RT Journal Article ID 6f1e600b53873707 A1 Butorina, L. G. T1 Influence of the Daylight Duration and Water Temperature on Numbers and Demographic Composition of Population of Polyphemus pediculus (Crustacea: Cladocera) JF Hydrobiological Journal JO HYD YR 2011 FD 2011-03-23 VO 47 IS 2 SP 3 OP 14 K1 Polyphemus pediculus K1 population K1 sexual composition K1 numbers K1 development cycle K1 daylight duration K1 temperature K1 correlation and multiple regression coefficients K1 type of photoperiodic reactions. AB Numbers, demographic composition and ratio of sexes in P. pediculus population are affected by absolute value and vector variation of the daylight duration. Different types of specimens display their maximal numbers under different environmental conditions. Photoperiodic reaction of crustaceans belongs to a long-day type. Maximum population development and parthenogenetic females predomination are observed in a limited daylight duration range, from 15.5 to 17.5 hours per day. The daylight duration of 14 hours per day is a threshold, the beginning of mass transition into the dormant state. Period with the daylight duration 12 hours per day and less is unfavorable for the population. PB Begell House LK https://www.dl.begellhouse.com/journals/38cb2223012b73f2,00453d637272b815,6f1e600b53873707.html