Tidal-migration
Guides
Amphiporeia virginiana
Amphiporeia virginiana is a sand-burrowing amphipod crustacean described by Shoemaker in 1933. It is a dominant inhabitant of high-energy sandy beaches along the Atlantic coast of North America, from Nova Scotia to South Carolina. The species exhibits distinctive tidal migration behavior, swimming into the water column during flood tides and burrowing into sediments during ebb tides. Females brood eggs and young in a ventral marsupium.
Excirolana chiltoni
sand piranha
Excirolana chiltoni is a small intertidal isopod, commonly called 'sand piranha,' inhabiting sandy beaches of the Pacific Rim from Japan and Korea to Colombia. Adults reach approximately 8 mm in length and form dense aggregations exceeding 1,000 individuals. The species exhibits ovoviviparous reproduction with direct development, a 2-year lifespan, and pronounced spatial segregation during breeding.
Pardosa lapidicina
Stone Spider
Pardosa lapidicina, commonly known as the stone spider, is a small wolf spider in the family Lycosidae. It inhabits cobble beaches and rocky shorelines near water, particularly above the tide line. The species exhibits distinctive migration patterns tied to tidal cycles and seasonal temperature changes. Research has documented its use of sit-and-wait foraging behavior combined with sun-basking, and its diet includes small arthropods such as dipterans, collembolans, and amphipods. Males recognize females through a contact sex pheromone located on the female's carapace and legs, requiring physical contact for detection.