Notes on the reproduction and survival of Moina hutchinsoni Brehm, 1937 (Moinidae: Anomopoda) grown in media of varying salinity

Moina hutchinsoni, a North American species distributed in saline and alkaline waters, was isolated from temporary puddles in the former Texcoco Lake basin near Mexico City. Its growth under laboratory conditions was assayed at different salinity values. Two culture media were tested: reconstituted hard-water plus sea salts and diluted natural brine. The alga Ankistrodesmus falcatus was supplied as food at a concentration of 0.4 x 10⁶ cells ml^-1. Salinity levels ranged from 2 to 20. For all experiments, twenty replicates, consisting of one neonate female individually placed in a glass container with 80 ml culture volume, were used. All vessels were reviewed daily and the progeny counted and removed. Culture media and food were renewed each day. Data on the survival and reproduction of M. hutchinsoni were recorded during its entire life cycle. The high average longevity (22.6) days, number of clutches (17.8), and average total progeny (138.9 neonates). were recorded at a salinity of 10 of natural brine water. In the synthetic medium reconstituted hard water plus sea salts, the highest average longevity 9.2 days, one of the highest number of clutches (9.6), and the highest average total progeny (29.5) neonates. were recorded at a salinity of 4. Reproduction and survival was affected by salinity and the culture medium, with the best results recorded in diluted natural brine. The information presented here is the first biological data surveyed for this euryhaline species in experimental conditions.