Among the oldest fossil crustaceans are those of the Late Cambrian (Furongian 499 ± 0.3-488.3 ± 1.7 Ma) of Västergötland, central Sweden and the lower Ordovician (Tremadocian 488.3 and 478.6 Ma) of the island of Őland. These are three-dimensionally preserved in nodules from the so called 'stinkstone' ('Orsten') limestone. 'Orsten'-like fossils represent tiny, often meiobenthic organsisms (Haug,...

Many animals have an abundance and diverse assortment of peripheral sensors, both across and within sensory modalities. Multiple sensors offer many functional advantages to an animal's ability to perceive and respond to environmental signals. Advantages include extending the ability to detect and determine the spatial distribution of stimuli, improving the range and accuracy of discrimination a...

Aeglidae are anomuran freshwater “crabs” found only in southern South America. In Brazil, the greatest species diversity occurs in hydrographic basins of the state of Rio Grande do Sul. Two new species, Aegla georginae and Aegla ludwigi, are described from the Ibicuí and Ijuí Rivers, respectively (Uruguay River Basin). The new taxa can be distinguished from other Aegla species based on both mor...

The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retai...

The functions of the blood cells of crustaceans have received little investigation. The majority of the work reported in the literature to date has been concerned with the involvement of the haemocytes in the phenomenon of plasma coagulation. In several crustacean species highly fragile blood cells have been described ' Hardy's explosive corpuscles' which are generally believed to contain subst...

A sandwich-type enzyme-linked immunosorbent assay (ELISA) was utilized to quantify crustacean hyperglycemic hormone (as Carcinus maenas equivalents) released by single X-organ­sinus gland systems of the crab Cardisoma carnifex during continuous perifusion. Basal rates of secretion (20­60 pg min-1) were stable for at least 4 h. Electrical stimulation (600 stimuli in 5 min) of the axon tr...