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Red crab (Thalamita spinimana) is a type of crab that has a light body color, favored by coastal communities for its thick meat and high protein content at a low selling price. This research purpose to determine the maturity level of female red crabs. This research was conducted using a survey method with sampling twice for two months which was carried out from April to May 2021 in Dompak Waters, Tanjungpinang. The results of the research found that TKG I was immature gonads. Female red crabs incubate eggs (Ovigerous) with yellow and orange color, dominated by immature gonads, while brown and dark gray colors are dominated by mature gonads.

Yellowtail scad fish was an economic value fish that many fishermen in Kelong Village catch. One of fishing ground in Bintan was Merapas Waters. Fishing activities without considering fish stocks in nature will caused overfishing. The objective of this research was to determine the Maximum Sustainable Yield (MSY), rate and effort of utilization, and Total Allowed Catch (TAC) of Yellowtail Scad fish in Merapas waters landed on Kelong Village. The fishing gear that Fishermen in Kelong Village used to catch Yellowtail Scad fish was hand line. This research used survey method. Primary data from this research were catch and effort of Yellowtail Scad Fish, while secondary data obtained from fishermen interviews and related literature. Data analysis of this research used Schaefer method. The result of this research was the potential value of MSY is 2,501.37 kg/month with the optimum effort (f opt) 178 trip. The utilization rate of Yellowtail Scad fish was 38.48% and effort rate of Yellowtail Scad fish was 22.16%. Total allowed catch value of Yellowtail Scad fish was 2,001.1 kg. Overall, the catch of Yellowtail Scad Fish hasn’t reach overfishing, so the fishing effort can be more optimized.

The morphometric characteristics of the red crab (Thalamita spinimana) have not been widely studied. This research was conducted from March to May 2021 in the waters of Dompak Tanjungpinang, Riau Islands. Each sample obtained directly measured the morphometric part using a caliper or calipers with an accuracy of 0.05 mm and the crab body weight was also weighed using a digital scale with an accuracy of 0.1 g. The samples obtained during the study were 119 crabs, of which 84 female red crabs and 35 male red crabs. The carapace width range for female crabs is 55.40 – 88.32 mm, while in male crabs the carapace width range is 16.35 and 34 individuals 68.96 – 90.94 mm. The weight of female red crabs is in the range of 50.0 – 103.6 g, while the weight of male crabs is in the range of 49.0 – 142.8 g.

<strong>Food and Feeding Habits of Dog Conch (<em>Laevistrombus turturella</em>) on Penyengat Island, Tanjungpinang</strong>. Dog conch (Laevistrombus turturella) in Tanjungpinang, including commodities of high economic value. The purpose of this study was determine the ratio of the length of gut and the total body length, type of food and feeding habits of dog conch on the Penyengat Island, Tanjungpinang, Riau Islands. The study was conducted from May to November 2019. The sampling location was determined based on the purposive sampling method. The station were divided into 3 stations based on 1) the catch zone of the dog conch, 2) the characteristics of the dog conch habitat and 3) activities along the coast. Analysis of the data were provided the ratio of the length of gut and the total body length, index of preponderance, Viscero Somatic Index (VSI), total organic matter and index of electivity. The results showed that the ratio of the length of gut and the total body length of the dog conch were 1,53; 1,60; 1,66 and classified as an omnivore based on the ratio of the length of gut and the total body length.  Types of dog conch food that have been found were detritus and microalgae class <em>Bacillariophyceae, Chlorophyceae,</em> and <em>Crustaceans</em>.  The feeding habits of dog conch were detritus with the index of preponderance of 65-70% as the main food.  VSI values were ranged from 24,27 to 36,35%.  Value Index of electivity were ranged from 0,99-1% or close to 1.

Keberadaan dan kelimpahan gastropoda dan bivalvia sangat ditentukan oleh adanya vegetasi mangrove yang ada di daerah pesisir. Tekanan dan perubahan lingkungan dapat memengaruhi jumlah jenis dan perbedaan struktur dari gastropoda dan bivalvia. Tujuan dari penelitan ini yaitu untuk mengetahui kepadatan gastropoda dan bivalvia di ekosistem mangrove, mengetahui struktur komunitas gastropoda dan bivalvia di ekosistem mangrove, serta mengetahui kualitas perairan pada ekosistem mangrove Perairan Desa Pangkil. Penelitian ini dilakukan pada bulan Juli-Agustus 2021. Penelitian ini menggunakan metode survei dan analisis laboratorium. Penentuan titik sampling menggunakan metode purposive sampling sebanyak 120 titik dari 8 stasiun, yang dimana pada setiap stasiun terdapat 15 titik dari 3 plot. Hasil analisis struktur komunitas gastropoda dan bivalvia yang diperoleh yaitu, nilai kepadatan gastropoda dan bivalvia tertinggi terdapat pada stasiun 4 yaitu dengan total kepadatan berjumlah 60.667 ind/ha, sedangkan gastropoda dan bivalvia dengan nilai kepadatan terendah yaitu pada stasiun 8 yaitu dengan total kepadatan 12.000 ind/ha. Hasil indeks keanekaragaman gastropoda dan bivalvia pada semua stasiun yaitu dikategorikan sedang. Hasil indeks keseragaman gastropoda dan bivalvia pada semua stasiun yaitu dikategorikan tinggi. Hasil indeks dominasi gastropoda dan bivalvia pada semua stasiun yaitu dikategorikan rendah. Nilai parameter fisika-kimia pada perairan Desa Pangkil masih mendukung untuk kehidupan gastropoda dan bivalvia.

Perairan Pengudang, memiliki sumberdaya kelautan perikanan yang beragam. Salah satu potensi yang ada yaitu ekosistem terumbu karang dan ikan yang berasosiasi di ekosistem tersebut. Penelitian ini bertujuan untuk memperoleh informasi persentase terumbu karang hidup dan kelimpahan ikan indikator Chaetodontidae beserta hubungannya. Pengambilan data dilakukan dengan menggunakan metode Underwater Photo Transeck (UPT) untuk kondisi terumbu karang dan Underwater Visual Cencus (UVC) untuk ikan chaetodontidae, selanjutnya data karang diolah dengan aplikasi CPCe 4.0. Untuk data ikan Chaetodontidae yang diperoleh dihitung jumlah individu dan diidentifikasi jenis Species yang didapati. Lalu untuk melihat hubungan dari persentase tutupan terumbu karang terhadap kelimpahan ikan indikator Chaetodontidae menggunakan regresi linier sederhana. Persentase karang hidup Perairan Pengudang untuk lokasi pengamatan 1 sebesar 54,14% dengan kategori baik, lokasi pengamatan 2 sebesar 52,57% dengan kategori baik, dan untuk lokasi pengamatan 3 sebesar 35,34% dengan kategori sedang. Adapun untuk jenis ikan Caetodonthidae ditemukan yaitu Chaetodon octofasciatus dengan kelimpahan dan Chelmon rostratus. Untuk keterkaitan diketahui bahwa persentasi karang hidup berpengaruh positif terhadap kelimpahan ikan Chaetodontidae dengan total pengaruh sebesar 7,61% sedangkan 92,39% dipengaruhi oleh faktor lainnya. nilai korelasi ini merupakan nilai korelasi yang sangat rendah