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POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA
No full textThe Malayan leaf fish or locally named as kepor (Pristolepis grooti) is one of important biotic components in Ranau Lake ecosystems. This study aimed to estimate population dynamic and exploitation rate of kepor in Ranau Lake, South Sumatera. The population parameters are estimated based on length frequency data which were collected in March to October 2013. Growth parameters and fishing mortality rates were calculated using FiSAT software package. The results showed that kepor’s growth was negative allometric, which tended to gain length faster than weight. Kepor population was dominated (42%) by individual length of 10.0 to 11.0 cm. Predicted length infinity (L) was 17.28 cm with high value of growth rates (K) of 1.4 year-1. The natural mortality rate (M) is 2.57 year-1, the fishing mortality rate (F) is 5.36 year-1 and total mortality rate (Z) is 7.93 year-1. The exploitation rate of Malayan leaf fish in Ranau Lake (E = 0.68 year-1) has passed the optimum score.
STATUS KERAGAMAN IKAN BELIDA (Chitala spp.) DI SUNGAI TULANG BAWANG, PROPINSI LAMPUNG BERDASARKAN PADA KARAKTER MORFOMETRIK DAN INDEKS FLUKTUASI ASIMETRIK
Get PDFPenelitian tentang status keragaman ikan Belida (Chitala spp.) dari Sungai Tulang Bawang berdasarkan pada karakter morfometrik dan indeks fluktuasi asimetrik dilakukan selama tahun 2005 di daerah aliran Sungai Tulang Bawang Propinsi Lampung. Estimasi keragaman berdasarkan pada karakter morfometrik dengan menggunakan nilai coefficient variation diperoleh dengan cara membagi standar deviasi karakter dengan rata-rata, pada 25 karakter morfometrik dari 26 spesimen ikan belida (Chitala spp.). Indeks fluktuasi asimetrik ikan belida (Chitala spp.) dari Sungai Tulang Bawang diestimasi menggunakan formula Palmer dan Strobeck, untuk kemudian melihat CVDI sebagai estimasi keragaman dengan terlebih dahulu melakukan analisis uji ttest untuk mengetahui signifikasi karakter sebelah kiri dan kanan. Klasifikasi nilai coefficient variation untuk karakter morfometrik CVd”25% = sangat seragam, 25%<CVd”50% = cukup seragam, 25 <CVd”50% = cukup bervariasi, dan CVe”75% = sangat bervariasi. Sedangkan nilai fluktuasi asimetrik digunakan indeks 3 tingkatan variasi yang rendah (CVDI=0,1), variasi sedang (CVDI=0,5), dan sangat bervariasi (CVDI=1). Berdasarkan pada nilai coefficient variation sebagian besar karakter morfometrik tergolong cukup seragam 72% (25%<CVd”50%) dan cukup bervariasi 28% (50 <CVd”75%), dengan rata-rata 47,60% tergolong cukup seragam. Berdasarkan pada indeks CVDI terlihat 60% karakter asimetrik tergolong variasi sedang dan sangat bervariasi (CVDI=0,5) dan CVDI=1), 40% termasuk variasi yang rendah. Hasil analisis karakter morfometrik dan indeks fluktuasi asimetrik mengkonfirmasi bahwa populasi ikan belida (Chitala spp.) di Sungai Tulang Bawang telah berada pada kondisi mendekati seragam atau memiliki variasi genetik yang rendah. Research on the status of knife fish (Chitala lopis) diversity in Tulang Bawang River (Lampung Province) based on morphometric charactes and indeks of fluctuating asimetric had been carried out during 2005 at Tulang Bawang River (Lampung Province). Diversity was estimated based on morphometric characters using coefficient variation values, which is derived from dividing the standard deviation characters by its mean, on 25 morphometric characters from 26 knife fish (Chitala lopis) specimens. Fluctuating asimetric indeks of knife fish (Chitala lopis) Tulang Bawang River were estimated using Palmer and Strobeck formula, and then see CVDI as the estimate of diversity, as previously conduct Ttest analysis to find signification character between the right and left of the body. Coefficient variation values derived on morphometric character classified four categories, CVd”25% = as highly uniform, 25%<CVd”50% = middle uniform, 25%<CVd”50% = middle variation, and CVe”75% = highly variation. Meanwhile fluctuating asimetric value employed three rate clasification, low variation (CVDI=0.1), middle variation (CVDI=0.5), and high variaton (CVDI=1). Based on coefficient variation value, most of the morphometric characters were middle uniform 72% (25%<CVd”50%) and middle variation 28% (50%<CVd”75%), with means value is 47.60% classified as middle uniform. Based on indeks CVDI shown 60% asimetric characters classified as variation middle and high variation (CVDI=0.5 and CVDI=1), 40% identified had low variation. Research confirms that knife fish (Chitala lopis) at Tulang Bawang river were in state of closing uniform or presumby have low genetic variation
KELIMPAHAN DAN KERAGAMAN PLANKTON DI DANAU ARANG-ARANG, JAMBI
Get PDFPengamatan kelimpahan dan keragaman plankton telah dilakukan di Danau Arang-Arang, Jambi pada Bulan Juli, Agustus, September, November, dan Desember tahun 2000 dengan menetapkan 4 stasiun pengamatan yaitu inlet, tengah, outlet, dan hutan rawa. Penelitian ini bertujuan untuk mengetahui kelimpahan dan keragaman plankton dalam kaitannya dengan kesuburan perairan
PENGELOLAAN IKAN HAMPAL (Hampala macrolepidota Kuhl & Van Hasselt 1823) DI DANAU RANAU, SUMATERA SELATAN DAN LAMPUNG
Get PDFPemanfaatan dan pengelolaan perikanan harus memperhatikan aspek konservasi agar sumberdaya hayati yang ada didalamnya seperti ikan dapat tetap lestari. Danau Ranau merupakan salah satu sumberdaya alam yang potensial menghasilkan ikan yang telah lama dimanfaatkan masyarakat nelayan setempat sebagai sumber kehidupan. Ikan hampal (Hampala macrolepidota, Kuhl & Van Hasselt 1823) mempunyai peran atau fungsi ekonomis dan ekologis di perairan Danau Ranau. Penelitian dilakukan pada tahun 2013 di perairan Danau Ranau Kabupaten Ogan Komering Ulu Selatan Provinsi Sumatera Selatan dan Kabupaten Lampung Barat Provinsi Lampung. Tujuan penelitian untuk mendapatkan konsep pengelolaan ikan hampal di Danau Ranau. Penelitian mengintegrasikan secara menyeluruh aspek lingkungan perairan, biologi ikan, penangkapan dan dinamika populasi ikan hampal. Pengelolaan ikan hampal di Danau Ranau dapat dilakuan melalui: 1) pengelolaan habitat, 2) pengelolaan populasi dan 3) pengelolaan penangkapan. Pengelolaan ikan hampal di Danau Ranau dapat dilakukan sebelum populasi ikan tersebut menurun sehingga dapat tetap lestari. Merekomendasikan konsep pengelolaan ikan hampal di Danau Ranau kepada Pemerintah Daerah Sumatera Selatan dan Lampung untuk dituangkan dalam Peraturan Daerah.Utilization and water management have to consider the aspect of conservation therefore biological resources such as fish can be preserved. Ranau Lake is one of the potential natural resources to produce fish that has long been used by local fishing communities as a source of lifehood. Hampal barb (Hampala macrolepidota, Kuhl & Van Hasselt in 1823) has economically and ecologically role or function in Ranau Lake. This study was conducted in 2013 in Ranau Lake, South OKU Regency, South Sumatera Province and West Lampung Regency,Lampung Province. The aim of research was to obtain a concept of management of hampal barb in Ranau Lake. The management of hampal in Ranau Lake could be attempted through the integration study of environmental aspects, fish biology, capture fishery and fish population dynamic data. It can be done prior to the fish population decline in order to maintain their stable population. Recommending the concept of hampal barb management in Ranau Lake to South Sumatra and Lampung Government for consideration of developing a local government regulation.
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
BIOLOGICAL CHARACTERS OF SNAKEHEAD GUDGEON (Giuris margaritacea Valenciennes, 1837) IN TONDANO LAKE, MINAHASA, NORTH SULAWESI, INDONESIA
Get PDFSnakehead gudgeon (Giuris margaritacea) or Payangka in Indonesian’s local name, has a high population and been used as a consumption fish mainly by people around Lake Tondano, not only the consumption size, but also the juvenile (it called Nike) are preferred. The fish resources are the essential source and need to keep their sustainable in the future. The research was carried out in 2015. The study was aimed to identify and record some aspects of snakehead gudgeon fish biology in Lake Tondano Mi-nahasa Regency of North Sulawesi. Fish samples were obtained from fisher's catch. The morphometric and meristic character was measured, and also was performed surgery to observe reproduction and food. The results showed that the growth pattern of Giuris margaritacea was positive allometric with sex ratio 1: 1.41. The fish was spawning whole year with fecundity between 36,892-90,102 eggs, and diameter of the egg was 0.285 mm on average. The size of the first mature female was 10.75 cm gonads. Snakehead gudgeon was a carnivorous fish with shrimp as the primary food, and the relative length of the digestive tract was 82.88%
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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