Judul: Phylogenetic relationships and genetic population structure of giant clams (Tridacna crocea and tridacna maxima) in Indonesia
Abstrak: There is an increasing concern that heavy-exploitation of marine populations ature populations of giant clam at high risk, leading to long-term consequences to· conservation and fisheries management. Information concerning taxonomy, s tematic, genetic population structure and connectivity of populations are vital for s tial arrangement of marine protected areas (MPAs) and fisheries management fa tne species. However, there is an uncertainty about the relationships between s c·es of Tridacnidae, in particular between species that belong to Chametrachea s· . genus; T. crocea, T maxima and T squamosa, resulted from several studies u.. g different genetic marker and not much is known about connectivity of marine p pulations in the Indonesian Archipelago. This study was carried out in order to el cilfate about the relationships among giant clam species, population structure of crocea and T. maxima, distribution pattern, and connectivity of those giant clam populations across the Indonesian Archipelago. Here we use fragment of 454 bp of the itocnondrial DNA cytochrome c oxidase I gene from T crocea, T maxima, T squamosa, T gigas and several sequences from GenBank as the out groups. The analysis of population structure of T crocea is based on 456 bp fragment of the cytoc::hrome oxidase I gene from 300 individuals collected from 15 localities across the Inda-Malay Archipelago, whereas for T maxima based on 484 bp fragment of the c::ytochrome c oxidase I gene from 211 individuals collected from 14 localities across the Indonesian Archipelago and the Red Sea. The result showed that giant clams formed a monophyletic group. Within Tridacna group, T crocea was closely related to T squamosa than to T maxima and formed monophyletic group. T crocea and T squamosa were sister taxa and sister group to T maxima and T. gigas. T. crocea shows a very strong genetic population structure and isolation by distance, indicating restricted gene flow among almost all sample sites. The observed Cl>₅rvalue of 0.28 is very high compared to other studies on giant clams. According to the pronounced genetic differences, the sample sites can be divided into five groups from West to East: (1) Padang, (2) Java Sea, (3) Makassar Strait (inclwding northern Borneo), (4) eastern coast of Sulawesi (including Sembilan, Komodo, and Kupang), and (5) Biak. This complex genetic population structure and pattern of connectivity can be attributed to the geological history and prevailing current regimes in the Inda-Malay Archipelago. T maxima showed a very strong genetic population structure but limited isolation by distance, indicating restricted gene flow is only among a few sample sites. The observed Cl>₅rvalue of 0.74 is very high compared to other studies on giant clams, even higher than such value in T crocea (0.28) According to the pronounced genetic differences, the sample sites can be divided into four groups from West to East: (1) the Red Sea, (2) Padang (Indian Ocean) and Java Sea, (3) Sulawesi (including Sangalaki, Komodo, and Kupang), and (4) Biak (Western Pacific).
Keyword: Phylogeny, Giant clam, Genetic structure, Population

Judul: Giant Clams (Tridacna sp.) Community Bioecology Studies  in, Central Halmahera regency
Abstrak: Kima merupakan jenis hewan moluska raksasa yang hidup di habitat dengan cara berdiam diri dan ditemukan di perairan laut dangkal hingga kedalaman 20 meter, terutama di lingkungan terumbu karang dan padang lamun. Eksploitasi kima dilakukan untuk memenuhi kebutuhan protein, bahan souvenir, dan hiasan aquarium. Pemanfaatan kima yang dilakukan nelayan menyebabkan ketersediaannya di alam mengalami ancaman kepunahan. Eksploitasi Kima yang berlebihan menempatkan kima sebagai salah satu jenis biota laut yang harus diperhatikan kelangsungan hidupnya. Pemerintah Indonesiaasejak tahun 1987 sudah melindungi melalui Pengumuman MenteriiKelautannNo. 12/Kpts/II/1987 dan diundangkan melalui undang-undang No. 77Tahun 1999. Penelitian ini dilaksanakan di Halmahera Tengah, yaitu Pulau Sayafi, Pulau Liwo, dan teluk Patani pada November hingga Desember 2022. Pengamatan dilakukan dengan snorkeling sambal menghitung jumlah kima yang ditemukan pada setiap stasiun. Pengukuran parameter fisika-kimawi dilakukan disetiap lokasi pengamatan kima. Pengambilan sampel menggunakan metode purposive sampel dengan alat bantu belt transek. Analisis data menggunakan analisis kerapatan relatif, kepadatan, indeks morisita, hirarki klaster menggunakan algoritma k-means, dan analisis regresi linear berganda. Analisis menunjukkan nilai kepadatan relatif kima tertinggi adalah jenis kima Tridacna crocea sebesar 46.55% pada stasiun 2 di Pulau Liwo dan terendah Tridacna squamosa sebesar 6.90%. Kepadatan di Pulau Sayafi tertinggi adalah Tridacna maxima sebesar 44.90%, kepadatan terendah jenis kima Hippopus hipopus sebesar 6.25%. Kepadatan di Teluk Patani tertinggi jenis Tridacna maxima sebesar 0.60% dan terendah Tridacna squamosa. Jenis kima Hippopus hippopus tidak ditemukan pada setiap stasiun pengamatan. Kepadatan jenis tertinggi di Pulau Liwo yaitu pada jenis Tridacna crocea sebesar 180 ind/ha dan terendah Tridacna squamosa sebesar 0.0267 ind/ha. Nilai kepadatan jenis tertinggi di Pulau Sayafi yaitu Tridacna maxima sebesar 0.147 ind/ha dan terendah Hippopus hippopus sebesar 0.013 ind/ha. Kepadatan jenis Teluk Patani Tridacna maxima sebesar 26 ind/ha dan terendah yaitu jenis kima Tridacna squamosa. Jenis kima Hippopus hippopus tidak ditemukan dilokasi pengamtan. Pola distribusi secara keseluruhan mengelompok. Distribusi secara mengelompok disebabkan karena sifat spesies bergerombol atau adanya kesamaan habitat dan ketersediaan makanan. Terdapat 2 klaster yaitu klaster Teluk Patani dan klaster Pulau (Liwo-Sayafi). Hasil regresi linear menunjukkan bahwa suhu, pH, dan kecerahan sangat berpengaruh signifikan terhadap kelimpahan sedangkan kedalaman dan salinitas tidak berpengaruh secara signifikan
Keyword: Komunitas Kima, Bioekologi, Halmahera Tengah

Judul: Mempelajari Keseimbangan Energi dan Kecepatan Aliran Udara Berdasarkan Letak Kipas pada Model Alat Pengering
Abstrak: A1at pengering efek rumah kaca merupakan alat pengering buatan yang memanfaatkan tenaga surya terkontrol dimana memungkinkan untuk mengatur kondisi operasi alat, sehingga hasilnya memenuhi standar mutu pengeringan. Mengingat beragamnya (posisi) bahan yang dikeringkan, distribusi udara dalam ruang pengering perlu diperhatikan.
Keyword: