Claim Missing Document
Check
Articles

Found 20 Documents
Search
Journal : JURNAL ILMIAH PLATAX

Length-Weight Relationship and Reproduction of Spotcheek emperor Lethrinus rubrioperculatus Sato, 1978 at Napo Nain Likupang North Sulawesi Laura, Azhar; Kambey, Alex D.; Bataragoa, M.Sc, Dr. Ir. Nego E.; Pratasik, Silvester B.; Lohoo, Anneke V.; Kusen, Janny D.
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.46348

Abstract

Spotcheek emperor L. rubrioperculatus lives in association with coral reefs, at a depth of 10-168 m. This species lives on sandy bottoms and along the outer reef slopes. The lemur fish L.rubriopercelatus is a protogynous hermaphrodite fish, there is a sex change from the female phase to the male phase. Research related to sea urchins in Likupang waters has never been carried out, even in general it is very limited in Indonesia. This study aims to analyze the length-weight relationship and reproductive aspects of spotcheek emperor at Napo Nain Likupang waters. Length-weight relationships are growth patterns and condition factors. Reproductive aspects are the level of gonadal maturity, gonadal maturity index, and fecundity. Fish samples were caught using two types of hand lines, hook number 10 with monofilament line number 90 and hook number 12 with monofilament line number 100. Sampling was carried out three times in May, June, and July 2022. The total samples were 80 individuals. consisting of 44 male individuals with a fork length range of 14.7-22.7 cm, 42 female individuals with a fork length range of 13.0-24.0 cm, and 2 individuals of transitional elephant fish, respectively 19.5 and 20.0 cm. Male length-weight relationship W= 0.2332L2.1642 (R2=0.7881) negative allometric growth pattern. Females W = 0.0868L2.505 (R2=0.9575) negative allometric growth pattern. The condition factor for male fish is 1.03 ± 0.22 and 0.99 ± 0.12 for females. The gonadal maturity was found in May for both males and females. Gonad Maturity Index for males ranged from 0.03-0.18 and for females 0.02-1.49. Fecundity ranged from 21.035-3.9497 with an average of 31.530 ± 5.929. The relationship between fecundity and length F=3152L0.7721 (R2=0.24340) Keywords: Growth pattern, Allometric, Gonad, Fecundity. Abstrak Ikan lencam L. rubrioperculatus hidup berasosiasi dengan terumbu karang, pada kedalaman 10-168 m. Spesies ini hidup di dasar berpasir dan di sepanjang lereng terumbu bagian luar. Ikan lencam L.rubriopercelatus adalah ikan hermaprodit protogini, terjadi perubahan kelamin dari fase betina ke fase jantan. Penelitian berkaitan ikan lencam di perairan Likupang belum pernah dilakukan, bahkan secara umum di Indonesia sangat terbatas. Penelitian ini bertujuan untuk menganalisis hubungan panjang-berat dan aspek reproduksi. Hubungan Panjang- berat meliputi pola pertumbuhan dan faktor kondisi di parairan Napo Nain Perairan Likupang. Aspek reproduksi meliputi tingkat kematangan gonad, indeks kematangan gonad dan fekunditas. Sampel ikan ditangkap dengan menggunakan dua jenis pancing ulur (hand line) mata pancing nomor 10 dengan tali monofilament nomor 90 dan mata pancing nomor 12 dengan tali monofilament nomor 100. Sampling dilakukan tiga kali pada bulan Mei, Juni dan Juli 2022. Jumlah sampel 80 individu terdiri atas terdiri dari 44 individu jantan dengan kisaran panjang garpu 14,7-22,7 cm, 42 individu betina dengan kisaran panjang garpu 13,0-24,0 cm, 2 individu ikan lencam transisi kelamin masing 19,5 dan 20,0 cm. Hubungan panjang-berat jantan W= 0,2332L2,1642 (R2=0,7881)pola pertumbuhan alometrik negatif. Betina W = 0,0868L2,505 (R2=0,9575) pola pertumbuhan alometrik negatif. Faktor kondisi jantan bernilai 1,03 ± 0,22 dan 0,99 ± 0,12 ikan betina. Tingkat kematangan gonad ikan yang siap memijah (TKG IV) ditemukan pad bulan Mei baik jantan maupun betina. Indeks Kematangan Gonad jantan berkisar antara 0,03-0,18 dan betina 0,02-1,49. Fekunditas berkisar antara 21.035-3.9497 dengan rata-rata 31.530 ± 5.929. Hubungan fekunditas dengan panjang F=3152L0,7721 (R2=0,24340) Kata kunci : Pola pertumbuhan, Allometrik, Gonad, Fekunditas
Gastropod Community An Vertical Distribution Pattern Of Littoraria Scabra (Linnaeus, 1758) In Mangrove Ecosystem, Tombariri District, Nort Sulawesi Bilaleya, Iman; Lalita, Jans; Mantiri, Rose O. S. E.; Kepel, Rene Ch.; Lumingas, Lawrence J.; Lohoo, Anneke V.
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.46497

Abstract

The Coast water of Tombariri District is an area that has a main ecosystem like mangroves, seagrass, and reef. This research is to aim to know the species various, the structure of the gastropod community, and the vertical distribution pattern of Littoraria scabra in the mangrove ecosystem in Tombariri District, North Sulawesi. Process of gastropod sampling horizontally where transects were put horizontal coastline on every location including Mokupa, Elu, and Tambala. Every transect long has 65 m and also has every transect has 15 quadrats where every quadrat is one-meter square. Therefore, every transect has 15 quadrats, so a total of 45 quadrats. Every quadrant was put systematic method, that is, at terrestrial closing mangrove of 5 quadrats, middle mangrove of 5 quadrats, and coast close mangrove of 5 quadrats. Process of sampling particularly L.scabra where taking vertically, especially on microhabitats that is, roots, stems, branches, and leaves of mangroves. High measuring by meter unit, conducted from the ground where L.scabra found at mangrove until the top vegetation. Based on the result of observation on the identification of gastropod sampling found in the mangrove ecosystem, Tombariri District, North Sulawesi as many 235 of individuals consisting of 5 orders, 23 families, and 32 genera having 78 species. The density of species on every location Mokupa, Elu and Tambala, that is, (D) = 4.60, 5.47, and 5.60 in ind/m2, index of diversity,(H) = 2.54, 3.07, and 3.51 and index of dominance, ID = 0.04, 0.07 and 0.13. Keywords: Microhabitat, density, diversity, and dominance Abstrak Perairan pantai Kecamatan Tombariri merupakan daerah yang memiliki ekosistim utama pesisir seperti mangrove, lamun, dan terumbu karang. Penelitian ini bertujuan untuk mengetahui jenis-jenis, struktur komunitas gastropoda dan pola distribusi vertikal spesies Littoraria scabra di ekosistem mangrove Kecamatan Tombariri, Sulawesi Utara. Proses pengambilan sampel gastropoda secara horizontal, di mana transek ditempatkan sejajar garis pantai pada setiap lokasi yakni di Mokupa, Elu, dan Tambala. Panjang setiap transek 65 m dan setiap transek memiliki 15 kuadrat di mana kuadrat berukuran 1 x 1 m. Setiap transek punya 15 kuadrat sehingga total kuadrat seluruh transek adalah 45 kuadrat. Penempatan kuadrat menggunakan metode sistematik yaitu di bagian darat 5 kuadrat, pertengahan 5 kuadrat dan mangrove pinggir laut 5 kuadrat. Proses pengambilan sampel secara vertikal khusus Littoraria scabra, di mikrohabitat akar, batang, cabang dan daun mangrove,Sementara pengambilan sampel L.scabra diukur ketinggian di mana spesies Littoraria scabra ditemukan ldi pohon mangrove dengan menggunakan meteran, dimulai dari dasar sampai ke ujung pohon mangrove. Berdasarkan hasil pengamatan dan identifikasi sampel gastropoda yang ditemukan di ekosistem mangrove Kecamatan Tombariri, Sulawesi Utara ditemukan sebanyak 235 individu yang terbagi ke dalam 5 ordo, 23 famili dan 32 genera dari 78 spesies. Kepadatan Jenis pada masing-masing lokasi = 4,60, 5,47, dan 5,60 ind/m2. Keanekaragaman H’= 2,54, 3,07, dan 3,51. Dominansi C= 0,04, 0,07, dan 0,13. Kata Kunci : Mikrohabitat, Kepadatan, Keanekaragaman, Dominansi.
Potential Management And Utilization Levels Of Decaptureus macarells In Manado Bay Lohoo, Anneke V.
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.48148

Abstract

This study aims to determine the meristic and morphometric characteristics of the flying catfish in Manado Bay. It is hoped that it will be useful in the optimal management process based on characteristics, and become reference material for policymakers, practitioners, and the public so that they are more concerned about the preservation of flying catfish, and serve as a basis for managing flying fish resources. Data for flying fish are taken from the Fish Auction Place (TPI), fishing boat landing sites, and several markets in Manado City. Measurement of morphometric and meristic data was carried out directly at the sampling location, including observations of fish fins and scales. Morphometric data analysis is presented in the total length frequency distribution graph. The relationship between two certain morphometric characters is determined by the formula: regression Y = a + b X and the correlation value is r to see the closeness of the relationship between the two characters. The relationship between the two calculated characters is presented in graphical form. The morphometric value of the blue swallow is obtained, namely the Y axis which is the same as FL with a value of 5.297, and the X axis which is the same as TL with a value of 0.887. Keywords: morphometrics, meristic, flying fish, Manado Bay Abstrak Penelitian ini bertujuan mengetahui karakter meristik dan morfometrik ikan layang di Teluk Manado. Diharapkan bermanfaat dalam proses pengelolaan secara optimal berdasarkan karakteristik, dan menjadi bahan referensi bagi pengambil kebijakan, praktisi, dan masyarakat agar lebih peduli dalam pelestarian ikan layang, serta dijadikan sebagai dasar dalam pengelolaan sumber daya  ikan layang. Data ikan layang diambil dari Tempat Pelelangan Ikan (TPI), tempat pendaratan perahu nelayan, dan beberapa pasar di Kota Manado. Pengukuran data morfometrik dan meristik dilakukan secara langsung di lokasi pengambilan sampel, termasuk pengamatan sirip dan sisik ikan. Analisis data morfometrik disajikan dalam grafik sebaran frekuensi panjang total. Hubungan antara dua karakter morfomterik tertentu ditentukan dengan rumus : regresi Y = a + b X dan nilai korelasinya yakni r untuk melihat keeratan hubungan kedua karakter. Hubungan kedua karakter yang dihitung akan disajikan dalam bentuk grafik.  morfometrik ikan layang biru diperoleh nilai yaitu sumbu Y yang sama dengan FL dengan nilai 5.297, dan sumbu X yang sama dengan TL dengan nilai 0.887.   Kata kunci: morfometrik, meristik, ikan layang, Teluk Manado
Morphometrics and Meristics of Lemuru Fish Sardinella lemuru Bleeker, 1853 landed at TPI Aertembaga Bitung City Rustandi, Yogi; Manginsela, Fransine; Bataragoa, Nego; Lumingas, Lawrence; Mandagi, Stephanus; Lohoo, Anneke V.
Jurnal Ilmiah Platax Vol. 11 No. 2 (2023): ISSUE JULY-DECEMBER 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i2.49318

Abstract

The morphometric and meristic study of the lemuru Sardinella lemuru landed at TPI Aertembaga, Bitung City aims to examine the ratio and proportion ratio between the total length and other morphometric parameters, the correlation index of growth patterns, the correlation index of closeness and correlation, determining the caudal fin ratio and determining its meristic character. The research was conducted in February-June 2023 and used a quantitative descriptive method. Of the 100 lemuru fish observed, there were 35 males with a total length between 13,184-15,589 cm and 65 females which were longer between 12,083-16,420 cm. The growth pattern of lemuru both male and female is positively allometric dominant with the lowest correlation index r (closeness) in the relationship of eye diameter to the total length of the male fish, namely r = 0.01 (very weak) and the highest in the standard length relationship to the total length of the female fish, namely r = 0.97 (very strong). The highest percentage ratio of other size parameters and total length was for the fork length of the male fish, which was 91.1% and the lowest was for the diameter of the female's eye, 4.2%. The tail fin aspect ratio of female fish is greater than male fish with a value of 1.61 for females and 1.57 for males. The meristics of the male lemuru are D 13-18, P 13-18, V 5-8, A 15-23 and C 17-25 and the females are D 13-18, P 12-18, V 6-9, A 13- 26 and C 15-28. Keywords: total length, small pelagic, growth status Abstrak Penelitian mengenai morfometrik dan meristik ikan lemuru Sardinella lemuru yang didaratkan di TPI Aertembaga Kota Bitung bertujuan untuk mengkaji rasio serta persentase rasio antara panjang total dan paramter morfometrik lainnya, indeks korelasi pola pertumbuhan, indeks keeratan hubungan korelasi dan, menentukan ratio sirip ekor serta menentukan karakter meristiknya. Penelitian dilaksanakan pada bulan Februari-Juni 2023 dan menggunakan metode deskriptif kuantitatif. Dari 100 individu ikan lemuru yang diamati ada 35 individu jantan dengan panjang total selang 13,184-15,589 cm dan 65 individu betina yang lebih panjang selang 12,083-16,420 cm. Pola pertumbuhan ikan lemuru baik jantan dan betina dominan allometrik positif dengan indeks korelasi r (keeratan) terendah pada hubungan diameter mata terhadap panjang total ikan jantan yakni r = 0,01 (sangat lemah) dan tertinggi pada hubungan panjang standar terhadap panjang total ikan betina yakni r = 0,97 (sangat kuat). Persentase rasio parameter ukuran lain dan panjang total tertinggi pada panjang garpu ikan jantan yakni 91,1 % dan terendah pada diameter mata betina 4,2 %. Aspek rasio sirip ekor lebih besar ikan betina daripada ikan jantan dengan nilai 1,61 pada betina dan 1,57 pada ikan jantan. Meristik ikan lemuru jantan yakni D 13-18, P 13-18, V 5-8, A 15-23 dan C 17-25 serta betina yakni D 13-18, P 12-18, V 6-9, A 13-26 dan C 15-28. Kata kunci: panjang total, pelagis kecil, status pertumbuhan  
Aquatic Pollution Study Based on Analysis of Mollusk Diversity as a Bioindicator Lohoo, Anneke V.; Manu, Gaspar; Mantiri, Rose O.S.E.; Kambey, Alex D.
Jurnal Ilmiah Platax Vol. 11 No. 2 (2023): ISSUE JULY-DECEMBER 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i2.51420

Abstract

This research aims to determine the condition of coastal water quality at Sam Ratulangi University's Marine Field Station by looking at the diversity of mollusks and the physical and chemical parameters of the waters as supporting parameters. The method used to determine the research location was the Quadratic Transect method, while to determine the sampling point the random sampling method was used, namely selecting sampling locations randomly based on areas with dominant activities. The mollusks taken are mollusks that are still alive and can be seen attached, both on the surface of the substrate and inside the substrate. Observations of the place and substrate where the individual attached/immersed themselves were carried out by measuring the water quality, where the temperature was 300C, salinity 28%0, and pH 8). The identification results obtained were 29 types. In the final step after the sample has been identified, all data obtained will be analyzed to obtain results from the research carried out. This research is expected to provide information about the condition of water pollution at Sam Ratulangi University's Marine Field Station in determining management policies and preserving the aquatic ecosystem. Keywords: Bioindicators, Molluscs, Diversity, Pollution. Abstrak Penelitian ini bertujuan untuk mengetahui kondisi kualitas perairan pesisir Marine Field Station Universitas Sam Ratulangi dengan melihat keanekaragaman moluska serta parameter fisika kimia perairan sebagai parameter pendukung.  Metode yang digunakan dalam menentukan lokasi penelitian adalah metode Transek Kuadrat, sedangkan untuk menentukan titik pengambilan sampel digunakan metode random sampling, yaitu pemilihan lokasi pengambilan sampel secara acak berdasarkan kawasan dengan kegiatan yang dominan. Moluska yang diambil adalah Moluska dalam keadaan masih hidup yang terlihat menempel, baik di permukaan substrat maupun di dalam subtrat. Pengamatan tentang tempat maupun substrat dimana individu tersebut menempel/membenamkan diri dilakukan pengukuran kualitas air, di mana suhu 300C, salinitas 28%0 dan pH 8). Hasil  indentifikasi diperoleh sebanyak 29 jenis. Langkah terakhir setelah sampel diidentifikasi, semua data yang diperoleh akan dianalisis untuk memperoleh hasil dari penelitian yang dilakukan. Penelitian ini diharapkan sebagai informasi tentang kondisi pencemaran perairan Marine Field Station Universitas Sam Ratulangi dalam penentuan kebijakan pengelolaan serta menjaga kelestarian ekosistem perairan. Kata kunci: Bioindikator, Moluska, Keanekaragaman, Pencemaran.
Morphology and Anatomy of Macroalgae Community in Rap Rap Coastal Waters, Tongkaina Village, Manado City Rafii, Keken Angliyana; Kepel, Rene Ch.; Kondoy, Khristin F I.; Mandagi, Stephanus V.; Tombokan, John L.; Lohoo, Anneke V.
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.52140

Abstract

Macroalgae are low-level plants that generally grow attached to certain substrates such as corals, mud, sand, rocks, and other hard objects. Macroalgae are algae that have a macroscopic body shape and size. A community is a group of beings living together in the same place. Thus the macroalgae community is a group of lower plants that have macroscopic body sizes living together. The coastal area of Rap-Rap Beach is located in Tongkaina Village, Manado City, North Sulawesi Province. This location is one of the stable macroalgae habitats, meaning that there is still little habitat damage that occurs, so macroalgae can still be obtained directly from nature. This coast is also known as mangrove ecotourism and the path to Bunaken Island. The purpose of this study is to describe the morphology and anatomy of each macroalgae species. Data collection using the Line Transect method with a squared sampling technique was carried out at the lowest low tide. Temperature measurement using a thermometer and salinity using a refractometer, and for determination of substrate visually see the type of substrate. Keywords: morphology, anatomy, community, macroalgae, Rap Rap. Abstrak Makroalga merupakan tumbuhan tingkat rendah yang umumnya tumbuh melekat pada substrat tertentu seperti pada karang, lumpur, pasir, batu dan benda keras lainnya. Makroalga yaitu alga yang memiliki bentuk dan ukuran tubuh makroskopik. Komunitas adalah kelompok makhluk yang hidup secara bersama-sama dalam suatu tempat yang bersamaan. Dengan demikian komunitas makroalga adalah kelompok tumbuhan rendah yang memiliki ukuran tubuh makroskopik yang hidup bersamaan. Wilayah pesisir Pantai Rap-Rap terletak di Kelurahan Tongkaina, Kota Manado, Provinsi Sulawesi Utara. Lokasi ini merupakan salah satu habitat makroalga yang stabil artinya masih sedikit kerusakan habitat yang terjadi, sehingga makroalga masih dapat diperoleh secara langsung dari alam. Pesisir ini juga dikenal sebagai ekowisata mangrove dan jalur ke Pulau Bunaken. Tujuan penelitian ini adalah mendeskripsikan morfologi dan anatomi masing-masing spesies makroalga. Pengambilan data menggunakan metode Line Transect dengan teknik sampling kuadrat yang dilakukan pada saat surut terendah. Pengukuran suhu menggunakan Thermometer dan salinitas menggunakan Refraktometer, dan untuk penentuan substrat dilihat secara visual jenis dari substrat tersebut. Kata kunci: morfologi, anatomi, komunitas, makroalga, Rap Rap.
The Relationship Between Length and Weight of Sardine Fish, Sardinella spp Manginsela, Fransine B.; Lohoo, Anneke V.; Lasabuda, Ridwan; Rustandi, Yogi
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.52863

Abstract

Fish are vertebrates that live all or part of their lives in water, breathe with gills, are equipped with fins for movement and balance, and are cold-blooded (poikilotherm). Lemuru fish are grouped into fish (poikilotherm). Lemuru fish are grouped in the order Cluipeiformes which is part of small pelagic fish. The research was carried out in January-August 2023 to determine the diversity of total length and weight as well as the relationship between the length and weight of male and female lemuru fish, which was carried out using quantitative descriptive methods. Of the 135 lemuru fish individuals observed, there were 40 male individuals with a total length of between 13,184-15,589 cm and 95 female individuals which were longer between 12,083-16,420 cm, and the weight of male individuals between 17,450 - 43,040 grams and female individuals were 19,630 - 52,470 grams. The length-weight regression equation for females is W = 0.018204 L 2.76026 and for males W = 0.01179 L 2.89363.. Keywords: panjang , small pelagic, growth status. Abstrak Ikan adalah vertebrata yang seluruh atau sebagian hidupnya di air, bernafas dengan insang, dilengkapi sirip untuk pergerakan dan keseimbangannya serta berdarah dingin (poikilotherm). Ikan lemuru dikelompokkan pada  adalah ikan (poikilotherm). Ikan lemuru dikelompokkan pada ordo Cluipeiformes yang menjadi bagian ikan pelagis kecil. Penelitian dilaksanakan pada bulan Januari-Agustus 2023 bertujuan menentukan keragaman panjang total dan berat serta hubungan panjang berat ikan lemuru jantan dan betina yang pelaksanaannya menggunakan metode deskriptif kuantitatif. Dari 135 individu ikan lemuru yang diamati ada 40 individu jantan dengan panjang total selang 13,184-15,589 cm dan 95 individu betina yang lebih panjang selang 12,083-16,420 cm, dan berat individu jantan selang 17,450 - 43,040 gram dan selang individu betina 19,630 – 52,470 gram. Persamaan regresi panjang-berat betina adalah W = 0.018204 L 2,76026 dan jantan W = 0.01179 L 2,89363. Kata kunci: panjang, berat, regresi, korelasi, Bitung.
The Fish Community Of The Sario River Estuary In Manado City Dauhan, Dulce Maria; Rondonuwu, Ari B.; Rangan, Jety K.; Lumingas, Lawrence J. L.; M.Si, Fransine B.; Lohoo, Anneke V.
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.54104

Abstract

The purpose of this research was to determine the fish species composition, relative abundance, and community structure, including ecological indices. The methods used in this study were general field survey methods and fish capture methods using the “swept area” method (Sparre & Venema, 1998). Data were collected based on the time of collection using beach seine gear. The research was conducted in several stages, including fish catching in the field, data analysis, and discussion. The results of this study showed that there were 13 species from 11 families of fish in the Sario River Estuary. The total population obtained in June and July was 292 individuals. 215 individuals were caught in June and 77 individuals were caught in July. The highest composition in both months was the species Ambassis urotaenia, while the lowest number was several species, namely Caranx ignobilis, Osteomugil cunnesius, and Zenarchopterus buffonis. The highest relative abundance in both months was the species Ambassis urotaenia (73.49% and 66.23%). The lowest relative abundance was Caranx ignobilis, Tylosurus crocodilus, and Zenarchopterus buffonis with values of (1.30%). Sillago sihama, Chelonodontops patoca (0.93%). The results of the study showed the community structure in Sario River Estuary in June and July (H' = 0.91 – 0,97, J' = 0.44 – 0.54, D = 0.49 -0.57). Keywords: Fish, Sario River Estuary, Relative Abundance, Community Structure Abstrak Penelitian ini bertujuan untuk mengetahui komposisi jenis ikan, kelimpahan relatif dan struktur komunitas yang meliputi indeks ekologi.Metode yang digunakan dalam penelitian ini yaitu metode umum survei lapangan dan metode penangkapan ikan menggunakan metode “swept area” (Sparre & Venema, 1998). Pengambilan data dilakukan berdasarkan waktu pengambilan menggunakan alat tangkap pukat pantai (beach seine). Penelitian ini dilakukan dengan beberapa tahapan yaitu penangkapan ikan di lapangan yang akan menjadi data, analisis data serta pembahasan.Hasil penelitian ini menunjukkan terdapat 13 spesies dari 11 famili ikan di Muara Sungai Sario. Dengan total populasi yang didapat pada bulan Juni dan sbulan Juli 292 individu. 215 individu tertangkap pada bulan Juni dan 77 individu tertangkap pada bulan Juli. Komposisi tertinggi pada kedua bulan adalah jenis Ambassis urotaenia, sedangkan jumlah terendah ada beberapa jenis yaitu Caranx ignobilis, Osteomugil cunnesius, Zenarchopterus buffonis. Kelimpahan relatif tertinggi pada kedua bulan adalah jenis Ambassis urotaenia (73,49% dan 66,23%). Sedangkan kelimpahan relatif terendah yaitu Caranx ignobilis, Tylosurus crocodilus dan Zenarchopterus buffonis dengan nilai (1,30%). Sillago sihama, Chelonodontops patoca (0,93%). Hasil penelitian menujukkan struktur komunitas di Muara Sungai Sario pada bulan Juni dan bulan Juli (H' = 0,91 – 0,97, J' = 0,44 – 0,54, D = 0,49 -0,57). Kata kunci: Ikan, Muara Sungai Sario, Kelimpahan Relative, Struktur Komunitas.
Community Structure of Macroalgae in the Coastal Waters of Bahowo Tamara, Giovanni Matthew A. J.; Kepel, Rene Charles; Lumingas, Lawrence J. L.; Wantasen, Adnan S.; Lasabuda, Ridwan; Lohoo, Anneke V.
Jurnal Ilmiah PLATAX Vol. 13 No. 2 (2025): ISSUE JULY-DECEMBER 2025
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v13i2.61576

Abstract

This research aims to describe the morphology and anatomy of each species from the research location and to analyze the community structure of macroalgae from the research location. Data collection was done using the Line Transect method with a quadrat sampling technique during the lowest tide. Temperature and salinity checks were measured using a thermometer and refractometer. Substrate determination was done visually based on the type of substrate. The results of this study found 9 species, consisting of 4 red algae species (Rhodophyceae) and 5 green algae species (Ulvophyceae). The morphology of these algae species varies, with different anatomy based on transverse and longitudinal sections of each part of the alga's thallus. The highest species density was H. edulis, while the lowest densities were A. fragilissima, D. versluysii, T. fragilis, and C. racemosa. The macroalgae diversity index values in the three transects are in the medium category, the species evenness index values are stable, the species richness index values are in the low category, and the dominance index values are in the low category. Keywords: Macroalgae, Community, Transect, Quadrat, Bahowo.   Abstrak Tujuan penelitian ini adalah mendeskripsikan morfologi dan anatomi masing-masing spesies dari lokasi penelitian, dan menganalisis struktur komunitas makroalga dari lokasi penelitian. Pengambilan data menggunakan metode Line Transect dengan teknik sampling kuadrat yang dilakukan pada saat surut terendah. Pengecekan suhu dan salinitas diukur dengan menggunakan termometer dan refractometer. Untuk penentuan substrat dilihat secara visual terhadap jenis dari substrat tersebut. Hasil penelitian ini ditemukan 9 spesies yang terdiri dari 4 spesies alga merah (Rhodophyceae), dan 5 spesies alga hijau (Ulvophyceae). Morfologi jenis-jenis alga tersebut beragam dengan anatomi yang berbeda berdasarkan potongan melintang dan memanjang dari masing-masing bagian thallus alga. Kepadatan spesies tertinggi yaitu H. edulis sedangkan kepadatan terendah yaitu A. fragilissima, D. versluysii, T. fragilis, dan C. racemosa. Nilai indeks keanekaragaman makroalga pada ketiga transek termasuk dalam kategori sedang, nilai indeks kemerataan jenis dalam keadaan stabil, nilai indeks kekayaan jenis dalam kategori rendah dan nilai indeks dominasi dalam kategori rendah. Kata kunci: Makroalga, Komunitas, Transek, Kuadrat, Bawoho
The length-weight relationship of the bigeye scad (Selar crumenophthalmus) captured by purseseiner from FMA 716 of North Sulawesi seawaters: A comparative study of the target species sizes on May and August 2022 Sitanggang, Effendi P.; Budiman, Johnny; Sitanggang, Dyan F. D.; Lohoo, Anneke V.; Kalalo, Flora P.
Jurnal Ilmiah PLATAX Vol. 14 No. 1 (2026): ISSUE JANUARY-JUNE 2026
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v14i1.66508

Abstract

Bigeye scad (Selar crumenophthalmus Bloch 1793) is rich source of proteins, Omega-3 fatty acids, and various important vitamins and minerals for human body, that makes the fish has an important economic value. Additionally, because of forming an important shoal on coastal seawaters, the fish is frequently captured, notably by purseseiners in an important quantity from the FMA 716 of North Sulawesi seawaters. The intensiveness captures of the fish may affect the sustainability and continuity life of the species. The research aims at analyzing some biological reproduction aspects of species based on gender and fishing season. The 400 samples, 200 tails on May and 200 tails on August 2022, have selected by a purposive random sampling from the captures. Data analisys refers to some common formulas, such as the length and weight size structure, sex and weight ratio, W-L relationship (W = aLb, W = weight, g), L = length (cmFL), a and b constants, condition factor (K), length at first capture (Lc50%). The legal size is determined by comparing the length at first capture (Lc50%) observed and at first maturity (Lm50%) reference. On May, the sample weight is 33,439 g (51.8% of 400 samples), the sex and weight ratios are 1:1.08 and 1:1.36 respectively with the conversion factor (cf) of 1.26. The average length and weight sizes are 21.62 ± 0.17 cm and 167.20 ± 5.15 g respectively, where the average weight per 1 cmFL is 7.67 ± 0.18 g. The L-W relationship follows W = 0.1492 L 3.0785 (r = 0.86) for male, W = 0.0566 L 3.8088 (r = 0.90) for female, and W = 0.0864 L 3.4940 (r = 0.91) for all, with K average of 1.60 ± 0.02 for male, 1.66 ± 0.03 for female, and 1.63 ± 0.02 for 200 samples. On August, the sample weight is 31,115 g (48.2% of 400 samples), the sex and weight ratios are 1:1.50 and 1:1.82 respectively, with cf of 1.21. The average length and weight sizes are 21.49 ± 0.16 cm and 155.58 ± 4.71 g respectively, where the average weight per 1 cmFL is 7.19 ± 0.17 g. The L-W relationship follows W = 0.1515 L 3.047 (r = 0.88) for male, W = 0.0789 L 3.5485 (r = 0.88) for female, and W = 0.0836 L 3.5023 (r = 0.90) for all samples, with K average of 1.50 ± 0.02 for male, 1.58 ± 0.03for female, and K of 1.55 ± 0.02 for 200 samples. On both fishing seasons, all captures are categorized a positive allometry (b>3) and 96.75% of captures has a legal size. All females have passed their first maturity stage. For this reason, the fishermen must consider carefully when they catch the fishes, outside of the two months. Considering the intensiveness of fishing activities to such species, it is indispensable since early for all stakeholders designing a regulation to limitate captutes by gender size and fishing seasons, for all species of high potential and economic value of high density of shoals. Key words: bigeye scad, biological reproduction aspects, FMA 716, North Sulawesi, fish conservationn