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Sukamto Sukamto - One of the best experts on this subject based on the ideXlab platform.
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TEKNIK PENANGKAPAN IKAN MENGGUNAKAN JARING INSANG PERCOBAAN (experimental gillnets), DI DANAU MATANO SULAWESI SELATAN
2019Co-Authors: Sukamto Sukamto, Tri Muryanto, Henra KuslaniAbstract:Danau Matano adalah bagian dari komplek Danau Malili (Malili Lakes Complexs) merupakan danau purba yang terletak wilayah Kabupaten LuwuTimur, Sulawesi Selatan. Danau Matano adalah danau tektonik purba, terbentuk pada akhir/pliosen sekitar 2-4 juta tahun lalu, luas permukaan 16.410 hektar. Danau Matano merupakan 10 besar danau terdalam di seluruh dunia dan terdalam di Asia Tenggara (Rusdianto, 2018). Selain danau Matano terdapat beberapa danau lainnya yaitu Danau Mahalona, Danau Towuti, Danau Wawontoa/Lantoa dan Danau Masapi. Danau-danau di komplek Malili tersebut saling terhubung oleh sistem suatu daerah aliran sungai yang terkait dengan yang lain. Danau Matano, Mahalona dan Towuti merupakan danau yang bersifat kaskade, dimana danau Matano terletak di bagian hulu, danau Mahalona di bagian tengah serta danau Towuti dibagian hilir. Ketiga danau tersebut merupakan ekosistim air tawar yang dialiri oleh sungai kecil yang juga berada di kawasan tersebut (Nasution, 2008). Fungsi danau Matano antara lain diantaranya untuk tranportasi air, pariwisata, air minum selain fungsi tersebut diatas juga dimanfaatkan masyarakat sekitar untuk usaha perikanan yaitu dengan cara menangkap ikan menggunakan jaring tangkap dan pancing. Danau Matano merupakan sumber daya alam yang sangat potensial maka perusahaan tambang nikel terbesar kedua dunia, PT. INCO (kini PT Vale Indonesia) memanfaatkan Sungai Larona yang berhulu dari Danau Matano sebagai pembangkit listrik tenaga air (PLTA) untuk pemanfaatan di pabrik, dan juga untuk digunakan oleh masyarakat (BRPSDI, 2016).
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ANALISIS KANDUNGAN N-NITRAT DAN ORTHOFOSFAT DI BIBILO DAN DAERAH BEBAS DANAU LIMBOTO, PROVINSI GORONTALO
2016Co-Authors: Dedi Sumarno, Sukamto SukamtoAbstract:Danau Limboto terletak di Provinsi Gorontalo mempunyai peranan dalam bidang perikanan, transportasi, pariwisata, sumber air, dan pencegah banjir. Sumber air utama Danau Limboto berasal dari 20 sungai, empat diantaranya merupakan sungai besar, yaitu Bionga, Molalahu, Alo-pohu, dan Meluopo. Sungai Topadu merupakan outlet Danau Limboto dan bermuara langsung ke laut (Teluk Tomini), dengan jarak antara outlet dan muara Sungai Bone sekitar 15 km (Krismono et al., 2008). Seiring dengan perkembangannya, danau ini mengalami degradasi lingkungan berupa pendangkalan yang diakibatkan oleh banyaknya tumbuhan air, salah satunya adalah eceng gondok (Eichhornia crassipes). Selain itu pula adanya kegiatan pembukaan lahan untuk pertanian dan penambangan batu kapur di lereng bukit di sekitar Danau Limboto dapat mempengaruhi lingkungan danau.
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TEKNIK PENANGKAPAN IKAN DENGAN ALAT TANGKAP DUDAYAHO DI DANAU LIMBOTO GORONTALO (SULAWESI)
BULETIN TEKNIK LITKAYASA Sumber Daya dan Penangkapan, 2016Co-Authors: Sukamto SukamtoAbstract:Danau Limboto terletak di Kabupaten Gorontalo Propinsi Gorontalo (Sulawesi) dengan luas perairan pada tahun 1932 mencapai 7.000 ha dan tahun 1999 menyusut menjadi luas permukaan sekitar 3.000 ha dengan kedalaman rata-rata 2 sampai dengan 3 m (Sarnita et al., 1994). Jarak Danau Limboto sekitar 10 km dari Bandara Jalaludin. Danau Limboto mempunyai banyak fungsi antara lain sebagai pertanian, perikanan, pariwisata, dan pencegah banjir. Kegiatan perikanan selain budi daya juga sebagai perikanan tangkap. Kegiatan ini dilakukan oleh masyarakat sekitar Danau Limboto, sehingga cukup untuk meningkatkan pendapatan nelayan. Jenis alat tangkap yang digunakan oleh nelayan sangat beragam antara lain bunggo, dudayaho (push net), pancing (line fishing), jaring (gill net), sero (winget bambo trap), dan bubu atau bungo (tubular traf). Alat tangkap dudayaho merupakan alat tangkap yang sering ditemukan di Danau Limboto selain jaring lingkar, jaring, dan bibilo. Alat ini menyerupai seser berbentuk segitiga mempunyai ukuran yang besar. Lokasi penangkapan dilakukan di bawah tanaman air seperti eceng gondok, kangkung air, dan hydrilla yang banyak ditemukan di Danau Limboto.
Matthew L. Aardema - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic incongruence and the evolutionary origins of cardenolide resistant forms of na k atpase in Danaus butterflies
Evolution, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.
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Phylogenetic incongruence and the evolutionary origins of cardenolide‐resistant forms of Na+,K+‐ATPase in Danaus butterflies
Evolution, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.
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phylogenetic incongruence and the origins of cardenolide resistant forms of na k atpase in north american Danaus butterflies
bioRxiv, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Rapid species radiations can obscure phylogenetic relationships between even distantly related species and lead to incorrect evolutionary inferences. For this reason, we examined evolutionary relationships among the three North American milkweed butterflies, Danaus plexippus, D. gilippus and D. eresimus using >400 orthologous gene sequences assembled from transcriptome data. Contrary to previous phylogenetic assessments, our results indicate that D. plexippus and D. eresimus are the sister taxa among these species. This result explains many previously noted phylogenetic incongruences such as an amino acid substitution in the sodium-potassium pump (Na+,K+-ATPase) of D. eresimus and D. plexippus, which increases resistance to the toxins found in these butterflies host plants. In accordance with a rapid radiation of Danaus butterflies, we also find evidence that both incomplete lineage sorting and post-speciation genetic exchange have contributed significantly to the evolutionary histories of these species. Furthermore, our findings suggest that D. plexippus is highly derived both morphologically and behaviorally.
Jayne E Yack - One of the best experts on this subject based on the ideXlab platform.
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hearing in caterpillars of the monarch butterfly Danaus plexippus
The Journal of Experimental Biology, 2019Co-Authors: Chantel J Taylor, Jayne E YackAbstract:ABSTRACT Many species of caterpillars have been reported to respond to sound, but there has been limited formal study of what sounds they hear, how they hear them and how they respond to them. Here, we report on hearing in caterpillars of the monarch butterfly (Danaus plexippus). Fourth and fifth instar caterpillars respond to sounds by freezing, contracting, and flicking their thorax in a vertical direction. Behavioural responses were evoked by sound frequencies between 50 and 900 Hz, with best sensitivity at 100–200 Hz. The lowest mean threshold was 79 dB SPL (particle velocity 605 μm s−1) at 150 Hz. When presented with a repeated 200 Hz sound tone, caterpillars habituate by no longer responding. A series of ablation experiments confirmed that the primary sensory receptors are a pair of long hairs, called trichoid sensilla, located on the upper prothorax. These sensilla are ∼450 µm long, rest in a socket and are innervated by a single bipolar sensory neuron. Removal of these setae reduced responses significantly compared with controls. Other setae contributed minimally to hearing in response to 200 Hz tones, and tubercles and prothoracic shields played no apparent role in sound reception. We propose that hearing functions to prevent attacks by aerial insect predators and parasitoids, which produce flight sounds in the frequency range to which the caterpillars are sensitive. This research lays the foundation for further investigations on the function and evolution of hearing in caterpillars, and has significance for the conservation of threatened monarch butterfly larvae living near noisy urban environments and roadways.
Peter Andolfatto - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic incongruence and the evolutionary origins of cardenolide resistant forms of na k atpase in Danaus butterflies
Evolution, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.
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Phylogenetic incongruence and the evolutionary origins of cardenolide‐resistant forms of Na+,K+‐ATPase in Danaus butterflies
Evolution, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.
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phylogenetic incongruence and the origins of cardenolide resistant forms of na k atpase in north american Danaus butterflies
bioRxiv, 2016Co-Authors: Matthew L. Aardema, Peter AndolfattoAbstract:Rapid species radiations can obscure phylogenetic relationships between even distantly related species and lead to incorrect evolutionary inferences. For this reason, we examined evolutionary relationships among the three North American milkweed butterflies, Danaus plexippus, D. gilippus and D. eresimus using >400 orthologous gene sequences assembled from transcriptome data. Contrary to previous phylogenetic assessments, our results indicate that D. plexippus and D. eresimus are the sister taxa among these species. This result explains many previously noted phylogenetic incongruences such as an amino acid substitution in the sodium-potassium pump (Na+,K+-ATPase) of D. eresimus and D. plexippus, which increases resistance to the toxins found in these butterflies host plants. In accordance with a rapid radiation of Danaus butterflies, we also find evidence that both incomplete lineage sorting and post-speciation genetic exchange have contributed significantly to the evolutionary histories of these species. Furthermore, our findings suggest that D. plexippus is highly derived both morphologically and behaviorally.
Stefan W. Toennes - One of the best experts on this subject based on the ideXlab platform.
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poor sequestration of toxic host plant cardenolides and their rapid loss in the milkweed butterfly Danaus chrysippus lepidoptera nymphalidae danainae danaini
Toxicon, 2017Co-Authors: Dietrich Mebs, Cora Wunder, Stefan W. ToennesAbstract:Abstract Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus , is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus , larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus . Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus , calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus , cardenolides seem to be less important for that butterfly's defence against predators.
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Selective sequestration of cardenolide isomers by two species of Danaus butterflies (Lepidoptera: Nymphalidae: Danainae)
Chemoecology, 2012Co-Authors: Dietrich Mebs, Moritz G. Wagner, Stefan W. Toennes, Cora Wunder, Michael BoppréAbstract:Several species of milkweed butterflies (Danaini) are known to sequester cardenolides from their milkweed host plants. In adults of Danaus plexippus and D. gilippus, jointly raised on Asclepias curassavica (Asclepiadaceae), two host-plant cardenolides (calotropin and calactin) were found in significantly different ratios: in D. plexippus and the plant, they occurred in roughly equal ratios, but in D. gilippus, calotropin had a 10–12 times lower concentration, suggesting a selective sequestration of calactin. The two Danaus species belong to different subgenera and the results may be relevant to a better understanding of the evolution of cardenolide sequestration in Danaini.
