Habitat Type: Marine
Comments: Common in salt marsh flats, estuaries, and tidal creeks, especially where there is abundant submergent and emergent vegetation. Adults use intertidal zone only when it is flooded; young remain on marsh even at low tide, inhabiting shallow puddles (Kneib 1986). Occasionally enters freshwater streams and rivers (Lee et al. 1980). May burrow into bottom mud in winter. Spawns in fresh, brackish, or saltwater; generally in estuarine and salt marsh environments. Eggs are laid in various sites at levels reached only by high spring tides; usually in sand in New England populations and in Spartina alterniflora or empty Geukensia demissa shells in Middle Atlantic and southern populations (Taylor 1986). Eggs normally incubate in air (aerial incubation apparently is essential for survival), not submerged until next spring tide. Abrupt decreases in salinity (e.g. due to spring freshets) may decrease fertilization success and increase larval mortality in local populations (Able and Palmer 1988).