baleen whales, along with two external blowholes. Toothed whales possess teeth and only one external blowhole, though internally they have two nasal passages. Five species of baleen whales and twenty-one species of toothed whales have been recorded in the waters of Sri Lanka.
Baleen is made of a horny substance similar to human fingernails and is embedded in rows of plates in the gums of baleen whales. The inside of these plates are rough and bristle-like – the fineness of the bristles varies from species to species depending on an individual diet! Baleen whales feed by taking in water through their mouth and expelling it through the baleen plates to sieve out food, such as plankton and small fish. Only one family of baleen whales, which includes the blue whale (Balaenoptera musculus), the largest animal to have ever lived, weighs up to 160 tonnes and 40m in length! Other species of baleen whales to have been recorded in Sri Lankan waters are Bryde’s whale (Balaenoptera edeni), and is commonly seen. Generally, under 14m in length, these aquatic beasts are relatively small. Mink whales (Balaenoptera acutorostrata) are smaller still, as adults seldom exceed 10m! Fin whales (Balaenoptera physalus) the second-largest species, measures 27m in length and weighs up to 100 tonnes.