Mysida

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Mysida
Hemimysis anomala GLERL 4.jpg
Hemimysis anomala (Mysidae)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Superorder: Peracarida
Order: Mysida
Boas, 1883 [1]
Families

Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in this pouch and are not free-swimming characterises the order. The mysid's head bears a pair of stalked eyes and two pairs of antennae. The thorax consists of eight segments each bearing branching limbs, the whole concealed beneath a protective carapace and the abdomen has six segments and usually further small limbs.

Contents

Mysids are found throughout the world in both shallow and deep marine waters where they can be benthic or pelagic, but they are also important in some fresh water and brackish ecosystems. Many benthic species make daily vertical migrations into higher parts of the water column. Mysids are filter feeders, omnivores that feed on algae, detritus and zooplankton. Some mysids are cultured in laboratories for experimental purposes and are used as a food source for other cultured marine organisms. They are sensitive to water pollution, so are sometimes used as bioindicators to monitor water quality.

Description

The head of a mysid bears two pairs of antennae and a pair of large, stalked eyes. The head and first segment (or sometimes the first three segments) of the thorax are fused to form the cephalothorax. The eight thoracic segments are covered by the carapace which is attached only to the first three. The first two thoracic segments bear maxillipeds which are used to filter plankton and organic particulate from the water. The other six pairs of thoracic appendages are biramous (branching) limbs known as pereopods, and are used for swimming, as well as for wafting water towards the maxillipeds for feeding. Unlike true shrimps (Caridea), females have a marsupium beneath the thorax. This brood pouch is enclosed by the large, flexible oostegites, bristly flaps which extend from the basal segments of the pereopods and which form the floor of a chamber roofed by the animal's sternum. This chamber is where the eggs are brooded, development being direct in most cases. [2]

The abdomen has six segments, the first five of which bear pleopods, although these may be absent or vestigial in females. The fourth pleopod is longer than the others in males and has a specialized reproductory function. [2]

The majority of species are 5–25 mm (0.2–1.0 in) long, and vary in colour from pale and transparent, through to bright orange or brown. They differ from other species within the superorder Peracarida by featuring statocysts on their uropods (located on the last abdominal segment). These help the animal orient itself in the water and are clearly seen as circular vesicles: together with the pouch the statocysts are often used as features that distinguish mysids from other shrimp-like organisms. [3]

Distribution

Mysids have a cosmopolitan distribution and are found in both marine and freshwater environments, the deep sea, estuaries, shallow coastal waters, lakes, rivers and underground waters. They are primarily marine and fewer than ten percent are found in freshwater. There are about 72 freshwater species in total, being predominantly found in the Palearctic and Neotropical realms. These non-marine mysids occur in four distinct types of habitats; some are estuarine species; some were isolated in the Ponto-Caspian Basin where Paramysis has since radiated enormously (23 species); some are glacial relicts and some are subterranean Tethyan relicts. [4]

Behavior

Mysis relicta Mysis relicta..jpg
Mysis relicta

Some species are benthic (living on the seabed) and others pelagic (living in mid-water), but most are found close to, crawling on or burrowing into the mud or sand. Most marine species are benthic by day but leave the seabed at night to become planktonic. Locomotion is mostly by swimming, the pleopods being used for this purpose. Some mysids live among algae and seagrasses, some are solitary while many form dense swarms. Mysids form an important part of the diet of such fish as shad and flounder. [2] In general, they are free-living, but a few species, mostly in the subfamily Heteromysinae, are commensal and are associated with sea anemones and hermit crabs. [5] Several taxa have also been described from different freshwater habitats and caves. [5] Mysis relicta and its close relatives inhabit cold, deep lakes and have a diurnal cycle of vertical migrations. [6] The species Mysidium integrum has a mutualistic relationship with longfin damselfish, the shrimp providing nutrients for the algae farms the fish feed on and the fish providing protection from predators. [7] [8]

The majority of Mysida are omnivores, feeding on algae, detritus, and zooplankton. Scavenging and cannibalism are also common, with the adults sometimes preying on their young once they emerge from the marsupium. [3] The pelagic and most other species are filter feeders, creating a feeding current with the exopods of their pereopods. This wafts food particles into a ventral food groove along which they are passed before being filtered by setae (bristles) on the second maxillae. Larger planktonic prey can be caught in a trap composed of the endopods of the thoracic appendages. [2] Some benthic species, especially members of the subfamily Erythropinae, have been observed feeding on small particles which they collected by grooming the surfaces of their bodies and legs. [5]

Neomysis integer Brackwasserkrebs, Spaltfusskrabbe (Mysis vulgaris).jpg
Neomysis integer

Individual mysids are either male or female, and fertilisation is external. The gonads are in the thorax and are tubular in shape. Males have two gonopores in the eighth thoracic segment and a pair of long penises. The female gonopores are in the sixth thoracic segment and the oostegites are attached to the first to seventh pereopods to form a brood pouch. [2] Mating usually takes place at night and lasts only a few minutes. [3] During the process, the male inserts his penises into the marsupium and releases sperm. This stimulates the female and the eggs are usually released into the marsupium within an hour. Here they are fertilised and retained, development of the embryos in the brood pouch being direct with the young hatching from the eggs as miniature adults. [2] The size of a mysid brood generally correlates with body length and environmental factors such as density and food availability. [9] The age at which mysids reach sexual maturity depends on water temperature and food availability. [9] [10] [11] For the species Mysidopsis bahia , this is normally at 12 to 20 days. [11] The young are released soon afterwards, and although their numbers are usually low, the short reproductive cycle of mysid adults means a new brood can be produced every four to seven days. [3] [11] [12]

Uses

Some species of mysids are easy to culture on a large scale in the laboratory as they are highly adaptive, and can tolerate a wide range of conditions. Despite low fecundity, these species have a short reproductive cycle which means they can quickly reproduce in vast numbers. [3] [12] They can be cultured in static or flow-through systems, the latter having been shown to be able to maintain a higher stocking density than a static system. [13] In flow-through systems, juvenile mysids are continuously separated from the adult brood stock in order to reduce mortality due to cannibalism. [9] Artemia (brine shrimp) juveniles (incubated for 24 hours) are the most common food in mysid cultures, sometimes enriched with highly unsaturated fatty acids to increase their nutritional value. [9]

Cultured mysids are thought to provide an ideal food source for many marine organisms. They are often fed to cephalopods, fish larvae, and commercial farmed shrimp due to their small size and low cost. [9] [14] [15] [16] Their high protein and fat content also makes them a good alternative to live enriched Artemia when feeding juveniles (especially those that are difficult to maintain such as young seahorses) and other small fauna. [15] [16]

Their sensitivity to water quality also makes them suitable for bioassays. Americamysis bahia and Americamysis almyra are frequently used to test for pesticides and other toxic substances, with A. bahia found to be more sensitive during the periods when it is moulting. [17]

Systematics

The Mysida belong to the superorder Peracarida, which means “near to shrimps”. Although in many respects mysids appear similar to some shrimps, the main characteristic separating them from the superorder Eucarida is their lack of free-swimming larvae. [3] The order Mysida is extensive and currently includes approximately 160 genera, containing more than 1000 species. [5]

Traditionally, Mysida were united with another, externally similar group of pelagic crustaceans, the Lophogastrida, into a broader order Mysidacea, but that classification is generally abandoned at present. [1] [18] [19] [20] [21] While the previous grouping had good morphological support, molecular studies do not corroborate the monophyly of this group. [22] Previously Mysida included two other families, Lepidomysidae and Stygiomysidae, but these have now been placed in a separate order, Stygiomysida. [22]

Classification

Related Research Articles

<span class="mw-page-title-main">Malacostraca</span> Largest class of crustaceans

Malacostraca is the second largest of the six classes of crustaceans just behind hexapods, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, amphipods, mantis shrimp, tongue-eating lice and many other less familiar animals. They are abundant in all marine environments and have colonised freshwater and terrestrial habitats. They are segmented animals, united by a common body plan comprising 20 body segments, and divided into a head, thorax, and abdomen.

<span class="mw-page-title-main">Isopoda</span> Order of arthropods

Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax.

<span class="mw-page-title-main">Eucarida</span> Superorder of crustaceans

Eucarida is a superorder of the Malacostraca, a class of the crustacean subphylum, comprising the decapods, krill, and Angustidontida. They are characterised by having the carapace fused to all thoracic segments, and by the possession of stalked eyes.

<span class="mw-page-title-main">Lophogastrida</span> Order of crustaceans

Lophogastrida is an order of malacostracan crustaceans in the superorder Peracarida, comprising shrimp-like animals that mostly inhabit the relatively deep pelagic waters of the oceans throughout the world.

<span class="mw-page-title-main">Peracarida</span> Order of crustaceans

The superorder Peracarida is a large group of malacostracan crustaceans, having members in marine, freshwater, and terrestrial habitats. They are chiefly defined by the presence of a brood pouch, or marsupium, formed from thin flattened plates (oostegites) borne on the basalmost segments of the legs. Peracarida is one of the largest crustacean taxa and includes about 12,000 species. Most members are less than 2 cm (0.8 in) in length, but the largest is probably the giant isopod which can reach 76 cm (30 in). The earliest known perecaridian was Oxyuropoda ligioides, a fossil of which has been found dating to the Late Devonian of Ireland.

<span class="mw-page-title-main">Cumacea</span> Order of crustacean

Cumacea is an order of small marine crustaceans of the superorder Peracarida, occasionally called hooded shrimp or comma shrimp. Their unique appearance and uniform body plan makes them easy to distinguish from other crustaceans. They live in soft-bottoms such as mud and sand, mostly in the marine environment. There are more than 1,500 species of cumaceans formally described. The species diversity of Cumacea increases with depth.

<i>Hemimysis anomala</i> Species of crustacean

The bloody-red mysid, Hemimysis anomala, is a shrimp-like crustacean in the Mysida order, native to the Ponto-Caspian region, which has been spreading across Europe since the 1950s. In 2006, it was discovered to have invaded the North American Great Lakes.

<i>Mysis relicta</i> Species of crustacean

Mysis relicta is a shrimp-like crustacean in the Mysida order, native to lakes of Northern Europe and to the brackish Baltic Sea.

<i>Mysis diluviana</i> Species of crustacean

Mysis diluviana is a mysid crustacean found in freshwater lakes of northern North America.

<span class="mw-page-title-main">Mysidacea</span> Group of crustaceans

The Mysidacea is a group of shrimp-like crustaceans in the superorder Peracarida, comprising the two extant orders Mysida and Lophogastrida and the prehistoric Pygocephalomorpha. Current data indicate that despite their external similarities, the three orders are not closely related, and the taxon Mysidacea is not used in modern taxonomy.

Phylogeny of Malacostraca is the evolutionary relationships of the largest of the six classes of crustaceans, containing about 40,000 living species, divided among 16 orders. Its members display a great diversity of body forms. Although the class Malacostraca is united by a number of well-defined and documented features, which were recognised a century ago by William Thomas Calman in 1904, the phylogenetic relationship of the orders which compose this class is unclear due to the vast diversity present in their morphology. Molecular studies have attempted to infer the phylogeny of this clade, resulting in phylogenies which have a limited amount of morphological support. To resolve a well-supported eumalacostracan phylogeny and obtain a robust tree, it will be necessary to look beyond the most commonly utilized sources of data.

<i>Praunus flexuosus</i> Species of crustacean

Praunus flexuosus, known as the chameleon shrimp, is a species of opossum shrimp found in European waters. It reaches 26 mm (1.0 in) long, with a distinctly bent body, and closely resembles Praunus neglectus. It lives in shallow water and tolerates a wide range of salinities. It is found from northern France to the Baltic Sea, and was introduced to North America in the mid 20th century.

An oostegite is a large, flexible plate-like flap extending medially from the coxae of the pereiopods in some female crustaceans. It forms part of the marsupium or brood pouch of members of the superorder Peracarida, from the class Malacostraca.

Petalophthalmidae is a family of marine crustaceans in the order Mysida, the opossum shrimps.

Americamysis bahia is a shrimp-like crustacean in the order Mysida, the opossum shrimps. It is native to estuarine waters in Texas and Florida in the United States. It is often referred to in the literature as Mysidopsis bahia and is widely cultured and used in the laboratory for toxicology testing.

<i>Gastrosaccus spinifer</i> Species of crustacean

Gastrosaccus spinifer is a shrimp-like crustacean in the order Mysida, the opossum shrimps, native to the eastern Atlantic Ocean and the coasts of Northern and Western Europe.

Prodajus ostendensis is a species of marine isopod in the family Dajidae and is found in the North Sea. It is an ectoparasite of the opossum shrimp Gastrosaccus spinifer. It is normally found living in the host's marsupium and devouring its eggs.

<i>Heteromysis</i> Genus of crustaceans


Heteromysis is a genus of marine mysid crustaceans from the family Mysidae, associated with various shallow-water invertebrates. The name describes differentiation of its pereiopods as possible adaptation to commensal life-style. Heteromysis is one of the largest mysid genera, containing more than 100 species. The genus is distributed globally, but predominantly in tropical and subtropical waters.

Neobirsteiniamysis inermis is a deepwater mysid crustacean species of the genus Neobirsteiniamysis. One of the largest and the only known mysid, distributed in both polar regions.

Boreomysinae is a subfamily of large, mostly deep-water oceanic mysid crustaceans from the family Mysidae. The name, which can be translated as "northern mysids", comes from the genus Boreomysis G.O. Sars, 1869, established for Boreomysis arctica from the boreal waters of Atlantic. As more species have been discovered subsequently, the subfamily is considered panoceanic, and includes 38 species from two genera, Boreomysis and Neobirsteiniamysis Hendrickx et Tchindonova, 2020.

References

  1. 1 2 Mees, J. (2013). "Mysida". WoRMS. World Register of Marine Species . Retrieved 2014-01-30.
  2. 1 2 3 4 5 6 Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 652–654. ISBN   978-81-315-0104-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. 1 2 3 4 5 6 Mauchline, J. (1980). Blaxter, J. H. S.; Russell, F. S.; Yonge, M. (eds.). The Biology of Mysids and Euphausiids. Advances in Marine Biology: Volume 18. Academic Press. ISBN   978-0-08-057941-2.
  4. ↑ Porter, Megan L.; Meland, Kenneth; Price, Wayne (2008). "Global diversity of mysids (Crustacea-Mysida) in freshwater". Developments in Hydrobiology. 198: 213–218. doi:10.1007/978-1-4020-8259-7_23. ISBN   978-1-4020-8258-0.
  5. 1 2 3 4 Meland, Kenneth (October 2, 2000). "Mysidacea: Families, Subfamilies and Tribes". Australian Museum . Retrieved 2010-09-07.
  6. ↑ Audzijonytė, Asta; Väinölä, Risto (2005). "Diversity and distributions of circumpolar fresh- and brackish-water Mysis (Crustacea: Mysida): descriptions of M. relicta Lovén, 1862, M. salemaai n.sp., M. segerstralei n.sp. and M. diluviana n.sp., based on molecular and morphological characters". Hydrobiologia. 544 (1): 89–141. doi:10.1007/s10750-004-8337-7. S2CID   20925048.
  7. ↑ "We found algae-farming fish that domesticate tiny shrimp to help run their farms". 2020-12-08.
  8. ↑ Brooker, Rohan M.; Casey, Jordan M.; Cowan, Zara-Louise; Sih, Tiffany L.; Dixson, Danielle L.; Manica, Andrea; Feeney, William E. (2020). "Domestication via the commensal pathway in a fish-invertebrate mutualism". Nature Communications. 11 (1): 6253. Bibcode:2020NatCo..11.6253B. doi: 10.1038/s41467-020-19958-5 . PMC   7721709 . PMID   33288750. S2CID   227948531.
  9. 1 2 3 4 5 Domingues, P. M.; Turk, P. E.; Andrade, J. P.; Lee, P. G. (1999). "Culture of the mysid, Mysidopsis almyra (Bowman), (Crustacea: Mysidacea) in a static water system: effects of density and temperature on production, survival and growth". Aquaculture Research . 30 (2): 135–143. doi: 10.1046/j.1365-2109.1999.00309.x .
  10. ↑ Sudo, H. (2003). "Effect of temperature on growth, sexual maturity and reproduction of Acanthomysis robusta (Crustacea: Mysidacea) reared in the laboratory". Marine Biology . 143 (6): 1095–1107. doi:10.1007/s00227-003-1160-2. S2CID   83480469.
  11. 1 2 3 Culturing Mysidopsis bahia. Supplemental Report. EPA 505/8-90-006b. Environmental Protection Agency. 1990.
  12. 1 2 Domingues, Pedro M.; Turk, Philip E.; Andrade, Jose P.; Lee, Philip G. (1998). "Pilot-scale production of mysid shrimp in a static water system". Aquaculture International . 6 (5): 387–402. doi:10.1023/A:1009232921784. S2CID   37703503.
  13. ↑ Lussier, Suzanne M.; Kuhn, Anne; Chammas, Melissa J.; Sewall, John (1988). "Techniques for the laboratory culture of Mysidopsis species (Crustacea: Mysidacea)". Environmental Toxicology and Chemistry . 7 (12): 969–977. doi:10.1002/etc.5620071203.
  14. ↑ Woods, Chris M. C. (2005). "Growth of cultured seahorses (Hippocampus abdominalis) in relation to feed ration". Aquaculture International. 13 (4): 305–314. doi:10.1007/s10499-004-3100-7. S2CID   42514195.
  15. 1 2 Woods, Chris M. C.; Valentino, Fiamma (2003). "Frozen mysids as an alternative to live Artemia in culturing seahorses Hippocampus abdominalis" (PDF). Aquaculture Research. 34 (9): 757–763. doi:10.1046/j.1365-2109.2003.00882.x.
  16. 1 2 Vidal, E. A. G.; DiMarco, F. P.; Wormuth, J. H.; Lee, P. G. (2002). "Optimizing rearing conditions of hatchling loliginid squid". Marine Biology . 140: 117–127. doi:10.1007/s002270100683. S2CID   85108374.
  17. ↑ Nimmo, D. R.; Hamaker, T. L. (1982). "Mysids in toxicity testing – a review". Hydrobiologia . 93 (1–2): 171–178. doi:10.1007/BF00008110. S2CID   44057913.
  18. ↑ Brusca, R.; Brusca, G. (2003). Invertebrates. Sunderland, Massachusetts: Sinauer Associates
  19. ↑ Martin, Joel W.; Davis, George E. (2001). An Updated Classification of the Recent Crustacea (PDF). Natural History Museum of Los Angeles County.
  20. ↑ Peracarida fact sheet - Guide to the marine zooplankton of south eastern Australia Archived 2011-10-04 at the Wayback Machine
  21. ↑ Anderson, Gary (2010-01-20): Peracarida Taxa and Literature (Cumacea, Lophogastrida, Mysida, Stygiomysida and Tanaidacea) Archived 2010-01-24 at the Wayback Machine
  22. 1 2 Meland, K.; Willassen, E. (2007). "The disunity of "Mysidacea" (Crustacea)" (PDF). Molecular Phylogenetics and Evolution . 44 (3): 1083–1104. doi:10.1016/j.ympev.2007.02.009. PMID   17398121.
  23. ↑ Mees, J. (2013). "Mysidae Haworth, 1825". WoRMS. World Register of Marine Species . Retrieved 2014-01-30.
  24. ↑ Mees, J. (2013). "Petalophthalmidae Czerniavsky, 1882". WoRMS. World Register of Marine Species . Retrieved 2014-01-30.
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