SEAFDEC/AQD Institutional Repository: Recent submissions

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    • Effect of different diets on the ultrastructure of hepatocytes of Chanos chanos fry (Chanidae: Teleostei): An electron microscopic and morphometric analysis 

      Storch, Volker; Stählin, W.; Juario, Jesus V. (Springer-Verlag, 1983)
      The hepatocytes of milkfish fry offered different artificial diets (carbohydrate-, lipid-, protein-oriented) and live food (Artemia spp., Brachionus plicatilis) differ considerably both qualitatively and quantitatively as was shown by means of transmission electron microscopy and planimeter. Food deprivation, too, resulted in ultrastructural alterations of milkfish fry hepatocytes. Thus, this cell type might be used as an indicator of quality and quantity of food in teleosts.

    • Effect of artificial diets on growth and survival of milkfish fry in fresh water 

      Santiago, Corazon B.; Bañes-Aldaba, Mercedes; Songalia, Edna T. (Elsevier, 1983)
      Wild milkfish fry (mean weight = 15 mg) were reared in fresh water for 5 weeks using four artificial dry diets, Moina, or blended water hyacinth leaves as feed. The fry fed with artificial diets attained 83–95% mean survival rates and 0.16–0.18 g mean weight gains. Those fed with Moina and blended water hyacinth leaves had much lower growth and survival. The four dry diets containing 40% crude protein appeared adequate for the fry. Substitution of up to 5% crude protein by soybean meal and/or ipil-ipil leaf meal did not affect growth, but diets containing ipil-ipil leaf meal gave slightly lower survival rates.

    • Survival and some histological changes in Penaeus monodon Fabricius juveniles fed various carbohydrates 

      Piedad-Pascual, Felicitas; Coloso, Relicardo M.; Tamse, Catherine T. (Elsevier, 1983)
      Juveniles of P. monodon Fabricius (initial mean weight 1.76 g) were reared on semipurified diets containing 10 or 40% maltose, sucrose, dextrin, molasses, cassava starch, corn starch or sago palm starch for 6 weeks. Highest survival (56%) was obtained in juveniles fed with a diet containing 10% sucrose. Within 10 days of rearing, complete mortality was observed in prawns fed with higher levels of maltose and molasses. After 6 weeks, among the starches, sago palm starch provided for the best survival at 10% level. There was no relationship between time to death and size of the prawn (r = −0.10). Significant differences were observed between the type, as well as the level, of carbohydrate in the diet on the survival of juvenile prawn. Histopathological changes in the hepatopancreas, gills and exoskeleton of juveniles fed with the various carbohydrates were also studied.

    • The effect of thyroxine on the larvae and fry of Sarotherodon niloticus L. (Tilapia nilotica) 

      Nacario, Jonathan F. (Elsevier, 1983)
      Effects of thyroxine (T4) (0.1 ppm; 0.3 ppm; 0.5 ppm) on Sarotherodon niloticus L. yolk sac larvae were studied after 4 weeks of treatment from hatching. T4 at 0.5 ppm accelerated yolk resorption but did not significantly increase growth after the first week of treatment. Increase in length and in weight among fry treated with T4 at 0.1 ppm and 0.3 ppm was significant after the fourth week. T4 at 0.1 ppm increased significantly the length of the pectoral fin; but at 0.3 ppm and 0.5 ppm caused abnormal shapes in the pectoral fins as well as lordosis and scoliosis. T4 reduced pigmentation in treated yolk sac larvae for 3 days only and caused thickening of the epidermis in both treated yolk sac larvae and fry. Thyroid follicles were absent in the yolk sac larvae but present in the fry.

    • The effect of starvation and subsequent feeding on the hepatocytes of Chanos chanos (Forsskal) fingerlings and fry 

      Storch, Volker; Juario, Jesus V. (Academic Press, 1983)
      Excised liver sections of the milkfish, Chanos chanos, fry and fingerlings were studied by transmission electron microscopy. The hepatocytes underwent marked ultrastructural alterations in response to food deprivation of 10-day starvation for fry and 2 months for the fingerlings. The prominent features characterizing the hepatocytes of starved fish were: a reduction of cell and nucleus size; apparent loss of nucleoli; condensation of chromatin material in fry; loss of stored glycogen; reduction of ER profiles; increase in the number of electron-dense bodies containing large amounts of iron in fingerlings; and an increase in mitochondrial size. These changes were reversible following short periods of re-feeding, i.e. 2 days for fry and 4 days for fingerlings, using natural food for the fry and formulated diet for the fingerlings.

    • Supplement of various attractants to a practical diet for juvenile Penaeus monodon Fabricius 

      Murai, Takeshi; Sumalangcay, Amado, Jr.; Piedad-Pascual, Felicitas (Fisheries Research Society of the Philippines, 1983)
      Practical diets supplemented with krill meal (5%), earthworm meal (5%), glycine (2%), sucrose (5%) or mussel extract as an attractant were fed for eight weeks to juvenile Penaeus monodon. The major protein sources of the diets were locally available full-fat soybean meal, fish meal and shrimp meal, and the crude protein level of each diet was adjusted to approximately 40%. For a four to eight-week period, dietary groups supplemented with any type of attractant resulted in better average weight gain than the control group (without any attractant). Prawns fed with a supplementary diet of earthworm meal registered the best growth rate (160% weight gain in eight weeks) which was significantly better than that of the control group. Dietary groups supplemented with earthworm meal and sucrose showed the best and worst survival rates, respectively, in zero to eight-week period. The feed conversion of the latter group was poorest among the dietary groups supplemented with the attractant.

    • Traditional devices for capturing crabs used in the Philippines today 

      Motoh, Hiroshi (Carcinological Society of Japan, 1983)
      The author intends to illustrate and describe the indigenous devices traditionally used to capture crabs including the constructions and the operational manners. Also the present writing is hoped to play a role in disseminating the record of the unique devices among local Philippine people and continued use of them. It may be added that the biological significance related to these devices may worth to be recorded.

    • A further note to “fishing gear for prawn and shrimp used in the Philippines today” 

      Motoh, Hiroshi (Carcinological Society of Japan, 1983)
      Motoh (1980) reported 9 and 13 kinds of shrimping gear for the fry and the adult respectively, of which most of them are indigenously used today in the Philippines. Howerver, druing the continued ecological survey of penaeids in the country conducted by him and his staff, six kinds of shrimping gear or devices were additionally found by them, which have been used traditionally in the country. The reasons that the present author intends to introduce the gear or devices are as follwos: 1) To record theses unque devices from the nature conservation point of view, which were invented by local people through their long experiences, though devices been forgotten due to their poor catching effectiveness, and 2) To recommend the continuous use of these devices by local people, which impose much less construction technique and energy on the users compared to modern mechanized catching tools.

    • Gonadotropin profiles in serum of milkfish treated with salmon pituitary homogenate 

      Marte, Clarissa L.; Crim, Laurence W. (University of the Philippines Los Baños, 1983)
      Serum gonadotropin (GtH) levels were determined by radioimmunoassay (RIA) in adult regressed milkfish injected or implanted with various doses of salmon pituitary homogenate (SPH). Gonadotropin profiles of injected or implanted milkfish show similar trends. Elevation of serum GtH occurred a day after treatment in all groups irrespective of the administered dose. The level dropped after 2 or 3 days and in the implanted fish, was at the initial level 10 days after treatment. The expected slow and sustained release of hormone from the SPH pellet was not obtained even at the high dose given. A preliminary investigation of the milkfish pituitary homogenate using the salmon-GtH-RIA system shows no cross reaction of milkfish GtH with salmon GtH antibody, indicating that the milkfish and salmon gonadotropins are immunologically distinct molecules.

    • The mechanics of mass occurrence and recruitment strategy of milkfish Chanos chanos (Forsskal) fry in the Philippines 

      Buri, Prasit; Kawamura, Gunzo (Kagoshima University Research Center for the South Pacific, 1983)
      The daily and hourly catch of milkfish Chanos chanos (Forsskal) fry in the coast of Hamtic, Panay Island in the Philippines was recorded over a period of 16 weeks, and correlated with time, location, types of gear, and lunar and tidal variations. About 4000 fry were marked and released, scanning electronmicroscopy was employed to examine the feeding habit of the fish. The results obtained suggest an active process governing the occurrence and movement of fry in coastal waters. The appearance of the fry is related to the developmental stage of the fry and is subject to lunar modulation. Interaction with predators in coastal waters has produced diverse and selective antipredator adaptations, such as body transparency, the use of timing (seasonality, tidal conditions), and distribution patterns. The maximization of resource utilization and minimization of resource sharing also occurs in a seasonal basis. High mortality rate in shallow coastal waters is counteracted by high recruitment rate and specific behavioural and physiological adaptations to ensure successful and fast colonization of backwaters. It is suggested that higher food availability in the nursery ground exerts a stronger selective pressure over predation, and act as the major force in the migration from offshore to shore waters.

    • Intestinal glucose transport in carnivorous and herbivorous marine fishes 

      Ferraris, Ronaldo P.; Ahearn, Gregory A. (Springer Verlag, 1983)
      The influx and transepithelial movements of glucose and their effects on the electrophysiology and Na transport in upper and lower intestines of the herbivorous surgeonfish, Acanthurus mata , and carnivorous eel, Gymnothorax undulatus , were measured. The K t G and J max G of glucose influx into the tissues were higher in the surgeonfish upper intestine than in the surgeonfish lower intestine or in both segments of the eel intestine. A prominent diffusion-like transport component was also measured in all four segments during influx experiments. Net transepithelial glucose fluxes (0.05 mM) were greater in eel intestine than in those of the surgeonfish largely due to an apparent lower apical membrane permeability of the former coincident with reduced backflux of glucose from epithelium to lumen. All four stripped intestinal segments exhibited non-significant (from zero; P >0.05) or small, serosa-negative transepithelial potential differences (-0.1 to -2.2 mV), and low transepithelial resistances (40–88 O cm -2 ). Each tissue displayed significant ( P P >0.05) change the transepithelial resistance, but did induce a significant ( P J net Na with added luminal glucose, these increased net cation fluxes were not quite significant ( P >0.05). It is concluded that coupled Na-glucose transport occurs in these tissues, but that metabolic enhancement of unrelated current-generating mechanisms also takes place and may modify depolarizing effects of organic solute transfer.

    • The visual feeding threshold and action spectrum of northern anchovy (Engraulis mordax) larvae 

      Bagarinao, Teodora ORCID; Hunter, John R. (California Cooperative Oceanic Fisheries Investigations, 1983)
      The visual feeding threshold and action spectrum of 10-15-mm northern anchovy larvae were determined, using as criterion the incidence of two or more rotifers in the guts of 50% of larvae tested under different spectral irradiances. The threshold sensitivity ot broadbank blue-green light is at 0.15 µWcm-2=0.61 lux. The action spectrum shows a mixumum in the green wavelengths around 530 nm: the weighted threshold irradiances at various wavelength bands converge at a mean value of 0.14 µWcm-2anch eff. The visual abilities of the anchovy allow them to feed at a depth of 74 m at noon on clear days, and at the surface during twilight and bright nights, and appear to be well adapted to the anchovy's habitat in turbid, greenish coastal waters. Comparisons with younger anchovy larvae show that changes in visual function accompany changes in eye and retinal morphology, specifically the recruitment of rods. Moreover, 10-15-mm anchovy larvae can feed to a limited extent (10%) in the dark when food densities are high (20-40 rotifers/ml). In March, which is the peak spawning season of the anchovy in southern California and Baja California, the 10-15-mm larvae have 13 hours each day to feed.

    • The quantitative dietary protein requirements of Penaeus monodon juveniles in a controlled environment 

      Alava, Veronica R.; Lim, Chhorn (Elsevier, 1983)
      Penaeus monodon juveniles (average weight = 1.32 g) were kept in individual 2 l perforated plastic containers, 10 of which were placed in each of the twenty-four 50 l rectangular wooden-glass aquaria supplied with seawater filtered through a sand-gravel filter (32–34 ppt; 26.5–29.0°C; pH, 7.6–8.2) at 0.8–1.01 l/min. Eight diets were prepared containing 25–60% protein and fed at 10% of the body weight/day for the first 2 weeks and 8% for the succeeding 4 weeks. Shrimps fed the 40% protein diet produced the best growth, feed conversion ratio (FCR), protein efficiency ratio (PER) and survival rate. However, shrimps fed the 30, 35 and 45% protein diets produced comparable results. The protein content of the shrimps was directly related to the level of protein diet up to 50%; whereas fat content seemed to be inversely related up to 50% protein diet.

    • Seasonal variation in food and feeding of Penaeus monodon Fabricius (Decapoda, Natantia) 

      Marte, C. L. (E.J. Brill, 1982)
      A preliminary study on feeding habits of P. monodon F. (cf. Marte, 1980) indicated seasonal variations in feeding in this species. Similar observations have been reported for P. aztecus Ives and P. duorarum Burkenroad. The present paper confirms this preliminary observation and provides indications of a relationship between feeding activity and spawner occurrence.

    • In vitro effect of fungicides on hyphal growth and sporogenesis of Lagenidium spp. isolated from Penaeus monodon larvae and Scylla serrata eggs. 

      Lio-Po, Gilda D.; Sanvictores, M. E. G.; Baticados, Maria Cecilia L.; Lavilla, Celia R. (Blackwell, 1982)
      The sensitivity of Lagenidium spp. isolated from Penaeus monodon and Scylla serrata to 34 antimycotic compounds was determined. Mycostatic effects were evaluated from observations of chemicals on the development of vesicles, zoospores and mycelial growth and on these bases three classes of mycostatic effect were recognized. Zoospores were inhibited by < 1 mg/1 of clotrimazole, crystal violet, econazole nitrate, malachite green, treflan and trifluralin; 1-5 mg/1 of benzalkonium chloride, daconil, domestic detergent, basic fuchsin and furanace; and 10-50 mg/1 benlate, formalin, griseofulvin, phenol and potassium permanganate. Variable mycostatic levels, however, were exhibited with copper sulphate, 2,4-D, hydrogen peroxide, methylene blue, pimaricin, resiguard and tolnaftate while amphotericin, iodine, nystatin, triacetin, boric acid, fungitox and PVP-iodine proved to be poor antifungal agents.

    • Gill lesions associated with acute exposure to ammonia. 

      Cruz, Erlinda R.; Enriquez, Gloria L. (University of the Philippines, 1982)
      The histopathological effects of the 96 hr LC50 at 20.65 ppm NH3-N on the gills of milkfish fingerlings were examined qualitatively. Lesions observed were hypertrophy, hyperplasia, fusion of the lamellae, epithelial lifting, lamellar telangiectasis, disruption of the epithelial layer, lamellar detachment, vacuolation of the lamellae and the blood cells, and presence of several mitotic cells. The physiology of the histopathological lesions observed is discussed.

    • Vertical diurnal migration of Daphnia cucculata and Eudiaptomus graciloides in eutrophic Frederiksborg Castle Lake, Denmark 

      Carlos, Manuel H. (University of the Philippines at Los Baños, 1982)
      In euthrophic Frederiksborg Castle Lake, Berg & Nygaard were the first to study vertical migration. They obtained water samples at various time intervals over several days and concluded that the bulk of the population of the zooplankton they were studying shifted from one depth to another. D. cucculata and E. graciloides are the two most dominant zooplankters in Frederiksborg Castle Lake. The vertical migration of these species was studied, and the observations are reported in this paper.

    • Studies on the digestive proteases of the milkfish Chanos chanos 

      Benitez, Lita V.; Tiro Jr., Leonardo B. (Springer, 1982)
      The protease activity of crude extracts from various organs of the digestive tract of two groups of milkfish was determined. One group (Sample A) derived their food from ponds that had predominantly unicellular algae while the other group (Sample B) were reared on ponds dominated by the filamentous green algae Chaetomorpha brachygona . In general, crude extracts from Sample A fish had a higher protease activity than Sample B fish. In both samples, high protease activity was observed in crude extracts from the pyloric caeca, intestines and pancreas. Chymotryptic activity was observed in crude extracts of pancreas, intestines and pyloric caeca of both fish samples. Tryptic activity was, however, observed only in fish grown on unicellular algae. Experimental evidence suggests that a powerful trypsin inhibitor in Chaetomorpha brachygona may account for the absence of tryptic activity in all crude extracts of Sample B fish. The presence of this inhibitor may also explain the widely observed poor growth rate of milkfish reared on this natural food.

    • Ascorbic acid sulfate sulfohydrolase (C2 sulfatase): the modulator of cellular levels of L-ascorbic acid in rainbow trout. 

      Benitez, Lita V.; Halver, John E. (National Academy of Sciences of the United States of America, 1982)
      The enzyme L-ascorbic acid 2-sulfate sulfohydrolase (C2 sulfatase) was purified from rainbow trout liver. The enzyme catalyzes the hydrolysis of L-ascorbic acid 2-sulfate and has a pH optimum at 6.0. It has a molecular weight of about 117,500 at pH 5.0 and is inhibited by a number of sulfhydryl blocking agents including L-ascorbic acid. C2 sulfatase activity was observed in most metabolic organs of rainbow trout. These findings suggest that the physiologic role of the enzyme is to maintain adequate cellular concentrations of L-ascorbic acid in the fish. The activity of the enzyme is controlled by L-ascorbic acid through feedback inhibition. Comparison of kinetic constants and inhibition patterns suggests that C2 sulfatase is structurally identical to human arylsulfatase A. However, unlike C2 sulfatase, human arylsulfatase A may not be involved in ascorbate metabolism. Its physiologic substrate is reported to be cerebroside-3-sulfate, not L-ascorbic acid 2-sulfate. A scheme is proposed to account for the functional divergence of these two structurally identical enzymes.

    • Developmental stages of a microsporidian parasite of the white prawn, Penaeus merguiensis de Man 1888 

      Baticados, Ma. Cecilia L.; Enriquez, Gloria L. (University of the Philippines, 1982)
      A microsporidian parasite found to invade the ovaries of the white prawn, Penaeus merguiensis de Man, 1888, causes the whitening of the mature female gonads. Ultrastructure examination of the white ovaries reveal the presence of spores and other developmental stages of the parasite. The earliest stage observed is the schizont which contains a few cisternae of endoplasmic reticulum, many ribosomes and a thin plasma membrane. The next stage is the sporont characterized by a pansporoblast membrane, an increase in the amount of endoplasmic reticulum, appearance of more vesicles and of polar filament precursors. Diplokaryotic schizonts and sporonts are also found. Division of the sporonts gives rise to uninucleate sporoblasts. At this stage, the spore organelles start to form and the cell acquires a degree of plarity. The polar filament and the polar sao appear and the sporont membrane complex develops into a sporoblast wall. The sporoblast is transformed into a spore with a polar cap, posterior vacuole, polaroplast, and two laters of spore wall, the exospore and the endospore. The polar filament is a tubular structure consisting of seven coils which after the second coil taper abruptly distally. All these stages of development of the parasite are observed in the infected ovaries within which its life cycle is completed. A probable mode of transmission and life cycle of the parasite is presented.