The cyprinids embryo development biology is well-known in many countries of the world, but in Romanian speciality literature there are relatively few references to this. Also there is little information regarding the embryo development environment and especially the way in which certain environment factors influence the embryogenesis of the cyprinids. Several studies have shown that the light is for majority of the fish species a negative factor - the increasing of the light intensity induced the multiplication of abnormal development and even the inhibition of embryo evolution. At a series of fish, whose spawn grows in luminosity naturals conditions, the increasing of the light intensity induced a sizeable acceleration of embryos development. The aim of this paper is to emphasize the main aspects of the ways in which light influences the development of carp (Cyprinus carpio) embryos. During the experiments 3 variants with natural light (control variant), continuous light and total darkness were used to monitor the development of carp embryos in 80x15 mm Petri dishes at an optimal density (1 embryo/ 3 ml) and at a 24 o C temperature. We wanted to observe the morphological aspect of the embryos and to establish the embryonic stage in which they are at one point , in order to determine the possible aspect changes, the possible a synchronic development between the variants. It could be noticed that at carp embryos the incubation time in all three variants was of 72 hours for 60-100% of the embryos. However in total darkness, 10% of the embryos doubled their hatching period and 144 hours after the fertilization they died inside the corion. In continuous light the embryos hatched faster than in natural light. At the end of the experiment the hatching rate was of 100% in these two variants and of 90% in the third variant. The development of carp embryos it's directly influenced by darkness, the period of hatching being the most sensitive period. Statistically, there are no differences between the three variants.

carp; embryo development; light

Presentation: oral