The susceptibility of Aedes aegypti Linnaeus 1762, Culex quinquefasciatus Say 1823 and Anopheles gambiae Giles 1902 was tested on 0.75 % permethrin pyrethroid in the laboratory. All Larval and pupal stages of the mosquitoes were collected from different localities within Zaria, Nigeria and reared to adulthood in the laboratory. The adults that emerged were tested on 0.75 % permethrin strips using WHO Standard Test Kit. Mortalities were recorded at five minutes interval for 1 hr and maintained for 24hrs post-exposure on 7 % sucrose solution after which a final mortality was recorded. The Knockdown times (KDT50 and KDT95) were determined by Probit Analysis. 100 % mortality was obtained for Ae. aegypti and Cx. quinquefasciatus after 1hr and 24hr exposures, respectively, whereas An. gambiae recorded 92.11 % and 90.91 % mortalities after 1hr and 24hr exposure, respectively. The KDT50 and KDT95 did not differ significantly (P>0.05) between Ae. aegypti and Cx. quinquefasciatus but differed significantly (P<0.05) with An. gambiae. The study shows that Ae. aegypti and C. quinquefasciatus are susceptible to permethrin whereas An. gambiae is resistant to the insecticide in the area.

Availability of quality and effective tiger barb seeds is highly limited and leads to unfulfilled market demand. This study was conducted from April - May 2018 in the Laboratory of Aquaculture, Faculty of Agriculture, University of Asahan. Result of analysis of variance (ANOVA) shows that Fstatistic≫Ftable (636,097≫0,17), thus H0 is rejected and H1 is accepted, hence treatment of different substrates significantly affected egg number of tiger barb. Similarly, the value of fecundity, hatching rate, and survival rate obtained in this study resulted in Fstatistic≫Ftable (353.676≫0,17) or H0 is rejected and H1 is accepted, hence significant effect on hatching rate was obtained due to substrate treatment and Fstatistic≫Ftable (38,741≫0,17) H0 is rejected and H1 is accepted which reflected significant influence on tiger barb survival by reason of different substrate treatment. Hatching Rate is obtained by calculating the number of eggs hatched by tiger barbs (Puntiustetrazona). The highest hatching rate of tiger barb in this study was observed in treatment of Hydrillasp (88,14%) followed by palm fiber (72,89%) and water hyacinth (72,75%), while the lowest percentage was obtained by treatment of twigs and raffia rope.

Kecerahan warna tubuh ikan mas koki akan meningkatkan nilai jualnya namun kualitas warna tubuh dapat menurun apabila kandungan pigmen warna berkurang seiring lamanya masa pemeliharaan. Rekayasa nutrisi dengan menambahkan sumber karatenoid yang berasal dari tumbuhan dapat mempertahankan kualitas warna ikan hias. Penelitian bertujuan untuk mengevaluasi efektivitas pemberian tepung ubi jalar ungu yang ditambahkan kedalam pakan buatan terhadap kecerahan warna, pertumbuhan dan kelulushidupan ikan mas koki. Ikan uji adalah ikan mas koki orlada berat 2-3 gram dengan padat tebar 10 ekor per wadah. Perlakuan berupa perbedaan persentase tepung ubi jalar kedalam pakan buatan yaitu P0 (Kontrol); P1 (2,5 % tepung ubi jalar ungu); P2 (5 %); P3 (7,5 %) dan P4 (10 %). Penambahan 10% tepung ubi jalar memperlihatkan peningkatan warna terbaik dari semua perlakukan dengan nilai/skor rata-rata 4. Namun tidak berpengaruh terhadap pertumbuhan panjang dan berat mutlak serta kelangsungan hidup ikan mas koki.

The purpose of this study was to determine the type and level of prevalence and intensity of ectoparasites that infect mud crabs (Scylla serrata) in Asahan district. The method of data collection was carried out by field observation methods carried out in the sea silos, Pematang Baru, and Sei Kepayang areas. The crab samples observed were live crabs, the number of mud crabs taken for the sample was 10% of each population. Furthermore, in the carapace, the type of parasite that attacks is Trichodina sp with a prevalence rate of 38%. This parasite infected 5 of the 13 samples. Then the types of parasites Carchesium sp and Poecilasmatidae each with a prevalence rate of 31% these two types of parasites infect 4 samples of crabs found at the foot of theroad, this type of parasite infects 4 out of 13 samples. Then the types of parasites Carchesium sp and Poecilasmatidae each with a prevalence rate of 31% these two types of parasites infect 4 samples of crabs found at the foot of theroad, this type of parasite infects 4 out of 13 samples. Then the types of parasites Carchesium sp and Poecilasmatidae sp each with a prevalence rate of 31% these two types of parasites infect 4 samples of crabs found at the foot of theroad, this type of parasite infects 4 out of 13 samples. The crabs that attack the sea silos are Octolasmis sp, Ichtyopthyrius multifilis, Trichodina sp, Zoothamnium sp. The parasites that attack the new ponds are Octolasmis sp, Carchesium sp, Zoothamnium sp, and the parasites that attack Sei Kepayang are Octolasmis sp, Carchesium sp, Poecilasmatidae sp, Trichodina sp. The intensity of the parasites found was classified as moderate but for the parasite Octolasmis sp.

Penelitian ini dilaksanakan pada tanggal 27 Juli hingga 18 Agustus 2008, diperairan Teluk Tapian Nauli Kota Sibolga Tapanuli Tengah Provinsi Sumatera Utara. Penelitian ini bertujuan untuk mengetahui perbedaan hasil tangkapan jaring insang permukaan (Surface Gillnet) yang dioperasikan pada pagi, sore dan malam hari ditinjau dari oseaanografi diperairan teluk tapian nauli kota sibolga tapanuli tengah.Metode yang digunakan dalam penelitian ini adalah metode eksperimen yaitu metode percobaan dengan cara menghitung hasil tangkapan jring insang permukaan pada pagi, sore dan malam hari dari jumlah berat dan jenis ikan yang tertangkap dengan cara pengamatan dan langsung praktek langsung kelapangan. Adapun analisis varian yang digunakan adalah rancangan acak lengkap (RAL) yang disesuaikan dengan asumsi yang dilengkapi pada saat penelitian..Hasil yang diperoleh pada pengopersian alat tangkap jaring insang permukaan pada pagi, sore dan malam hari terdapat perbedaan jumlah berat ikan. Hasil tangkap pada pagi hari ikan yang tertangkap rata-rata 5.6 kg, sore hari ikan yang tertangkap rata-rata 4.5 kg dan pada malam hari ikan yang tertangkap rata-rata 6.6 kg, sehingga dapat disimpulkan bahwa hasil tangkap ikan berdasarkan berat paling banyak pada malam hari dengan berat 6.6 kg. Jumlah individu ikan yang tertangkap pada pagi, sore dan malam hari adalah 1149 ekor, hasil tangkap yang terbanyak pada pengoperasian malam hari 478 ekor sedangkan yang terkecil pengoperasian pada sore hari 317 ekor. Dari penelitian ini dapat disimpulkan bahwa analisis data yang diperoleh adalah F hit &gt; F tabel dan Ho ditolak dan HI diterma maka kesimpulannya adalah adanya pengaruh yang signifikan terhadap hasil tangkapan pada pagi, sore dan malam hari. Hasil tangkapan jaring insang permukaan (Surface gillnet) pada malam hari lebih banyak dibandingkan pada pagi dan sore hari, hal ini dipengaruhioleh oseanografi yang berupa parameter kualitas air dan keadaan disekeliling perairan yaitu suhu, salinitas, kecerahan, kedalaman, arah angin, arus, dan pasang surut diteluk tapian nauli