SYNOPTIC DESCRIPTION OF THE SUBPHYLUM CRUSTACEA (BRÜNNICH 1772)

EUKARYA> UNIKONTA> OPISTHOKONTA> ANIMALIA> BILATERIA> PROTOSTOMATA> ECDYSOZOA> PANARTHROPODA> ARTHROPODA> CRUSTACEA |
CRUSTACEA LINKS
The following information came from Margulis and Schwartz (1998), Buchsbaum (1938), Barnes (1980), Barnes (1984), Brusca and Brusca (2003), Hickman (1973), Storer and Usinger (1965), and Tudge (2000). |
I. SYNONYMS: crustaceans, arthropods.
II. NUMBER: >39,000 species known.
III. PHYLUM CHARACTERISTICS:
- A. Structure
- Symmetry: Bilateral; segmented body regions organized into head, thorax and abdomen.
- Body Cavity: True coelom reduced and absent in adults. Haemocoel (text with tooltip) A haemocoel is the primary body cavity of arthropods and related organisms. It is characteristic of organisms with an open circulatory system in which the blood 'circulates' in a large open sinus that surrounds the organs. the only body cavity.
- Body Covering: Covered by chitinous and often calcified exoskeleton.
- Support: Hardened exoskeleton.
- Digestive System: Food tube simple. Mouth at anterioventral end flanked by modified legs that serve as mandibles (text with tooltip) Mandibles are the lower jaws of vertebrates. In arthropods mandibles are modified legs that serve as biting mouthparts. and a terminal anus on the telson (last body segment). Digestive gland formed of a pair of diverticula which serves as a hepatopancreas (text with tooltip) The hepatopancreas is the is a gland in many invertebrate groups that releases digestive enzymes and functions as a liver. .
- Circulatory System: Open. Haemocoel of blood sinuses with a dorsal heart. Respiratory pigments ( haemocyanin (text with tooltip) Haemocyanin is a respiratory pigment characteristic of arthropods and annelids. It is a protein complexed with copper, which is blue in the oxidized state. or erythrocruorin (text with tooltip) Erythrocruorin is a heme-protein respiratory pigment of many different invertebrates (e.g. crustaceans, annelids, and mollusks). ) in the plasma.
- Locomotion: Segments of the thorax and abdomen equipped with pairs of jointed appendages. Those of the abdomen are usually non-ambulatory or absent. Each appendage has a basal protopodite (text with tooltip) The protopodite is basal segment of the arthropod leg. , an inner endopodite (text with tooltip) Endopodite is the inner branch of a biramous arthropod limb. and and outer exopodite (text with tooltip) An exopodite is the outer branch of an arthropod biramous limb. .
- Excretory System: Glands comprising a closed end sac and a tubule located in one or more pairs of appendages (antennae, 2nd maxillae (text with tooltip) Maxillae (maxilla, sing.) are the paired lateral jaw-like appendages on the head or cephalothorax of arthropods; the upper jaw in vertebrates. , etc.).
- Nervous System: A circumesophagial ganglion, a pair of ventral nerve cords, usually connected by ganglia (text with tooltip) A ganglion (ganglia, pl.) is a cluster of nerve cells. A brain is an enlarged ganglion. at each segment. Sensory organs may be complex; compound eyes, antennae and sensory hairs.
- Endocrine System:
- Respiratory System: Modifications of appendages that function as gills. Respiratory pigments in the plasma.
- B. Reproduction:
- Reproductive System: Dioecious. Gonads paired. Fertilization internal. Oviparous.
- Development: Zygote develops by modified spiral cleavage (text with tooltip) Spiral cleavage is typical of the Protostomata and is characterized by the division planes of early cytokinesis products of the zygote being oblique to the plane of the polar axis. This produces unequal cells in the developing blastula. Usually spiral cleavage is determinant. . Eggs hatch into nauplius larva (text with tooltip) The nauplius larva is the earliest larval form of crustaceans. It is characterized by having three pairs of legs. with three pairs of appendages (antennules, antennae, and mandibles (text with tooltip) Mandibles are the lower jaws of vertebrates. In arthropods mandibles are modified legs that serve as biting mouthparts. ) and a median compound eye (text with tooltip) A type of eye characteristic of most arthropods. It is made of many individual simple ommatidia (ommatidium, sing.), each of which is like a simple eye with a lens and light-sensitive cells. . Successive segments added as the larva molts, usually many times until an adult.
- C. Ecology: Mostly free-living, terrestrial and aquatic (marine and freshwater). Most found in the oceans.
LITERATURE CITED Averof, M. and M. Akam. 1995. Insect-crustacean relationships: insights from comparative developmental and molecular studies. Phil. Trans. R. Soc. London. B. 347: 293-303. Ax, P. 2000. Multicellular Animals II. Springer Verlag. Berlin. Brusca, R. C. and G. J. Brusca. 2003. Invertebrates. Sinauer Associates, Inc. Sunderland, Mass. Buchsbaum, R. 1938. Animals Without Backbones, An Introduction to the Invertebrates. The University of Chicago Press. Chicago. Budd, G. E. 1998. Arthropod body plan evolution in the Cambrian with an example from anomalocaridid muscle. Lethaia. 31: 197-210. Budd, G. E. 2001. Tardigrades as ‘Stem-Group Arthropods’: The evidence from the Cambrian fauna. Zool. Anz. 240: 265-279. Conway Morris, S. (1998). The crucible of creation: the Burgess Shale and the rise of animals. Oxford [Oxfordshire]: Oxford University Press. pp. 56–9. Dunn, C.W., A. Hejnol, D.Q. Matus, K. Pang, W.E. Browne, S.A. Smith, E. Seaver, G.W. Rouse, M. Obst, G.D. Edgecombe, M.V. Sørensen, S.H.D. Haddock, A. Schmidt-Rhaesa, A. Okusu, R.M. Kristensen, W.C. Wheeler, M.Q. Martindale, and G. Giribet. 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature. 452: 745-749. Garey, J. R. 2001. Ecdysozoa: The relationship between Cycloneuralia and Panarthropoda. Zoologischer Anzeiger 240: 321-330. Giribet, G., G. D. Edgecombe, J. M. Carpenter, C. A. D’Haese, and W. C. Wheeler. 2004. Is Ellipura monophyletic? A combined analysis of basal hexapod relationships with emphasis on the origin of insects. Organisms, Diversity and Evolution. 4: 319-340. Hickman, C. P. 1973. Biology of the Invertebrates. The C. V. Mosby Company. Saint Louis. Ivantsov, A. Yu. 2004. New Proarticulata from the Vendian of the Arkhangel’sk Region. Paleontological Journal. 38(3): 247-253. Lavrov, D. V., W. M. Brown, and J. L. Boore. 2004. Phylogenetic position of the Pentastomida and (pan)crustacean relationships. Proceedings of the Royal Society of London. Series B. 271: 537-544. Mallatt, J. M., J. R. Garey, and J. W. Shultz. 2003. Ecdysozoan phylogeny and Baysean inference: first use of nearly complete 28S and 18S rRNA gene sequences to classify the arthropods and their kin. Molecular Phylogenetics and Evolution. 31: 178-191. Manton, S. F. 1977. The arthropod habits, functional morphology, and evolution. Clarendon Press. Oxford. Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Company. New York. Mayer, G. 2006. Structure and development of onychophoran eyes: What is the ancestral visual organ in arthropods? Arthropod Structure and Development. 35: 231-245. Mayer, G. and P. M. Whittington. 2009. Velvet worm development links myriapods with chelicerates Nielsen, C. 2001. Animal Evolution: Interrelationships of the Living Phyla. 2nd Edition. Oxford University Press. Oxford. Patel, N. H., E. Martin-Blanco, K. G. Coleman, S. J. Poole, M. C. Ellis, T. B. Kornberg, and C. S. Goodman. 1989. Expression of engrailed proteins in arthropods, annelids, and chordates. Cell. 58: 955-968. Pechenik, J. A. 2005. Biology of the Invertebrates. McGraw-Hill. New York. Regier, J. C., J. W. Shultz, and R. E. Kambic. 2005. Pancrustacean phylogeny: hexapods are terrestrial crustaceans and maxillopods are not monophyletic. Proceedings of the Royal Society of London. Series B. 272: 395-401. Reiger, J. C., J. W. Schultz, A. R. D. Ganley, A. Hussey, D. Shi, B. Ball, A. Zwick, J. E. Stajich, M. P. Cummings, J. W. Martin, and C. W. Cunningham. 2008) Resolving arthropod phylogeny: exploring phylogenetic signal within 41 kb of protein-coding nuclear gene sequence. Syste. Biol 57(6): 920-938. Ruppert, E. E. and R. D. Barnes. 1994. Invertebrate Zoology. 6th edition. Saunders. Ft Worth, TX. Ruppert, E. E., R. S. Fox, and R. D. Barnes. 2004. Invertebrate Zoology: A Functional Evolutionary Approach. Seventh Edition. Thomson, Brooks/Cole. New York. pp. 1-963. Strausfeld, N. J., C. M. Strausfeld, R. Loesel, D. Rowell, and S. Stowe. 2006. Arthropod phylogeny: onychophoran brain organization suggests an archaic relationship with a chelicerate stem lineage. Proc. R. Soc. London. B. 273: 1857-1866. Telford, M. J. S. J. Bourlat, A. Economou, D. Papillion, and O. Rota-Stabelli. 2008. The evolution of Ecdysozoa. Phil. Trans. R. Soc. B. 363: 1529-1537. Tudge, C. 2000. The Variety of Life, A Survey and a Celebration of all the Creatures That Have Ever Lived. Oxford University Press. New York. Waggoner, B. M. 1996. Phylogenetic hypotheses of the relationships of arthropods to Precambrian and Cambrian problematic fossil taxa. Systematic Biology 45(2): 190-222. Whittington, H. B. and D. E. G. Briggs. 1985. The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Phil. Trans. R. Soc. London. B. 309: 569-609. Willmer, P. 1990. Invertebrate relationships, patterns in animal evolution. Cambridge University Press. Cambridge. |
By Jack R. Holt and Carlos A. Iudica. Last revised: 02/03/2013 |