Now showing items 578-597 of 1065

    • Article

      Janitor fish Pterygoplichthys disjunctivus in the Agusan Marsh: A threat to freshwater biodiversity 

      M Hubilla, F Kis & J Primavera - Journal of Environmental Science and Management, 2007 - University of the Philippines Los Baños (UPLB)
      The aim of this study is to verify reports on the presence of invasive alien catfish, known locally as janitor fish, including their possible impact on freshwater biodiversity in the Agusan Marsh, Northeastern Mindanao in southern Philippines. Morphological analysis, field sampling and questionnaire survey were conducted to determine the exact taxonomic status, habitat, distribution, and the population and size estimates of the fish. The results showed that the South American vermiculated sailfin catfish, Pterygoplichthys disjunctivus, a species earlier reported from Laguna Lake and nearby rivers in Luzon, northern Philippines, has invaded the Agusan Marsh. The exotic fish can be found in lakes, rivers and creeks of the municipalities of Talacogon, La Paz, Loreto, Bunawan, Rosario, San Francisco, Veruela and Sta. Josefa. They may also be present in upstream and downstream areas. Total catches of fishermen ranged from 0 to 146 individuals per fishing trip. Practical control measures to reduce the janitor fish population in the Agusan Marsh were discussed.
    • Article

      Knowledge, gender, and resources in small-scale fishing: The case of Honda Bay, Palawan, Philippines 

      SV Siar - Environmental Management, 2003 - Springer Verlag
      The coastal zone is a place of intense activity where resources, users, and resource-use practices interact. This case study of small-scale fisheries in Honda Bay, Palawan, Philippines shows that resources, space, and gender are intertwined. The study was conducted between June 1997 and July 1998. The data were gathered using free listing, pile sort, ranking, resource mapping, and key informant interviews. The results showed that women's knowledge about fishery resources and their fishing activities are associated with the intertidal zone whereas men's knowledge is associated with coral reefs. In classifying fishery resources, appearance is the main consideration for women whereas a combination of appearance, habitat, and type of fishing gear is the consideration used by men. Market price is very important because of its dependence on the demand of the export market as well as the local market. Women dominate the buying of fishery products. Many women market their husband's catch, process fish, or gather shells and sea cucumber for sale. Among the fishing households, type of fishing gear provides an indication of socioeconomic standing. This paper concludes that access to resources is shaped by gender and age. The differences in resource knowledge possessed by men and women lead to differential access to fishery resources. In addition, the differences in socioeconomic status also influence resource access. The socialization of children into fishing reinforces the gender division of labor and space in the coastal zone.
    • Koi herpesvirus-associated mortalities in quarantined koi carp in the Philippines 

      JR Somga, LD de la Peña, CD Sombito, MG Paner, VS Suarnaba, GC Capulos, PI Santa Maria & GL Po - Bulletin of the European Association of Fish Pathologists, 2010 - European Association of Fish Pathologists
      Illegally imported koi carp were confiscated at the Ninoy Aquino International Airport (NAIA), Manila, Philippines by the Fisheries Quarantine and Inspection Service Officers of the Bureau of Fisheries and Aquatic Resources (BFAR). The confiscated fish were turned over to the BFAR Fish Health Laboratory where they were held for observation at a water temperature of 28 degree C. After 5 days, some fish were showing abnormal swimming behavior and some had died. The most prominent disease signs in the freshly dead and moribund fish were body ulcerations and pale gills showing white necrotic patches, consistent with the clinical signs of KHV infection. Gills were dissected and fixed in 95% ethanol. All of the samples tested positive for KHV in a 1-step PCR assay.

      This paper reports the first case of KHV associated mortalities in illegally important koi carp confiscated by the Fisheries Quarantine and Inspection Service Officers of BFAR. This highlights the importance of the quarantine and inspection service s role in preventing the illegal entry of fish into the country and the introduction of exotic aquatic diseases.
    • Article

      L-ascorbyl-2-phosphate Mg as source of vitamin C for juvenile Penaeus monodon 

      MR Catacutan & CR Lavilla-Pitogo - The Israeli Journal of Aquaculture-Bamidgeh, 1994 - Society of Israeli Aquaculture and Marine Biotechnology
      Phosphated ascorbic acid (MAP), a stable vitamin C derivative, was used in practical diets for Penaeus monodon (wet weight, 126-254 mg) as a source of vitamin C. In Experiment I, the levels were from 0 to 1,500 ppm MAP. No significant differences in weight gain, SGR, survival and FCR were observed among treatment means after 92 days of feeding but the lowest values were obtained in the group fed without the MAP dietary supplement. At the start of the experiment shrimps were infected with monodon baculovirus (MBV). However, the histological structure of the hepatopancreas showed improvement in animals fed diets containing 100 ppm MAP and above, after 92 days.

      In Experiment II, shrimps were given different MAP levels (0 to 8,000 ppm) for 81 days. The FCR and survival of shrimps in MAP supplemented diets were significantly higher than those without MAP. In both experiments, shrimps without dietary MAP were weak and developed blackened subcuticular tissues, a symptom of vitamin C deficiency. MAP was utilized by P. monodon as a source of vitamin C. An adequate level in a practical diet would be 100 to 200 ppm MAP, equivalent to 50 to 100 ppm ascorbic acid.
    • Article

      Laboratory manipulation of Gracilariopsis bailinae Zhang et Xia (Gracilariales, Rhodophyta) 

      SF Rabanal, R Azanza & A Hurtado-Ponce - Botanica Marina, 1997 - Walter de Gruyter
      Carpospore germination, carposporeling development and tetraspore formation were investigated in Gracilariopsis bailinae Zhang et Xia by manipulating photoperiod, photon flux density, temperature, salinity and nutrients. Laboratory-generated sporelings attained mean growth rate from 4.05 to 10.31% d-1 during the first week of incubation. Duncan s multiple range test (DMRT) showed that growth rates were significantly different (P < 0.05) between the treatment combinations and between weekly intervals. The optimal condition for growth of sporelings, irrespective of culture age, was attained at treatment combinations of 26°C, 11:13 (h. L:D) photoperiod, 100 µEm-2s-1 photon flux density (PFD), 25 µM NH4Cl: 2.5 µM K2HPO4 and 25ppt salinity followed by a treatment combination of 26°C, 11:13 (h. L:D) photoperiod, 100 µEm-2s-1 photon flux density (PFD), 50 µM NH4Cl: 5 µM K2HPO4 and 25 ppt salinity. For the first time in this species, tetraspore formation was induced in the laboratory. The tetrasporophyte produced many tetraspores in almost all branches of the thallus grown at 26°C, 11:13 (h. L:D) photoperiod, 100 µEm-2 s-1, 25 µM NH4Cl: 2.5 µM K2HPO4 and at 30 ppt salinity while those grown at lower light, higher nutrient level and higher salinity had fewer tetraspores. No tetraspores were formed at a higher temperature (30°C), longer photoperiod (13:11 h. L:D), and at 25 ppt salinity and the plants remained vegetative from 4 to 7 months. Logistic regression analysis showed that tetrasporangial induction was significantly affected by nutrients and salinity (P < 0.05).
    • Article

      Lactate dehydrogenase isozyme patterns during the development of milkfish, (Chanos chanos (Forskal)) 

      PD Requintina, LM Engle & LV Benitez - Kalikasan, The Philippine Journal of Biology, 1981 - University of the Philippines at Los Baños
      Polyacrylamide disc gel electrophoresis was done to determine the lactate dehydrogenase (LDH) isozyme patterns for fry (5-3 mg), fingerling (6-12 g), pond-size (150-250 g) and adult (6-9 kg) milkfish. The patterns were tissue specific; the different tissues examined, viz., eye, liver, heart, and skeletal muscle had different expressions of LDH isozymes. The resolved patterns appeared to be products of LDH gene loci A, B, and C. Subunits A and B were present in all tissues. A4 and B4 were predominant in skeletal and heart muscle, respectively; the two associated non-randomly in vivo and formed only the heteropolymers A3B and AB3. A liver band, L4, was most conspicuous in the fingerling, pond-size, and adult; it was assumed to be coded by locus C. A negatively charged band, X4, was detected in fully developed ovary and in fry homogenized as whole individuals, but it could not be resolved in tissues of fingerling.

      Six-mo old stunts and 3-mo old fingerlings had similar LDH patterns for all tissues examined. The patterns for 11-mo old stunts and fingerlings also were similar but the one for the eye of the former was the same pattern resolved for the eye of adults.

      There was no change in the LDH isozyme patterns of milk fish stunted for 6 mo under different salinity levels (0-5, 15-20, 32-35 ppt).
    • Article

      The lancelets [Cephalochordata, Amphioxi] of Lucena Anchorage, Quezon, Philippines 

      NC Carandang - Kalikasan: The Philippine Journal of Biology, 1978 - University of the Philippines at Los Baños
      Two species of lancelets (amphioxi) are described from Philippine waters: Branchiostoma belcheri and Epigonichthys cultellus. The characters suited for numerical evaluation in both species were examined statistically.

      Epigonichthys cultellus is reported for the first time from the Philippines. The specimens examined differ by the presence of a dark band behind the rostrum and anterior to the first myotome, the greater number of myotomes in the preatrioporal region, and the numerous sense papillae on the buccal cirri.
    • Article

      Large scale hatchery production of Penaeus monodon using natural food and artificial diets 

      MN Bautista, F Parado-Estepa, OM Millamena & EL Borlongan - The Israeli Journal of Aquaculture-Bamidgeh, 1991 - Society of Israeli Aquaculture and Marine Biotechnology
      Natural food in combination with either SEAFDEC formulated or other commercial larvae diets was tested for large scale production of Penaeus monodon postlarvae. Two trials of 3 treatments each, 2 replications of each treatment, were conducted in 10 m3 circular concrete tanks. Shrimps were reared from nauplii to postlarvae. Dietary treatments for trial I included:(a) natural food (NF) alone, (b) NF+ commercial plankton substitute (PS) and (c) NF+ SEAFDEC diet (SD).For trial II, commercial powder diets SP or SMP were added:(a) NF + SP, (b) NF + PS + SP + SMP and (c) NF + SD + SP + SMP. Larvae survival was significantly higher in treatments containing the SEAFDEC diets than in the treatments receiving natural food alone (trial I) or natural food in combination with SP (trial II). Larval development was faster in the group fed the SEAFDEC diet; larvae in these groups metamorphosed into postlarvae an average of 1-2 days earlier than groups fed other diets. The presence of either SP or SMP did not improve the efficiency of the feeds. Results showed that larvae performance was affected by the nutrient composition of the diets and that by using proper feeding techniques and management of water quality, large scale hatchery production of P. monodon using natural food in combination with the SEAFDEC diet or plankton substitute is possible.
    • Article

      Larvae and juveniles of pempheridid fishes, Pempheris xanthoptera and P. japonica 

      H Kohno - Japanese Journal of Ichthyology, 1986 - The Ichthyological Society of Japan
      Larval developments of Pempheris xanthoptera and P. japonica were described on 31 (6.45–22.40 mm SL) and 5 (10.35–35.70 mm SL) specimens, respectively, with particular attention to cartilaginous development. Comparison between the two species indicated that P. xanthoptera was discriminated from P. japonica by the following key characters: two supracleithral spines (one in P. japonica); longer pectoral fin; shorter ventral fin; and absence of melanophore on mid-ventral part of lower jaw and anterolateral region of trunk, and web of ventral fin.
    • Article

      Larvae of decapod crustacea of the Philippines - I. The zoeal stages of a swimming crab, Charybdis cruciata (Herbst) reared in the laboratory 

      H Motoh & AC Villaluz - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1976 - The Japanese Society of Scientific Fisheries
      Six zoeal stages of Charybdis cruciata (Herbst) which are reared in the laboratory, are described. The zoea has a rostral, a dorsal and a pair of laterial spines. There are a pair of lateral hooks on the 2nd and 3rd abdominal segments. The number of natatory hairs on the rirst and second maxillipeds increased by one pair at each molt, being 4, 6, 8, 10, 12 and 14, in the 1st to 6th zoea, respectively. The number of inner setae on the telson are 3+3 in stage 1; 4+4 in stages 2 and 3, 4+1+4 in stage 4, and 5+5 in stages 5 and 6. Spinal arrangement form proximal to distal segment of the endopodite of the first maxillipeds are 2-2-0-2-5 in stages 1-3 and 2-2-1-2-6 in stages 4-6 and that of the second maxillipeds are 1-1-4 in stages 1 and 2 and 1-1-5 in stages 3-6.
    • Article

      Larvae of decapod crustacea of the Philippines. III. Larval development of the giant tiger prawn, Penaeus monodon reared in the laboratory 

      H Motoh - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1979 - The Japanese Society of Scientific Fisheries
      The egg, larval stages and the first postlarva of the giant tiger prawn, Penaeus monodon Fabricius, reared from egg in the laboratory are described and illustrated.

      Six naupliar, three protozoeal and three mysis stages are recognized. The larvae of P. monodon are morphologically similar to those of P. japonicus described by Hudinaga except for the following characters: 1) number of setae on first antenna of fourth and fifth nauplii is 5 or 6 in P. monodon, but it is 7 in P. japonicus; 2) supra-orbital spine of second protozoea is bifurcated at base in P. monodon, but at tip in P. japonicus; 3) number of segments of endopod of second maxilliped of second mysis is 5 in P. monodon, but it is 4 in P. japonicus; 4) number of rostral spines in second and third myses is 0 and 0 or 1 respectively in P. monodon, but it is 1 and 2 respectively in P. japonicus.
    • Article

      Larvae of decapod crustacea of the Philippines. IV. Larval development of the banana prawn, Penaeus merguiensis reared in the laboratory. 

      H Motoh & P Buri - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1979 - The Japanese Society of Scientific Fisheries
      The eggs, the larval stages and the first postlarva of the banana prawn, Penaeus merguiensis, from Philippine waters are described and illustrated.

      The complete larval stage consisting of six naupliar, three protozoeal and three mysis sub-stages were reared from egg spawned in the laboratory. The larval and postlarval stages of the present materials are compared with those of P. merguiensis from India, P. monodon from the Philippines and P. japonicus from Japan. The morphological characteristics of P. merguiensis are identical with those of genus Penaeus in Gulf of Mexico, except for the absence of the dorso-median spine on the third abdominal segment in the mysis stage of. P. merguiensis.
    • Article

      Larval and early juvenile development of silver therapon, Leiopotherapon plumbeus (Actinopterygii: Perciformes: Terapontidae), reared in mesocosms 

      FA Aya, MNC Corpuz, MA Laron & LMB Garcia - Acta Ichthyologica et Piscatoria, 2017 - Szczecińskie Towarzystwo Naukowe
      The silver therapon, Leiopotherapon plumbeus (Kner, 1864), is an endemic and economically important freshwater food fish in the Philippines. The natural populations of this species have been declining during the past years, mainly due to intense fishing pressure, habitat degradation, and introduction of invasive alien species. At present, it is considered a target species for domestication and conservation efforts. Despite several attempts of artificial reproduction and larval rearing, little is known on larval and early juvenile development of silver therapon. The presently reported study was therefore intended to fill this gap in the knowledge by determining the growth and describing body proportions, pigmentation, and fin formation of this fish. Newly hatched larvae were reared in mesocosm tanks at a mean temperature of 29.5°C. Larvae up to 30 days after hatching were sampled at irregular intervals and preserved in 5% buffered formalin. Early development stages for 245 preserved specimens were described in detail with reference to changes in morphology, growth and body proportions, pigmentation, and fin formation. Five developmental stages of silver therapon were identified: yolk sac larva (1.88 mm TL), preflexion (2.51 mm TL), notochord flexion (4.50-8.27 mm TL), postflexion larva (6.90-12.21 mm TL), and early juvenile (>13.40 mm TL). Growth was isometric for eye diameter and gape size whereas positive allometry was observed for body depth, head length, and preanal length. Some body proportions showed abrupt changes from preflexion to postflexion larvae before it stabilized during the early juvenile stage. Pigmentation in the form of stellate and punctate melanophores increased with developmental stage, with larvae becoming heavily pigmented from postflexion to early juvenile stage. These morphological changes, together with the full complement of fin rays and squamation observed in specimens larger than 13.4 mm TL, suggest the attainment of the juvenile stage of this species. These morphological changes may explain the food and feeding habits during the early life stages of silver therapon which is critical to their survival and recruitment in the wild and in a mesocosm hatchery environment.
    • Article

      Larval and early juvenile fishes associated with milkfish fry at Malandog, Hamtik, Antique 

      VC Banada - Fisheries Research Journal of the Philippines, 1983 - Fisheries Research Society of the Philippines
      From 5 May 1981 to 7 November 1981 a total of 122,841 specimens of milkfish fry and early juvenile fishes was collected with the use of a milkfish fry sweeper. Of these, 66,361 or 54.02% consisted of early juvenile stages of 30 species of finfish and the rest were 56,480 milkfish fry of 45.98% of the total collection.

      The most abundant finfish excluding milkfish fry was Ambassis sp. comprising 59.43% of the total fish catch, followed by Elops machnata, 12.7%; Sillago sihama, 8.66% Gobiidae, 6.11%; Therapon jarbua, 5.49% Stolephorus sp., 2.06%; Chonoporus sp., 1.53%; Mullet, 0.97% and Scatophagus argus, 0.32%. The rest of the species combined comprised less than 1%.

      Water temperature, pH and dissolved oxygen (D.O.) showed inverse relationships with fish abundance at the early hours of the day (0800H-1200H) but incosistent correlations were noted during night time when these parameters were rather constant. Salinity did not show any correlation to fish abundance although more species were collected after a heavy downpour. Fish catch was higher during low tide than at high tide.
    • Article

      Larval and postlarval development of the window pane shell, Placuna placenta Linnaeus, (Bivalvia: Placunidae) with a discussion on its natural settlement. 

      AL Young - Veliger, 1980 - California Malacozoological Society, Inc.
      Stages of development of P. placenta from the straight-hinge veliger to the adult are described. Mature larvae metamorphose at lengths from 220-230 m. Larvae probably attach byssally to the water surface at metamorphosis and remain in the plankton for some time before finally settling on the mud bottom.
    • Article

      Larval mycosis in Penaeus monodon 

      MCL Baticados, GL Po, CR Lavilla & RQ Gacutan - Kalikasan: The Philippine Journal of Biology, 1979 - University of the Philippines, Los Baños
      A phycomycetous fungus, presumably a Lagenidium, was observed to infect Penaeus monodon larvae. Monitoring of the hatchery in 1976 and 1977 showed that it occurred in 35 out of 51 and 22 out of 37 runs, respectively. So devastating was the infection that whole tank populations had to be discarded after 48 hr.

      Extramatrical tubes are sent out profusely; a discharge vesicle is formed from each tube. The cytoplasmic contents of the hypha then flow into the vesicle, and zoospore formation occurs. Zoospore release is facilitated by rupture of the vesicle after continuous movement of the zoospores. The hyphae in infected larvae measure 2.5-6.3 microns wide. The discharge vesicles are 14.5-25.0 microns in diameter; each one releases 14-32 zoospores 3.8-6.3 microns wide by 5.0-6.3 microns long.
    • Article

      Larval rearing of bighead carp, Aristichthys nobilis Richardson, using different types of feed and their combinations 

      AC Fermin & RD Recometa - Aquaculture Research, 1988 - Blackwell Publishing
      The effects of different types of feed, given singly or in combination, on the growth and survival of bighead carp, Arislichlhys nobilis Richardson, larvae reared for a period of 12 weeks were determined. Growth was highest for fish fed with the combination of Moina and artificial feed followed by fish fed with artificial feed alone. Significantly lower (P < 0.05) growth was found in fish fed with green water +Moina+ artificial feed; green water + artificial feed; green water +Moina and Moina alone, in a descending order. Carp larvae reared in green water alone did not survive after the fifth day of feeding. Specific growth rales ranging from 0.59% day−1 to 2.75% day−1 were exhibited by fish in all the remaining six treatments.

      Although green water alone did not support the growth of the larvae, enhanced survival rates were observed when green water was given in combination with other feeds. Survival rate was highest in fish fed with the combination of green water, Moina and artificial feed, but was not significantly different (P > 0.01) from those given Moina+ artificial feed. Consequently, normalized biomass index was significantly high (P < 0.05) in fish fed with the combination of green water, Moina and artificial feed.
    • Article

      Larval rearing of mud crab (Scylla): What lies ahead 

      K Waiho, H Fazhan, ET Quinitio, JC Baylon, Y Fujaya, G Azmie, Q Wu, X Shi, M Ikhwanuddin & H Ma - Aquaculture, 2018 - Elsevier
      The increasing global demand for mud crabs (genus Scylla) and threats to the wild populations highlight the urgency of fully rearing them in captivity. Despite considerable progress in mud crab production, most crab farms still rely heavily on wild-caught crablets and juveniles while the low and inconsistent success rates of larviculture remain as the main bottleneck impeding the development of mud crab aquaculture. Over the years, numerous studies have been conducted to determine the optimum larval rearing parameters, the ontogenic changes in digestive function and feeding behaviour, and the diets for different larval stages. These data, however, are dispersed and not summarised to inform culture practices. This review provides an update on the current progresses and to pinpoint the gaps in knowledge regarding mud crab larval rearing. We include all four mud crab species under the genus Scylla, i.e. Scylla serrata, Scylla olivacea, Scylla tranquebarica and Scylla paramamosain. Knowledge compiled in this review serves as an important guideline for prospective mud crab larviculture. Future research should gear towards filling in the gaps in our knowledge to advance mud crab larval rearing, thus fully incorporating mud crab into the aquaculture sector.
    • Article

      Larval rearing of the grouper Epinephelus suillus under laboratory conditions 

      MN Duray, CB Estudillo & LG Alpasan - Aquaculture, 1997 - Elsevier
      A protocol for rearing orange-spotted rockcod, Epinephelus suillus in the hatchery is described. The feeding regime consisted of Chlorella, Brachionus, Artemia and minced fish. With this regime, survival rates at Day 24 were 19.8% in 3-ton tanks and only 7.4% in 0.5-ton tanks. From an initial length of 1.62 mm on Day 0, larvae grew to 10.94 mm on Day 24 and 51.4–65.1 mm on Day 60. Larval growth and survival rate were improved when larvae were fed screened (less than 90 μm) Brachionus during the first 2 weeks. Survival was even better among larvae fed Brachionus until Day 35. Artemia, at a density of 3 ml−1, given once daily to larvae in 24 ppt seawater improved growth and survival.
    • Article

      Larval rearing of the Philippine freshwater catfish, Clarias macrocephalus (Gunther), fed live zooplankton and artificial diet: A preliminary study 

      AC Fermin & MEC Bolivar - The Israeli Journal of Aquaculture-Bamidgeh, 1991 - Society of Israeli Aquaculture and Marine Biotechnology
      A preliminary study was conducted to determine growth and survival of Clarias macrocephalus fed live zooplankton (Artemia or Moina macrocopa ) and/or a dry artificial diet. The specific growth rate over a 14-day rearing period was higher for fish fed Artemia plus a dry diet than for other treatment groups fed either live zooplankton or a dry artificial diet alone. C. macrocephalus larvae can directly take dry diet during the early days of exogenous feeding, however, continued feeding on dry artificial diet resulted in poor fish growth and survival. Mortality due to observed cannibalism in fish fed exclusively an artificial diet increased from 4% to 18% during the last two days of the rearing period. A significantly lower proportion of mortality due to cannibalism was observed in those fed an artificial diet after a 7-day period of feeding on Artemia . The survival rate was generally high, except for the fish fed a dry diet alone.