“…Other studies have demonstrated that anostracan egg hatching is increased by favourable temperatures (Hall, 1961;Broch, 1965;Moore, 1967;Daborn, 1976;Modlin, 1982), suppressed by unfavourable temperatures (Hall, 1961;Nourisson, 1961;Broch, 1965;Moore, 1967; Mossin, 1986;Saiah and Perrin, 1990;Belk and Nelson, 1995), and that variation in annual appearance of co-occurring species is attributed to variation in favourable temperatures between species (Moore, 1963;Prophet 1963c;Horne, 1967Horne, , 1971. Moore (1967) noted in Streptocephalus sealii Ryder, 1879 populations from a pool in Louisiana, USA, that the optimal hatching temperature was 21°C, however hatching percentage increased if eggs were subjected to a temperature fluctuation from 19 to 23°C over a ten hour period every day.…”