Green Global
Foundation   Journal
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STUDY ON THE EMBRYONIC AND LARVAL DEVELOPMENT OF AN ENDANGERED SPECIES OF BATA (Labeo bata) (Pages : 72 - 82)

The embryonic and larval development of critically endangered local Bata (Labeo bata) was studied at the hatchery of the Field Laboratory Complex, Faculty of Fisheries, Water Quality Laboratory of the Department of Fisheries Management and Field Fertility Clinic Laboratory of the Department of Surgery and Obstetrics, Bangladesh Agricultural University (BAU), Mymensingh during April 2007 to July 2008. This study presents preliminary observations on the embryonic and larval development of Labeo bata under laboratory conditions. The brood fish of L. bata was collected from the Jamuna river of Sirajgonj district for breeding purpose. The eggs were obtained after reproductive induction. At fertilization; the eggs were 0.7 mm in diameter. Samples were taken every 10 minutes interval till completion of morula and then every 1 hour interval up to hatching. After hatching, newly hatched larvae were observed daily until the attainment of the fingerling stage. The eggs presented brownish-yellow coloration. They were spherical, demersal and adhesive. The stages of embryonic development observed with cleavage, followed by blastula, morula, early gastrula, middle gastrula, late gastrula and until hatching of non-pigmented larvae which displayed total average length of 2.0±0.01 mm, 20 hours after fertilization. First cleavage was recorded within 45 minutes after fertilization and the embryonic rudiments of developing eggs appeared at 10 hours at 27.0°C-31.0°C. The yolk sac was completely absorbed at 66 hours during embryonic development on attainment of 6.2±0.02 mm total length. At the same time the digestive system became fully developed and the larvae searched for feeding.Download