Malacostraca
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Latreille, 1802
Subclasses
Eumalacostraca Hoplocarida Phyllocarida See text for orders. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting Pierre André Latreille ( November 20, 1762 - February 6, 1833) was a French entomologist. The Eumalacostraca (Greek "true soft shell" are a subclass of Crustaceans containing almost all living Malacostracans about 22000 described species Mantis shrimp or stomatopods are marine Crustaceans the members of the order Stomatopoda. Leptostraca (from the Greek words for thin and shell   is an order of small marine Crustaceans Its members including the

The Malacostraca (Greek: "soft shell")are the largest class of crustaceans and include most of the animals that non-experts recognize as crustaceans, including decapods (such as crabs, lobsters and shrimp), stomatopods (mantis shrimp) and euphausiids (krill). Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting The decapods or Decapoda ( literally means "ten footed") are an order of Crustaceans within the class Malacostraca, including many Crabs are decapod Crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (βραχύ / brachy Clawed lobsters compose a family ( Nephropidae, sometimes also Homaridae) of large marine Crustaceans Lobsters are economically important as True shrimp are swimming decapod Crustaceans classified in the Infraorder Caridea, found widely around the world in both fresh Mantis shrimp or stomatopods are marine Crustaceans the members of the order Stomatopoda. Krill are a type of Shrimp -like marine Invertebrate animal These small Crustaceans are important organisms of the Zooplankton, particularly They also include the amphipods and the only substantial group of land-based crustaceans, the isopods (woodlice and related species). Amphipoda (amphipods are an order of animals that includes over 7000 described Species of Shrimp -like Crustaceans ranging from 1 mm to 140 mm Isopods are one of the most diverse orders of Crustaceans with many species living in all environments but are most common in shallow marine waters Woodlice (known by many Common names see below) are Crustaceans with a rigid segmented long Exoskeleton and fourteen jointed limbs With more than 22,000 members, this group represents two thirds of all crustacean species and contains all the larger forms. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. The first malacostracans appeared in the Cambrian. The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with

The classification of crustaceans is currently being debated, and the Malacostraca are regarded by some authors as a class and by others as a subclass. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order.

The phylogeny of this group of organisms is debated ^[1], recent molecular studies (18S ^[2]and 28S^[3]) have even disputed the monophyly of the Peracarida by removing the Mysida and have firmly disproven the monophyly Edriophthalma (Isopoda and Amphipoda) and the Mysidacea (Mysida, Lophogastrida and Pygocephalomorpha). Edriophthalma is a disused peracarid ( Malacostraca) classification comprising Isopoda and Amphipoda, first proposed by Frederick Schram Isopods are one of the most diverse orders of Crustaceans with many species living in all environments but are most common in shallow marine waters Amphipoda (amphipods are an order of animals that includes over 7000 described Species of Shrimp -like Crustaceans ranging from 1 mm to 140 mm The Mysidacea is a group of small Shrimp -like creatures comprising the two related orders Mysida and Lophogastrida. The Mysidacea is a group of small Shrimp -like creatures comprising the two related orders Mysida and Lophogastrida. The Mysidacea is a group of small Shrimp -like creatures comprising the two related orders Mysida and Lophogastrida.

Contents 1 Morphology 2 Classification 3 References 4 External links

Morphology

Their characteristics include:

• The head has 6 segments, with a pair of antennules and a pair of antennae, as well as mouthparts. A body plan, or bauplan, is essentially the blueprint for the way the body of an organism is laid out Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are The mouthparts of Arthropods have evolved into a number of forms each adapted to a different style or mode of feeding
• They usually have 8 pairs of thoracic legs, of which the first pair or several pairs are often modified into feeding appendages called maxillipeds. The first pair of legs behind the maxillipeds is often modified into pincers.
• There are 8 thoracic segments. The cephalothorax is covered by a carapace form via fusion of 3 of them, letting the 5 other uncovered. The cephalothorax (call prosoma in some groups is an anatomical term used in Arachnids and Malacostracan Crustaceans for the A carapace is a dorsal section of an Exoskeleton or shell in a number of animal groups
• The abdomen is behind and often used for swimming. In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis. There are 6 abdominal segments.
• They have compound stalked or sessile eyes.
• They have a two-chambered stomach. In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following
• They have a centralised nervous system. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself

Classification

Martin and Davis^[4] present the following classification of living malacostracans into orders, to which extinct orders have been added, indicated by †.

Class Malacostraca Latreille, 1802

• Subclass Phyllocarida Packard, 1879

• †Order Archaeostraca
• †Order Hoplostraca
• †Order Canadaspidida
• Order Leptostraca Claus, 1880

• Subclass Hoplocarida Calman, 1904

• Order Stomatopoda Latreille, 1817 (mantis shrimp)

• Subclass Eumalacostraca Grobben, 1892
  • Superorder Syncarida Packard, 1885
    • †Order Palaeocaridacea
    • Order Bathynellacea Chappuis, 1915
    • Order Anaspidacea Calman, 1904
  • Superorder Peracarida Calman, 1904
    • Order Spelaeogriphacea Gordon, 1957
    • Order Thermosbaenacea Monod, 1927
    • Order Lophogastrida Sars, 1870
    • Order Mysida Haworth, 1825
    • Order Mictacea Bowman, Garner, Hessler, Iliffe & Sanders, 1985
    • Order Amphipoda Latreille, 1816
    • Order Isopoda Latreille, 1817 (woodlice, slaters)
    • Order Tanaidacea Dana, 1849
    • Order Cumacea Krøyer, 1846
  • Superorder Eucarida Calman, 1904
    • Order Euphausiacea Dana, 1852
    • Order Amphionidacea Williamson, 1973
    • Order Decapoda Latreille, 1802 (crabs, lobsters, shrimp)

References

External links

• Malacostraca image key - Guide to the marine zooplankton of south eastern Australia, Tasmanian Aquaculture and Fisheries Institute

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