The research was conducted in the seagrass ecosystem of Lihunu Village, East Likupang Subdistrict, North Minahasa Regency, and North Sulawesi Province.  The area is one of the coastal areas in North Sulawesi that lack information about gastropod resources. Therefore, the main reason for conducting research is to find out the presence of gastropods in the area.  The purpose of the study was to know the types of gastropods and to know the structure of communities through species density, relative density, diversity, and dominance. Sampling is done using the quadratic transect technique measuring 50 x 50 cm.  Quadrate used 50 cm x 50 cm, then converted to square meters to 0,25 m2. The density of the species is 4,80 Ind/m2.  The relative density value of the species with the highest percentage is in Euplica scripta Species with a value of 14,44% and the species with the lowest percentage value, namely Cymbiola vespertilio Species with a value of 0,56%.  Diversity index values in 3 transects fall under the high criteria. Transect 1 is H'= 5.30, transect 2 is H'= 4,18 and transect 3 is H' = 3,95. And the highest dominance value in Euplica scripta Species with a value of C = 0,48.  The water area of Lihunu Village of North Minahasa Regency has an average temperature of 30 ° C.  Salinity is obtained with an average of 30‰. The degree of acidity (pH) obtained is 8.Keywords: Gastropod; Community Structure; Lihunu.AbstrakPenelitian dilakukan di ekosistem lamun perairan Desa Lihunu, Kecamatan Likupang Timur, Kabupaten Minahasa Utara, Provinsi Sulawesi Utara. Daerah tersebut menjadi salah satu daerah pesisir di Sulawesi Utara yang kekurangan informasi mengenai sumberdaya gastropoda. Oleh karena itu, yang menjadi alasan utama melakukan penelitian adalah untuk mengetahui keberadaan gastropoda di daerah tersebut. Tujuan dari penelitian ini yaitu mengetahui jenis-jenis gastropoda serta mengetahui struktur komunitas melalui: Kepadatan spesies, kepadatan relatif, keanekaragaman, dan dominansi. Pengambilan sampel dilakukan dengan menggunakan teknik transek kuadrat berukuran 50 x 50 cm. Kuadrat yang dipakai 50 cm x 50 cm, kemudian dikonversikan ke meter persegi menjadi 0,25 m2. Nilai kepadatan spesies yaitu 4.80 Ind/m2. Nilai kepadatan relatif jenis dengan persentase tertinggi terdapat pada Spesies Euplica scripta dengan nilai 14.44% dan spesies dengan nilai persentase terendah yaitu Spesies Cymbiola vespertilio dengan nilai sebesar 0,56%. Nilai indeks keanekaragaman di 3 transek masuk dalam kriteria tinggi. Transek 1 yaitu H’= 5,30 ,pada transek 2 yaitu H’= 4,18 dan transek 3 yaitu H’ = 3,95. Dan nilai dominansi tertinggi pada Spesies Euplica scripta dengan nilai C = 0.48. Daerah perairan Desa Lihunu Kabupaten Minahasa Utara memiliki rata-rata suhu 30°C. Salintas yang diperoleh dengan rata-rata 30‰. Derajat keasaman (pH) yang diperoleh yaitu 8.Kata kunci :Gastropoda; Struktur Komunitas; Lihunu.

This research was found the ecological adaptive significance for their survivorship in mangrove microhabitat was as follow resting place, avoiding high tide, finding food, lying larvae, avoid sunshine, and hiding from predators. Significance of clumped distribution was taken to reduce drying stress, temperature, fallen from substrate against wave strikes, feeding and reproduction activity, suitable habitat. Significance of population abundance to balance strong predation and response to pressure of nature selection for their survivorship. Key Words : Littoraria scabra,  significance, ecology, survival, and mangrove ABSTRAKPenelitian ini menemukan bahwa signifikansi ekologi Littoraria scabra untuk survival di mikrohabitat mangrove Tombariri yang ekstrim adalah sebagai berikut berfungsi sebagai tempat istirahat, menghindari perendaman air, mencari makanan, meletakkan larva, menghindar cahaya dan bersembunyi dari predator-predator. Signifikansi L. scabra  distribusi spasial mengelompok untuk mereduksi stres kekeringan, suhu, terlepas di substrat akibat gelombang, aktivitas makan, reproduksi, kecocokan habitat. Signifikansi distibusi mengelompok dengan populasi tinggi untuk mengimbangi kuatnya predasi serta merespons tekanan seleksi alam yang kuat demi kelangsungan hidupnya. Kata Kunci : Littoraria scabra, signifikansi, ekologi, survival dan mangrove

This research was found  novelty of reproduction strategy uniqueness of  L. scabra that very rare in nature, reverse male function fertilized eggs are sucked for brooding in mantle of male up to hatching as veligers, and thus, the males are capable of releasing the larvae in full and new moon at spring tide during the research. The second finding in reproduction strategy uniqueness of  L. scabra that mating individuals, both males and females, released their larvae during research period. Key Words : Littoraria scabra,  uniqueness, releasing, veliger, male and female ABSTRAKPenelitian yang amat langka di alam ini menemukan kebaharuan keunikan strategi reproduksi Littoraria. scabra, di waktu kopulasi jantan berperan seks terbalik menyedot sebagian  telur yang dibuahi dan dierami telur-telur yang dibuahi dalam tubuhnya sampai menetas menjadi larva-larva serta melepaskan larva-larva tersebut di bulan penuh dan  baru yang mengikuti siklus pasang selama penelitian. Temuan amat langka kedua keunikan strategi reproduksi L. scabra, yang amat langka di alam dengan pasangan jantan-betina lagi kawin melepaskan larva-larva baik jantan maupun betina pada siklus bi-lunar bersamaan dengan siklus pasang selama penelitian. Kata Kunci : Littoraria scabra, keunikan,pelepasan, veliger, jantan dan betina

This study aims to determine the species of fish from the Acanthuridae family in Bitunuris Village, Salibabu Island, Talaud Islands Regency. Fish samples were caught using monofilament gill nets with a mesh size of 1.5 inches, net length of 15 m, and net height of 2 m. Sampling was carried out in April and May 2021. A total of 63 individuals were caught consisting of nine species. Acanthurus nigrofuscus 40 individuals, 10.0-17.0 cm in length and 18-77 g in weight. Acanthurus lineatus three individuals, 9.4-17.7 cm in length and 17-96 g in weight. Acanthurus triostegus is seven individuals, 9.3-12.4 cm in length, and weighs 21-55 g. Acanthurus nigricans two individuals each measuring 13.9-13.9 cm in length and weighing 67-70 g each. One individual Ctenochaetus cyanocheilus, a total length of 10.3 cm, and weight of 29 g. Naso lituratus four individuals, length 15.1-17.7 cm and weight ranging from 68-115 g. Naso brevirostris one individual measuring 23.0 cm in length and weighing 186 g. One individual Naso brachycentron, 24.5 cm in length and 172 g in weight. Zebrasoma scopas four individuals, 12.1-15.8 cm in length and weighing 54-105 g.Keywords: Species, gill nets.AbstrakPenelitian ini bertujuan untuk mengetahui spesies ikan Famili Acanthuridae di Desa Bitunuris Pulau Salibabu Kabupaten Kepulauan Talaud. Sampel ikan ditangkap menggunakan jaring insang monofilamen dengan ukuran mata jaring 1,5 inci, panjang jaring 15 m, tinggi jaring 2 m. Pengambilan sampel dilakukan pada April dan  Mei 2021. Sebanyak 63 individu yang tertangkap terdiri atas sembilan spesies.  Acanthurus nigrofuscus 40 individu, panjang berkisaran 10,0-17,0 cm dan berat 18-77 g.  Acanthurus lineatus tiga individu, panjang berkisaran 9,4-17,7 cm berat berkisaran 17-96 g.  Acanthurus triostegus  tuju individu, panjang 9,3-12,4 cm dan berat berkisaran antara 21-55 g.  Acanthurus nigricans dua individu masing-masing ukuran panjang 13,9-13,9 cm berat masing-masing ukuran 67-70 g.  Ctenochaetus cyanocheilus satu individu, panjang total 10,3 cm dan  berat 29 g.  Naso lituratus empat individu, ukuran panjang 15,1-17,7 cm berat berkisaran 68-115 g.  Naso brevirostris satu individu ukuran panjang 23,0 cm memiliki berat 186 g.  Naso brachycentron satu individu,  panjang 24,5 cm dan berat 172 g.  Zebrasoma scopas empat individu,  panjang 12,1-15,8 cm dan  berat 54-105 g.Kata Kunci: Spesies, jaring insang.

Benthic foraminifera are protozoans that are readily preserved in marine sediments. The relative proportion of benthic foraminifera that harbor symbionts compared to the proportion that are opportunistic or small/heterotrophic can be used to indicate the quality of the aquatic environment for coral reefs via the FoRAM Index (Foraminifera in Reef Assessment and Monitoring). This study assesses the functional composition of benthic foraminifera in the waters of Manado Bay using the FoRAM Index. Sampling was carried out at 4 stations with 3 replicates each using SCUBA equipment at a depth of 3-6 meters. The 4,124 benthic foraminifera specimens collected were distributed over 37 genera and the FoRAM Index ranged from 1.90 to 9.12. The water conditions at three of the stations (Meras, Molas, and Malalayang) are very conducive to the growth of coral reefs, with FoRAM Index values ranging from 5.64 to 9.12, while at the Sario station the FoRAM Index value was only 1.90 to 2.04, indicating that this aquatic environment is unsuitable for the growth and development of coral reefs.