Now showing items 1-3 of 3

    • Article

      Comparative study on the embryonic development of three mud crabs Scylla spp. 

      MCD Ates, GF Quinitio, ET Quinitio & RC Sanares - Aquaculture Research, 2012 - Blackwell Publishing
      Morphological changes in the embryos, egg size and development, incubation period and morphological structures of newly hatched zoea of three mud crab Scylla species were determined. The three species exhibited similar embryonic development composed of 10 stages. The mean egg diameter of Scylla serrata was significantly larger (P<0.05) at the prehatch stage. The mean egg diameters of Scylla tranquebarica and Scylla olivacea were similar (P>0.05). The incubation period was the longest in S. serrata and the shortest in S. olivacea. There was a positive relationship between egg size and larval size, as S. serrata exhibited the largest egg size and first zoea. However, no correlation was detected between egg size at prehatch and lengths of the morphological structures of the newly hatched zoea. The three species exhibited similar lengths of cephalic structures, but S. olivacea had significantly shorter (P<0.05) abdominal structures. The duration of spawning from ablation was the shortest in S. tranquebarica and the longest in S. olivacea. The study is relevant to aquaculture and fisheries management of Scylla species.
    • Article

      Feeding regimes in relation to reproduction and survival of ablated Penaeus monodon 

      JH Primavera, C Lim & E Borlongan - Kalikasan, The Philippine Journal of Biology, 1979 - University of the Philippines at Los Baños
      Pond-reared P. monodon were stocked in four 12-cu m flowthrough maturation tanks at 25 males and 50 females per tank; females were unilaterally ablated. The combinations of feeds for the morning and afternoon rations were pellet-pellet, frozen mussel-frozen mussel, frozen mussel-pellet, and frozen squid-pellet. Reproductive performance in terms of total number of spawnings, total number of eggs produced, total number of nauplii produced, average number of eggs per spawning and average hatching rate was best for the mussel-pellet combination followed by the mussel-mussel and squid-pellet rations. The all pellet diet gave the poorest results.
    • Article

      Seed production of Charybdis feriatus (Linnaeus) 

      FD Parado-Estepa, ET Quinitio & E Rodriguez - Aquaculture Research, 2007 - Blackwell Publishing
      Some aspects of the reproductive biology of Charybdis feriatus (Linnaeus) were investigated to identify suitable techniques for broodstock management and seed production. Likewise, factors such as ablation, water depth and light requirements affecting survival or reproductive performance were tested. Production of megalops in tanks and juveniles in net cages installed in earthen ponds was conducted. Wild-caught berried females produced a significantly higher number of zoeae per gram body weight (BW) of the female (3300±600) than captive spawners (867±58). Ablated and unablated crabs spawned after a month and ovaries of both had oocytes in all developmental stages after spawning, indicating that ablation was not necessary. Broodstock survived higher when stocked in 1 m-deep water and kept in dark conditions compared with shallow (0.5 m depth) water or ambient lighting. There were six zoea and one megalopa stage. Megalops were produced (survival of 2–22% in 1 tonne or 23–55% in 3 L tanks) when methods for the mud crab Scylla serrata (Forsskål) were used, but feeding with Artemia started only at the Z4 stage. Survival of megalops after 1 month was higher when stocked in net cages installed in an earthen pond (32–82%) than when reared continuously in land-based tanks (5–11%).