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Cumacea is an order of small marine crustaceans, occasionally called hooded shrimps. Iphinoe trispinosa is a species of Cumacean belonging to the family Bodotriidae and the Genus Iphinoe. 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 The Malacostraca (Greek "soft shell" are the largest class of Crustaceans and include most of the animals that non-experts recognize as crustaceans including The superorder Peracarida is a large group of Crustaceans having members in marine freshwater and terrestrial habitats This article is about the taxonomic rank for the sequence of species in a taxonomic list see Taxonomic order In scientific classification used Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting Their unique appearance and uniform body plan makes them easy to distinguish from other crustaceans. A body plan, or bauplan, is essentially the blueprint for the way the body of an organism is laid out
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Anatomy
Cumaceans have a strongly enlarged carapace (head shield) and pereon (breast shield), a slim abdomen and a forked tail. A carapace is a dorsal section of an Exoskeleton or shell in a number of animal groups The decapod Crustacean such as a crab lobster shrimp or prawn is made up of nineteen Body segments grouped into two main body parts the Cephalothorax In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis. The length of most species varies between 1 and 10 mm. The Millimetre ( American spelling: millimeter, symbol mm) is a unit of Length in the Metric system, equal to
The carapace of a typical cumacean is composed of several fused dorsal head parts and the first three somites of the thorax. A somite is a division of the body of an animal In vertebrates this is mainly discernible in the embryo stage in arthropods it is a characteristic of a hypothetical ancestor The thorax is a division of an Animal 's body that lies between the head and the Abdomen. This carapace encloses the appendages that serve for respiration and feeding. In living organisms a respiratory system functions to allow Gas exchange. In most species, there are two eyes at the front side of the head shield, often merged into a single eye lobe. The five posterior somites of the thorax form the pereon. The pleon (abdomen) consists of six cylindrical somites. The decapod Crustacean such as a crab lobster shrimp or prawn is made up of nineteen Body segments grouped into two main body parts the Cephalothorax
The first antenna (antennula) has two flagella, the outer flagellum usually being longer than the inner one. A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it The second antenna is strongly reduced in females, and consists of numerous segments in males. Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are
Cumaceans have six pairs of mouthparts: one pair of mandibles, one pair of maxillula, one pair of maxillae and three pairs of maxillipeds. In arthropods the mandible is either of a pair of Arthropod Mouthparts used for biting cutting and holding food In certain Arthropods the maxillae are paired Mouthparts located behind the mandibles. The decapod Crustacean such as a crab lobster shrimp or prawn is made up of nineteen Body segments grouped into two main body parts the Cephalothorax
Ecology
Cumaceans are mainly marine crustaceans. Bodotria scorpioides is a species of Crustacean belonging to the order Cumacea and the Genus bodotria. However, some species can survive in water with a lower salinity rate, like in brackish water (e. Salinity is the Saltiness or dissolved salt content of a body of Water. g. estuaries). An estuary is a semi-enclosed Coastal body of Water with one or more Rivers or Streams flowing into it and with a free connection to the open In the Caspian Sea they even reach some rivers that flow into it. The Caspian Sea is the largest enclosed body of water on Earth by area variously classed as the world's largest lake or a full-fledged Sea. Few species live in the intertidal zone.
Most species live only one year or less, and reproduce twice in their lifetime. Deepsea species have a slower metabolism and presumably live much longer. Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life.
Cumaceans feed mainly on microorganisms and organic material from the sediment. A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually Organic matter (or organic material) is Matter that has come from a once-living Organism; is capable of Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Species that live in the mud filter their food, while species that live in sand browse individual grains of sand. In the genus Campylaspis and a few related genera, the mandibles are transformed into piercing organs, which can be used for predation on forams and small crustaceans. The Foraminifera, ("Hole Bearers" or forams for short are a large group of Amoeboid Protists with reticulating Pseudopods fine
Many shallow water species show a diurnal cycle, with males emerging from the sediment at night and swarming to the surface. In Animal behavior, diurnality indicates an Animal that is active during the Daytime and rests during the Night.
Importance
Like Amphipoda, cumaceans are an important food source for many fishes. Amphipoda (amphipods are an order of animals that includes over 7000 described Species of Shrimp -like Crustaceans ranging from 1 mm to 140 mm Therefore, they are an important part of the marine food chain. Food chains, also called food networks and/or trophic networks, describe the feeding relationships between species within an Ecosystem. They can be found on all continents.
Reproduction and development
Cumaceans are a clear example of sexual dimorphism: males and females differ significantly in their appearance. Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. Both sexes have different ornaments (setation, knobs, and ridges) on their carapace. Other differences are the length of the second antenna, the existence of pleopods in males, and the development of a marsupium in females. The decapod Crustacean such as a crab lobster shrimp or prawn is made up of nineteen Body segments grouped into two main body parts the Cephalothorax The marsupium or brood pouch, in Peracarida such as Amphipods Isopods or Cumaceans is an egg chamber formed by the ventral plates There are generally more females than males, and females are also larger than their male counterparts.
Cumaceans are epimorph, which means that the number of body segments doesn't change during the different developmental stages. This is a form of incomplete metamorphosis. Metamorphosis is a Biological process by which an Animal physically develops after Birth or hatching involving a conspicuous and relatively Females carry the embryos in their marsupium for some time. The larvae leave the marsupium during the so-called manca-stadium, in which they are almost fully grown and only miss their last pair of pereopods.
History of research
The order of Cumacea was already known since 1780, when Ivan Ivanovich Lepekhin described the species Oniscus scorpioides (later renamed to Diastylis scorpioides). During that time, many scientists thought that the cumaceans were some kind of larval stadium of decapods. The decapods or Decapoda ( literally means "ten footed") are an order of Crustaceans within the class Malacostraca, including many In 1846, they were recognized as a separate order by Henrik Nikolaj Krøyer. Twenty-five years later about fifty different species had been described, and currently there are more that 1,400 described species. German zoologist Carl Wilhelm Erich Zimmer studied the order Cumacea very intensively. Carl Wilhelm Erich Zimmer (1873 - 1950 was a German Zoologist specialising in Crustaceans especially the order Cumacea.
Taxonomy
Cumaceans belong to the superorder of Peracarida, within the class of Malacostraca. The superorder Peracarida is a large group of Crustaceans having members in marine freshwater and terrestrial habitats The Malacostraca (Greek "soft shell" are the largest class of Crustaceans and include most of the animals that non-experts recognize as crustaceans including The order of Cumacea is subdivided into 8 to 11 families, and about 120 genera. The families most marine zoologists recognize are:
- Bodotriidae Scott, 1901 (360 species)
- Ceratocumatidae Calman, 1905 (8 species)
- Diastylidae Bate, 1856 (281 species)
- Gynodiastylidae Stebbing, 1912 (103 species)
- Lampropidae Sars, 1878 (90 species)
- Leuconidae Sars, 1878 (121 species)
- Nannastacidae Bate, 1866 (350 species)
- Pseudocumatidae Sars, 1878 (29 species)
References
- Bacescu, M. Bodotriidae is a family of Crustaceans belonging to the order Cumacea. Ceratocumatidae is one of the eight most commonly recognised families of Crustaceans of the order Cumacea. William Thomas Calman ( December 29 1871 - September 29 1952) was a Scottish Zoologist, specialising in the Crustacea Diastylidae is one of the eight most commonly recognised families of Crustaceans of the order Cumacea. Charles Spence Bate, or Spence Bate, FRS ( March 16 1819 - July 29 1889) was a British Zoologist and Gynodiastylidae is one the eight most commonly recognised families of Crustaceans of the order Cumacea. Thomas Roscoe Rede Stebbing ( February 6, 1835, London &ndash July 8, 1926, Tunbridge Wells) was a British Lampropidae is a family of cold-water Crustaceans belonging to the order Cumacea. Georg Ossian Sars ( April 20 1837 - April 9 1927) was a Norwegian marine biologist Leuconidae is a family of Crustaceans belonging to the order Cumacea. Nannastacidae is a family of Crustaceans belonging to the order Cumacea. Pseudocumatidae are a family of Crustaceans of the order Cumacea. , (1988). Cumacea I. Crustaceorum Catalogus 7:1-173.
- Bacescu, M. , (1992). Cumacea II. Crustaceorum Catalogus 8:175-468.
- Brusca, R. & G. Brusca, (2003). Invertebrates. Sunderland, Massachusetts: Sinauer Associates, Inc. .
- Day, J. , (1980). Southern African Cumacea. Pt. 4. Families Gynodiastylidae and Diastylidae. Annals of the South African Museum 82:187-292.
- Jones, N. S. , (1963). The marine fauna of New Zealand: Crustaceans of the Order Cumacea. New Zealand Oceanographic Institute, Memoir 23:1-80.
- Jones, N. S. , (1976). British Cumaceans. Synopses of the British Fauna No. 7, Academic Press.
- Watling, L. , (1979). Marine flora and fauna of the Northeastern United States. Crustacea: Cumacea. NOAA Technical Report NMFS Circular 423:1-22.
External links
Extensive literature list on Cumaceans A, (1995 Circatidal swimming activity rhythm in a subtidal cumacean Dimorphostylis asiatica (Crustacea
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