Kemampuan ekosistem mangrove untuk memberikan jasa lingkungan tidak terlepas dari peran berbagai fauna akuatik termasuk moluska. Penelitian di hutan mangrove Tanjung Lesung bertujuan untuk mengetahui peran komunitas moluska dalam mendukung fungsi hutan mangrove melalui penghitungan data-data penyusun struktur komunitas moluska, serta memberikan gambaran awal mengenai peluang moluska sebagai agen penyimpan karbon. Pengambilan sampel moluska dilakukan pada enam stasiun yang berbeda dengan metode petak contoh. Struktur komunitas moluska diketahui dengan menghitung nilai frekuensi, kepadatan, keanekaragaman, kemerataan, serta dominansi. Kandungan karbon pada cangkang diukur dengan menggunakan alat C-N analyzer. Komunitas moluska di hutan mangrove Tanjung Lesung terdiri dari delapan spesies. Tiga spesies dengan nilai kepadatan (K i) dan Indek Nilai Penting (INP) tertinggi adalah Cerithidea cingulata (K i =187 ind/m2; INP=76,71%), Clithon squarrosus (K i =99 ind/m2; INP=39,95%) dan Terebralia palustris (K i =42 ind/m2; INP=24,75%). Spesies T. palustris dan Telescopium telescopium merupakan moluska asli hutan mangrove sehingga kedua spesies tersebut memegang peran penting terutama sebagai pengurai serasah. Kandungan karbon dalam cangkang T. palustris dan T. Telescopium terukur berturut-turut sebesar 10,92 ± 2,33 dan 10,32 ± 0,63% berat kering. Namun, potensi kedua spesies moluska sebagai penyimpanan karbon masih membutuhkan evaluasi dan penelitian lebih lanjut. Kata kunci : Ekosistem mangrove, komunitas moluska, struktur komunitas, kandungan karbon, pengurai serasah.

The freshwater gastropod Tarebia H. Adams & A. Adams, 1854, are found in rivers, lakes, and other limnetic habitats. In Indonesia, Tarebia granifera (Lamarck, 1822) is the only species within the genus that has a wide distribution. The systematics and identity of this species are still doubtful due to high variation in shell morphology, especially shell height and ornamentation or sculpture of shell. To determine the identity of T. granifera from Lombok, Banten, and Maros, ontogenetic studies have been conducted. The results showed that T. granifera from Lombok produce the highest number of embryonic shells. The number of progeny in the brood pouch from a single individual of T. granifera can vary between 9 to 203 embryonic shells which are found in various stages of 0.22 mm to about 5 mm in size inside the brood pouch.

A study on the malacofauna of Laiwangi Wanggameti National Park (LWNP) in Sumba Island has been conducted. This study aims were to reveal the diversity of malacofauna in Sumba and compare it with those in the Lesser Sunda Islands. Observations were made on 20 stations using plots (10 x 10 m) in Wanggameti and Laiwangi. Specimens were collected for two hours in each plot. Twenty families and 44 species have been identified. The overall number of species from Sumba increased from 126 to 143 species. The LWNP represents 31% diversity of malacofauna in Sumba Island. Seventeen species are considered as new records for the island. Five endemic land snail species are still observed inside the park. The diversity and population density tend to be higher in Laiwangi area with lower altitudes than in Wanggameti area with higher altitudes. Two dominant species are Asperitas bimaensis cochlostyloides and Tarebia granifera. Species composition in Sumba is more similar to Bali compared with the other six neighboring islands.

Radula in gastropods is considered as a constant and conservative character that can be used in classification and phylogenetic at certain taxa level. However, character of radula is also ecophenotypic, so that the morphology of the radula can also indicates intraspecific variations that able to detect differences among species. The insights of the radular morphology specific to Thiaridae is important for classifying species within this family. Through an enzymatic procedure using the proteinase-K, five radula of Thiarid from Raja Ampat were extracted. The results of research on radula showed that the five species studied had the taeniglossan radula type. The band of the radula is 1.8 - 4.8 mm long and consists of marginal teeth, lateral teeth, and rachidian. The radula formula is 2/1/R/1/2 with a 3-4/1/3-4 rachidian pattern and a 2-3/1/2-3 lateral teeth pattern. The mesocone shape of the rachidian and lateral teeth varies between rounded and pointed.

The freshwater Melanoides tuberculata (Thiarid) has wide distribution and have many variation in color, size, and scluptured of their shells. Comparing with another Thiarid so called Stenomelania punctata, shell of M. tuberculata similar in having turreted shape, blackish color, number of whorls, and size of the shells. This study aim to compare more detailed between M. tuberculata and S. punctata based on their morphology, ontogeny and type of reproduction. Ontogeny studies of these two species show that M. tuberculata produces juveniles in embryonic shell form during their reproduction. This embryonic shell is nourished and developed in the subhaemocoelic brood-pouch organ as evidenced by being found in the size range 0.12–5.95 mm. One individu M. tuberculata can produce 1–66 embryonic shells. Meanwhile, in subhaemocoelic brood-pouch of S. punctata only the unshell embryo was seen and embryonic shell was not found. The difference of reproduction system determines the reproductive strategy in both species. M. tuberculata conduct euviviparity reproduction whereas S. punctata is ovoviviparous that releases juveniles in free-swimming veliger form.