Now showing items 41-60 of 64

    • Article

      Nature parks, museums, gardens, and zoos for biodiversity conservation and environment education: the Philippines 

      T Bagarinao - AMBIO: A Journal of the Human Environment, 1998 - Springer Verlag
      Public consciousness about biodiversity and the environment, and their importance for sustainable development is not widespread in the Philippines. This article advocates nonformal environment education through nature recreation as a means toward 'greening, the mind and the spirit of the citizens. Information is provided about biodiversity, and the status and potential of nature parks, museums, gardens, and zoos in the country. Many of the 116 national parks and protected areas have been exploited for products and energy, and only some provide for recreation-cum-education. The Philippines has no national botanical garden, zoo, or aquarium, and the National Museum is not the proud institution that it should be. Some universities have small museums, botanical gardens, and other biodiversity exhibits for instruction and research, but these and the few zoos and wildlife centers are poorly funded or managed.
    • Article

      Occurrence and distribution of milkfish larvae, Chanos chanos off the western coast of Panay Island, Philippines 

      T Bagarinao & S Kumagai - Environmental Biology of Fishes, 1987 - Springer Verlag
      The occurence and distribution of milkfish larvae (∼3–17 mm TL) off western Panay Island, Philippines are reported based on 594 plankton net tows made in April and May 1980. Forty-two tows yielded 44 larvae, together with 1149 milkfish eggs by 98 tows. About 70% of the larvae of all stages came from stations less than 100 m deep and 1–2 km from land. Younger larvae up to 6 mm and about 1 week old occurred at stations of various distances from shore, while older larvae occurred only near shore. About 48% of larvae of all stages were caught by surface tows; younger larvae occurred also in deeper layers (20 and 30 m). Larval abundance increased towards May. Younger larvae tended to occur during the quarter moon periods and older ones during the full and new moon periods.
    • Article

      On publishing scientific papers in peer reviewed ISI-covered journals 

      T Bagarinao - The Philippine Scientist, 1994 - San Carlos Publications, University of San Carlos
      This article exhorts university graduate students and researchers everywhere to publish their scientific papers in peer-reviewed journals, preferably those covered by the Institute for Scientific Information (ISI), rather than in the gray literature – technical reports, conference proceedings, and books. Philippine journals are also used to work for stringent peer review, frequent and prompt issues, wide circulation, high standards, and ISI coverage – so that Filipino scientists contribute to, and benefit from, the mainstream literature of the international scientific community.
    • Article

      Optimum low salinity to reduce cannibalism and improve survival of the larvae of freshwater African catfish Clarias gariepinus 

      G Kawamura, T Bagarinao, ASK Yong, PW Sao, LS Lim & S Senoo - Fisheries Science, 2017 - Springer Verlag
      The freshwater African catfish Clarias gariepinus is carnivorous and cannibalistic even during the larval and juvenile stages and this behavior causes economic losses in aquaculture. This study examined for the first time the effect of salinity on cannibalism, survival, and growth of African catfish larvae in the hatchery. Larvae (4 days old, median 7.8 mm TL, 2.8 mg BW) of the African catfish were reared for 21 days at nominal salinity 0, 1, 2, 3, 4, 5, 6, and 7 ppt. After 21 days, they grew to 10–39 mm (median 22 mm) and 10–490 mg (median 90 mg), with no significant difference by salinity treatments. Survival ratios were similarly low (24–31%) at 0, 1, 3, and 7 ppt and significantly higher (49–55%) at 2, 4, 5, and 6 ppt. Cannibalism was significantly lower, 15–30% at 4–6 ppt, than the 40–50% at 0–3 and 7 ppt. Size variation was lower at 4–6 ppt and higher at 0–3 and 7 ppt. We recommend hatchery rearing of African catfish at the optimum low salinity of 4–6 ppt rather than in full fresh water at least up to 21 days. This rearing method fosters larval welfare and improves hatchery production.
    • Book chapter

      Order Gonorynchiformes: Chanidae: Milkfish 

      T Bagarinao - In KE Carpenter & VH Niem (Eds.), FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 3. Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophrynidae), 1999 - Food and Agriculture Organization of the United Nations
    • Article

      Protected areas for biodiversity conservation and environment education in the Philippines 

      T Bagarinao - Philippine Journal of Science, 1999 - Science and Technology Information Institute
      The Philippines holds the distinction of having enormous biodiversity with the highest density of endemic species but has the problem of very fast decline in old-growth forests and the highest number of endangered mammal and bird faunas in the world. Among the recorded 53,577 species in the country are 512 unique species of land birds, mammals, reptiles and amphibians with 43-73% endemicity. This biodiversity is seriously threatened by habitat destruction due to the expansion of human population and activities. Loss of biodiversity impairs ecosystem functions and results in floods, drought, erosion, pests and diseases, low productivity, and food shortages, with serious socioeconomic consequences. To arrest the loss of biodiversity, in situ conservation is imperative and the remaining natural habitats and biodiversity must be protected. Bu the 73 million Filipinos in 1997 demand more land, water, biological resources, and income. Most Filipinos are unaware about the country's biodiversity and the imperative for conservation. Environment education for the general public is essential, and the nature recreation and ecotourism can be effective means towards "greening" the minds of citizens. The National Integrated Protected Areas System includes 290 sites occupying about four million hectares (about 13% of the countrys' total land area), mostly in the remaining forests, but increasingly more in marine ecosystems in the country. This paper provides information about the biodiversity in the protected areas, their ecotourism status or potential, and the threats to them. Many protected areas have been exploited for products and energy, only some provide for ecotourism, and only a few are actually protected. Some accessible areas should be funded and managed more effectively for ecotourism and public education, but others must be left alone and actively protected. Encounter with nature engender pride in the national heritage, generates responsible citizen action, and helps ensure biodiversity conservation.
    • Book

      Regional guidelines for responsible fisheries in Southeast Asia : responsible aquaculture. 

      T Bagarinao - 2005 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This 43-page guidebook presents the code of conduct that has been re-written, expanded, clarified and annotated with definitions and examples to consider the fish farming industries in Southeast Asia. The source of the code is the Food and Agriculture Organization's technical guidelines ~ Articles 9.1 to 9.4 ~ which were discussed in regional consultation in 2001.
    • Article

      Results of drift card experiments and considerations on the movement of milkfish eggs and larvae in the northern Sulu Sea 

      S Kumagai & T Bagarinao - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
      For a period of one year beginning December 1977, drift card experiments were conducted off the western and southern coasts of Panay Island to determine the surface currents in the area. Of a total 2,384 drift cards released during the study, 382 (16.02%) were recovered, 92% of them within 30 days following dispatch. The surface currents in the study area are strongly influenced, in direction and speed, by the prevailing monsoon winds. During the NE monsoon period, the surface currents move away from the coast; during the SW monsoon, toward and/or parallel to the coast. Based on the results, the probable movement and transport of milkfish (chanos chanos) eggs and larvae from the spawning ground to the fry collection ground are also discussed.
    • Article

      Results of drift card experiments and considerations on the movement of milkfish eggs and larvae in the northern Sulu Sea 

      S Kumagai & TU Bagarinao - Fisheries Research Journal of the Philippines, 1979 - Fisheries Research Society of the Philippines
      For a period of one year beginning December 1977, drift card experiments were conducted off the western and southwestern coasts of Panay Island to determine the surface currents in the area.

      Of a total 2,384 drift cards released during the study, 382 (16.02%) were recovered, 92% of them within 30 days following dispatch. The surface currents in the study area are strongly influenced, in direction and speed, by the prevailing monsoon winds. During the NE monsoon period, the surface currents move away from the coast; during the SW monsoon, toward and/or parallel to the coast. Based on the results, the probable movement and transport of milkfish eggs and larvae from the spawning ground to the fry collection ground are also discussed.
    • Article

      The sea turtles captured by coastal fisheries in the northeastern Sulu Sea, Philippines: Documentation, care, and release 

      TU Bagarinao - Herpetological Conservation and Biology, 2011 - Herpetological Conservation and Biology
      This paper presents the first substantive data on sea turtles in the northeastern Sulu Sea. Working with fishers and government, the Southeast Asian Fisheries Development Center (SEAFDEC FishWorld) documented 109 juvenile and adult sea turtles captured or stranded around Panay and Guimaras Islands, Philippines from 2001 to mid- 2011. These included 65 Green Turtles (Chelonia mydas), 15 Hawksbill Turtles (Eretmochelys imbricata), 24 Olive Ridley Turtles (Lepidochelys olivacea), three Leatherback Turtles (Dermochelys coriacea), and two Loggerhead Turtles (Caretta caretta). From the four fishing villages within 1 km of FishWorld came 29 Green Turtles, eight Olive Ridleys, and one specimen each of the three other species. Approximately 77% of the Green Turtles were caught in nearshore fish corrals, mostly between October and May; whereas, 75% of the Olive Ridley Turtles were caught in offshore gill nets and long lines between April and October. Seventy-nine captured turtles were released, 73 of them with inconel flipper tags. Several turtles died from entanglement, serious injuries, slaughter for market, or diseases. An Olive Ridley Turtle and three Green Turtles were seen nesting at three beaches in southern and western Panay. Nesting of Hawksbill Turtles has been recorded at secluded beaches in Lawi, Guimaras about every three years; several batches of hatchlings have been raised by local residents before being released. Size-specific growth rates of Green Turtles and Hawksbill Turtles were highest among post-hatchlings and decreased sharply with size among juveniles and adults.
    • Conference paper

      The SEAFDEC Aquaculture Department at 21: R&D for sustainable aquaculture 

      EEC Flores & TU Bagarinao - In TU Bagarinao & EEC Flores (Eds.), Towards sustainable aquaculture in Southeast Asia and Japan: Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia, Iloilo City, Philippines, 26-28 July, 1994, 1995 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This paper reviews the research output of the SEAFDEC Aquaculture Department (AQD) over the past 21 years of its existence. These realized studies are compared with the priority problem areas recommended for research by international or regional seminar-workshops convened by AQD in 1983, 1987, 1991 and 1994. Between 1976 and 1994, AQD researchers produced 554 publications, including 274 in journals indexed by the Institute for Scientific Information, 122 in other journals, and 158 in conference proceedings. Another 82 publications from work done outside AQD were authored or co-authored by AQD researchers, mostly during their graduate programs. In addition, AQD published 21 extension manuals and 14 technical reports and monographs by AQD researchers, and co-published two other monographs by non-AQD researchers. AQD's major contributions have been the technologies for tiger shrimp seed production, grow-out culture, feeds, and disease control; milkfish seed production and feeds; rabbitfish seed production; and tilapia feeds and strain selection. Communication and two-way feedback among AQD researchers and representatives of the aquaculture industry and the SEAFDEC Member Countries must be improved to fine-tune AQD research. In the late 1980s, AQD started redirecting some of its research towards environmental problems in aquaculture. Much of the near future will be spent implementing research imperatives in sustainable and responsible aquaculture.
    • Article

      Sensory systems and feeding behaviour of the giant freshwater prawn, Macrobrachium rosenbergii, and the marine whiteleg shrimp, Litopenaeus vannamei 

      G Kawamura, TU Bagarinao & ASK Yong - Borneo Journal of Marine Science and Aquaculture, 2017 - Borneo Marine Research Institute, Universiti Malaysia Sabah
      Information on the sensory basis of shrimp feeding provides the means for assessment of the effectiveness of food items in terms of smell, taste, size, and colour. This chapter summarizes information about the sensory basis of the feeding behaviour of the giant freshwater prawn (Macrobrachium rosenbergii) and the marine whiteleg shrimp (Litopenaeus vannamei). Existing literature on these shrimp species and other decapod crustaceans is reviewed, and unpublished experiments using the selective sensory ablation technique to determine the involvement of vision, chemoreception, and touch sense in the feeding behavior of the juveniles of M. rosenbergii and L. vannamei are also described. To determine the role of vision in feeding, the eyes of the juveniles were painted over (deprived of vision) with white manicure and their feeding response to commercial pellets was compared with those with untreated eyes. The untreated eyed juveniles detected and approached a feed pellet right away, but the specimens blinded by the coating detected a pellet only after random accidental touch with the walking legs while roaming on the aquarium bottom. Juveniles that had learned to feed on pellets showed food search and manipulation responses to a pellet-like pebble without smell and taste. The early larvae (zoeae) of M. rosenbergii already have colour vision (that likely persists through life) and colour preference for blue and white. The adults of L. vannamei discriminated a blue-colored well among seven grey wells in a palette, also showing colour vision in this shrimp. A behavioural experiment with dyed prawn flesh showed that L. vannamei has innate color preference for yellow food over black, red, green, and blue food regardless of the background colours of the aquarium bottom. To disrupt chemoreception, the juveniles of both the species were abruptly transferred to water of drastically different salinity and the osmotic ablation destroyed the chemosensitive sensilla. The osmotically ablated juveniles approached a pellet right away but failed to ingest it; they had learned the visual cue and texture of the pellets and recognized them by vision and tactile sense. To determine the role of sensory appendages in feeding of L. vannamei juveniles, the antennal flagella, antennular flagella, and the pincers of the pereiopods were ablated. The ablated juveniles roamed the bottom, touched a pellet at random, grabbed it with the maxillipeds, and ingested it. Subsequently they learned to lower the head, actively swim forward, sweep the bottom with the maxillipeds, detect a pellet, and ingest it—thus indicating a plasticity in feeding behaviour in L. vannamei.
    • Article

      Shelter colour preference of the postlarvae of the giant freshwater prawn Macrobrachium rosenbergii 

      G Kawamura, T Bagarinao, ASK Yong, TC Fen & LS Lim - Fisheries Science, 2017 - Springer Verlag
      The addition of artificial shelters of various materials has been used in Macrobrachium rosenbergii tanks and ponds as a means of increasing productivity. The present study investigated the shelter colour preference of M. rosenbergii postlarvae (age 15–18 days after metamorphosis) in the laboratory. Shelter occupancy tests were performed on four groups of 200 postlarvae in four 57-l aquaria, into which were placed shelters made of rigid coloured netting sewn into four-layered cubes open on two sides. The shelters were presented in six colour pairs: black vs dark green, black vs light green, black vs blue, dark green vs light green, dark green vs blue, and light green vs blue. Colour preference was tested six times for each colour pair. The data obtained were analyzed using Thurstone’s law of comparative judgment. The mean z-score was significantly highest (i.e., highest preference) for the black shelter. Vision was involved in the detection of and approach to the shelter. When released in aquaria, intact-eyed individual postlarvae directly approached the shelter straight away, whereas blind postlarvae (paint over the eyes) swam around randomly and occupied the shelter only after accidental contact much later. Postlarvae in open water out of the shelter exhibited frequent aggressive contact, while those in the shelter were quiescent. The use of black shelters in rearing tanks is thus recommended for reducing stress and aggression among M. rosenbergii postlarvae in the hatchery.
    • Article

      Studies on the habitat and food of juvenile milkfish in the wild 

      S Kumagai & TU Bagarinao - Fisheries Research Journal of the Philippines, 1981 - Fisheries Research Society of the Philippines
      Juvenile milkfish (Chanos chanos ) were collected from several different wild environments in Panay Island and neighboring islands. The fish were measured and the food ingested examined. Conditions of milkfish habitats were also described. It was found that the fish can live and grow in almost any kind of coastal wetlands of calm and rich sediments, such as coralline lagoon, mangrove lagoon, estuary, and bay. In the waters where plant materials were rich at the bottom, the fish fed on them and their intestines were significantly long, while in other waters where less plant materials were available at the bottom, the fish fed but with considerable amount of animal elements and possessed shorter intestines. These differences are considered as adaptations of the fish to different habitats.
    • Technical Report

      A study on the milkfish fry fishing gears in Panay Island, Philippines 

      S Kumagai, T Bagarinao & AS Unggui - 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Technical report / SEAFDEC Aquaculture Department; no. 6
      This study was conducted to obtain information for evaluating the present fry fishing practices and for understanding the behaviour of the fry. A description of the milkfish, Chanos chanos, fry fishing gears is presented. Each gear is illustrated and its operation explained.
    • magazineArticle

      Sulfide as a toxicant in aquatic habitats 

      TU Bagarinao - SEAFDEC Asian Aquaculture, 1993 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The toxic effects of sulphide are best understood in mammals and are generally similar in aquatic organisms. At the physiological level sulphide has 2 major effects on mammals: 1) local inflammation and irritation of moist membranes including the eye and respiratory tract; and, 2) cardiac arrest due to paralysis of the respiratory centres of the brain. The toxicity of sulphide to plants, macroinvertebrates, freshwater fish and marine fish is discussed in detail. It is concluded that the role of sulphide in mass kills of fish, shrimp and other animals in brackishwater earthen ponds, lakes and sea cages should be determined.
    • Article

      Sulfide as an environmental factor and toxicant: tolerance and adaptations in aquatic organisms 

      T Bagarinao - Aquatic Toxicology, 1992 - Elsevier
      This review brings together a large number of independent and seemingly unrelated studies in various disciplines under four major topics: (1) sulfide as an environmental factor in aquatic habitats; (2) sulfide as a toxicant; (3) sulfide tolerance of aquatic organisms; and (4) adaptations limiting sulfide toxicity. Sulfide is widely distributed in the aquatic environment, but has been largely overlooked as an environmental factor for aquatic organisms. Sulfide at nanomoiar to millimolar concentrations adversely affects cytochrome c oxidase, various other enzymes, oxygen transport proteins, cellular structures, and consequently the physiological functions of organisms. These toxic effects are well documented in the biomedical literature, and also occur in the aquatic organisms that have been studied. Sulfide tolerance varies widely among protozoans, sediment meiofauna, polychaetes, bivalves, crustaceans, marine and freshwater fishes, and aquatic plants, often in correlation with the relative sulfide levels in the respective habitats. Aquatic organisms have evolved various adaptations against sulfide toxicity, possibly several acting in concert. Most animals are able to avoid and escape from sulfide, but cannot exclude sulfide from the body. No sulfide-resistant cytochrome c oxidase has been demonstrated, and most animals are capable of some degree of anaerobic meabolism. Various invertebrates have entered into symbiotic associations with sulfide-oxidizing bacteria. Some of these invertebrates immobilize and transport sulfide by means of sulfide-binding proteins or persulfides in the blood. Detoxication of sulfide occurs by methylation, non-specific oxidation, and enzymatic oxidation by mitochondria. Oxidative detoxication of sulfide to thiosulfate by mitochondria is common to several major taxa (protozoan, mollusk, teleosts, mammal), and is effective at low micromolar sulfide concentrations. Among organisms lacking sulfide-oxidizing bacterial symbionts, the mitochondria may thus provide the chief defense against environmental sulfide, and may allow the whole organism to tolerate sulfide concentrations 2–3 orders of magnitude greater than would inhibit cytochrome c oxidase.
    • Article

      The sulfide tolerance of milkfish and tilapia in relation to fish kills in farms and natural waters in the Philippines 

      T Bagarinao & I Lantin-Olaguer - Hydrobiologia, 1998 - Kluwer Academic Publisher
      Fish kills of milkfish Chanos chanos and tilapia Oreochromis spp. now occur frequently in brackish, marine, and freshwater farms (ponds, pens, and cages) in the Philippines. Aquafarms with high organic load, limited water exchange and circulation, no aeration, and high stocking and feeding rates can become oxygen-depleted and allow sulfide from the sediments to appear in the water column and poison free-swimming fish. The sulfide tolerance of 2-5 g milkfish and 5-8 g O. mossambicus was determined in 25-liter aquaria with flow-through sea water (100 ml min-1) at 26-30 °C and sulfide stock solutions pumped in at 1ml min-1. Total sulfide concentrations in the aquaria were measured by the methylene blue method and used in the regression against the probits of % survival. Four experiments showed that the two species have similar sulfide tolerance. In sea water of pH 8-8.5, about 163 ± 68 μM or 5.2 ± 2.2 mg l-1 total sulfide (mean ± 2 se) or 10 μM or 313 μg l-1 H2S was lethal to 50% of the fish in 4-8 h, and 61 ± 3 μM total sulfide or 4 μM H2S in 24-96 h (to convert all sulfide concentrations: 1 μM = 32 μg l-1). Earthen pond bottoms had 0-382 μM total dissolved sulfide (mean ± sd - 54 ± 79 μM, n - 76); a tenth of the samples had >200 μM. The water column may have such sulfide levels under hypoxic or anoxic conditions. To simulate some of the conditions during fish kills, 5-12 g milkfish were exposed to an abrupt increase in sulfide, alone or in combination with progressive respiratory hypoxia and decreasing pH. The tests were done in the same flow-through set-up but with sulfide pumped in at 25 ml min-1. The lethal concentration for 50% of the fish was 197 μM total sulfide or 12 μM H2S at 2 h, but 28-53 μM sulfide allowed fish to survive 6-10 h. Milkfish in aquaria with no aeration nor flow-through sea water died of respiratory hypoxia in 5-8 h when oxygen dropped from 6 to 1 mg l-1. Under respiratory hypoxia with 30-115 μM sulfide, the fish died in 2.5-4 h. Tests with low pH were done by pumping a weak sulfuric acid solution at 25 ml min-1 into aquaria with flow-through sea water such that the pH dropped from 8 to 4 in 5 h. Under these conditions, milkfish died in 7-9 h when the pH was 3.5. When 30-93 μM sulfide was pumped in with the acid, the fish died in 2-6 h when the pH was still 4.5-6.3. Thus, sulfide, hypoxia, and low pH are each toxic to milkfish at particular levels and aggravate each other's toxicity. Aquafarms must be well oxygenated to prevent sulfide toxicity and fish kills.
    • Article

      Sulfide-hemoglobin interactions in the sulfide-tolerant salt marsh resident, the California killifish Fundulus parvipinnis 

      T Bagarinao & RD Vetter - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, 1992 - Springer-Verlag
      Sulfide can potentially damage hemoglobin or be detoxified by hemoglobin. In the sulfide-tolerant California killifish neither seems to be the case at environmentally realistic (micromolar) and physiologically relevant (millimolar) sulfide concentrations. An 8-h exposure of killifish to 5 and 8 mmol sulfide · 1 -1 results in 50–100% mortality, but not due to sulfhemoglobin (where sulfide covalently binds to the porphyrin) nor ferric hemoglobin (Hb + ), both dysfunctional hemoglobin derivatives. Killifish hemoglobin converts to sulfhemoglobin in vitro only in the presence of 1–5 mmol sulfide · 1 -1 . The amount of sulfhemoglobin formed increases with time and heme concentration but decreases with pH. Hb + binds sulfide as ferric hemoglobin sulfide (Hb + S, an unstable complex where sulfide ligates to the iron), and also as sulfhemoglobin. Killifish blood does not catalyze the oxidation of 10–500 µmol sulfide · 1 -1 to any appreciable extent. Radiolabeled sulfide incubated with oxyhemoglobin or whole blood disappears at rates greater than in buffers, but only minimal amounts of thiosulfate and no sulfate nor sulfite are formed (elemental sulfur and bound sulfide not quantified). Sulfide disappearance rates increase linearly with initial sulfide concentration. Hb + does catalyze the oxidation of sulfide to thiosulfate in vitro. Similar experiments on another sulfide-tolerant species, the long-jawed mudsucker Gillichthys mirabilis , produced similar results.
    • Article

      Sulphide tolerance and adaptation in the California killifish, Fundulus parvipinnis, a salt marsh resident 

      T Bagarinao & RD Vetter - Journal of Fish Biology, 1993 - Wiley-Blackwell
      Hydrogen sulphide is a toxicant naturally produced in hypoxic marine sediments, hydrocarbon and brine seeps and hydrothermal vents. The California killifish, a salt marsh resident, is remarkably tolerant of sulphide. The 50% lethal concentration is 700 μM total sulphide in 96 h, and 5 mM in 8 h (determined in flow-through, oxygenated sea water). Killifish exposed to sulphide produce thiosulphate which accumulates in the blood. The cytochrome c oxidase (a major site of toxicity) of the killifish is 50% inhibited by <1 μM sulphide. Killifish liver mitochondria are poisoned by 50–75 μM sulphide but can oxidize 10–20 μM sulphide to thiosulphate. Sulphide causes sulphhaemoglobin formation (and impairment of oxygen transport) at 1–5 mM in vitro and to a small extent at 2 mM in vivo. Killifish blood neither catalyses sulphide oxidation significantly nor binds sulphide at environmental (low) sulphide concentrations. Exposure to 200 μM and 700 μM sulphide over several days causes significant increases in lactate concentrations, indicating shift to anaerobic glycolysis. However, individuals with the most lactate die. In terms of diffusible H2S, the killifish can withstand concentrations two to three orders of magnitude greater than would poison cytochrome c oxidase. The high sulphide tolerance of the killifish, particularly of concentrations typical of salt marshes, can be explained chiefly by mitochondrial sulphide oxidation. Sulphide tolerance and mitochondrial sulphide oxidation in the killifish have a constitutive basis, i.e. do not diminish in fish held in the laboratory in sulphide-free water for 1–2 months, and are improved by prior acclimation.