The aim of this research was to increase immune response of common carp (Cyprinus carpio L.) in cage to microbial infection and environmental change. This research used completed randomized (RAL) one factor, four treatments and each of three replicates. This treatment was immersion extract miswak (Salvadora persica L.) dose 0, 4.5, 9, and 13.5 g/L. The cage 1 x 1 x 1.2 m, with density 50 fish/ cage (average initially 10-15 cm). Immersion was done once time a week along three weeks, l0 min, and after it fish reared in cage along 30 days. The response parameters assayed were survival rate, haematocrit, erythrocytes, leukocytes, and water quality. The results of experiment showed that the dose optimum 9 mg/L (P2) with survival rate 99.66% and P0 (70.66%). The level of haemotocrit was 18.93-34.36%, erythrocytes 3.597.000-6.112.000 cells/mL3, leukocytes 24.748-143.070 cells/mL3. It was concluded, which miswak extract at a dosage 9 mg/L can increase survival rate and immune response of common carp.© 2008 Jurusan Biologi FMIPA UNS SurakartaKey words: Salvadora persica L., Cyprinus carpio L., haematology.

The mangrove ecosystem holds a lot of potentials to be utilized by local communities in the Riau Coastline. Therefore, this study was carried out to assess the biodiversity of flora and fauna in the Riau Coastline mangrove ecosystem and its impacts on local communities. The transect was performed to identify soil conditions, distribution, and the dominance of flora species, while field observations and interviews with residents were conducted to determine the presence of fauna and discover the ecosystem’s benefit to the local community's economy. Based on the results, Rhizophora mucronata and Rhizophora apiculata has the highest relative dominance (RDC) and important value index in all observed stations. On the other hand, the fish/water biota species has the highest diversity and have economic that mostly serve as a catch for local fishermen. Ecotourism is also encouraged to boost the community's economy and aid ecological learning for sustainability purposes. The mangrove ecosystem's existence remains sustainable because fisheries are the main commodity, however, logging is less desirable as a source of income.

Probiotik adalah mikroba hidup yang menguntungkan bagi ikandan bermanfaat untuk meningkatkan kesehatan ikan, memperbaiki nutrisi dalam pakan dan memperbaiki kualitas air.Penelitian ini bertujuan untuk menentukan interval waktu pemberian probiotik terbaik ke media pemeliharaan terhadap pertumbuhan ikan nila salin (Oreochromis niloticus). Ikan uji yang digunakan adalah ikan nila merah yang telah diadaptasi pada media bersalinitas. Wadah yang digunakan adalah bak fiber dengan kapasitas 250 liter dengan padat tebar 300 ekor/m3 dan dipelihara selama 56 hari pada salinitas 17 ppt. Metode yang digunakan adalah metode eksperimen, menggunakan Rancangan Acak Lengkap (RAL) dengan 2 faktor, yaitu faktor tetap (dosis 10 ml/m3)dan faktor bebas (interval waktu) dengan 4 taraf perlakuan dan 3 kali ulangan, yaitu P0 (sekali selama pemeliharaan, P1 (5 hari sekali), P2 (10 hari sekali) dan P3 (15 hari sekali). Parameter yang diukur adalah pertumbuhan panjang dan bobot mutlak, laju pertumbuhan harian, kelulushidupan, konversi pakan dan efisiensi pakan. Hasil dari penelitian menunjukkan bahwa perbedaan interval waktu pemberian probiotik 5 hari sekali untuk pemeliharaan ikan nila salin sistim bioflok dapat meningkatkan pertumbuhan bobot mutlak 36,04 g, panjang mutlak 8,41 cm, laju pertumbuhan harian 4,86%, kelulushidupan 94,44%, konversi pakan 0,86 dan efisiensi pakan 116,75%. Sedangkan kualitas air, seperti suhu 25,3-27,4oC, pH 7,0-8,1, DO 6,3-7,5 mg/L, CO22,34-9,32 mg/L, salinitas17-18,2 ppt, alkalinitas 40,0-66,7, NH30,001-1,50 mg/L, NO20,01-2,23 mg/L dan NO30,12-1,14 mg/L tergolong baik karena sudah sesuai dengan baku mutu budidaya ikan nila.Kata kunci : Oreochromis niloticus, Probiotik,bioflok, pertumbuhan