The parasitic dinoflagellate, Hematodinium perezi, negatively impacts the commercially important blue crab, Callinectes sapidus. The parasite is a host generalist, but it has not been reported from littoral fiddler crabs living within a few meters of habitat known to harbor infected blue crabs. In the first study, populations of three species of fiddler crab were screened for natural infections...

Fiddler crabs (Uca spp., Decapoda: Ocypodidae) are commonly found forming large aggregations in intertidal zones, where they perform rhythmic waving displays with their greatly enlarged claws. While performing these displays, fiddler crabs often synchronize their behavior with neighboring males, forming the only known synchronized visual courtship displays involving reflected light and moving b...

The nontarget effects of temephos (as Abate 4E, 44.6% active ingredient) on fiddler crabs were examined on the salt marsh at Bombay Hook National Wildlife Refuge, near Dover, DE. Six 170 x 170-m plots were established; 3 were sprayed on 4 occasions at a rate of 1.5 fl oz/acre (0.054 kg active ingredient/ha) and 3 were controls. On each plot, marsh fiddler crab (Uca pugnax) populations were moni...

Foraging fiddler crabs (Uca spp.) monitor the location of, and are able to return to, their burrows by employing path integration. This requires them to accurately measure both the directions and distances of their locomotory movements. Even though most fiddler crabs inhabit relatively flat terrain, they must cope with vertical features of their environment, such as sloping beaches, mounds and ...

Foraging fiddler crabs form a strict spatial relationship between their current positions and burrows, allowing them to run directly back to their burrows when startled even without visual contacts. Path integration (PI), the underlying mechanism, is a universal navigation strategy through which animals continuously integrate directions and distances of their movements. However, we report that ...

What are fiddler crabs? Fiddler crabs belong to the genus Uca. They are members of the ocypodid family of brachyuran crabs, the most recent marine animals to have invaded land. They spend the first part of their life as aquatic plankton and only settle in the intertidal zone after their last larval moult. Adults live in burrows on intertidal mudand sand-flats within dense, mixedage, mixed-sex a...

The cordgrass Spartina alterniflora Loisel is a foundation species critical to the establishment and maintenance of western Atlantic salt marshes. Although the factors regulating cordgrass growth along sheltered, fine-sediment shorelines have been exhaustively studied, less is known about the mechanisms that maintain cordgrass production in high-energy marshes characterized by sandy substrates....

Clapper rails (Rallus longirostris) were used as an indicator species of estuarine marsh habitat quality because of their strong site fidelity and predictable diet consisting of mostly benthic organisms. Mercury (Hg) and the polychlorinated biphenyl (PCB) Aroclor 1268 concentrations were determined for sediments, crabs, as well as clapper rail adults and chicks collected from salt marshes assoc...

The predatory xanthid crabs Eurytjum limosurn and Panopeus herbstii are common components of benthic assemblages in different intertidal habitats within salt marshes around Sapelo Island. Georgia, USA. E. limosum feed primarily on other crabs and are found where cordgrass Spartina altemiflora stems are the dominant structural elements in the environment. P: herbstii feed largely on bivalve moll...