ABSTRAKIkan baung (Hemibagrus nemurus Val. 1840) termasuk kelompok catfish bernilai ekonomis, di Asia populer dengan nama "green catfish". Informasi tentang variasi genetik dan keragaan bioreproduksi dari ketiga kandidat populasi hasil kegiatan 2011, yaitu: populasi Cisadane (Sdn), Cirata (Crt), dan Serayu (Sry) telah dijadikan informasi dasar dalam keperluan seleksi atau persilangan antar strain agar diperoleh ikan yang cepat tumbuh. Populasi Serayu menunjukkan tingkat variasi genetik paling kecil, namun memiliki aspek bioreproduksi lebih baik, sementara populasi Cirata menunjukkan kekerabatan dan variasi genetik lebih tinggi dari populasi Serayu dan Cisadane. Penelitian ini bertujuan untuk mengetahui keragaan bioreproduksi dan pertumbuhan hasil persilangan dari tiga populasi yang digunakan. Keturunan hasil persilangan antara ketiga populasi telah diamati pada aspek Spesific Growth Rate (SGR), bobot akhir, dan sintasan (SR) pada stadia benih umur 42 hari, serta parameter bioreproduksi dari masing-masing populasi induk antara lain: perkembangan gonad, fekunditas, dan indeks ova somatik. Hasil persilangan antara populasi Sdn x Sry menghasilkan nilai heterosis tertinggi pada parameter SGR (8,72%); heterosis sintasan tertinggi dicapai oleh persilangan Sry dengan Sdn (45,45%); sedangkan bobot akhir dicapai oleh persilangan Crt dengan Sdn (22,08%). Persilangan dua arah antara populasi Cisadane dan populasi Cirata adalah persilangan dengan respons tertinggi pada parameter SR dan bobot akhir nilai IOS (Indeks Ova Somatik) Cisadane 15,9% dan Cirata 20,7%. KATA KUNCI: ikan baung, persilangan, intraspesifik, heterosis ABSTRACT:Bioreproduction

Aquaculture of the African catfish Clarias gariepinus has rapidly increased in SouthEast Asia over recent years, which has now become one of the most cultivated species. This culture intensification has resulted in the development of various diseases, among which the Motile Aeromonas Septicaemia (MAS) caused by Aeromonas hydrophila. The present study aimed at investigating the potential of three plants, Piper betle, Psidium guajava and Tithonia diversifolia, to prevent this disease using an enriched fish diet during four weeks. Though the minimum inhibitory and bactericidal concentrations of acetone-extracts were relatively high (2-32 mg mL-1 and 8-64 mg mL-1 , respectively), all 3 plant powders imbedded in feed significantly reduced fish mortalities following an experimental infection with A. hydrophila, as indicated by relative percent survivals (RPS) ranging from 77% to 79%. When used in combination, the 3 plant extracts showed no interaction in vitro. Even though they improved RPS in comparison with controls, they were, however, less efficient in reducing mortalities than single plants. None of the plant-enriched diet had a clear effect on blood cell count or on reactive oxygen species (ROS) production (except for P. betle, which significantly increased ROS production after infection); however, both individual plants and their combinations significantly limited the drop of haematocrit following infection. Altogether, these results indicate that selection of plants for herbal therapy is complex and might depend on several in vivo criteria, and as such should not solely rely upon measurement of their antimicrobial activity.

In Indonesia, the Nile tilapia (Oreochromis niloticus) is the most widely farmed and available fish for consumption. Production loss due to bacterial infection by Aeromonas hydrophila and Streptococcus agalactiae is the main problem in tilapia cultivation. This study aimed to determine the occurrence of concurrent infection of Aeromonas hydrophila AHL 0905-2 and Streptococcus agalactiae N14G in Nile tilapia based on biochemical and molecular characteristics. From the results of biochemical assay and sequence analysis of the 16S rRNA fragment, Aeromonas hydrophila and Streptococcus agalactiae were confirmed. Genes for aerolysin (417 bp), nuclease (504 bp), lipase (155 bp), and serine protease (211 bp) were found in Aeromonas hydrophila AHL 0905-2, while Streptococcus agalactiae N14G was determined as a 1b serotype group that had genes for CPS L (688 bp), CPSG (621 bp), and CPS J (272 bp). The confirmation in tilapia of Aeromonas hydrophila and Streptococcus agalactiae by PCR and sequencing is important for enabling the detection of these organisms and also for the development of a combined vaccine to tackle co-infection.

This study examined the effect of two Lactobacillus bacteria on protease activity and growth rate of Litopenaeus vannamei. An experiment was conducted to examine protease activity and growth rate. The experiment consisted of two treatment tanks, the first tank was provided with artemia immersed in 2.6 x 10 16 cfu/mL of bacteria solution, the second tank served as the control tank. After 20 days, the L. vannamei in the tank that received Lactobacillus have significantly different in growth, survival rate and protease activity (P<0.05) compared to the control, but no significant difference between Lactobacillus casei and Lactobacillus plantarum treatments. Within the digestive organ, protease activity of hepatopancreas and stomach demonstrated significant higher activity (P<0.05) compared to the intestine.

Identification of Gouramy is required to obtain phenotype characteristics information of the population for sustainable aquaculture  practices. In this study phenotype diversity of giant gouramy strain bastar and bluesafir was analyzed based on  meristic and morphometric measurement. Sample, are taken from 30 individuals of each population. The result showed that there were differences in colour patterns between the two populations, bastar population had yellowish brown body and red fins, whilst bluesafir population had brown blackish brown body and fins. The canonical function of truss morphometric analysis on 21 characteristics showed the measurement distribution of that both populations were in different quadrants. The intrapopulation similarity index showed that population of strain bluesafir had higher genetic similarity (80%) with interpopulation similarity index of 23.3%, while the intrapopulation similarity index of strain bastar was 76.7%.