SHORELINE OF SEA CREATURES – GEHAN’S JOURNAL
de Silva Wijeyeratne, G. (2006). Shoreline of Sea Creatures – Gehan’s Journal. Sunday Times Plus. June 4th.
Details of a walk along the short on the Galle beach.
It was a dull day, overcast with clouds. We heard that it had rained in the morning all the way from Colombo to Beruwela. Fortunately for me the rain did not come to Galle and it became sunny by noon. We took advantage of the overcast day to go for a sea shore walk with the children.
I spent a lot of time perched atop the rocks besides the several rock pools besides the 300 m or more of shoreline which runs besides the Lighthouse Hotel & Spa. The rockpools are another amazing world of natural wonders which very few visitors see. A number of small fish darted around the pools, coming with large waves and going with large wave waves which would sweep in and out a fast flowing torrent of water.
There was a large number of Rock Crabs which would scurry away at my approach. After a while they would regain the confidence to emerge again. The Mudskippers were also quite wary. I observed them through my 400 mm lens. I noticed how the pair of eyes have migrated to the top enabling them to keep watch in the direction from which danger would arise. As they wriggle about on the rocks, danger can only be from above. The same applies to the crabs whose eyes are also at the top. The Mudskippers can fling themselves off the rocks into a nearby pool of water if they feel threatened. Otherwise they would use the flow of the waves which wash over the rocks every fifteen seconds or so. They only seemed to be present on rocks where a well aerated wave would wash over frequently. Some seemed to have a curved hump on their head rather like the early bird dinosaurs in Jurassic Park. They seemed to be feeding rather feverishly by grazing the rocks for algae or tiny animals. Their pectoral fins are wide with strong radiating bones to enable them to use their fins for gripping onto the rocks. They are such extraordinary animals.
Sea Urchins, limpets and clams clung onto the rocks on the tide line. I had bought a copy of the Periplus Nature Guides Tropical Shells of India & Sri Lanka. This was a big hit with the two little girls and mum who together with Anoma Alagiyawadu attempted to identify some of the seashells on the beach. The seashells are nothing more than the outer skeleton of dead animals, many of whom are marine snails. Although snails don’t seen particularly exciting, the Periplus guide provides some fascinating insights into a group of animals which are interesting in their own right. For example we learnt that the Moon Shells (Naticidae) are blind or nearly blind because they live under the sand and use chemical detection to use their prey. When it locates another marine snail it will prey on, it excretes a chemical substance to make hole in the shell of its prey. Seashells with a small hole on the side could be victims of a Moon Shell.
Some of the families which we identified included Limpets (Acamaeidae/Fissurellidae), Abalones (Haliotidae), Top Shells (Torchidae), Periwinkles (Littorinidae), Cowries (Cypraeidae), Murex Shells (Muricidae), Olive Shells (Olividae), Augurs (Terebridae), and Sundials (Architectonicidae).
Gehan’s Journal is an ad hoc series of lightly edited extracts from the ‘on the hoof’ notes maintained on his laptop by writer and photographer Gehan de Silva Wijeyeratne (email@example.com)