Nematocarcinus

”Nematocarcinus” has a number of [[Autapomorphy|diagnostic characters]], such as the shape and teeth of the [[Rostrum (anatomy)#Invertebrates|rostrum]], the shape of the third [[abdominal]] [[tergite]], the shape of the fifth abdominal pleura along with short protuberances or a ridge on the inner surface of its anterior margin, the accessory teeth of the [[telson]], and the ventral margin of the sixth abdominal [[somite]] (the [[wikt:distoventral|distoventral]] organ) along with its associated [[seta]]e. Another notable trait is their “mud shoes”; the long and slender pereopods possess tufts of long setae at the dactyls, which presumably helps distribute their weight over the [[pelagic sediment]]. In general, the bodies of these shrimp are rather delicate, and [[Zoological specimen|specimens]] are often damaged when collected by traditional methods such as [[trawling]].<ref>{{cite journal |last1=Cardoso |first1=Irene A. |last2=Burukovsky |first2=Rudolf N. |title=Nematocarcinus Milne Edwards, 1881 (Crustacea, Decapoda) from Southwestern Atlantic, including the Southern Mid-Atlantic Ridge area |journal=Zootaxa |date=26 November 2014 |volume=3887 |issue=3 |pages=437–458 |doi=10.11646/zootaxa.3887.4.3 |pmid=25543942 |url=https://www.mapress.com/zootaxa/2014/f/z03887p458f.pdf |access-date=20 November 2025}}</ref><ref name=”MexPac”/>

”Nematocarcinus” has a number of [[Autapomorphy|diagnostic characters]], such as the shape and teeth of the [[Rostrum (anatomy)#Invertebrates|rostrum]], the shape of the third [[abdominal]] [[tergite]], the shape of the fifth abdominal pleura along with short protuberances or a ridge on the inner surface of its anterior margin, the accessory teeth of the [[telson]], and the ventral margin of the sixth abdominal [[somite]] (the [[wikt:distoventral|distoventral]] organ) along with its associated [[seta]]e. Another notable trait is their “mud shoes”; the long and slender pereopods possess tufts of long setae at the dactyls, which presumably helps distribute their weight over the [[pelagic sediment]]. In general, the bodies of these shrimp are rather delicate, and [[Zoological specimen|specimens]] are often damaged when collected by traditional methods such as [[trawling]].<ref>{{cite journal |last1=Cardoso |first1=Irene A. |last2=Burukovsky |first2=Rudolf N. |title=Nematocarcinus Milne Edwards, 1881 (Crustacea, Decapoda) from Southwestern Atlantic, including the Southern Mid-Atlantic Ridge area |journal=Zootaxa |date=26 November 2014 |volume=3887 |issue=3 |pages=437–458 |doi=10.11646/zootaxa.3887.4.3 |pmid=25543942 |url=https://www.mapress.com/zootaxa/2014/f/z03887p458f.pdf |access-date=20 November 2025}}</ref><ref name=”MexPac”/>

These shrimp are inhabitants of the [[deep sea]], with some species living at over {{convert|2500|m|abbr=on}} deep,<ref name=”Cali”/><ref name=”NOAA”>[https://archive.oceanexplorer.noaa.gov/okeanos/explorations/ex1803/logs/photolog/welcome.html#cbpi=/okeanos/explorations/ex1803/dailyupdates/media/apr17-3.html Gulf of Mexico 2018: Image and Video Gallery]</ref> and up to {{convert|5000|m|abbr=on}} deep on the [[abyssal plain]]s.<ref>Burukovsky, R.N. (2012) Deep sea shrimps of the family Nematocarcinidae (history of study, systematic, distribution, and biology). Prospekt nauki. St. Petersburg, 287 pp. [In Russian with English abstract]</ref> They may sometimes occur around [[hydrothermal vent]]s.<ref>Komai, T. & Collins, P. (2009) Two species of caridean shrimps (Decapoda: Hippolytidae and Nematocarcinidae) newly recorded from hydrothermal vents on the Manus Basin, southwestern Pacific. Crustacean Research, 38, 28–41.</ref> In some regions, such as the [[Pacific Coast of Mexico]], ”Nematocarcinus” may be locally abundant; up to 500 shrimp per [[hectare]].<ref name=”Cali”/><ref name=”MexPac”>{{cite journal |last1=Hernandez-Payan |first1=J.C. |last2=Hendrickx |first2=M.E. |title=Two species of the deep-water shrimp genus Nematocarcinus A. Milne–Edwards, 1881 (Crustacea, Decapoda, Caridea, Nematocarcinidae) from the Mexican Pacific |journal=Zootaxa |date=21 June 2016 |volume=4126 |issue=4 |pages=587–599 |doi=10.11646/zootaxa.4126.4.9 |url=https://www.vliz.be/imisdocs/publications/ocrd/300481.pdf}}</ref> Members of this genus are very tolerant of [[Hypoxia (environmental)|hypoxic]] conditions (low [[dissolved oxygen]] content).<ref name=”Cali”/><ref name=”MexPac”/> Other than [[the Americas]],<ref name=”NOAA”/><ref>{{cite book |title=Annotated catalogue and bibliography of marine and estuarine shrimps, lobsters, crabs and their allies (Crustacea: Decapoda) of Argentina and Uruguay (Southwestern Atlantic Ocean) |date=April 2019 |publisher=Comisión Técnica Mixta del Frente Marítimo |url=https://www.researchgate.net/publication/332768059}}</ref> ”Nematocarcinus” is also known from the southern [[Indian Ocean]],<ref>{{cite journal |last1=Burukovsky |first1=R.N. |last2=Pakhomov |first2=E.A. |title=A new record of the shrimp Nematocarcinus romenskyi (Decapoda: Nematocarcinidae) in the vicinity of the Prince Edward Islands, south Indian Ocean |journal=Marine Biodiversity Records |date=2009 |volume=2 |article-number=e107 |doi=10.1017/S1755267209001249 |bibcode=2009MBdR….2E.107B }}</ref> [[South-Western Pacific]],<ref>{{cite journal |last1=Komai |first1=Tomoyuki |last2=Collins |first2=Patrick |title=Two species of caridean shrimps (Decapoda: Hippolytidae and Nematocarcinidae) newly recorded from hydrothermal vents on the Manus Basin, southwestern Pacific |journal=Crustacean Research |date=January 2009 |volume=38 |pages=28–41 |doi=10.18353/crustacea.38.0_28}}</ref><ref>{{cite journal |last1=Farrelly |first1=Caroline A. |last2=Ahyong |first2=Shane T. |title=Deepwater decapod, stomatopod and lophogastrid Crustacea from Eastern Australia and the Great Australian Bight collected in 2015–2017: preliminary identifications of 191 species |journal=Museum Victoria Science Reports |date=January 2019 |volume=21 |pages=1–97 |doi=10.24199/j.mvsr.2019.21 |issn=1833-0290}}</ref> [[North-Western Pacific]],<ref>{{cite journal |last1=Gan |first1=Zhibin |last2=Li |first2=Xinzheng |title=First records of three Nematocarcinus species (Crustacea, Decapoda, Nematocarcinidae) in the deep-waters of the north-western Pacific |journal=Biodiversity Data Journal |date=7 November 2022 |volume=10 |article-number=e95101 |doi=10.3897/BDJ.10.e95101 |pmid=36761602 |pmc=9836412 |doi-access=free }}</ref><ref>{{cite journal |title=Additional records of deep-water shrimps (Crustacea, Decapoda, Dendrobranchiata and Caridea) from off Northeastern Japan |journal=Bull. Natl. Mus. Nat. Sci., Ser. A |date=22 February 2016 |volume=42 |issue=1 |pages=23–48}}</ref> and the [[Southern Ocean]].<ref>{{cite journal |last1=Basher |first1=Zeenatul |last2=Costello |first2=Mark J. |title=The past, present and future distribution of a deep-sea shrimp in the Southern Ocean |journal=PeerJ |date=23 February 2016 |volume=4 |article-number=e1713 |doi=10.7717/peerj.1713 |pmid=26925334 |pmc=4768674 |bibcode=2016PeerJ…4e1713B |doi-access=free }}</ref><ref>{{cite journal |last1=Dambach |first1=Johannes |last2=Raupach |first2=Michael J. |last3=Mayer |first3=Christoph |last4=Schwarzer |first4=Julia |last5=Leese |first5=Florian |title=Isolation and characterization of nine polymorphic microsatellite markers for the deep- sea shrimp Nematocarcinus lanceopes (Crustacea: Decapoda: Caridea) |journal=BMC Research Notes |date=September 2013 |volume=6 |issue=75 |article-number=75 |doi=10.1186/1756-0500-6-75 |pmid=23448502 |doi-access=free |url=https://www.researchgate.net/publication/256428081 |access-date=20 November 2025}}</ref>

These shrimp are inhabitants of the [[deep sea]], with some species living at over {{convert|2500|m|abbr=on}} deep,<ref name=”Cali”/><ref name=”NOAA”>[https://archive.oceanexplorer.noaa.gov/okeanos/explorations/ex1803/logs/photolog/welcome.html#cbpi=/okeanos/explorations/ex1803/dailyupdates/media/-3.html Gulf of Mexico 2018: Image and Video Gallery]</ref> and up to {{convert|5000|m|abbr=on}} deep on the [[abyssal plain]]s.<ref>Burukovsky, R.N. (2012) Deep sea shrimps of the family Nematocarcinidae (history of study, systematic, distribution, and biology). Prospekt nauki. St. Petersburg, 287 pp. [In Russian with English abstract]</ref> They may sometimes occur around [[hydrothermal vent]]s.<ref>Komai, T. & Collins, P. (2009) Two species of caridean shrimps (Decapoda: Hippolytidae and Nematocarcinidae) newly recorded from hydrothermal vents on the Manus Basin, southwestern Pacific. Crustacean Research, 38, 28–41.</ref> In some regions, such as the [[Pacific Coast of Mexico]], ”Nematocarcinus” may be locally abundant; up to 500 shrimp per [[hectare]].<ref name=”Cali”/><ref name=”MexPac”>{{cite journal |last1=Hernandez-Payan |first1=J.C. |last2=Hendrickx |first2=M.E. |title=Two species of the deep-water shrimp genus Nematocarcinus A. Milne–Edwards, 1881 (Crustacea, Decapoda, Caridea, Nematocarcinidae) from the Mexican Pacific |journal=Zootaxa |date=21 June 2016 |volume=4126 |issue=4 |pages=587–599 |doi=10.11646/zootaxa.4126.4.9 |url=https://www.vliz.be/imisdocs/publications/ocrd/300481.pdf}}</ref> Members of this genus are very tolerant of [[Hypoxia (environmental)|hypoxic]] conditions (low [[dissolved oxygen]] content).<ref name=”Cali”/><ref name=”MexPac”/> Other than [[the Americas]],<ref name=”NOAA”/><ref>{{cite book |title=Annotated catalogue and bibliography of marine and estuarine shrimps, lobsters, crabs and their allies (Crustacea: Decapoda) of Argentina and Uruguay (Southwestern Atlantic Ocean) |date=April 2019 |publisher=Comisión Técnica Mixta del Frente Marítimo |url=https://www.researchgate.net/publication/332768059}}</ref> ”Nematocarcinus” is also known from the southern [[Indian Ocean]],<ref>{{cite journal |last1=Burukovsky |first1=R.N. |last2=Pakhomov |first2=E.A. |title=A new record of the shrimp Nematocarcinus romenskyi (Decapoda: Nematocarcinidae) in the vicinity of the Prince Edward Islands, south Indian Ocean |journal=Marine Biodiversity Records |date=2009 |volume=2 |article-number=e107 |doi=10.1017/S1755267209001249 |bibcode=2009MBdR….2E.107B }}</ref> [[South-Western Pacific]],<ref>{{cite journal |last1=Komai |first1=Tomoyuki |last2=Collins |first2=Patrick |title=Two species of caridean shrimps (Decapoda: Hippolytidae and Nematocarcinidae) newly recorded from hydrothermal vents on the Manus Basin, southwestern Pacific |journal=Crustacean Research |date=January 2009 |volume=38 |pages=28–41 |doi=10.18353/crustacea.38.0_28}}</ref><ref>{{cite journal |last1=Farrelly |first1=Caroline A. |last2=Ahyong |first2=Shane T. |title=Deepwater decapod, stomatopod and lophogastrid Crustacea from Eastern Australia and the Great Australian Bight collected in 2015–2017: preliminary identifications of 191 species |journal=Museum Victoria Science Reports |date=January 2019 |volume=21 |pages=1–97 |doi=10.24199/j.mvsr.2019.21 |issn=1833-0290}}</ref> [[North-Western Pacific]],<ref>{{cite journal |last1=Gan |first1=Zhibin |last2=Li |first2=Xinzheng |title=First records of three Nematocarcinus species (Crustacea, Decapoda, Nematocarcinidae) in the deep-waters of the north-western Pacific |journal=Biodiversity Data Journal |date=7 November 2022 |volume=10 |article-number=e95101 |doi=10.3897/BDJ.10.e95101 |pmid=36761602 |pmc=9836412 |doi-access=free }}</ref><ref>{{cite journal |title=Additional records of deep-water shrimps (Crustacea, Decapoda, Dendrobranchiata and Caridea) from off Northeastern Japan |journal=Bull. Natl. Mus. Nat. Sci., Ser. A |date=22 February 2016 |volume=42 |issue=1 |pages=23–48}}</ref> and the [[Southern Ocean]].<ref>{{cite journal |last1=Basher |first1=Zeenatul |last2=Costello |first2=Mark J. |title=The past, present and future distribution of a deep-sea shrimp in the Southern Ocean |journal=PeerJ |date=23 February 2016 |volume=4 |article-number=e1713 |doi=10.7717/peerj.1713 |pmid=26925334 |pmc=4768674 |bibcode=2016PeerJ…4e1713B |doi-access=free }}</ref><ref>{{cite journal |last1=Dambach |first1=Johannes |last2=Raupach |first2=Michael J. |last3=Mayer |first3=Christoph |last4=Schwarzer |first4=Julia |last5=Leese |first5=Florian |title=Isolation and characterization of nine polymorphic microsatellite markers for the deep- sea shrimp Nematocarcinus lanceopes (Crustacea: Decapoda: Caridea) |journal=BMC Research Notes |date=September 2013 |volume=6 |issue=75 |article-number=75 |doi=10.1186/1756-0500-6-75 |pmid=23448502 |doi-access=free |url=https://www.researchgate.net/publication/256428081 |access-date=20 November 2025}}</ref>

Females may be highly fecund, with records of up to 15500 eggs carried by a female ”N. ensifer”, though species such as ”N. lanceopes” carry only 2400.<ref name=”Cali”>{{cite journal |last1=Hendrickx |first1=Michel E. |last2=Hernández-Payán |first2=José Carlos |title=Distribution and abundance of Nematocarcinus spp. (Crustacea: Decapoda: Caridea: Nematocarcinidae) off western Mexico, eastern Pacific |journal=Regional Studies in Marine Science |date=September 2018 |volume=23 |pages=47–52 |doi=10.1016/j.rsma.2017.10.012 |bibcode=2018RSMS…23…47H }}</ref>

Females may be highly fecund, with records of up to 15500 eggs carried by a female ”N. ensifer”, though species such as ”N. lanceopes” carry only 2400.<ref name=”Cali”>{{cite journal |last1=Hendrickx |first1=Michel E. |last2=Hernández-Payán |first2=José Carlos |title=Distribution and abundance of Nematocarcinus spp. (Crustacea: Decapoda: Caridea: Nematocarcinidae) off western Mexico, eastern Pacific |journal=Regional Studies in Marine Science |date=September 2018 |volume=23 |pages=47–52 |doi=10.1016/j.rsma.2017.10.012 |bibcode=2018RSMS…23…47H }}</ref>