Diversitas Ikan Pada Ekosistem Terumbu Karang Di Perairan Pulau Menjangan, Taman Nasional Bali Barat

Tujuan penelitian adalah mengkaji keragaman ikan-ikan karang dan mengetahui penutupan terumbu karang di perairan Pulau Menjangan, Taman Nasional Bali Barat. Penelitian dilaksanakan dari akhir bulan April sampai awal bulan Mei 2012 di perairan Pulau Menjangan. Jumlah stasiun pengamatan ditetapkan sebanyak 8 lokasi berdasarkan perbedaan habitat. Pengukuran kondisi lingkungan dan pengambilan sampel dilakukan dengan penyelaman pada kedalaman 3 dan 10 m. Jumlah dan jenis ikan yang berada pada jangkauan 2,5 m dari transek sepanjang 50 m disensus dengan metode Underwater Visual Census. Jenis ikan karang diidentifikasi secara langsung insitu. Jenis dan luas penutupan karang dicatat dengan metode Line Intercept Transect. Pencatatan jenis terumbu karang yang dilewati transek didasarkan pada bentuk pertumbuhan (lifeform), sedangkan luas penutupan terumbu karang menggunakan Lifeform Report. Data yang diperoleh dianalisis secarakuantitatif berdasarkan indeks biologis. Hasil dari penelitian diperoleh nilai indeks keanekaragaman ikan (H’) berkisar antara 0,8499–2,1360, keseragaman (E) antara 0,36–0,73 dan indeks dominansi (C) berkisar antara 0,163–0,647. Cacah individu ikan sebanyak 5753 ekor dari 62 genus yang berasal dari 32 suku, sedangkan kemelimpahan ikan (D) berkisar antara 0,756–2,680 ekor/m2. Jumlah individu dan suku ikan mayor dominan pada semua lokasi. Tutupan terumbu karang berada pada kisaran 0,66–67,34% yang dikategorikan pada kondisi sedang hingga baik

Food and the Growth of Introduced Milkfish, Chanos Chanos (Forsskal, 1775) in Sermo Reservoir, Kulon Progo

Tujuan penelitian adalah untuk mengkaji makanan dan pertumbuhan ikan bandeng tebaran di waduk Sermo Kabupaten Kulon Progo. Penelitian dilakukan dengan menebar yuwana ikan bandeng yang panjang tubuh berkisar 5-7 cm dan bo-bot 0,6-1,0 g ke perairan Waduk Sermo sebanyak 10.000 ekor. Sampling ikan bandeng menggunakan jaring insang dilakukan tiap bulan sekali dari Mei sampai Oktober 2015. Ikan bandeng yang terjerat jaring dibawa ke laboratorium untuk diukur panjang, ditimbang bobot individu, dan dilakukan pembedahan untuk diambil saluran pencernaannya. Sampling plankton dilakukan dengan mengambil air permukaan menggunakan ember dan menyaring dengan plankton net, kemudian diawetkan dalam larutan formalin hingga identifikasi dan penghitungan jenisnya. Data dianalisis untuk me-nentukan jenis makanan dan pemilihan makanan, laju pertumbuhan, panjang usus relatif, dan hubungan panjang bobot. Hasil penelitian menunjukkan panjang usus relatif ikan bandeng sebesar 5,4-6,4 yang dikategorikan sebagai ikan herbi-vora. Jenis makanan yang ditemukan pada ikan berukuran 15 cm. Proporsi zooplankton pada usus ikan semakin banyak seiring ukuran ikan bandeng. Jenis fitoplankton yang ditemukan dominan pada saluran pencernaan adalah Nitzschia sp., sedangkan zooplankton adalah Cyclop sp. dan Diaptomus sp. Yuwana ikan bandeng dapat tumbuh baik di kawasan Waduk Sermo. Laju pertumbuhan panjang harian berkisar 0,0084 - 0,2056 cm, sedangkan laju pertumbuhan bobot harian berkisar 0,06301,1182 g. Hubungan panjang bobot ikan bandeng membentuk persamaan W=0,0069 L 3,0186 dengan indeks regresi R2=0,98, sehingga ikan bandeng cenderung memiliki pola pertumbuhan isometrik. Penelitian lebih lanjut diperlukan untuk mengetahui dampak introduksi ikan bandeng pada komunitas ikan di Waduk Sermo

Biological Parameters of Bonylip Barb (Osteochilus Vittatus Valenciennes, 1842) in Lake Rawa Pening Semarang Regency

Bonylip barb (Osteochilus vittatus Valenciennes, 1842) is an indigenous fish which is the main target of fishermen in lake Rawa Pening. This study aims to determine the biological parameters including length-weight relationship, con-dition factor, and sex ratio of bonylip barb in lake Rawa Pening, Semarang Regency. Fish sampling was conducted biweekly from October 2019 to March 2020, caught using bamboo blinds operated by local fishermen. Data collected consisted of total length, individual weight, and sex. Data on the length-weight relationship and condition factors were analyzed descriptively, while the sex ratio was analyzed with the chi-square test (χ2). The results showed that female bonylip barb was obtained as many as 392 individuals with a length-range between 10.0-26.0 cm and a weight range between 14.5-264.1 g. The male counted 255 individuals with a length range of 10.2-22.4 cm and a weight range of 15.0-160.9 g. The growth pattern was allometric negative. The equation of the length-weight relationship of female was W = 0.0186 L 2.9096 (R² = 0.9527), and the male was W = 0.0151 L 2.9689 (R² = 0.9386). The value of the average condition factor of females was 1.05, and the males was 1.02. The condition factor in females was in excellent condition (> 1.05), and males were in good condition (0.95-1.05). The overall sex ratio of male and female was 1:1.54. It means that females population was significantly higher than males

Reproductive Biology of Striped Snakehead, Channa Striata (Bloch, 1793) in Lake Rawa Pening, Central Java

The striped snakehead (Channa striata Bloch, 1793) is the top predator fish found in Lake Rawa Pening and other freshwaters. Its population was declining due to very high fishing pressures, habitat quality decreases, and other fac-tors. The aim of this study was to examine the condition factor and fecundity of snakehead in Lake Rawa Pening. Fish sampling was carried out monthly from October 2017 to August 2018, using fish fence made from bamboo blinds operated by local fishermen. Total length, individual body weight, stage of gonadal maturity (MS), gonadal weight, and oocytes diameter of fish samples were measured. Fish condition factor, gonado somatic index (GSI), oocyte diameter, fecundity, and the size of first maturity of fish were determined. There were 409 individuals snakehead fish collected consisting of 138 females and 271 males. Fish length ranged from 234-646 mm (males) and 242-648 mm (females). The average of the condition factor (K) of male ranged from 0.778 to 0.923, while in female ranged from 0.826 to 0.929. The relationship between the length-weight of male and female was isometric. The percentage of female snakehead that reached MS I; II; III; IV was 15.6; 27.0; 37.4; 20.0%, respectively. The GSI ranged from 1.52 to 3.54. Oocyte diameter ranged from 0.5 to 1.7 mm with an average of 1.2 mm. Fecundity ranged from 2,843-23,230 eggs with an average of 9,167 eggs. The female snakehead was predicted to reach the first sexual maturity at a total length of 315 mm

Length-weight Relationship and Condition Factor of an Endemic Lagusia Micracanthus Bleeker, 1860 in Rivers of the Maros Watershed

Lagusia micracanthus is one of endemic freshwater fish in Sulawesi. It also has been locally consumed. The purpose of this research was to analyze length-weight relationship and condition factors of L. micracanthus in rivers of the Maros Watershed, South Sulawesi Province . The study was conducted in three rivers, namely Pattunuang River, Bantimurung River and Pucak River. The sampling was conducted monthly from May 2018 to April 2019. Fish samples were collected by an electric shocker (12 V and 9 A). A total of 1850 individual fishes with samples ranging from 31.58-127.79 mm in total length and 0.76-31.07 g in weight. The length-weight relationship was W = 0.00009L2.6241 (r = 0.95) in Pattunuang River, W = 0.0001L2.5237 (r = 0.94) in Bantimurung River, and W = 0.0001L2.4953 (r = 0.92) in Pucak River. The slope (b) values of L. micracanthus obtained a negative allometric growth pattern (b <3). The relative condition factors of L. micracanthus was fluctuated from 0.86 to 1.43 in Pattunuang River, 0.65 to 1.45 in Bantimurung River, and 0.55 to 1.26 in Pucak River. The condition factor increased towards the peak of the spawning season and decreased after the spawning period. The condition factor increased with the increasing of gonad maturity stage up to stage IV and decreased after spawned or stage V

Morphometric and Meristic Characteristics of an Endemic Lagusia Micracanthus Bleeker, 1860 in the Rivers of Maros and Walanae Cenranae Watersheds

Pirik (Lagusia micracanthus Bleeker, 1860) is one of endemic fishes in Sulawesi. Morphometric and meristic infor-mation of Pirik population in various habitats are unknown. The present study aimed to determine the morphometric and meristic variations of Pirik in Maros and Walanae Cenranae Watersheds. Sampling collection was carried out monthly from May 2018 to April 2019 in the Maros watershed, namely Pattunuang River (M1), Bantimurung River (M2), Pucak River (M3); and in Walanae Cenranae watershed particularly in Camba River (W1), Sanrego River (W2), and Ompo River (W3). Morphometric measurements consisted of 31 characters and meristic measurements consisted of 10 characters. Morphometric data was standardized by dividing all morphometric characters by standard length (SL). Analysis of vari­ance (ANOVA) and discriminant analysis (Discriminant Function Analysis) were applied for data analysis. The results showed that the Pirik taken from rivers in the Maros and Walanae Cenranae watershed are two different population groups. There are 12 distinguishing morphometric features for Pirik of the Maros and Walanae Cenranae watershed, i.e. TL (total length), SL (standard length), BDdSA (body depth-dorsal fin origin), HL (head length), Jlup (upper-jaw length), PAfL (pre-anal fin length), ABL (Anal fin base length), PelRL (pelvic ray length), AFRL (anal fin ray length), CPL (caudal peduncle length), CLLup (upper caudal lobe length) and CLLmid (mid-caudal length). There is no significant difference of meristic characters of Pirik obtained from the Maros and Walana