Available Online: http://www.ejpau.media.pl/volume1/issue1/fisheries/abs-01.html
PECULIARITIES OF EMBRYOGENESIS IN SCARDINIUS ERYTHROPHTHALMUS L.
Agata Korzelecka, Aleksander Winnicki
Morphomechanical changes appearing during embryonic development of Scardinius erythrophthalmus L. were followed. Upon complete egg hydration, the yolk together with the embryo was found to occupy about 30% of egg volume, the perivitelline space making up the remaining 70%. The embryonic disc, and the embryo later on, were always located laterally in the egg.
As in many other cyprinids, the developing eggs of S. erythrophthalmus contain no strucutral lipids in the form of droplets.
At the mid-point of embryogenesis, the yolk begins to divide; as a result, a vitellar diverticulum – elongating as the development continues – appears under the caudal part of the fast growing embryo. After hatching, the diverticulum is transformed into the posterior part of the body cavity. Until hatching, the S. erythrophtalmus embryos lack melanophores both in the skin and in the eyes.
Key words: Scardinius erythrophthalmus, egg structure, embryonic development, morphogenesis..