Populations of horseshoe crabs Limulus polyphemus are widely distributed from Maine to the Gulf of Mexico, are commercially harvested, and are thought to have decreased in abundance in recent decades. To provide information needed to manage exploited populations of horseshoe crabs, we conducted comprehensive field sampling in a major shallow estuary containing preferred habitat for horseshoe cr...

Sesarmid crabs are important ecosystem engineers in mangroves because they remove a large proportion of mangrove leaf litter. However, the effects on mangrove sediments of sesarmid crab foraging on mangrove leaves has been poorly quantified. Through a laboratory experiment, the present study aimed to quantify changes in nutrient concentrations and enzyme activities in mangrove sediment due to f...

Crabs of the genus Lybia have the remarkable habit of holding a sea anemone in each of their claws. This partnership appears to be obligate, at least on the part of the crab. The present study focuses on Lybia leptochelis from the Red Sea holding anemones of the genus Alicia (family Aliciidae). These anemones have not been found free living, only in association with L. leptochelis. In an attemp...

Stock assessment and reproductive biology of the blue swimming crab, Portunus pelagicus, in Bandar Abbas coastal waters was conducted from August 2006 to July 2007. A total of 424 male and 348 female crabs were taken to the laboratory for length, weight and reproductive biometry. Estimate of growth parameter of crab showed t asymptotic carapace width (CW) was 172.5 mm, the curvature parameter, ...

The impact of microbial gill infestations on the pathology and physiology of the freshwater crab Potamonautes warreni was investigated by comparison of infested and uninfested crab populations from, respectively, a polluted and an unpolluted site along the Mooi River, North West Province, South Africa. Heavy gill infestations by bacteria (70%), peritrichous ciliates such as Lagenophrys sp. (15%...

Freshwater habitats of the Caribbean island Jamaica are unique, in so far that they are not inhabited by freshwater Decapoda Reptantia with a long evolutionary history in fresh water, like crayfish or old lineages of freshwater crabs. Instead, a relatively young invasion and radiation of originally coastal crabs from the family Sesarmidae took place, resulting in currently ten endemic sesarmid ...

Dispersal of Eriocheir sinensis from its native habitat is a worldwide concern. As one of the most invasive species known, this crab causes significant disruption to foreign ecosystems. In particular, populations in the United Kingdom (UK) are increasing in number and E. sinensis has been reported from many river catchments (www.mittencrabs.org.uk). The ecological implications of this invasion ...

Hermit crabs play an important role in the Northern Adriatic Sea due to their abundance, wide range of symbionts, and function in structuring the benthic community. Small-scale (0.25 m(2)) hypoxia and anoxia were experimentally generated on a sublittoral soft bottom in 24 m depth in the Gulf of Trieste. This approach successfully simulates the seasonal low dissolved oxygen (DO) events here and ...

Adult abundance is determined by both recruitment and survival of juveniles. Blue crabs exhibit a distinct population size-structure reflecting seasonal cycles of recruitment and growth in the Rhode River, a subestuary lacking submerged vegetation in central Chesapeake Bay. Seasonally shifting modes in the size-structure, corresponding to juvenile, prepubertal and mature crabs, allowed trawl ca...

Observations were performed to detcrminc the relationship bctwccn the time of maximal pigment dispersion in the fiddler crabs, Uca pugilator and Uca minax, and the tidal events on the beach where the crabs were collcctcd. Uca pugilator obtained from burrows above the high tide mark did not have an overt tidal rhythm but did have 24-hour and 14.8-day cycles of color change. The tidal rhythm was ...