Abstract. Purnama MF, Sirza LOMJ, Sari SF, Salwiyah, Haslianti, Abdullah, Suwarjoyowirayatno, Findra MN, Nurhikma, Agriansyah A, Hidayat H, Syukur, Anwar K. 2022. Diversity report of freshwater gastropods in Buton Island, Indonesia. Biodiversitas 23: 1938-1949. This study was located in Buton Island consisted of 5 administrative districts/cities (Baubau City, Buton District, South Buton District, Muna District and North Buton District) and was conducted for 1 year (August 2019-August 2020). The output is to reveal the potential richness of the biodiversity of freshwater gastropods as a first step to optimize the utilization of freshwater gastropod resources in the Buton Islands. Determination of sampling location for gastropods was carried out by purposive sampling method and the selection of gastropod samples using simple random sampling method at a predetermined location based on the presence of gastropods. Gastropod samples (epifauna/infauna) were collected manually without special fishing gear with gloves, paralone pipes (3.5 inches), and filter (1 mm). The gastropods found in Buton Island consist of 18 genera and 40 species. Freshwater gastropods spread over 8 families, namely Cyclophoridae, Planorbidae, Lymnaeidae and Thiaridae. Among the species, there are several invasive alien species (IAS) such as Tarebia granifera, Melanoides tuberculata and Achatina fulica. These three species always dominate the habitat space where they are found. Most gastropod communities in 5 districts/cities live in fast-flowing rivers with rock, gravel and sand substrates. Only a few of them are found in artificial inland waters such as rice fields, embankments, dams and drainage. This study became a first step to optimize the utilization of gastropod resources and sustainable management, especially related to the conservation of native species from the threat of IAS.

Giant clam population has been decreased in a few years. Resource management requires information from various aspects, such as ecological, population, and other aspects. This study was aimed at assessing the genetic profile of Tridacna giant clam in Wakatobi National Park waters using Cytochrome oxidase subunit I (COI) genetic marker. Sample collection was conducted around the three main islands, i.e., Wangi-wangi, Kaledupa, and Tomia. Genetic analysis using COI gene may contribute in identifying giant clams up to the species level and showed the relationship among species. The research found 41 specific nucleotide sites for the clams. T. crocea, T. squamosa and T. maxima had 2, 15 and 24 sites, respectively. COI gene as a biological marker was able to separate groups of giant clam by species. Nucleotide variation of T. crocea from Wakatobi was the highest among other locations, so it could be used as a genetic source for translocation and domestication. Keywords: cytochrome oxidase subunit I, specific nucleotide, Tridacna, Wakatobi National Park

Sumber daya pesisir Perairan Nambo di Kota Kendari meliputi ekosistem mangrove dan lamun yang memberikan manfaat ekologi bagi kehidupan organisme bentik dan organisme lainnya. Salah satu organisme bentik yang dimanfaatkan oleh masyarakat setempat adalah kerang lentera. Tujuan penelitian ini untuk mengetahui preferensi habitat kerang lentera di Perairan Nambo. Pengambilan sampel menggunakan metode acak sistematis dengan interval waktu dua kali sebulan. Data kepadatan, pola distribusi dan distribusi ukuran dianalisis. Preferensi habitat kerang lentera dianalisis dengan Coresponden Analysis (CA) dan Principle Componen Analysis (PCA) untuk mengetahui karakteristik parameter perairan melalui program XLSTAT versi 2014. Hasil analisis menunjukkan nilai kepadatan kerang lentera yaitu 1,06–10,44 ind/m2. Indeks pola distribusi menunjukkan kerang lentera mempunyai penyebaran acak dan seragam. Sebaran ukuran panjang total (panjang cangkang dan pedikel) kerang lentera dikelompokkan dalam 10 kelas ukuran, dimana ukuran yang mendominasi adalah 77–102 mm. Preferensi habitat kerang lentera dikarakteristikkan oleh tekstur substrat pasir sedang dan berlumpur pada daerah ekosistem mangrove.

Sekitar kawasan Pantai Koguna yang berjarak ±157 meter dari garis pantai terdapat sebuah perairan tertutup semacam rawa. Perairan ini berair payau dan dihuni oleh udang merah (Parhippolyte uveae). Tujuan penelitian ini adalah untuk mengetahui karakteristik habitat udang merah. Penelitian ini dilaksanakan pada bulan November–Desember 2021 di Desa Mopaano Kecamatan Lasalimu Selatan Kabupaten Buton.  Lokasi penelitian ditetapkan secara sengaja pada dua zona dengan karakteristik habitat yang berbeda. Hasil penelitian menunjukkan bahwa Zona 1 ditemukan udang merah dengan kelimpahan relatif tinggi yang menunjukkan zona tersebut disukai oleh udang merah. Habitat pada zona tersebut memiliki karakteristik berupa bebatuan dan akar mangrove, kerapatan tutupan kanopi mangrove lebih tinggi, serta parameter lingkungan perairan yang sesuai dengan kehidupan udang merah. Habitat udang ini adalah perairan anchialine yang masih mendapat pengaruh pasang surut dari laut namun tidak terhubung secara langsung di bagian permukaannya.

One of the important capture fisheries commodities in Southeast Sulawesi, especially small-scale fisheries, is blue swimming crab (Portunus pelagicus) using traps. The catching is said to be successful if it gets the maximum profit for the business actor. The use of different types of bait in trap results in different catches. The purpose of this study was to analyze the financial aspects which include costs, income, profits, and the level of financial feasibility of catching crabs using different baits, namely peperek fish and anchovies. The method used in this study is a survey method, namely by reviewing, observing and collecting information data directly in the field. The results of the study indicated that the variable costs incurred annually have a greater amount than the fixed costs. The biggest revenue from the crab catching business was by using peperek fish bait, with the profits being able to cover the costs incurred. Crab fishing business using peperek fish is said to be feasible and profitable as seen from the value of NPV, IRR, and B/C Ratio with the return on capital in the category of medium return on capital. Meanwhile, by using anchovy bait, there is a loss, where the revenue obtained cannot cover the costs incurred.