Now showing items 1-5 of 5

    • Conference paper

      Occurrence of milkfish eggs in the adjacent waters of Panay Island, Philippines 

      T Senta, S Kumagai & L Ver - In Proceedings of the International Milkfish Workshop Conference, May 19-22, 1976, Tigbauan, Iloilo, Philippines, 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Location of spawning grounds of milkfish is one of the most important steps towards gaining knowledge on the spawning habits of the fish as well as the early life history and nature of its eggs and larvae. The present study is an attempt towards this objective. Surveys were made in selected areas in the sea around the Panay Island and milkfish eggs were collected on several occasions from surface to 20 m depth water by towing with larval nets. The eggs floated in the water in a glass jar. The eggs and newly hatched larvae had the same characteristics as described by Delsman (1929). A comparative study has been made to distinguish milkfish eggs from other more or less similar size pelagic eggs of fishes occurring in the same waters at the same time.
    • Article

      Occurrence of milkfish, Chanos chanos (Forsskal) eggs around Panay Island, Philippines 

      T Senta, S Kumagai & N Castillo - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Occurrence of milkfish, Chanos chanos (Forsskal) eggs around Panay Island, Philippines 

      T Senta, S Kumagai & NM Castillo - Bulletin of the Faculty of Fisheries, Nagasaki University, 1980 - The Faculty of Fisheries, Nagasaki University
      A total of 551 milkfish eggs was collected by horizontal tows with a fish larval net in the waters around Panay island during the period from April 1976 to June 1979. The maximum number obtained by a single tow was 33 eggs. Most of the eggs were collected from Cuyo East Pass, with some from the waters around the Cagayan Islands and a single egg from the Sibuyan Sea. Almost all the eggs were collected during the period frim March to June, with a peak in April, one month ahead of the peak of fry occurrence.

      Very often milkfish eggs occurred in shallow waters around islands or close to the coasts, while they were sometimes found at locations remote from land and as deep as 900 m. Water temperatures and salinities at locations shere milkfish eggs were found ranged from 26.7 to 30.8°C and from 32.9 to 34.5 ppt. The eggs were rather evenly distributed from the surface to at least 20 m down. The eggs found in the early morning collections were in the early stages of development; those found later in the day were more advanced. It seems that spawning of mikfish takes place at midnight, and that the incubation period of eggs in the wild is about 20 hours.
    • Conference paper

      Preliminary observation on the number of vertebra in milkfish, Chanos chanos (Forskal) 

      T Senta & S Kumagai - In Proceedings of the International Milkfish Workshop Conference, May 19-22, 1976, Tigbauan, Iloilo, Philippines, 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The existence of races and/or subpopulation in milkfish, a widely distributed species, is suggested by many workers. Comparison of mean numbers of vertebrae is one of the useful method of distinguishing subpopulations. The present paper reports the results of preliminary studies made on the vertebral counts of milkfish fry collected from several areas. The results obtained, though not conclusive, suggest the scope for further study in the line.
    • Article

      Variation in the vertebral number of the milkfish Chanos chanos, collected from various localities 

      T Senta & S Kumagai - Bulletin- Faculty of Fisheries Nagasaki University, 1977 - The Faculty of Fisheries, Nagasaki University
      A total of 2497 milkfish fry were collected in 1976 from nine localities in six countries, viz. India, Thailand, Indonesia, Philippines, Taiwan and Tahiti. Vertebra counts ranged from 40 to 45. The general trend of geographical gradient in vertebral counts in the milkfish was observed to be lower in the west (or otherwise, along continents) and higher in the east (or around oceanic islands). Extremes in the means of vertebral counts by localities were seen in the samples from India with 43.08 and from Tahiti with 43.82. It was suggested that there may be at least four subpopulations among the milkfish throughout the tropical Indo-Pacific waters.