Suitability of brackish water tilapia species from the Ivory Coast for lagoon aquaculture : 2. Growth and rearing methods

En élevage intensif, les deux espèces de tilapia lagunaire, #T. guineensis et #S. melanotheron, se sont avérées décevantes. En effet, même dans la situation la plus favorable, l'élevage monosexe mâle de #S. melanotheron$, une vitesse de croissance médiocre (de l'ordre de 0.5 g.j-1) et une mauvaise transformation des aliments artificiels ne permettent pas dans l'état actuel d'envisager une exploitation rentable. Les essais d'élevage extensif utilisant la technique originale des "acadja-enclos" ont par contre donné des résultats très encourageants. Des rendements annuels en poissons de plus de 8t/ha, dont 70 à 80$ de taille marchande, sont possibles sans aucun apport en aliment artificiel. (Résumé d'auteur

Penggunaan Bungkil Inti Kelapa Sawit Hasil Biokonversi Sebagai Substrat Pertumbuhan Larva Hermetia Illucens L (Maggot)

Telah dilakukan penelitian tentang Palm Kernel Meal (PKM) yang difermentasi selama 7 hari secara alami tanpa penambahan inokulum yang hasil fermentasi disebut dengan PKMK. Produk fermentasi ditambahkan telur Hermetia illucens L. (maggot) diinkubasi selama 14 hari. Hasil penelitian menunjukkkan adanya kenaikan berat dan panjang maggot. Analisis proksimat menunjukkan kenaikan berat kering, nitrogen total dan serat, tetapi terjadi penurunan lemak dan abu

Testicular structure, spermatogenesis and sperm cryopreservation in the African clariid catfish Heterobranchus longifilis (Valenciennes, 1840)

The morphological and physiological characteristics of the testes and the sperm of the catfish #Heterobranchus longifilis$ (Val.) are presented. The effect of cryopreservation on the fertilizing capacity of the sperm was also evaluated. Testicular structure and spermatogenesis are described using histological techniques. The coexistence in the lobules of spermatozoa and all the spermatogenic stages indicates that this species is able to perform continuous reproduction. No seasonal trend was noticed in the evolution of the gonadosomatic index and in the quantity of the sperm produced over a year's period. However, maximum sperm production was observed in April and September. Different cryopreservation trials were conducted using a cryoprotective solution composed of 5% dimethylsulphoxide (DMSO), 5% glycerol, 10% hen's eggyolk and 80% Mounib's solution. Fresh and cryopreserved semen gave equivalent hatching rates (81.1%, 83.4% and 78.9% respectively for the fresh, the 1-hour cryopreserved and the 8-month cryopreserved sperm). Percentages of normal and deformed larvae were not affected by sperm cryopreservation. (Résumé d'auteur

POTENSI MAGGOT UNTUK PENINGKATAN PERTUMBUHAN DAN STATUS KESEHATAN IKAN

Penggunaan maggot sebagai pakan alternatif ikan telah dikaji di Loka Riset Budidaya Ikan Hias Air Tawar (LRBIHAT), Depok. Maggot merupakan larva serangga black soldier (Hermetia illusence) yang dapat mengkonversi material organik menjadi biomassanya. Salah satu keunggulan maggot adalah dapat diproduksi dalam berbagai ukuran, sesuai dengan kebutuhan. Penyimpanan maggot pada suhu rendah dapat menghambat pertumbuhan dan mempertahankan kehidupannya. Produksi maggot pada ukuran kecil dimulai dari penyediaan telur, penetasan, dan pembesaran dalam media PKM (Palm Kernel Meal) atau bungkil kelapa sawit, pemanenan dan penyimpanan dalam suhu rendah. Nilai nutrisi maggot pada umur 6-7 hari adalah protein: 60,2%; lemak: 13,3%; abu: 7,7%; karbohidrat: 18,8%. Percobaan pemanfaatan maggot sebagai suplemen pakan diujikan terhadap ikan Balashark (Balantiocheilus melanopterus Bleeker) ukuran 2,0 ± 0,2 g. Hasil yang didapatkan menunjukkan bahwa pemberian maggot memberikan pertumbuhan dan sintasan yang lebih baik. Dampak penambahan maggot pada ikan terlihat signifikan terhadap gambaran darah ikan yang menunjukkan daya tahan tubuh ikan yang lebih baik.Maggot utilization as fish feed alternative has been studied at Loka Riset Budidaya Ikan Hias Air Tawar (LRBIHAT), Depok. Maggot is an insect larvae of black soldier (Hermetia illusence) that can convert organic material to its body biomass. One of the advantages in maggot culture is that it can be produced in different sizes according to fish requirement. Keeping maggot at low temperature can delay its growth while keeping it alive. Production of small size maggot starts from eggs preparation, hatching, and rearing in media of PKM (Palm Kernel Meal) or coconut oil cake of palm, cropping and then keeping it in low temperature. Nutritional value of maggot at the age of 6-7 days is as follows: protein, 60.2%, fat; 13.3%, ash; 7.7%, carbohydrate; 18.8%. Trial feeding using maggot as feed supplement was done on Balashark (Balantiocheilus melanopterus Bleeker) sized 2.0 ± 0.2 g. The result showed that maggot gave significant growth and survival rate to fish specimen. Blood configuration analysis showed that the maggot supplement has also contributed to a significant increase of body immunity of fish specimen

Perkembangan dan Kandungan Nutrisi Larva Hermetia illucens (Linnaeus) (Diptera: Stratiomyidae) pada Bungkil Kelapa Sawit

Hermetia illucens, is used as a reducing agent of palm kernel meal (PKM), as well as one of alternative protein sources for aquaculture purposes. Information about biology of H. illucens is absolutely required in mass production. The objectives of these researches were to study the development of H. illucens including the effect of supplementary food to the adult, and nutrient content of the immature stage. The sample of 20 larvae from each 3 replicates were measured and weighed on 0-19th day (larva) and 24th day (pupa) from egg hatching. H. illucens adults were fed by water and honey 5% (v/v). Eggs were collected and counted. Nutrient content of immature stage: 5, 10, 15, 20 days old (larvae), and 25 days old (prepupae) reared on PKM were analyzed proximately. Dry matter was determined by weight loss on drying at 105 oC during overnight. Crude protein was determined by Kjeldahl procedure (N x 6.25), crude fat by soxhlet (ether extract), crude ash by determining the residue after heating at 550 oC for 4–5 h. Data were analyzed descriptively by average from triplicate. The development of H. illucens was shorter than those in previous studies as the differences of abiotical factor. PKM was a suitable medium for development. It was better, however, to fed the adult with honey since it could enhance the fecundity. The young larva certainly contained the best quality of nutrition. To meet the quantity of mass production, however, the use of the elder larva (bigger) was suggested. KEY WORDS: Hermetia illucens, development, PKM, proximate analysi

Perkembangan Dan Kandungan Nutrisi Larva Hermetia Illucens (Linnaeus) (Diptera: Stratiomyidae) Pada Bungkil Kelapa Sawit

Hermetia illucens, is used as a reducing agent of palm kernel meal (PKM), as well as one of alternative protein sources for aquaculture purposes. Information about biology of H. illucens is absolutely required in mass production. The objectives of these researches were to study the development of H. illucens including the effect of supplementary food to the adult, and nutrient content of the immature stage. The sample of 20 larvae from each 3 replicates were measured and weighed on 0-19th day (larva) and 24th day (pupa) from egg hatching. H. illucens adults were fed by water and honey 5% (v/v). Eggs were collected and counted. Nutrient content of immature stage: 5, 10, 15, 20 days old (larvae), and 25 days old (prepupae) reared on PKM were analyzed proximately. Dry matter was determined by weight loss on drying at 105 oC during overnight. Crude protein was determined by Kjeldahl procedure (N x 6.25), crude fat by soxhlet (ether extract), crude ash by determining the residue after heating at 550 oC for 4–5 h. Data were analyzed descriptively by average from triplicate. The development of H. illucens was shorter than those in previous studies as the differences of abiotical factor. PKM was a suitable medium for development. It was better, however, to fed the adult with honey since it could enhance the fecundity. The young larva certainly contained the best quality of nutrition. To meet the quantity of mass production, however, the use of the elder larva (bigger) was suggested