Effects of temperature on behavior, growth, development and survival of young milkfish, Chanos chanos Forsskal

The effects of 3 temperature treatments on activity, feeding, growth, development and survival of young milkfish (Chanos chanos) were investigated under laboratory conditions. It is believed that the results may be applied to develop a land-based mass production technology in rearing milkfish fry to fingerlings

How to transport and acclimate prawn fry

The manual describes the procedures and techniques to follow for short and long duration transport of prawn fry. Regulations for acceptance and handling of wet shipment and the acclimation of the fry are also covered

Vegetational analysis in the lahar devastated area of Barangay Mancatian, Porac, Pampanga

A vegetational analysis was conducted in the lahar devastated town of Barangay Mancatian in Porac Pampanga to determine existing vegetation. Two sets of collections were done. The size of the plots for the first and second collection were 1 x 1 m. and 0.5 x 1 m. (determined through the Species Area Curve), respectively. The first collection had 19 species while the second collection had 10 species. Among the species collected during the two samplings were Brachiaria mutica, Bulbostylis barbata and Saccharum spontaneum which emerged as the dominant species. Physical parameters for light intensity, wind velocity, relative humidity, air and soil temperature were determined. The average of three readings for each parameter was obtained during the three sampling periods and was found to be 30.78 mph for wind velocity, 32.06 centigrade for air temperature, 34.78 centigrade for ash-soil temperature, 75.70% relative humidity and 32.61 fc. for light intensity. Ash-soil texture on the average was generally coarse, while moisture content was 13%. Obtained values for pH (6.12), Organic matter (Trace), Phosphorus (2.4), Potassium (62.4) and Nitrogen (Trace) were all analyzed at the Bureau of Soil and Water Management

Milkfish fry and fingerling resources of Sri Lanka

This report was partially supported by the Canadian International Development Research Centre under Project No. 3-P-78-0033.Sri Lanka has the milkfish (Chanos chanos) seed and water resources for the development of milkfish aquaculture as a new industry. Milkfish fry and fingerlings are present in all surveyed coastal wet lands, but are abundant in Mannar and Puttalam regions. The species enter tidal pools as larvae and develop into juveniles of about 50 mm. FL in one month. The fry and fingerlings are caught with seine net in tidal pools, transported in plastic bags and stocked in ponds and/or lakes. Mortality ranges 2-100% during transport; 2-15% during acclimatization; and 40-50% after 3 weeks in holding tanks. Careful handling and the application of appropriate transportation, acclimatization and nursing procedures would reduce mortality considerably

Histological observations on the rearing of milkfish, Chanos chanos, fry using different diets

Six different diets, commonly used in the Philippines for rearing milkfish, Chanos chanos, try, were tested by means of growth, survival and histology. These diets included: a) live food (Artemia nauplii); b) two different dry feeds; c) natural feed supplements (rice bran, egg yolk); d) a mixture of live and dry feeds. The mixed diet was found to give the best results, closely followed by live food. The dietary value of one of both artificial feeds improved with increasing age of the fish, whereas the other was clearly inadequate. The same was true for the natural compounds. Results obtained from statistical and histological analyses were congruent; the latter provided additional insights not obtained with statistic data alone

Meristic variations in milkfish Chanos chanos from Philippine waters

SEAFDEC Contribution No. 218.Variations in meristic characters occur within and between samples of milkfish Chanos chanos (Forsskal) collected on June 1977 from five localities in Philippine waters. The unbranched anal and ventral fin rays are the most plastic, and vertebral number is the most stable of nine meristic characters examined. The number of ventral fin rays is the only meristic feature which differed consistently enough to suggest distinct population groups: South China Sea, comprising samples from Ilocos and Panay Island; Pacific Ocean from Bicol; and Celebes Sea, from Zamboanga and Davao. A discriminant analysis which incorporated generalized distance (Mahanalobis D2) and percent overlap of a reduced set of characters indicated several morphometric subgroups of milkfish in Philippine waters, although geographic subgroups were not clearly demonstrated

Morphological aspects of the development of swimming and feeding functions in the milkfish Chanos chanos

Contribution No. 213 of the SEAFDEC Aquaculture Department.Development of swimming and feeding abilities based on morphological development of larval and early juvenileChanos chanos was investigated. In larvae smaller than about 6.5 mm SL, mechanical supports of fins and branchial arches were in a primordial stage of development. Supports and rays of the vertical fins and branchial arches rapidly developed from 6.5 mm SL, and all components appeared by about 10.5 mm SL. Thereafter body depth proportion changed and the supports and rays of the paired fins and gill-rakers developed. These developmental events were nearly or totally completed by about 17 mm SL, and we concluded that the larvae transformed to juveniles at this size. By this time, the mode of swimming of the fish shifted from undulating locomotion to caudal propulsion and that of feeding from swallowing paniculate food to filtering and concentrating substrate food matters using gill-rakers and the epibranchial organ. One of the most characteristic, and well-known, phenomena in the life history ofChanos chanos is the mass occurrence in the surf zone of postlarvae of a limited size range. In view of the scheme of the development of mechanical supports of the body and fins, they may acquire a swimming ability strong enough to move against the current only upon reaching about 10.5 mm SL, and if active shoreward migration of the larvae occurs, it is only during the late period of their journey from the spawning grounds to the shore. The sudden disappearance from the surf zone of larvae larger than 15–16 mm SL is obviously related to a change in food habit