|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
Isopoda
Isopoda (pill bugs, slaters, woodlice; class Malacostraca, superorder Pericarida) Large, diverse order of crustaceans, 5–15 mm long, forming a specialized subdivision of their superorder. Isopods occupy many habitats, from the deep sea to true terrestrial niches. Some are even parasitic. They are almost always dorsoventrally flattened and adapted for crawling, and lack a carapace. The pereon is made of up to seven somites, each bearing one pair of uniramous walking legs. The leathery, flexible exoskeleton may have brown or grey markings, and some species possess chromatophores which to some degree enable the animal to match its colour to the substratum. The head bears unstalked, compound eyes, and uniramous first antennae with sensory setae. Most isopods are scavengers and omnivores, with compact mouth-parts and a well-developed cardiac (or triturating) stomach. The pleopods, unlike those of most other Crustacea, have become developed for gaseous exchange. Burrowing is common in marine forms and some species can damage docks and wooden piling (e.g. Sphaeroma and the gribble, Limnoria). Characters such as internal fertilization, a marsupium (or brood pouch), and walking legs are pre-adaptations for the successful life-style of the terrestrial forms. There are 4000 known species, most of them marine.
|
|
|
Cite this article
MICHAEL ALLABY. "Isopoda." A Dictionary of Zoology. 1999. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Isopoda." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O8-Isopoda.html MICHAEL ALLABY. "Isopoda." A Dictionary of Zoology. 1999. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Isopoda.html |
|
isopod
isopod , common name for crustaceans belonging to the order Isopoda and in the same subclass as lobsters and crayfish. Isopods are characterized by their flattened bodies, lack of a carapace, and gills located on the abdominal appendages. About 4,000 species are known. Most are aquatic; they are bottom-dwellers or are associated with water plants in freshwater or marine habitats. Some live under rocks on the shore, and some are terrestrial, living inconspicuously in surface litter or under logs. These, the pill bugs, or sow bugs, are the only large group of terrestrial crustaceans. Some isopods roll up like armadillos when disturbed. Some are parasitic, living on other crustaceans or in the mouths or on the gills of fishes. Most isopods are small, less than 1/2 in. (1.27 cm) long, but Bathynomus gigantea, a deep-sea species, may be over 1 ft (30 cm) long. Isopods are classified in the phylum Arthropoda , subphylum Crustacea, order Isopoda. |
|
|
Cite this article
"isopod." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. "isopod." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1E1-isopod.html "isopod." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-isopod.html |
|
pill bugs
pill bugs See ARMADILLIDAE; ISOPODA.
|
|
|
Cite this article
MICHAEL ALLABY. "pill bugs." A Dictionary of Zoology. 1999. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "pill bugs." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O8-pillbugs.html MICHAEL ALLABY. "pill bugs." A Dictionary of Zoology. 1999. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-pillbugs.html |
|
isopod
isopod •bod, clod, cod, god, hod, mod, nod, od, odd, plod, pod, prod, quad, quod, rod, scrod, shod, sod, squad, tod, Todd, trod, wad
•demigod • amphipod • unipod
•tripod • isopod • myriapod • decapod
•cephalopod • monopod • macropod
•gastropod • arthropod • sauropod
•ramrod • Nimrod • hotrod • pushrod
•goldenrod • Novgorod • slipshod
•roughshod • eisteddfod • tightwad
|
|
|
Cite this article
"isopod." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. "isopod." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O233-isopod.html "isopod." Oxford Dictionary of Rhymes. 2007. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-isopod.html |
|
Search over 100 encyclopedias and dictionaries:
HighBeam™ Research, Inc. © Copyright 2012. All rights reserved.
The Encyclopedia.com advertising network includes:
