Now showing items 755-774 of 1064

    • Article

      Paralytic shellfish poisoning due to Pyrodinium bahamense var. compressa in Mati, Davao Oriental, Philippines 

      RQ Gacutan, MY Tabbu, EJ Aujero & F Icatlo Jr. - Marine Biology, 1985 - Springer Verlag
      On 26 August 1983, a single case of paralytic shellfish-poisoning (PSP) was reported in Davao City, Philippines. The poisoning was traced to ingestion of the green mussel Perna viridis Linnaeus, gathered from Balete Bay, Mati, Davao Oriental. Phytoplankton and zooplankton analyses on 12 October 1983 (47 d later), revealed the presence of the dinoflagellate Pyrodinium bahamense var. compressa, a cause of a series of red tides in the early and middle 1970's in Papua New Guinea, Sabah, and Brunei, and more recently, in Palau, and Western Samar and Leyte, Philippines. The dinoflagellate was not dominant; in fact the enumeration showed greater numbers of Ceratium sp., another dinoflagellate. Quantification of the neurotoxin by the standard mouse assay revealed a very high potency. Mussels collected from a new raft (transplanted in May 1983) had a toxicity of 7 960 mouse units (MU) per 100 g-1 meat. Those from an old raft (transplanted in May 1982) had a toxicity of 9 620 MU per 100 g-1 meat.
    • Article

      Paralytic shellfish poisoning toxin accumulation in shellfishes collected from various habitats in Murcielagos Bay, Philippines during harmful algal blooms occurrence 

      RJA Narceda, UM Montojo, MRR Eguia & GL Sia Su - Advances in Environmental Biology, 2014 - American-Eurasian Network for Scientific Information (AENSI)
      This study aims to determine whether the habitat of bivalves plays an influence in the occurrence of tropical shellfish toxicity during toxic red tide bloom occurrences in Murcielagos Bay, Misamis Occidental, Philippines. Various shellfish species were collected during the occurrence of red tide blooms. The type of habitat and the shellfish toxicities were investigated. Likewise, the phytoplankton profile in the seawater column was assessed. Results of our study revealed that the occurrence of shellfish toxicities was habitat specific in spite of the fact that the causative organism Pyrodinium bahamense var. compressum was present in low concentrations in the sampling sites. Shellfish collected from sea grass, coralline area, and seafloor habitats were notably susceptible against the paralytic shellfish poisoning toxin contamination compared to those samples obtained from soil substrate. Continuous monitoring of areas that are affected with shellfish toxicity must be conducted so as to safeguard the general public’s welfare dependent on these resources.
    • Article

      Parasites from the green mussel (Perna viridis Linnaeus 1758) (Mollusca: Mytilidae) of Ivisan, Capiz, Philippines 

      G Erazo-Pagador - Philippine Agricultural Scientist, 2018 - College of Agriculture and Food Science, University of the Philippines Los Baños
      This study reports the parasites found in green mussel (Perna viridis L.) from Ivisan, Capiz, Philippines. Samples were collected monthly from January to December 2009. A total of 360 samples were collected, fixed in 10% formalin in seawater solution, and processed by standard histological techniques that included staining the sections with hematoxylin and eosin (H & E). The water temperature ranged from 24 to 30°C and salinity from 18 to 23 ppt. Microscopic analysis showed that the most prevalent parasites were Nematopsis sp. occurring mostly in connective tissues (46%), metacestodes of Tylocephalum sp. in the mantle (12%), and a turbellarian (4%) and metacercariae in the mantle (4%). Based on these findings, these parasites may not yet be a problem to mussel farming as they were low and caused no apparent damage to the host.
    • Article

      Parasites of window-pane oyster (Placuna placenta Linnaeus, 1758) from Trapiche, Oton in west central Philippines 

      G Erazo-Pagador - The Philippine Agricultural Scientist, 2015 - College of Agriculture, University of the Philippines Los Baños
      Parasitology of edible and commercially valuable window-pane oysters (Placuna placenta L.) using gross macroscopic examination and histology was conducted. To screen for the presence of parasites, wild oysters were collected monthly from January 2008 to December 2008 from Trapiche, Oton in west central Philippines. Thirty live adult oysters with shell length (SL) of 52-89 mm were hand-picked monthly. Gross observation showed the presence of pea crabs (Pinnotheres sp.) in the mantle cavity of the oysters. The overall prevalence and intensity of P. placenta with pea crabs were 4.44% and 1, respectively. Histological examination revealed the occurrence of Tylocephalum sp. (prevalence and intensity of the parasites were 1.66 % and 0.5, respectively) in connective tissues around the digestive gland. Tylocephalum sp. was found surrounded by hemocytic infiltration. Ciliates (Ancistroma sp.) were also observed in the gills with overall prevalence of 38.83% and intensity of 7.51. Larval stages of trematodes of Bucephalus sp. (prevalence, 18.83%; intensity of 1.5) were found in the connective tissues of the female gonad. The study presents a documentation of parasites of P. placenta in the Philippines.
    • Article

      A parasitological survey of slipper-cupped oysters (Crassostrea iredalei, Faustino, 1932) in the Philippines 

      G Erazo-Pagador - Journal of Shellfish Research, 2010 - National Shellfisheries Association
      This paper describes the first screening in the Philippines of slipper-cupped oysters (Crassostrea iredalei) for the presence of parasites. Slipper-cupped oysters were sampled at 2 sites in Ivisan, Capiz, from September to December 2007. Macroscopical and histological analyses were carried out in oyster tissues. Histological examination showed gregarine protozoan Nematopsis sp. as the most prevalent parasite (71.33% and 65.0%) at 2 sites with a moderate intensity of infection. Tylocephalum sp. cestode was found in the connective tissue around the digestive gland, with a prevalence of 60% and 52.3% in 2 sites, with a moderate intensity of infection. Digenean trematodes had a 37.80% prevalence at site 1 and a 22.45% prevalence at site 2. Ciliates were also observed with a prevalence of 18.75% (site 1) and 13% (site 2). The observed infection of oysters had no apparent effect on oyster production at these sites maybe due to low infestation levels or to the fact that the parasites have no pathological effect.
    • Article

      Partial replacement of Artemia sp. by the brackishwater cladoceran, Diaphanosoma celebensis (Stingelin), in the larval rearing of sea bass, Lates calcarifer (Bloch) 

      MR de la Peña, AC Fermin & DP Lojera - The Israeli Journal of Aquaculture-Bamidgeh, 1998 - Society of Israeli Aquaculture and Marine Biotechnology
      A feed experiment was conducted to test the brackishwater cladoceran, Diaphanosoma celebensis, as a partial or complete substitute for Artemia in the larval rearing of the sea bass, Lates calcarifer. The cladoceran was fed either alone or in combination with Artemia to 15-day old sea bass larvae (5.6 mm SL, 2.7 mg wet BW) reared at 15 ppt salinity. Groups fed Artemia alone were reared at 15 and 32 ppt salinity levels. After 15 days of rearing, the survival (95-99%), observed mortality (0.8-1.2%) and apparent loss due to cannibalism (0.2-4.1%) did not differ significantly among treatments. The specific growth rates of fish fed only Artemia (18.7-19.1%/day) and combined Artemia+Diaphanosoma (18.7%/day) were significantly higher than that of fish fed only Diaphanosoma (16.3%/day). Diaphanosoma had higher crude protein and crude fat contents than Artemia but the percentage of n-3 highly unsaturated fatty acids, particularly 20:5n3 and 22:6n3, was lower than in Artermia. Results indicated the potential of Diaphanosoma as a partial substitute for Artemia in the larval rearing of sea bass at 15 ppt salinity.
    • Article

      Partial replacement of fishmeal by defatted soybean meal in formulated diets for the mangrove red snapper, Lutjanus argentimaculatus (Forsskal 1775) 

      MR Catacutan & GE Pagador - Aquaculture Research, 2004 - Blackwell Publishing
      This study was conducted to evaluate the effect on growth and feed efficiencies of the mangrove red snapper (Lutjanus argentimaculatus) when dietary fishmeal is partially replaced by defatted soybean meal (DSM). In the preliminary experiment, snapper (mean weight±SD, 58.22±5.28 g) were fed in triplicate with different dietary amounts of DSM (7.8–42.2%) that were formulated to be isonitrogenous and isocaloric. After 14 weeks, survival, growth and feed efficiencies, and hepatosomatic index (HSI) did not differ. Based on these results, a feeding trial was done using a positive control diet that contained 64% fishmeal, while the other four diets had DSM levels of 12%, 24%, 36%, and 48% that replaced fishmeal protein at 12.5%, 25%, 37.5%, and 50% respectively. All diets were formulated to have about the same protein level (50%), protein to energy ratio (P/E of 25-mg protein kJ−1), and dietary energy (19.8 MJ kg−1). These were fed to triplicate groups of snapper (mean total weight tank−1±SD, 73.19±1.2 g) at 15 fish (average weight, 4.88 g) per 1.5-t tank for 19 weeks. Growth (final average weight and specific growth rate (SGR), feed conversion ratio (FCR), survival, and HSI were not significantly different (P>0.05) while protein efficiency ratios or PERs were similar in treatments with DSM. Among snapper fed DSM, haematocrit value was significantly lower in fish fed 48% DSM and not different with fish fed 36% DSM. Whole-body crude fat of snapper fed 48% DSM was lowest while the crude protein and nitrogen-free extract (NFE) levels were highest. Histopathological analysis showed that lipid vacuoles in livers of snapper were reduced in size as dietary DSM increased. There was slight lipid deposition in the liver of snapper at 36% DSM while at 48% DSM it was excessive and hepatocytes were necrotic. There were no differences in the histology of snapper intestine. Under the experimental condition of this study, DSM can be used in snapper diets at 24% (replacing 25% of fishmeal protein) based on growth, survival and feed efficiencies, and histology of liver and intestine. For a lesser diet cost, an inclusion level higher than 24% DSM is possible with a bioavailable phosphorus supplement.
    • Article

      Partial replacement of soybean meal with fermented copra meal in milkfish (Chanos chanos, Forsskal) diet 

      MJS Apines-Amar, RM Coloso, CJ Jaspe, JM Salvilla, MNG Amar-Murillo & CA Saclauso - Aquaculture, Aquarium, Conservation and Legislation, 2015 - Bioflux
      Feeding trials were conducted to determine the optimum partial replacement level of soybean meal (SBM) with fermented copra meal (FCM). Isonitrogenous and isocaloric diets containing 0, 5, 10, 15, 20, and 25% of the locally produced FCM partially replacing SBM protein by 0, 12, 27, 41, 56, and 71%, respectively and fully replacing copra meal were formulated. The diets were fed to the fish with an initial weight of 2.83±0.14 g for 12 weeks. Thereafter, the best diet was further tested in a preliminary feeding trial in brackishwater grow-out ponds to verify the performance of the formulated diet against a commercial milkfish feed in an outdoor grow-out system. The results of the indoor tank feeding trial indicated that weight gain of the fish was significantly better in the group fed diet 2, with 5% dietary FCM but further increase in the FCM inclusion level up to 20% of the diet did not exhibit statistical differences against the control. Moreover in the preliminary pond feeding trial, growth and feed conversion ratio (FCR) of the fish fed the FCM diet were significantly higher than the commercial control diet. Survival and nutrient composition of the fish carcass were not adversely affected by the treatments. Hence, optimum dietary FCM inclusion level was determined at 5% of the milkfish diet replacing 100% copra meal and 12% SBM protein. However, in terms of economics, up to 20% FCM can be included in the diet replacing 56% SBM protein may be possible with growth comparable to the FCM-less control.
    • Article

      Participation of women in oyster and mussel farming in Western Visayas, Philippines 

      SV Siar, GP Samonte & AT Espada - Aquaculture Research, 1995 - Blackwell Publishing
      This paper provides baseline information on the involvement of women in small-scale coastal aquaculture such as the farming of slipper oyster, Crassostrea iredalei (Faustino 1933), and green mussel, Perna viridis (Linnaeus 1758). Data were gathered during a socio-economic survey of oyster and mussel farming in Western Visayas, Philippines conducted from July to December 1991.There were 175 respondents interviewed; 18.5% and 2.4% of oyster and mussel farmers were females. Fishing and related activities were the major source of livelihood for the majority of oyster and mussel farmers. In 1990, 79.4% and 69.8% of oyster and mussel farmers earned an annual income of less than P30 000 (1 USS P23). Based on the 1988 (latest data available) poverty threshold of P2654 (monthly) for Western Visayas, 80.4% and 71.7% of oyster and mussel farmers lived below poverty level in 1990. of 175 respondents. 79.3% and 48.2% of oyster and mussel farmers indicated that their household members participated in farming activities. More female household members were involved in oyster farming compared with mussel farming. Harvesting in mussel farming and both harvesting and marketing in oyster farming generated the widest participation among female household members.
    • Article

      Pathogenicity of the epizootic ulcerative syndrome (EUS)-associated rhabdovirus to snakehead Ophicephalus striatus 

      GD Lio-Po, LJ Albright, GS Traxler & EM Leaño - Fish Pathology, 2001 - Japanese Society of Fish Pathology
      The rhabdoviruses isolated from EUS-affected snakeheads in the Philippines was tested for pathogenicity to healthy, naive snakehead Ophicephalus striatus fry, fingerlings and juveniles. Virus exposure of naive snakehead fry and fingerlings by bath at 20-22.5°C resulted in significant mortalities (p<0.01) with no apparent lesions. Naive snakehead juveniles when injected intramuscularly (IM) with the EUS-associated rhabdovirus at ambient water temperature (28-32°C) did not develop any lesion. However, similarly treated snakehead juveniles at 20-22.5°C developed dermal lesions 3-5 days following treatment. The lesions progressed from slight to moderately advanced lesions by days 10-12 but not to deep ulcers as exhibited by naturally EUS-affected snakeheads. Mean mortalities were higher in the virus-injected fish (72%) compared to those in controls (33%). Moreover, the virus was reisolated from fish in the 20-22.5°C treatment but not from fish in the 28-32°C treatment. Virus from infected tissue filtrate and the virus passaged 3 or 4 times induced similar dermal lesions if the rhabdovirus concentration was 103 TCID50/fish or higher. When administered orally, by bath, by intraperitoneal (IP), IM and subdermal injections to snakehead juveniles, only the latter two viral routes induced dermal lesions. However, IP injection of the rhabdovirus caused 75% mortalities but none in control fish. The results demonstrate the pathogenicity of the rhabdovirus isolates to naive snakeheads at low (20-22.5°C) rearing water temperatures.
    • Article

      Pen culture of mud crab Scylla serrata in tidal flats reforested with mangrove trees 

      AT Triño & EM Rodriguez - Aquaculture, 2002 - Elsevier
      Growth and survival of mixed sex mud crabs Scylla serrata (Forskal), held in 200 m2 pens located in reforested mangrove tidal flats, were evaluated. The effects of stocking density (0.5 or 1.5 m−2) and feed (salted fish bycatch or a mixed diet of 75% salted brown mussel flesh and 25% salted fish bycatch) were determined in a replicated factorial experiment. Duration of the experiment was 160 days. There were no significant differences (P>0.05) in growth, apparent feed conversion ratio (FCR), survival, and production among the two types of feed. Regardless of feed, the mean±SE FCR of 5.30±0.34 and survival of 56.00±1.90% at 0.5 m−2 stocking density were significantly better (P<0.05) than at 1.5 m−2 stocking density (7.6±0.63 FCR and 33.00±3.61% survival). However, growth was not significantly affected by stocking density. Cost–return analysis on a per crop per 200 m2 basis showed that the use of either of the two stocking densities with either diet was economically viable with a return on capital investment of 49–68%. However, crabs stocked at 1.5 m−2 and fed a mixed diet of 75% salted brown mussel flesh and 25% salted fish bycatch is more profitable. The integration of crab aquaculture within natural mangroves is therefore feasible in the Philippines, providing both immediate and long-term commercial and environmental benefits.
    • Article

      Performance of recirculating systems for prawn hatchery and broodstock maturation tanks 

      OM Millamena, CM Casalmir & PF Subosa - Aquacultural Engineering, 1991 - Elsevier
      The potential use of recirculating systems with facilities for waste removal for prawn (Penaeus monodon) hatchery and broodstock maturation tanks was investigated. Recirculating systems evaluated for larval culture tanks were biological filtration and zigzag stream sedimentation. Systems using airlift and airstones as aeration devices with partial water change but with no provision for recirculation served as control. Results showed successful rearing of Penaeus monodon (nauplii-postlarvae) in systems with facilities for wastewater recirculation. Aeration systems became ineffective in maintaining acceptable water quality as shown by increases in 5-day biochemical oxygen demand (BOD5), ammonia (NH4-N) and nitrite (NO2-N) nitrogen, and decreases in dissolved oxygen (DO).

      For broodstock maturation, a recirculating system with a preconditioned biological filter was compared with a flow-through system. Biological filtration proved to be useful in meeting water quality requirements. Nitrification was satisfactory with ammonia levels lower than 1·0 mg liter−1. The pH values in the biofilter effluent were maintained at 7·8–8·3. BOD5 levels were below 10 mg liter−1 while DO tended to drop due to the nitrifying activity of the filter. Better reproductive performance of Penaeus monodon broodstock was obtained in the recirculating system than in the flow-through system.
    • Article

      Perna viridis (L.) 1758 as the correct name for the Southeast Asian green mussel (Bivalvia:Mytilidae) 

      AL Young & WG Yap - Philippine Journal of Science, 1984 - Science and Technology Information Institute
      The Southeast Asian green mussel is Perna viridis. The wide separation of the retractor mussel scars in the adult shell and the special set of teeth on the posterior shoulder of the larval shell definitely place the green mussel under the genus Perna ritzius.
    • Article

      Phenotypic differences between hatchery-reared and wild mud crabs, Scylla Serrata, and the effects of conditioning 

      L Parkes, ET Quinitio & L Le Vay - Aquaculture International, 2011 - Springer Verlag
      Hatchery-reared animals for stock enhancement should be competent to survive and grow at rates equivalent to those of wild conspecifics. However, morphological differences are often observed, and pre-conditioning steps may be required to improve the fitness of hatchery-reared juveniles prior to release. In the present study, hatchery-reared Scylla serrata juveniles were reared either individually (HR-solitary) or groups in tanks (HR-communal), the latter group being exposed to intraspecific competition and foraging for food. After 21 days, both groups were compared to similar size wild-caught juveniles in terms of morphometric measurements of carapace spination, abnormalities and carapace colouration. There were some limited significant differences between HR-communal crabs and HR-solitary crabs in terms of length of 8th and 9th lateral spines and in body-weight-carapace width ratio, but both treatments differed from wild crabs, which were heavier and had longer carapace spines for thei
    • Article

      Phosphorus utilization in rainbow trout (Oncorhynchus mykiss) fed practical diets and its consequences on effluent phosphorus levels 

      RM Coloso, K King, JW Fletcher, MA Hendrix, M Subramanyam, P Weis & RP Ferraris - Aquaculture, 2003 - Elsevier
      Excessive dietary phosphorous (P) concentrations in effluents from aquaculture present a major environmental problem. We therefore studied the effect of dietary P and vitamin D3 on P utilization by rainbow trout-fed practical diets and on P concentrations in the soluble, particulate and settleable components of the effluent from fish tanks. Rainbow trout (average weight: 78 g, initial biomass: 13 kg in 0.7 m3 tanks) were fed for 11 weeks, practical diets that varied in total P, available P, and vitamin D3 concentrations. Soluble, particulate (10–200 μm) and settleable (>200 μm) P in the effluent were sampled every 0.5–6 h for 1–3 days in the third and eleventh weeks of the experiment. Trout in all diets more than doubled their weight after 11 weeks. Increasing the concentrations of available dietary P from 0.24% to 0.88% modestly enhanced growth rate. Feed conversion ratio (FCR) and biomass gain per gram P consumed decreased as dietary P concentrations increased. Carcass P, daily P gain, and plasma P concentrations were lower in fish fed with low P diets. Soluble P concentrations in the effluent peaked immediately after and again 4–6 h after feeding, and is a linear function of available dietary P. No soluble P would be produced during consumption of diets containing less than 0.22±0.02% available P. Above this dietary concentration, soluble P would be excreted at 6.9±0.4 mg/day/kg for each 0.1% increase in available dietary P. Particulate P concentrations in the effluent were independent of dietary P concentrations. Settleable, presumably fecal, P concentrations tended to increase with dietary P concentrations. In trout fed with low P (0.24% available P, 0.6% total P) diets, 60% of total dietary P were retained by the fish and the remaining 40% were excreted in the effluent as settleable P (20–30%) and particulate or soluble P (10–20%). In trout fed with high P (0.59–0.88% available P; 0.9–1.2% total P) diets, 30–55% of total dietary P was retained by fish, and the remaining 15–25% appeared in the effluent as settleable P, 20–55% as soluble P, and 5–10% as particulate P. Vitamin D3 did not affect fish growth nor effluent P levels. Physicochemical management of aquaculture effluents should consider the effect of diets on partitioning of effluent P, the peaks of soluble P concentration following feeding, and the contributions of particulate P to total P in the effluent. Increasing our understanding of how dietary P is utilized and is subsequently partitioned in the effluent can contribute significantly towards alleviating this important environmental and industry problem.
    • Article

      Photosynthetic responses of ‘Neosiphonia sp. epiphyte-infected’ and healthy Kappaphycus alvarezii (Rhodophyta) to irradiance, salinity and pH variations 

      IAG Borlongan, MRJ Luhan, PIP Padilla & AQ Hurtado - Journal of Applied Phycology, 2016 - Springer Verlag
      Understanding the physiological condition of seaweeds as influenced by biotic and abiotic stress is vital from the perspective of massive expansion and sustainability of seaweed-based industries. The photosynthetic responses ofNeosiphonia sp. epiphyte-infected (INF) and healthy (HEA) Kappaphycus alvarezii under various combinations of irradiance, salinity and pH were studied using photosynthesis-irradiance (P-E) curves. Measurements of algal photosynthetic rates, expressed in terms of amount of oxygen production per fresh weight biomass per unit time (mg O2 g−1 FW h−1), were carried out using the light-dark bottle technique. Neosiphonia-infected K. alvarezii (INF) had lower photosynthetic rates than healthy ones (HEA). Similarities (p > 0.05) in light-saturated photosynthesis rates (Pmax) and significant differences (p < 0.05) in initial slope of curve (α) between INF and HEAK. alvarezii suggest that both samples are adapted to similar light conditions and differs only on photosynthetic efficiency. Low Pmax (0.7–2.0 mg O2 g−1 FW h−1) and high initial saturation irradiances (Ek = 90–519 μmol photons m−2 s−1) of INF seaweeds resulted to their low photosynthetic efficiency (α = 0.002–0.010). Such decline in α is attributed to the epiphyte, as Neosiphonia sp. covered almost the entire surface of K. alvarezii. An increase in chlorophyll-a (35–42.1 vs. 27.7–31.5 μg g−1 FW, HEA) and phycobilin (1.96–2.39 vs. 1.16–1.58 mg g−1 FW, HEA) contents was also observed in INF samples, suggesting acclimation to low-irradiance conditions, as a result of competition for light between the epiphyte and host. Both INF and HEA K. alvarezii also exhibited broad photosynthetic tolerance to short-term changes in irradiance, with no photoinhibition at the highest irradiance of 850 μmol photons m−2 s−1. K. alvarezii had a euryhaline photosynthetic response, with optimum salinity of 35 psu. Photosynthetic rates increased with decreasing pH, revealing K. alvarezii’s ability to modify its photosynthetic affinity for acidic seawater conditions; yet, their underlying mechanism of response to pH shifts still need to be further examined.
    • Article

      Phylogeographic patterns in the Philippine archipelago influence symbiont diversity in the bobtail squid-Vibrio mutualism 

      RL Coryell, KE Turnham, EG de Jesus Ayson, C Lavilla-Pitogo, AC Alcala, F Sotto, B Gonzales & MK Nishiguchi - Ecology and Evolution, 2018 - Wiley Open Access
      Marine microbes encounter a myriad of biotic and abiotic factors that can impact fitness by limiting their range and capacity to move between habitats. This is especially true for environmentally transmitted bacteria that cycle between their hosts and the surrounding habitat. As geologic history, biogeography, and other factors such as water temperature, salinity, and physical barriers can inhibit bacterial movement to novel environments, we chose to examine the genetic architecture of Euprymna albatrossae (Mollusca: Cephalopoda) and their Vibrio fischeri symbionts in the Philippine archipelago using a combined phylogeographic approach. Eleven separate sites in the Philippine islands were examined using haplotype estimates that were examined via nested clade analysis to determine the relationship between E. albatrossae and V. fischeri populations and their geographic location. Identical analyses of molecular variance (AMOVA) were used to estimate variation within and between populations for host and symbiont genetic data. Host animals demonstrated a significant amount of variation within island groups, while symbiont variation was found within individual populations. Nested clade phylogenetic analysis revealed that hosts and symbionts may have colonized this area at different times, with a sudden change in habitat. Additionally, host data indicate restricted gene flow, whereas symbionts show range expansion, followed by periodic restriction to genetic flow. These differences between host and symbiont networks indicate that factors “outside the squid” influence distribution of Philippine V. fischeri. Our results shed light on how geography and changing environmental factors can impact marine symbiotic associations at both local and global scales.
    • Article

      Physico-chemical characteristics and pathogenicity of Vibrio Parahaemolyticus-like bacterium isolated from eye lesions of Chanos chanos (Forsskal) juveniles 

      CR Lavilla-Pitogo - Fisheries Research Journal of the Philippines, 1991 - Fisheries Research Society of the Philippines
      Vibrio parahaemolyticus-like bacteria were isolated from eye lesions of milkfish juveniles. The tolerance of the typical isolate to various temperature, pH and salinity levels was tested. Pathogenicity tests done via both injection and immersion challenge techniques induced high mortalities in milkfish fingerlings. Juveniles challenged by immersion method exhibited a very low mortality rate, but eye lesions were observed and these ranged from various degrees of eye cover opacity, to cataract-like tissue formation around the lens, and the failure of the artificially injured site to heal. The impact of the present observations to the milkfish industry is discussed.
    • Article

      Physiological and avoidance responses of juvenile mud crab Scylla serrata to mercury 

      HM Monteclaro, RP Babaran, RC Sanares & ET Quinitio - Aquaculture, Aquarium, Conservation and Legislation, 2014 - Bioflux
      The physiological and avoidance responses of juvenile mud crab Scylla serrata to mercury was evaluated by determining mortality using a renewal-type acute toxicity test and assessing crabs’ ability to avoid toxic concentrations. The 96-h LC50 of mercury to juvenile mud crab was computed to be 0.04 mg L-1. When transferred to clean waters, crabs that survived exposure to concentrations lower than 0.04 mg L-1 had better chances of surviving than those that were exposed to higher mercury concentrations. Avoidance of juvenile mud crabs to mercury was determined using a fluvarium, which provided the crabs a choice between untreated and Hg-treated waters. Results showed that juvenile crabs were not able to avoid waters that contain 0.1 mg L-1 mercury, a concentration that was more than twice the 96-h LC50 value. Juveniles previously pre-exposed in 1/50th of the 96-h LC50 value had a higher avoidance threshold and were not able to avoid waters with 1 mg L-1 mercury. Results suggest that juvenile mud crab is unable to avoid waters containing lethal levels of mercury and this may have potential impacts on crab biomass, distribution, growth, and development.
    • Article

      Pigmentation pattern in the early developmental stages of milkfish (Chanos chanos): A key for larval identification. 

      P Buri - Fisheries Research Journal of the Philippines, 1981 - Fisheries Research Society of the Philippines
      Pigmentation patterns are presented for 5 - 20 day old milkfish (Chanos chanos) and are discussed in terms of their use in larval identification.