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All Journal JURNAL PESISIR DAN LAUT TROPIS JURNAL ILMIAH PLATAX
Mandagi, Stephanus
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Earth & Planetary Sciences Environmental Science

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Analisis molekuler DNA alga merah (Rhodophyta) Kappaphycus sp. Annisaqois, Manikmayang; Gerung, Grevo; Wullur, Stenly; Sumilat, Deiske; Wagey, Billy; Mandagi, Stephanus
JURNAL PESISIR DAN LAUT TROPIS Vol 6, No 1 (2018): JURNAL PESISIR DAN LAUT TROPIS
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jplt.6.1.2018.20589

Abstract

Indonesia dilaporkan memiliki sebanyak 555 spesies atau sekitar 6.24% dari total jumlah spesies rumput laut dunia yang teridentifikasi saat ini. Rumput laut dari kelas alga merah (Rhodophyceae) menempati urutan terbanyak dari jumlah jenis yang tumbuh di perairan laut Indonesia yaitu sekitar 452 jenis. Rumput laut dari kelas alga merah ini terutama dari jenis Kappaphycus sp. memiliki tingkat plastisitas morfologi yang tinggi sehingga teknik identifikasi konvensional menggunakan indikator karakter morfologi sering kurang maksimal dalam penelusuran identitas spesies rumput laut. Penelitian ini merupakan tahapan awal dalam rangkaian analisa molekuler rumput laut jenis Kappaphycus sp. Dalam penelitian ini, ekstraksi DNA Kappaphycus sp. dilakukan dengan metode CTAB (Doyle and Doyle, 1987; Allen, 2006; Nugroho et al., 2015) yang dimodifikasi. Gen rbcL diamplifikasi pada PCR menggunakan beberapa pasangan primer. Keberhasilan proses ekstraksi DNA genomik dan amplifikasi gen rbcL dari Kappaphycus sp. dideteksi melalui UV transilluminator setelah melalui proses elektroforesis gel. Munculnya pita DNA pada penggunaan primer rbcL F-7 (for) dan R-753 (rev) yang menghasilkan panjang pita DNA antara 1400-1600 bp dan primer rbcL F-577 (for) dan R-753 (rev) yang menghasilkan panjang pita DNA antara 900-1400 bp menjadi indikasi keberhasilan amplifikasi gen rcbL pada rumput laut Kappaphycus sp.
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  
The Fish Community Of The Tondano River Estuary In Manado City: Dei, Katrin Dowena; Rondonuwu, Ari B.; Wantasen, Adnan S.; Mandagi, Stephanus; Mantiri, Rose O. S. E.; Kambey, Alex D.
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.v12i1.54156

Abstract

This study was conducted to determine the relative abundance, species composition, relative abundance, and structure of fish communities. The data collection method used was the “Swept area” method. Sampling was conducted twice. The first sampling was conducted on June 17, 2023, and the second sampling was conducted on July 4, 2023, at the Tondano River estuary. Data collection was conducted at low tide. The data analysis used was relative abundance, diversity index, evenness index, and dominance index. The results of this study showed that the fish species composition in the Tondano River estuary consisted of 15 families, 15 genera, and 18 species with a total of 288 individuals. Between the two observed months, June and July, the number of species was higher in June. Based on the data analysis, the highest relative abundance in the Tondano River estuary was in the June phase, namely the Ambassis urotaenia species with a value of 31.5%. The diversity of fish species in the June and July phases was classified as quite high, considering the relatively high evenness index and low dominance index. Keywords: Tondano River Estuary, Relative Abundance, Diversity Index. Abstrak Penelitian ini dilakukan dengan tujuan untuk mengetahui kelimpahan relatif, komposisi spesies ikan, kelimpahan relatif dan struktur komunitas ikan. Metode pengambilan data ikan menggunakan metode metode “Swept area”. Pengambilan sampel dilakukan sebanyak 2 kali. Pengambilan sampel pertama dilakukan pada bulan juni tanggal 17 juni 2023 dan pengambilan sampel kedua dilakukan pada bulan juli tanggal 4 juli 2023 yang berlokasi di Muara Sungai Tondano. Pengambilan data dilakukan pada waktu surut. Analisis data yang digunakan adalah kelimpahan relatif, indeks keanekaragaman, indeks kemerataan, dan indeks dominansi. Hasil penelitian ini menunjukkan komposisi jenis ikan di Muara Sungai Tondano terdiri 15 famili, 15 genus dan 18 spesies dengan total 288 individu. Diantara kedua fase bulan yang diamati, yaitu bulan Juni dan bulan Juli, jumlah spesies lebih banyak ditemukan pada Juni. Berdasarkan hasil analisis data kelimpahan relatif tertinggi di Muara Sungai Tondano ada pada fase Juni yaitu spesies Ambassis urotaenia dengan nilai 31.5 %. Keanekaragaman jenis ikan pada fase bulan Juni dan Juli tergolong cukup tinggi dengan memperhatikan indeks kemerataan yang cukup tinggi dan indeks dominansi yang rendah. Kata kunci: Muara Sungai Tondano, Kelimpahan Relatif, Indeks Keanekaragaman.
Organic Carbon Dynamics In Mangrove Sediments Of North Minahasa, Indonesia Mandagi, Stephanus
Jurnal Ilmiah Platax Vol. 12 No. 2 (2024): ISSUE JULY-DECEMBER 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i2.57229

Abstract

This study aimed to investigate the carbon content in mangrove sediments within the North Minahasa District Marine Conservation Area and to understand the factors affecting organic carbon dynamics. It is revealed that the carbon content is significantly varied. Carbon content ranged from 13.874 to 132.65 Mg C ha-1 across different sampling locations, with an overall stored carbon content estimated at approximately 645.19 Mg C ha-1. Soil density and depth were identified as key factors influencing carbon storage, with thicker soil density associated with higher carbon reserves. These findings highlight the importance of understanding local sediment characteristics for effective blue carbon ecosystem management and conservation strategies. Keywords: carbon, sediment, mangrove, North Minahasa
Co-Authors Adnan Wantasen Alex D. Kambey Anneke V. Lohoo Annisaqois, Manikmayang Ari B. Rondonuwu Bataragoa, Nego Billy Theodorus Wagey Dei, Katrin Dowena Deiske Adeliene Sumilat, Deiske Adeliene Grevo S Gerung Lumingas, Lawrence Manginsela, Fransine Rose O. S. E. Mantiri, Rose O. S. E. Rustandi, Yogi Stenly Wullur