The Variability in Population Structure of Gastropods in Sedati Waters, Sidoarjo Regency, East Java

Abstract

Abstract Indonesia has a lot of mollusks wealth, one of which is gastropods. Sedati waters are one of the coastal areas of Sidoarjo Regency which has the potential of for mollusk resources in the form of sea snails. Catching mollusks continuously can cause the threat of decreasing the population of mollusks in the waters. This study aims to determine the variability of the gastropods population structure in Sedati waters, Sidoarjo Regency, East Java. This study uses an observation method with analysis statistic of variance. Gastropods identification was done by measuring length and weight, and looking at morphological characteristics. The result are gastropods found and dominant in Sedati waters in October to December are Natica vitellus, Notocochlis tigrina, Babylonia spirata, Turricula javana, Cryptospira ventricosa, Murex trapa, Rapana venosa, Nassarius olivaceus and Nassarius stolatus. Gastropod density and biomass values at station C is were greater than station A and B, with the highest values in December. The highest average value of gastropods biomass was 0.78 ton/km2 and the highest average gastropods density was 5 ind/10m2, namely in December at station C. The distribution of gastropods in Sedati waters was influenced by environmental such as substrate conditions, water quality and oceanographic, as well as fishing activities by fishermen.