Browsing by Author "Santiago Jr., Alfredo C."
Technical ReportAC Santiago Jr., L Rodriguez, R Mateo & R Obregon - 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
Series: Technical report / SEAFDEC Aquaculture Department; No. 1The full-scale cultivation of sugpo, P. monodon Fabricius, could only be realized if there is an assurance of continuous supply of fry. Obviously, a steady supply will depend largely on the availability of spawners. In December 1975, roughly after 2 1/2 years of intensive study, for the first time in the world, SEAFDEC Aquaculture Department has succeeded in inducing P. monodon to mature and produce normally the first generation of postlarval fry, thereby successfully effecting the completion of P. monodon's life cycle while in captivity. Another significant study the Department has initially carried out which could help augment and stabilize the supply of spawners and eventually stimulate the establishment of more prawn hatcheries and the development of ponds for prawn culture as a major export-oriented, dollar-earning industry, is the possible development of ovarian rematuration of spent spawners.
Induction of maturity and spawning in Penaeus monodon Fabricius, 1798, by unilateral eyestalk ablation (Decapoda, Natantia) Preliminary experiments carried out at the Aquaculture Department of the Southeast Asian Fisheries Development Centre in the Philippines have achieved success in the rearing of viable F1 postlarvae of Penaeus monodon from pond reared stocks. Unilateral eyestalk ablation was carried out on 100 female. 7 of these had successfully spawned at 23-months. Egg numbers up to 355,000 per female and successful hatch rates of up to 81% wee obtained. Bilaterally ablated female suffered total mortality by 196 days from eyestalk removal without 1 recorded spawning. Similarly, no spawnings were obtained from unablated controls. It is difficult to determine whether success can be solely attributed to unilateral ablation, or whether a fortuitous choice of experimental site played some major role. In any case, the data obtained are a valuable guide for future work aimed at propagating P.monodon commercially under fully controlled conditions.
ArticleAC Santiago Jr. -
Aquaculture, 1977 - ElsevierPreliminary experiments resulted in successful spawning of captive stock of the prawn Penaeus monodon, or “sugpo”, to complete the life cycle and produce a viable F1 generation of larvae. Gonadal development was induced using eyestalk ablation techniques on sexually mature females. Removal of one eyestalk was found to be sufficient to induce gonadal development, whereas bilateral ablation indirectly resulted in high mortality of the treated females. By comparison, successful spawning had not occurred in unablated animals after 9 months. Fry hatched from wild adult stock and reared to 25-day postlarvae were further impounded in brackishwater experimental ponds and reared for 4 months. A transfer of 1 500 animals were then made to marine pens. After a further 10 months, 600 animals were selected for the experiment; healthy females were ablated unilaterally and placed with 100 males for a further 9 months. Of the remaining 400 specimens, 200 were used as controls and the remainder ablated bilaterally, Seven of the 23-month old females with one eyestalk removed had spawned successfully by January 27, 1976. Egg numbers, hatching rate and larval survival compared favorably with data obtained from females of oceanic origin. It is not known if the success of the experiment was entirely due to the effect of ablation or to the choice of a suitable environment. Work is continuing to induce gonadal development under more closely controlled conditions to overcome the inadequate and unreliable supply of spawners.