Search results
Results from the WOW.Com Content Network
The coxal gland is thought to be homologous with the antennal gland of crustaceans. The gland consists of an end sac (saccule), a long duct (labyrinth) and a terminal bladder (reservoir). [2] There is generally only one pair (two in some spiders), and they open on the coxae of the walking legs [1] or at the base of the second antennae in the ...
In Crustacea, the saccate metanephridia are associated with the antennae and form the antennal gland. In freshwater crustacea, the saccate metanephridia are especially large due to their role in osmoregulation; crustacea must remove large amounts of water from the tissues, as the cells are hypertonic to the surrounding water.
A tripartite structure is recorded from near the antennae, consisting of elevated walls arranged in a semicircle (likely to enlarge the surface for an excretory organ as in modern crustaceans), a pore representing an opening of the “antennal gland” (the purpose of which is unknown) and a sickle-shaped furrow surrounding this pore.
Antennae (sg.: antenna) (sometimes referred to as "feelers") are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments.
In addition to the chitinous-proteinaceous composite of the cuticle, many crustaceans, some myriapods and the extinct trilobites further impregnate the cuticle with mineral salts, above all calcium carbonate, which can make up to 40% of the cuticle. The armoured product commonly has great mechanical strength.
The Aeglidae are a family of freshwater crustaceans currently restricted to South America. They are the only anomurans to be found in fresh water except for a single hermit crab species, Clibanarius fonticola, on Espiritu Santo, Vanuatu. [1] They live between 20° S and 50° S, [2] at altitudes between 320 and 3,500 m (1,050–11,480 ft). [3]
Acorn barnacles are attached to the substratum by cement glands that form the base of the first pair of antennae; in effect, the animal is fixed upside down by means of its forehead. In some barnacles, the cement glands are fixed to a long, muscular stalk, but in most they are part of a flat membrane or calcified plate.
A Jones fracture is a broken bone in a specific part of the fifth metatarsal of the foot between the base and middle part [8] that is known for its high rate of delayed healing or nonunion. [4] It results in pain near the midportion of the foot on the outside. [ 2 ]