Ecology
The sturgeon juveniles in the West region of the Middle Caspian sea feed during all day and night, but the intensity of their nourishment during the day is various and depends on the illumination.
There are two maximums for the sturgeon juveniles, at 6 and 24 o'clock, and for starred sturgeon juveniles – at 11 and 2 o'clock.
The value of the daily rations of the sturgeon and starred sturgeon juveniles changes by seasons. So, for sturgeon juveniles this value has the tendency to decrease along with their growing from June (21,72%) to October (2,83% of the fishes mass), for starred sturgeon juveniles, accordingly, from 23,29 to 4,02%.
For the energy exchange the sturgeon juveniles spend from 0,20 to 3,57%, starred sturgeon juveniles – from 0,15 to 1,89% of their weight; for plastic exchange (ichthyomass increase) – from 0,43 to 6,43%S for the young sturgeons and from 0,29 to 2,42% of the body mass for the young starred sturgeon.
Caspian Institute of Biological Resourses of Russian Academy of Sciences