Feeding habit of Strombus canarium in Tanjung Sebauk Bintan Island, Indonesia

Abstract

Several species of marine gastropod mollusk used by the community as economical food commodities, including the Strombus canarium was found in the Tanjung Sebauk, Bintan Island. The S. canarium diet as a deposit feeder significantly affects the consumption of the biota food varieties. Until now, there was limited information related to the classification of food consumed by S. canarium. Environmental factors affect S. canarium habitat substantially by providing a food source that is absorbed and influences the growth of S. canarium. Resettlement and restaurant activities in coastal areas affect changes in environmental conditions and modify the habitat and food variations of the organism. The Swept Area Sampling (SAS) method was applied to sweep and collecting S. canarium at a bed-ground area of 1500 m2 in Tanjung Sebauk. The shell splitting and surgery completion of S. canarium were handled in the laboratory. S. canarium samples were immersed with 10% formalin to serve and protect the gastric sample and prevent it from rupturing, including providing the possibility to observe the various food components from S. canarium. Each species of organism found in an S. canarium stomach sample was photographed and counted and measured three times. Photographs of the gastric sample obtained from observations in a microscope were analyzed and identified comprehensively to find the composition of food varieties from the S. canarium. The varieties of food composition obtained were distinguished by class and group of biota and analyzed using the Preponderance Index. The varieties of food composition in gastric samples from S. Canarium shown eight species with the majority composition from plankton groups (phytoplankton and zooplankton), and one species was the copepod class. The following species of biota found in the stomach S. canarium based on the Preponderance Index consisted of Thalassionema sp. (42.59%) as primary food, followed by Nocticula sp. and Coscinodiscus sp. as additional food with a percentage of 37.45% and 12.35%, respectively. In comparison, the variety of complementary food from S. canarium consisted of Entomoneis sp. (2.47%), Cymbella sp. (1.23%), Cochlodinium sp. (1.23%), Calanus sp. (1.85%), and Boreadinium sp. (0.82%).