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kologi Pemangsaan Ikan Oskar dan Potensi Dampak Introduksinya ( Trichoderma harzianum Potency as a Biofungicide on Tomato Plant ) Karyadi Baskoro; A Sjarmidi; A Rustama
Biosaintifika: Journal of Biology & Biology Education Vol 1, No 1 (2009): March 2009
Publisher : Department of Biology, Faculty of Mathematics and Sciences, Semarang State University . Ro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/biosaintifika.v1i1.41

Abstract

Penelitian mengenai ekologi pemangsaan ikan oskar (Astronotus ocellatus Agassiz) ini bertujuan untuk mengetahui pola waktu makan, pengaruh ukuran mangsa terhadap tingkat pemangsaan, pengaruh kepadatan mangsa terhadap tingkat pemangsaan, perilaku pemangsaan, dan mengkaji potensi dampak introduksi ikan oskar. Penelitian dilaksanakan di Danau Rawa Pening, Ambarawa, dan di Laboratorium Biologi Universitas Diponegoro. Pola waktu makan diuji dengan mencatat jumlah mangsa yang dikonsumsi setiap 2 jam. Pengujian pengaruh ukuran mangsa terhadap tingkat pemangsaan oskar dilakukan dengan memberi mangsa berbagai ukuran. Pengujian pengaruh kepadatan mangsa terhadap tingkat pemangsaan untuk uji satu mangsa, dilakukan dengan memberi mangsa secara bertahap sampai tercapai jumlah optimum. Untuk uji dua mangsa, jumlah mangsa diberikan dalam berbagai proporsi (16:4, 12:8, 10:10, 8:12, 4:16). Sifat pemangsaan ikan oskar diuji dengan mendedahkannya selama 1 hari di stasiun lapangan, kemudian dilakukan analisis saluran pencernaan. Sedangkan di laboratorium dicatat tingkat konsumsi tujuh jenis mangsa setiap 24 jam. Hasil penelitian menunjukkan bahwa ikan oskar bersifat diurnal. Ukuran mangsa (hambatan morfologi), mempengaruhi tingkat pemangsaan ditunjukkan dengan konsumsi mangsa yang berukuran lebih kecil dari ukuran mulut ikan oskar ( 1,4 cm). Tingkat pemangsaan dipengaruhi secara nyata oleh pertambahan tingkat kepadatan mangsa (y = -0,0233x2 + 1,4471x – 1,6357; r2 = 0,959; p0,05 dan y = -0,0348x2 + 1,9155x–4,7821; r2=0,855; p0,05) dan menunjukkan adanya respon fungsional (I dan II). Ikan oskar menunjukkan sifat pergeseran mangsa dari proporsi mangsa (16:4) ke (4:16), mengikuti kepadatan mangsa yang lebih tinggi. Ikan oskar mengkonsumsi semua jenis mangsa (tujuh jenis) sehingga dapat disebut sebagai karnivora generalis. Berdasarkan hasil percobaan dan studi literatur, dapat dinyatakan bahwa ikan oskar berpotensi untuk menjadi mantap dan invasif, dan menimbulkan gangguan terhadap komponen biotik lokal pada komunitas perairan. Kata Kunci : jenis introduksi, pemangsaan, oskar
THE LOCAL COMMUNITY UNDERSTANDING OF THE FACTORS INFLUENCING THE DECLINE OF SANINTEN (CASTANOPSIS ARGENTEA (BLUME) A.DC.) AND TUNGURUT (CASTANOPSIS TUNGURRUT (BLUME) A.DC.) IN THE BUFFER VILLAGES OF THE GUNUNG HALIMUN-SALAK NATIONAL PARK ELBIBIYA IZZUL PENIDDA; UMARI JUMARI; KARYADI BASKORO; DENI SAHRONI; PENIWIDIYANTI PENIWIDIYANTI; WAWAN SUJARWO
Reinwardtia Vol. 23 No. 1 (2024)
Publisher : BRIN Publishing (Penerbit BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/reinwardtia.2024.4710

Abstract

Saninten (Castanopsis argentea) and tungurut (Castanopsis tungurrut) are plant species belonging to the family Fagaceae, native to the mountainous forest ecosystem within the Gunung Halimun-Salak National Park (GHSNP). These species are currently classified as endangered according to the IUCN Red List due to their significance in providing seeds for consumption and wood for construction materials. This research aims to examine the local community’s knowledge concerning the presence, scarcity, and underlying causes of the decline of both species in the buffer villages of GHSNP. In this study, we employed survey methods and semi-structured interviews conducted with various informants. The data collected were meticulously described and analyzed descriptively. The findings revealed that the local community, in general, holds knowledge about the scarcity of species primarily based on field observations rather than legal or conservation status. Currently, both species are challenging to locate in the buffer villages of the GHSNP. According to the local community’s knowledge, the causes of species scarcity can be categorized into internal and external factors. Internal factors include both species having a slow natural regeneration pattern, difficulties in germination, and vulnerability of seedlings to environmental conditions. Meanwhile, external factors encompass seed and timber exploitation, habitat loss, climate changes, limited knowledge, skills, and understanding of forest plants, and the current perception among locals that C. argentea and C. tungurrut offer limited economic benefits, leading to the gradual neglect of these species’ existence.
THE LOCAL COMMUNITY UNDERSTANDING OF THE FACTORS INFLUENCING THE DECLINE OF SANINTEN (CASTANOPSIS ARGENTEA (BLUME) A.DC.) AND TUNGURUT (CASTANOPSIS TUNGURRUT (BLUME) A.DC.) IN THE BUFFER VILLAGES OF THE GUNUNG HALIMUN-SALAK NATIONAL PARK ELBIBIYA IZZUL PENIDDA; UMARI JUMARI; KARYADI BASKORO; DENI SAHRONI; PENIWIDIYANTI PENIWIDIYANTI; WAWAN SUJARWO
Reinwardtia Vol. 23 No. 1 (2024)
Publisher : BRIN Publishing (Penerbit BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/reinwardtia.2024.4710

Abstract

Saninten (Castanopsis argentea) and tungurut (Castanopsis tungurrut) are plant species belonging to the family Fagaceae, native to the mountainous forest ecosystem within the Gunung Halimun-Salak National Park (GHSNP). These species are currently classified as endangered according to the IUCN Red List due to their significance in providing seeds for consumption and wood for construction materials. This research aims to examine the local community’s knowledge concerning the presence, scarcity, and underlying causes of the decline of both species in the buffer villages of GHSNP. In this study, we employed survey methods and semi-structured interviews conducted with various informants. The data collected were meticulously described and analyzed descriptively. The findings revealed that the local community, in general, holds knowledge about the scarcity of species primarily based on field observations rather than legal or conservation status. Currently, both species are challenging to locate in the buffer villages of the GHSNP. According to the local community’s knowledge, the causes of species scarcity can be categorized into internal and external factors. Internal factors include both species having a slow natural regeneration pattern, difficulties in germination, and vulnerability of seedlings to environmental conditions. Meanwhile, external factors encompass seed and timber exploitation, habitat loss, climate changes, limited knowledge, skills, and understanding of forest plants, and the current perception among locals that C. argentea and C. tungurrut offer limited economic benefits, leading to the gradual neglect of these species’ existence.