Now showing items 1-4 of 4

    • Article

      Euryhaline rotifer Proales similis as initial live food for rearing fish with small mouth 

      A Hagiwara, S Wullur, HS Marcial, N Hirai & Y Sakakura - Aquaculture, 2014 - Elsevier
      The SS-type rotifer Brachionus rotundiformis is a common initial food for rearing fish larvae with a small mouth. However, there are commercially important fish species whose mouth sizes are too small to feed on SS-type rotifers. In 2004, we isolated a small (body length = 82.7 ± 10.9 μm; body width 40.5 ± 6.4 μm), flexible, and iloricate rotifer, Proales similis from an estuary in Okinawa, Japan. Under laboratory conditions (25 °C, 2–25 ppt) P. similis produced its first offspring on 2.5 to 2.8 days after hatching, and produced 4.3 to 7.8 offspring within 4.0 to 4.7 days life span. Batch cultured P. similis fed Nannochloropsis oculata suspension at 28.8 μg dry weight ml− 1 and cultured at 25 °C, 25 ppt filtered seawater, increased exponentially from 25 to 2400 ind ml− 1 after 11 days of culture with an overall intrinsic rate of natural increase (r) of 0.42 day− 1. The growth rate of P. similis was not significantly different when fed fresh N. oculata and super fresh Chlorella vulgaris-V12®. Total lipid per wet weight of P. similis fed by N. oculata and C. vulgaris were 2.4 and 2.6%, respectively. The compositions of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (ARA) of P. similis fed N. oculata were 23.2, 0.0 and 5.3%, respectively, while these were 11.0, 17.5 and 0.5% respectively, when fed C. vulgaris. The use of P. similis to feed small mouth fish including seven-band grouper Epinephelus septemfasciatus, rusty angelfish Centropyge ferrugata, and humphead wrasse Cheilinus undulatus showed that it is an excellent starter food for these species because of their high selectivity index and improved survival. In addition, P. similis was ingested by Japanese eel Anguilla japonica larvae with a complicated digestive system. The use of P. similis as starter feed for small mouth fish larvae is highly recommended.
    • Article

      Molecular cloning and localization of GABAA receptor-associated protein in the rotifer Brachionus plicatilis 

      HS Marcial, K Suga, S Kinoshita, G Kaneko, A Hagiwara & S Watabe - International Review of Hydrobiology, 2014 - Wiley-VCH Verlag
      γ-Aminobutyric acid receptor type A-associated protein (GABARAP) and its homologs constitute a protein family found in many eukaryotes from yeast to human, and are known to be involved in intracellular membrane trafficking of GABAA receptors and autophagy. In this study, we cloned cDNA-encoding GABARAP from the monogonont rotifer Brachionus plicatilis and examined for its tissue distribution at the protein level in neonates, males and females. Using reverse transcription (RT)-PCR and rapid amplification of cDNA ends (RACE) techniques, we showed that like other GABARAPs, rotifer GABARAP was also composed of 117 amino acids and highly homologous to vertebrate GABARAP2 ortholog (74–76% identity). GABARAP was demonstrated with its specific antibody to be ubiquitously distributed, irrespective of neonates, males, and females, in the coronal area that covers brain and contains most mechano- and chemoreceptors. Rotifer GABARAP was also expressed in the mature eggs but not in immature eggs. Double immunostaining with mammalian anti-GABA γ receptor antibody showed that rotifer GABARAP co-localized with GABA receptor, suggesting the association of the two proteins. The presence of GABARAP in rotifer implies that it is highly conserved during evolution, and plays important roles in various biological processes.
    • Article

      Occurrence and histopathogenesis of a didymozoid trematode (Gonapodasmius epinepheli) in pond-reared orange-spotted grouper, Epinephelus coioides 

      ER Cruz-Lacierda, RJG Lester, PS Eusebio, HS Marcial & SAG Pedrajas - Aquaculture, 2001 - Elsevier
      A didymozoid trematode encapsulated in the gills of orange-spotted grouper, Epinephelus coioides Hamilton, was observed in October 1997 and September 1999 among pond-reared fish in the Philippines. Capsule prevalence was 33% and 18% and mean intensity 2 and 1, respectively. The opaque-white and yellowish capsules were found only on the first gill arch and were attached lengthwise along the posterior surface of the primary gill filaments. When the capsules were opened, long thread-like worms were revealed, which were identified as Gonapodasmius epinepheli Abdul-Salam, Sreelatha and Farah. The parasites were encapsulated between the basement membrane of the epithelium and the efferent artery of the gill filament. The response of the host included mild hyperplasia of the interlamellar epithelium and an increase in the number of mucous cells.
    • Article

      Problems associated with tank-held mud crab (Scylla spp.) broodstock 

      CR Lavilla-Pitogo, HS Marcial, SAG Pedrajas, ET Quinitio & OM Millamena - Asian Fisheries Science, 2001 - Asian Fisheries Society
      To support studies on the development of broodstock and hatchery technology for mud crabs under the genus Scylla, the SEAFDEC Aquaculture Department maintains captive broodstock in land-based tanks. Disease problems seen in broodstock after being held for three months in these tanks include shell disease due to a combination of fouling organisms and chitinoclastic bacteria, bacterial contamination of the hemolymph, parasitic infestation on the gills and shell, and loss of appendages. Shell disease was manifested as off-white and black patches on the shell, that progressed and became perforations exposing underlying tissues. The hemolymph of a significant number of newly recruited crabs harbored mixed populations of sucrose-fermenting vibrios. Pedunculate cirripedes were found in large numbers both in the gill region and on the shell, boring through and creating perforations in the latter. Nematodes and other saprophytic organisms enter the crab through these perforations. The fouling problems that affect the integrity of the shell are considered to reduce the life span and reproductive potential of captive broodstock under tank conditions; therefore, regular cleaning of the shell is recommended to minimize shell fouling.