Now showing items 1-12 of 12

    • Conference paper

      Aqua-mangrove integrated farming: shrimp and mud crab culture in coastal and inland tidal flats with existing reforested or natural growth of mangroves 

      AT Triño - 2000
      Throughout the tropics, mangroves are being destroyed at an increasing rate for the development of aquaculture ponds. In the Philippines, for instance, mangroves were about 400,000 to 500,000 ha in 1918 but were reduced to 100,564 ha in 1987. On the average, about 3,500 ha of mangroves are lost every year in the country to accommodate the aquaculture industry (Baconguis et al., 1990). Loss of mangroves means loss of habitat, fishery, income, and livelihood for many coastal inhabitants. The annual catches of major fishing grounds in the Philippines were positively correlated with the areas of existing mangroves (Bagarinao, 1998). Restoration programs of the government such as mangrove reforestation and afforestation were attempted but could not catch up with the unending destruction. An alternative source of income which is directly supportive of resource management was therefore proposed to mitigate ecosystem degradation with the fisher communities in mind.

      Fishing villages in the Philippines are generally located in the fringes of arable land along coastal plains and are dependent on fishing as a source of income. The common denominator of these villages is the presence of large areas of tidal flats with existing mangroves. To utilize the aquaculture potential of these mangroves, aqua-mangrove integrated farming development projects were introduced to provide alternative livelihood for the fishers in the village. This integrated approach to conservation and utilization of mangrove resource allows for maintaining a relatively high level of integrity in the mangrove area while capitalizing on the economic benefits of brackishwater aquaculture. The projects took off from the concept of co-management, that is, taking into account the partnership between the local community, the local government unit, and the SEAFDEC Aquaculture Department (SEAFDEC/AQD) in the management of the project.
    • Article

      Commercial evaluation of monosex pond culture of the mud crab Scylla species at three stocking densities in the Philippines. 

      AT Triño, OM Millamena & C Keenan - Aquaculture, 1999 - Elsevier
      The effects of three levels of stocking density (0.5, 1.5 or 3.0 m−2) and monosex culture (male or female) on the growth, apparent feed conversion ratio (FCR), survival, and production of mixed species of mud crabs, Scylla serrata and S. tranquebarica, were investigated. The juvenile crabs were stocked in 150 m2 earthen ponds with Gracilariopsis bailinae as shelter and fed a mixed diet of 75% fresh mussel flesh and 25% fish bycatch. There was no interaction between stocking density levels and monosex culture (P<0.05) so that data were pooled for each sex or stocking density treatment. Highest survival and the most efficient FCR were obtained from stocking density of 0.5 m−2 (P<0.05). Crab growth rates in different stocking densities were not significantly different (P>0.05). Male crabs attained significantly higher (P<0.05) final weight and specific growth rate (SGR) than female crabs. However, final crab length, width, FCR, survival, and production were not significantly different between male and female crabs (P>0.05). Highest return on investment (ROI) and lowest production cost were obtained from 0.5 m−2. Partial budgeting analysis showed that no net benefit accrued from stocking beyond 1.5 m−2. Both male or female monosex cultures gave high net revenue and ROI of more than 100%. Results suggest that the culture of male or female mud crabs at 0.5–1.5 m−2 is economically viable but male monosex culture is more profitable.
    • Article

      Developmental and ecological stages in the life history of milkfish Chanos chanos Forsskal 

      P Buri, S Kumagai, V Bañada, A Triño & N Castillo - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - SEAFDEC Aquaculture Department
      Seven stages in the life history of the milkfish C. chanos , are recognized and suggested: A, embryonic; B, yolksac larval; C, larval; D, postlarval; E, juvenile; F, subadult; G. adult. An outline is presented of the life history. It is concluded that the milkfish, throughout the known stages of their life history are well adapted and equipped for optimal survival. High swimming performance, broad flexibility in feeding habits, high adaptability to a wide range of physicochemical conditions of the environment are but a few of the adaptations. The main driving force in all developmental stages is the evolutionary response to food distribution and availability followed by predation pressure.
    • Article

      Diet and harvesting regimen for the production of mud crab Scylla olivacea in brackish water ponds 

      EM Rodriguez, AT Triño & M Minagawa - Fisheries Science, 2003 - Japanese Society of Fisheries Science
      The effects of diet (fish bycatch or a mixed diet of 75% brown mussel flesh and 25% cooked cracked corn) and harvesting regimen (bimonthly selective harvesting, or single terminal harvesting) on growth, survival and production of mud crab Scylla olivacea (Herbst) in brackish water ponds were determined in a replicated factorial experiment. The crabs were stocked at 0.6 individuals per m2 for 118 days. There was no significant interaction (P > 0.05) between the diet and harvesting regimen treatments. Regardless of diet, the survival rate and net production of mud crabs were significantly higher (P < 0.05) when crabs were subjected to bimonthly selective harvesting than at single terminal harvest. Comparative cost–return analysis showed that bimonthly selective harvesting and mixed diet treatments attained higher net return and return on investment, and lower cost of production than the other treatments. Partial budgeting analysis showed that bigger profits can be earned by using a bimonthly selective harvesting and a mixed diet of 75% fresh or fresh-frozen brown mussel flesh and 25% cooked cracked corn.
    • Article

      Effect of a diet lacking in vitamin and mineral supplements on growth and survival of Penaeus monodon juveniles in a modified extensive culture system 

      AT Triño & JC Sarroza - Aquaculture, 1995 - Elsevier
      Penaeus monodon postlarvae (mean weight 6 mg) were reared in 330 m2 earthen ponds for 120 days at a stocking density of 7.5 m−2, following a modified extensive culture system where natural food organisms are available. Two diets were tested, one with vitamin and mineral supplements and the other without. The results showed that growth, survival, apparent food conversion ratio (FCR), net production, and net cost of production were not significantly different between the two diets. The difference in cost of production between the diets appeared to be lower in shrimp fed a diet without vitamin and mineral supplements. The favorable cost difference of P8.00 kg−1 shrimp produced would make it more profitable to use a diet that contained no vitamin and mineral supplements in a modified extensive culture system.
    • Article

      Effect of burning of rice straw on snails and soil in a brackishwater pond 

      AT Triño, EC Bolivar & DD Gerochi - International Journal of Tropical Agriculture, 1993 - Serials Publications
      The effects of burning the varying amounts of dried rice straw on snails and soil properties in brackishwater ponds in the Philippines were evaluated. Cerithium tenellum, Telescopium telescopium and other unidentified snail species present in a drained brackishwater ponds were exposed to heat by burning 1.3, 2.7, and 4.0 kg dried rice straw piled 5, 10, and 15 cm thick in nine 1 m2-plot. While T. telescopium and the unidentified snail species were killed (100%) in all the treatments, C. telellum mortality ranged fro 83±3.75 percent in plots with 1.3 kg straw. The chemical properties of the soil after burning the straw revealed a decrease in the organic matter and available phosphorous and increase in the available iron and potassium. There was no effect of burning on soil pH. The acetate soluble sulfate decreased with 1.3 kg of straw and increased with the higher amounts of straw.
    • Article

      Effects of feeding frequency and amount of feeding on the growth of the grouper, Epinephelus malabaricus 

      H Kohno, A Triño, D Gerochi & M Duray - Philippine Journal of Science, 1989 - Science and Technology Information Institute
      The effects of feeding frequency and amount of food on the growth of juvenile groupers (Epinephelus malabaricus) were investigated for 12 weeks of rearing in net-cages set in an earthen pond. The juveniles (110-130 g in body weight, BW) attained marketable size (500 g) in 12 weeks. Feeding to satiation levels once a day gave the best growth (mean BW = 509.4 ± 56.5 g) and relatively good food conversion ratio (4.78) compared to the other treatments (twice a day, once in two days and once in every three days). Concerning feeding levels, in which feed was given twice a day at 15, 10, 5 and 1% of total fish biomass per day, the best fish growth (426.6 ± 54.0 g) and a reasonable food conversion ratio (4.53) were obtained at 5% fish biomass. There was a positive correlation between the growth of fish and water temperature in both experiments.
    • Conference paper

      Mangrove-friendly aquaculture studies at the SEAFDEC Aquaculture Department 

      AT Triño & JH Primavera - In LMB Garcia (Ed.), Responsible Aquaculture Development in Southeast Asia. Proceedings of the Seminar-Workshop on Aquaculture Development … Southeast Asia organized by the SEAFDEC Aquaculture Department, 12-14 October 1999, Iloilo City, Philippines, 2001 - SEAFDEC Aquaculture Department
      The SEAFDEC Aquaculture Department studies on mangrove-friendly aquaculture (MFA) can be categorized under two models: a) mangrove filters where mangrove forests are used to absorb effluents from high-density culture ponds, and b) aquasilviculture or the low-density culture of crabs, shrimp and fish integrated with mangroves. In a study using the first model, shrimp pond effluents were retained in an enclosed mangrove area prior to release to receiving waters. Nutrients and other water quality parameters, and bacterial levels were monitored in the untreated effluents and post-mangrove water.

      In the second MFA model, mangrove pens and ponds installed in old growth and newly regenerating mangrove sites in Aklan, central Philippines were stocked with mud crab Scylla olivacea/S. tranquebarica and shrimp Penaeus monodon. Investment costs, survival and production, and cost-return analysis for the pens and ponds are reported in the paper. Aside from the aquasilviculture trials in collaboration with local government units, other activities in the Aklan mangrove sites are the survey and mapping of the 75-ha area in Ibajay, construction of a treehouse, and the educational use as field site by Coastal Resource Management trainees of SEAFDEC Aquaculture Department and field biology students of the University of the Philippines in the Visayas.
    • Conference paper

      Monosex culture of the mud crab Scylla serrata at three stocking densities with Gracilaria as crab shelter 

      AT Triño, OM Millamena & CP Keenan - In CP Keenan & A Blackshaw (Eds.), Mud Crab Aquaculture and Biology. Proceedings of an International Scientific Forum, 21-24 April 1997, Darwin, Australia, 1999 - Australian Centre for International Agricultural Research
      The effects of three levels of stocking density (0.5, 1.5 or 3.0/m2) and monosex culture (male or female) on the growth, survival and production of Scylla serrata were investigated. Juvenile crabs were stocked in 150 m2 enclosures in earthen ponds with Gracilaria as shelter and fed a mixed diet of 75% fresh brown mussel flesh and 25% fish bycatch. There was no interaction between stocking density levels and monosex culture (P<0.05) so the data were pooled for each sex or stocking density treatment. Results showed that highest survival was obtained from a stocking density of 0.5/m2 (P<0.05). Crab growth at different stocking densities was not significantly different (P>0.05). Highest return on investment (ROI) and lowest production costs were attained from 0.5/m2. Partial budgeting analysis showed that no net benefit accrued from stocking beyond 1.5/m2. Male crabs attained significantly better (P<0.05) final weight and specific growth rate than female crabs. Length, width, survival and production between male and female crabs were not significantly different (P>0.05). Male and female monoculture gave high net revenue and ROI of more than 100 but male monoculture is more profitable. Overall the results suggest that the culture of male or female mud crabs at 0.5–1.5/m2 with Gracilaria is economically viable.
    • Article

      Mud crab fattening in ponds 

      AT Triño & EM Rodriguez - Asian Fisheries Science, 2001 - Asian Fisheries Society
      Two independent experiments on mud crab (Scylla serrata, Portunidae) fattening were conducted simultaneously in 150 m2 ponds for 30 days: Expt. I - monosex male (286 ± 1.2 g) vs. monosex female (267 ± 0.9 g) stocked at 0.5·m-2, and Expt. II - monosex male (338 ± 3.1 g) or female (338 ± 2.8 g) vs. mixed sex (338 ± 3.4 g) stocked at 0.25·m-2. The crabs were fed daily a mixed diet of 75% brown mussel flesh and 25% fish bycatch at 10% of the crab biomass. Intermolt full male crabs weighing ≥ 400 g and roed females ≥ 350 g were partially harvested from the ponds after 20 days of culture using lift net and current method. Results of partial harvest from all treatments in both experiments showed a total yield of 51-55% of the total initial number of stocked crabs (450 crabs in Expt. I, and 338 crabs in Expt. II). From this partial harvest, crabs in Expt. I attained a mean final body weight of 496 g, a specific growth rate (SGR) of 2.75% in males and 432 g, SGR of 2.4% in females. Expt. II gave a mean final body weight of 520 g (males), 484 g (females), and 517 g (mixed sex) and SGR of 1.1, 0.73 and 0.81, respectively. Results of total harvest showed that the overall mean final body weight (372 ± 4.5 g) of monosex male crabs in Expt. I was significantly higher (P < 0.05) than monosex females. However, specific growth rate, carapace length and width, survival, and production were not significantly different (P > 0.05) between monosex males and females. On the other hand, growth and production of monosex crabs in Expt. II was not significantly different (P > 0.05) from mixed sex crabs. However survival of monosex crabs (100%) was significantly higher (P < 0.05) than mixed sex crabs (87 ± 1.88%).
    • Book

      Mudcrab 

      AT Triño, EM Rodriguez, EB Coniza & BP Juanga - 1999 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 27
      A 32-page manual that gives a general overview of mudcrab species of commercial value and their grow-out monoculture in ponds; polyculture with milkfish; and fattening in ponds, mangroves, and cages.
    • Article

      Pond culture of mud crab Scylla serrata (Forskal) fed formulated diet with or without vitamin and mineral supplements 

      AT Triño, OM Millamena & CP Keenan - Asian Fisheries Science, 2001 - Asian Fisheries Society
      The effects of three diets (Diet 1 – with vitamin and mineral supplements, Diet 2 – without vitamin and mineral supplements, and Diet 3 – fish bycatch) and monosex culture (male or female) on the growth, survival, feed conversion ratio (FCR), and production of mud crab Scylla serrata were investigated using a 2 x 3 factorial experiment with three replicates per treatment. Juvenile mud crabs were stocked at 1.0·m-2 in 150 m2 ponds and reared for 156 days. Results showed no significant interaction between monosex culture and diets (P > 0.05) so that data were pooled by sex and dietary treatment. Mean final body weight of male crabs (427 g) was significantly higher (P < 0.05) than female crabs (400 g). However, crab carapace length (CL) and width (CW), specific growth rate (SGR), FCR, survival, and production were not significantly different (P > 0.05) between the two sexes. Regardless of sex, crabs fed fish bycatch (Diet 3) gave significantly higher (P < 0.05) mean body weight (435 g) than those fed Diet 2 (395 g). Mean final body weight (410 g) of crabs fed Diet 1 was not significantly different from those fed Diets 2 or 3. The CL and CW, SGR, FCR, survival, and production of mud crabs fed the three diets, however, were not significantly different (P > 0.05). The economic viability of using a diet without vitamin and mineral supplements was comparable to that of a complete diet having about the same cost of production and return on investment of 74 to 75%. The study shows that cost-effective formulated diet could be used as alternative feed for fish bycatch thus saving on feed and storage costs.