STRUKTUR DAN FUNGSI GASTROPODA DI PANTAI TAMBAKREJO KABUPATEN BLITAR SEBAGAI SUMBER BELAJAR BIOLOGI

Gastropods have an important role in aquatic ecosystems as indicators of environmental pollution, because some gastropods are sensitive to environmental changes. Tambakrejo Beach, located in Blitar Regency, one of the beaches that has become a tourist spot and experiencing environmental pressure. Environment pressure causes changes in the physical-chemical component of the waters. Changes in the physical-chemical components of coastal waters result in changes in the structure and function of gastropods on the coast. The results of this study can be used as a learning resource. The lack of students' ability to understand the characteristics of gastropods in KD 3.8 about applying the classification principle to classify animals into phylum based on anatomical and morphological observations supports the results of this study being developed as a learning resource. The purpose of this study is to determine the structure and function of gastropods in Tambakrejo Beach, Blitar Regency as a source of biology learning. In this study, the method used was the transect method, which were selected 3 stations with 9 plots per station. The physical-chemical parameters observed were temperature, pH and salinity. The calculated gastropod structure includes diversity index, evenness index, dominance index and important value index. The results showed that the measurement of environmental parameters obtained temperature range of 30˚C-31˚C, pH range of 7,1-7,4, salinity range of 31‰-32‰. The gastropods found in Tambakrejo Beach, Blitar Regency are 5 orders, 7 families, 8 genera and 12 species. At the three stations obtained the Shannon-Wiener (H’) diversity index range of 2,05-2,43 is included in the "medium" category, the evenness index value (E) range of 0,89-0,98 is included in the "high" category, the dominance index value (D) range of 0,09 to 0,15 is included in the "low" category. The conditions of abiotic parameters that are still appropriate can affect the structure and function of gastropods in addition to the type of substrate inhabited by the gastropods. The results of the community structure parameters indicate that the aquatic environmental conditions are normal, optimal, still provides a suitable environment for gastropod life, and the community in stable condition despite environmental disturbances or pressures. The results of the study can be used as a source of learning on the material “Animalia” on X class of senior high school