Pattern of cutaneous wound healing in a live fish Clarias batrachus (L.)(Clariidae, Pisces.)

Incisional wounds of the same length and depth were made on skin between dorsal fin and the lateral line canal of Clarias batrachus and the pattern of wound closure has been studied histologically. Following infliction, a marked change in the colour of the skin surrounding the wound was observed which lasted for about 30 h and restored thereafter. Mucus and blood cells plugged the wound gap shortly after infliction. The epidermis surrounding the wound was found to be detached from the basement membrane. Mass movement of epidermal cells was observed from both side of the wound gap. The epidermal cells at the margin of the wound became hypertrophied. The epidermis became normal by 32 days. The dealing of sub-epidermal tissue indicated degenerative and regenerative changes of muscle fibres. The mucus and blood cells were accumulated in the wound gap and later fine blood vessels were formed. Gradually granulation tissue was formed and fibroblasts and myoblasts appeared. Myoblast differentiated into muscle bundles. The epidermal repair was completed within 35 days.

Hydrobiological studies of an irrigation tank with reference to the culture of large murrel, Channa marulius (Hamilton) and striped murrel Channa striatus (Bloch)

The importance of selection of species for culture according to the ecological niches and fish food organisms is highlighted with respect to the Fox Sagar, an irrigation take. The tank was infested with submerged vegetation as well as minnows and weed fishes, which rendered the tank unsuitable for the culture of Indian major carps. The tank was stocked with 8000 fingerlings of Channa marulius and C. striatus during 1981 by the local fisherman co-operative society. Only partial harvest was possible during 1982 because of high water level. The final harvest was in April-May, 1983. The yield obtained was 3640 kg during the culture period of about 20 months.

Seawater irrigation systems for intensive marine shrimp farming in Thailand

The aim of the seawater irrigation system (SIS) is to clean up shrimp pond effluent and provide high quality seawater for shrimp farming. The system has 3 components: water intake; treatment reservoir and discharge system. There are criteria for site selection because shrimp farmers are required to form associations so they can work closely together. The construction site must be on the coastal area outside a mangrove forest and located away from a production agricultural area. All construction sites must have undergone an environmental impact assessment, and should be located on the area listed in Thailand's Coastal Zone Management Plan. Five SIS projects, which cover a culture area of 6,500 ha with 1,300 farmers (families), were completed and operated. The Department of Fisheries has planned for another 28 projects, that will cover almost 44,000 ha of culture area.

The role of plants in channel-dyke and field irrigation systems for domestic wastewater treatment in an integrated eco-engineering system

Eight kinds of plants were tested in channel-dyke and field irrigation systems. The removal rates of TP, phosphate, TN, ammonia, CODcr and BOD, in the channel-dyke system with napiergrass (Pennisetum purpurem Schumach, x Pennisetum alopecuroides (L.) Spreng American) were 83.2, 82.3, 76.3, 96.2, 73.5 and 85.8%, respectively. The field irrigation systems with rice I-yuanyou No.1(88-132) (Oryza sativa L.) and rice II- suakoko8 (Oryza glaberrima) had high efficiency for N removal; the removal rate were 84.7 and 84.3%, respectively. The mass balance data revealed that napiergrass, rice I and II were the most important nutrient sinks, assimilating more than 50% of TP and TN. Plant uptake of N and P as percentage of total removal from wastewater correlated with biomass yield of and planting mode. (C) 2000 Elsevier Science B.V. All rights reserved.