Dinoflagellates of the genusHematodinium infect over 40 species of marine crustaceans. Since the initial description of this parasite in France in the 1930s [1], it appears to have spread globally, causing economic loss in some species, including Tanner crabs (Chionoecetes bairdi) in Alaska [2], blue crabs (Callinectes sapidus) in the United States [3], edible crabs (Cancer pagurus) and Norway ...

Transversely split sarcomeres are seen in mouthpart muscles of the blue crab in the electron microscope. Sarcomeres split only at the H zone. Two new sarcomeres are formed by a Z disk which appears in the H zone of the splitting sarcomere. Splitting may involve breaking of the thick filaments in the H zone, elongation of these filaments, and formation of both new actin filaments and Z-disk mate...

Parasitic dinoflagellates of the genus Hematodinium infect several commercially important decapod crustaceans. Different species of Hematodinium have different levels of virulence in their respective hosts. Enzyme activities were studied from two species of Hematodinium, one isolated from the Norway lobster (Nephrops norvegicus) and the other from the American blue crab (Callinectes sapidus). W...

When transferred from 865 to 250 m-osmol salinity, the blue crab C. sapidus maintains its blood Na+ and Cl~ concentrations significantly above those in the medium. When branchial carbonic anhydrase is inhibited by acetazolamide, ion regulation fails and the animals do not survive the transfer. An alkalosis occurs in the blood at low salinity, indicated by an increase in HCO3~ and pH at constant...

The behavior of crabs tracking odor in turbulent chemical plumes was compared to the performance of computer simulations of search behavior operating in similar chemical signal environments. The movement of blue crabs (Callinectes sapidus) towards a source of food odor was studied in controlled flow conditions in a flume. The evolving chemical stimulus field of a similar chemical source in an e...