DESICCATION RESISTANCE IN TIGRIOPUS-CALIFORNICUS (COPEPODA, HARPACTICOIDA)

In field populations and controlled laboratory microcosms, the suprali ttoral copepod Tigriopus californicus demonstrated the ability to reco ver populations from evaporated splashpools. The response to either se awater or rainwater introduction occurred mainly within 24 h, regardle ss of copepod abundance or substrate material (mixed sediment or dried samples of the alga Enteromorpha compressa). As a proportion of avail able individuals, the response was quite consistent over all life-hist ory stages. However, egg-carrying females and adult males showed the g reatest net increase in individual numbers due to their abundance in s ource (dried) materials. Enteromorpha compressa treatments hydrated wi th seawater yielded significantly greater re-animation (P<0.05), sugge sting a response to food resources rather than moisture or salinity al one. Overall, 10.7+/-8.5% (mean+/-SD) of individuals were re-animated following hydration. While a slight percentage, the tremendous density of individuals trapped in dried splashpools probably still yields suf ficient numbers of effective intra-pool recolonization. Such a respons e map be more practical for population endurance in ephemeral supralit toral habitats than reliance on environmental influences (waves, preci pitation or transport on coincident invertebrates) or the deposition o f encysted eggs. (C) 1996 Academic Press Limited