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Pertumbuhan Dan Kelulusan Hidup Kepitingbakau (Scylla serrata, Forskal) Dengan Perlakuan Salinitas Berbeda
Get PDFTujuan dari penelitian ini adalah untuk mendapatkan penurunan salinitas optimal bagi pertumbuhan dan kelulusan hidup kepiting bakau, Scylla serrata. Bobot benih yang digunakan sekitar 47,65-51,32 gram dan panjang karapas 64,35-71,30 mm dan dimasukkan dalam 12 tangki (1 m x 1 m x 0,4 m) dengan kepadatan 4 ekor. Kepiting diberi makan usus ayam segar sekitar 10% bobot perhari. Penggantian air lebih dari 150% per minggu. Pada awal percobaan setiap tangki berisi salinitas yang sama (33 ppt). Setiap minggu tiap tangki dilakukan penurunan salinitas sesuai perlakuan, yaitu (A) salinitas tetap, (B) penurunan salinitas 2 ppt, (C) penurunan salinitas 4 ppt, dan (D) penurunan salinitas 6 ppt. Hasil penelitian menunjukkan bahwa penurunan salinitas 4 ppt adalah perlakuan terbaik untuk kepiting bakau, tetapi tidak berpengaruh pada nilai kelulusan hidu
JENIS IKAN LAUT DALAM DI PERAIRAN TELUK MANADO SULAWESI UTARA
Get PDFThe aims of this study was to determine the types of fish in the deep sea ecosystem in the Manado Bay area, and to measure the water quality (temperature and salinity) at the study site. The study began with exploration of deep sea locations in Manado Bay, then determined the location of the station consisting of 3 fishing points determined randomly. Determination of depth using the Fish Finder. The method used in obtaining deep sea fish species is the Jigging technique. This technique uses artificial bait with a base of tin, stainless steel wire and a hologram. Some of the data measured from the research are fish species, morphometrics, and water quality. Based on water quality data (temperature and salinity), the waters of Manado Bay have sea surface temperatures ranging from 28.00C and 29.70C and surface salinity in the waters ranges from 33.19 ppt and 34.67 ppt. The types of deep sea fish obtained were 7 species spread out at station 1 there were 4 species consisting of Brama australis, Thysites atun, Lepidocybium flavobrunneum, Sphyraena barracuda, Gymnosarda unicolor, Carcharodon carcharias, Gempylus serpens. The number of fish recorded from the research is 41 individuals. The most common type found was Thyrsites atun, which consisted of 25 individuals spread out at stations 2 and 3.Keywords: fish in the deep sea, Jigging technique, temperature, salinityÂ
LAJU PERTUMBUHAN, EFISIENSI PEMANFAATAN PAKAN, KANDUNGAN POTASIUM TUBUH, DAN GRADIEN OSMOTIK POSTLARVA VANAME (Litopenaeus Vannamei, Boone) PADA POTASIUM MEDIA BERBEDA
Get PDFEffect of K+ concentration on growth rate, feed efficiency, potassium whole body, and osmoregulatory capacity of L. vannamei postlarvae Boone, 1931 were investigated. Treatments consisted of different concentration of K+ added to distilled water. Four treatments were set, namely A, B, C and D, where K2CO3 levels were 0, 30, 60 and 90 ppm, respectively. After the 42-days feeding trial, growth rate and potassium whole body of the shrimp under treatment D (90 ppm K2CO3) were significantly higher, while the value of osmoregulatory capacity in treatment A (0 ppm K2CO3) significantly higher than those under the other four treatments. The results indicated treatment C (60 ppm K2CO3) were the optimum K+ level for growth rate with increasing body size
GROWTH RESPONSE OF WHITE SHRIMP (Litopenaeus vannamei) REARED IN LOW SALINITY MEDIUM, FED DIFFERENT PROTEIN AND CALCIUM LEVELS
Get PDFThe white shrimp (Litopenaeus vannamei) has been an important commercial shrimp species in Indonesia. This species is tolerance to low salinity therefore, it is important to develop its aquaculture. The purpose of this study was to study the effect of protein and calcium levels in diet on growth performance of the white shrimp post larvae. A factorial experiment at three levels of dietary protein (25, 35, 45%) and three levels of calcium (0, 2, 4%) with three replicates were used in this experiment. Fifteen shrimps (PL25) were placed in triplicate 45-l glasses aquarium. Salinity in shrimp aquarium was 2 ppt. The shrimps were fed of about 8% of body weight four times per day for 28 days. Measured parameters were daily growth rate, feed efficiency, RNA/DNA ratio, frequency of moulting, calcium and protein retentions. Results showed that shrimp fed on diet 45% protein and 2% calcium levels produce higher daily growth rate, feed efficiency, RNA/DNA ratio, protein retention, compared to the other treatments. It was concluded that the white shrimp post larvae required 45% protein and 2% calcium for the shrimp maintenance in a low salinity condition. Keywords: protein, calcium, RNA/DNA ratio, moulting, Litopenaeus vanname
KUALITAS AIR DAN PERTUMBUHAN POPULASI ROTIFER Brachionus rotundiformis STRAIN TUMPAAN PADA PAKAN BERBEDA
Get PDFTujuan dari penelitian adalah membandingkan pertumbuhan populasi rotifer Brachionus rotundiformis yang diberi perlakuan pakan mikroalga Nannochloropsis oculata dan ikan mentah, serta mendapatkan data kualitas air dari medium kultur dengan pakan berbeda. Pengambilan sampel rotifer di desa Tumpaan Kabupaten Minahasa Selatan, berupa areal reklamasi dan tempat pembuangan air limbah rumah tangga. Rotifer kemudian diidentifikasi dan dikultur klon sehingga tersedia stok untuk penelitian. Perlakuan pakan menggunakan mikroalga Nannochloropsis oculata dan ikan mentah jenis tongkol (Euthynus sp.). Mikroalga sebelumnya diperbanyak lewat kultur menggunakan media KW21 dalam kondisi laboratorim. Ikan mentah sebanyak 3 g digunakan sedangkan kepadatan rotifer adalah 10 ind/ml. Pengambilan data populasi rotifer dimulai dari hari pertama hingga mencapai puncak populasi, sedangkan data kualitas air pada wadah kultur diambil pada akhir penelitian yaitu berupa data suhu, salinitas, DO, pH, ammonia, nitrat, dan nitrit. Hasil penelitian pertumbuhan populasi rotifer dengan pakan ikan mentah menunjukkan puncak populasi lebih tinggi (190 ind.ml-1) dibanding kultur dengan pemberian mikroalga (93 ind. ml-1). Nilai kualitas air yang terlihat berbeda adalah nilai ammonia yaitu pada media dengan pakan mikroalga 1,24 mg/l, sedangkan pada media ikan mentah adalah 9,80 mg/l
VIABILITAS ROTIFER Brachionus rotundiformis STRAIN MERAS PADA SUHU DAN SALINITAS BERBEDA
Get PDFRotifer jenis Brachionus rotundiformis merupakan salah satu spesies zooplankton yang dijumpai mendominasi perairan tambak di beberapa lokasi di Sulawesi Utara, antara lain di pertambakan Meras, Manado. Rotifer strain lokal ini telah diteliti untuk mengetahui potensi reproduksinya melalui kajian viabilitas lewat pemeliharaan pada suhu dan salinitas berbeda menggunakan pakan Chlorella sp. Metode yang digunakan dalam penelitian adalah metode kultur individu. Perlakuan yang digunakan adalah kombinasi suhu (250C, 300C, 350C) dengan salinitas (30 ppt, 35 ppt, 40 ppt). Percobaan diawali inokulasi telur generasi pertama ke dalam multiwellplate. Tiap cekungan wadah diisi satu individu dengan kepadatan pakan 3x106 sel/ml. Pengamatan dilakukan dua kali sehari dengan interval 12 jam. Data yang diperoleh selanjutnya dianalisis dengan metode life table. Hasil penelitian menunjukkan tingkat lulus hidup tertinggi sekitar 91% sampai 5 hari dicapai pada suhu 250C dengan salinitas 35 ppt, demikian juga harapan hidup terlama pada kondisi demikian yaitu sampai 8 hari. Sedangkan harapan hidup terpendek hanya 3,62 hari dicapai pada suhu 300C dengan salinitas 30 ppt. Puncak fertilitas tertinggi yaitu 7,3 didapatkan pada suhu 300C dengan salinitas 40 ppt, namun kombinasi suhu 250C dengan salinitas 35 ppt merupakan perlakuan optimal untuk laju pertumbuhan melalui hasil nilai Ro tertinggi yaitu 14,23
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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