RIPLEY, B.J.; VERGARA, L.V.; TORRES, J.D.; HOLTZ, J.; SIMOVICH, M.A.: Cyst Size in Relation to Female Size in the San Diego Fairy Shrimp Branchinecta sandiegonensis

In many organisms, larger females have larger offspring. Large offspring may have better survival, increasing fitness for these large females. The reproductive strategies of ephemeral pond crustaceans such as fairy shrimp include bet-hedging. Bet-hedging is a strategy in which fairy shrimp hatch at various wettings, thus surviving variation in rainfall from year to year. Little is known about fairy shrimp cyst size in relation to female characteristics or hatchling success. We raised individuals of the San Diego Fairy Shrimp Branchinecta sandiegonensis in the lab, mated pairs, and collected cysts of each female. Females were measured and clutches were collected daily. We measured twenty-five cysts each from an early clutch, when females were still small, and a late clutch, when females were full-sized, for nine females. There was no significant relationship between female size and cyst size. An alternative explanation for variation in cyst size may be that differences in cyst structure lead to differences in the timing of hatching.