{{Short description|Genus of priapulid worms}} {{Automatic taxobox | image = Halicryptus spinulosus 1.JPEG | image_caption = ''Halicryptus spinulosus'' | taxon = Halicryptus | authority = von Siebold, 1849 }}
'''''Halicryptus''''' is the sole genus of its class of priapulid worms,<ref name="Shirley1999">{{Cite journal| last1 = Shirley | first1 = T. C. | last2 = Storch | first2 = V. | title = Halicryptus higginsi n.sp. (Priapulida): A Giant New Species from Barrow, Alaska | jstor = 3227009 | journal = Invertebrate Biology | volume = 118 | issue = 4 | pages = 404–413 | year = 1999 | doi = 10.2307/3227009 | bibcode = 1999InvBi.118..404S }}</ref> and has an important effect on the structure of soft-sediment communities.<ref name="Aarnio1998">{{Cite journal | last1 = Aarnio | first1 = K. | last2 = Bonsdorff | first2 = E. | last3 = Norkko | first3 = A. | title = Role of Halicryptus spinulosus (Priapulida) in structuring meiofauna and settling macrofauna | doi = 10.3354/meps163145 | journal = Marine Ecology Progress Series | volume = 163 | pages = 145–153 | year = 1998 | bibcode = 1998MEPS..163..145A | doi-access = free }}</ref>
This genus contains the following species: * ''Halicryptus higginsi'' * ''Halicryptus spinulosus'' - type species
''Halicryptus spinulosus'' exhibits a wide distribution around the Arctic Ocean and can reach lengths of 4 cm as adults, while the distribution of ''Halicryptus higginsi'' appears to be restricted to the Beaufort Sea near Point Barrow, and can grow to about 40 cm, the largest known priapulids, even if 20 cm long adults are more common.<ref>{{cite journal | last1=Raeker | first1=Jan | last2=Worsaae | first2=Katrine | last3=Schmidt-Rhaesa | first3=Andreas | title=David versus Goliath: An interspecific comparison between small-sized Halicryptus spinulosus and large-sized Halicryptus higginsi (Priapulida) | journal=Zoologischer Anzeiger | date=2024 | volume=313 | page=1 | doi=10.1016/j.jcz.2024.08.003 | bibcode=2024ZooAn.313....1R | url=https://www.sciencedirect.com/science/article/pii/S0044523124000755 | doi-access=free }}</ref>
== Halicryptus spinulosus== Halicryptus spinulosus is a species of priapulid worm found in marine environments. It is a macrobenthic priapulid living in disjunct subarctic brackish seas, including the White Sea, waters off Iceland, northern Siberia and Alaska, and in an outlying range in the Baltic Sea. Known for its distinctive spiny appearance, this worm plays a role in the benthic ecosystem, often inhabiting sandy or muddy substrates. Like other priapulids, it has a relatively simple body structure and is considered a predator, feeding on small invertebrates.<ref>{{cite journal |last1=van der Land |first1=Jaap |title=Systematics, zoogeography, and ecology of the Priapulida |journal=Zoologische Verhandelingen |date=1 January 1970 |volume=112 |issue=1 |pages=1–118 |url=https://repository.naturalis.nl/pub/317612 |language=en}}</ref> Its presence provides insights into the evolutionary history and ecological roles of priapulids, linking modern forms to ancient lineages.<ref>{{cite journal |last1=Janssen |first1=Ralf |last2=Wennberg |first2=Sofia A |last3=Budd |first3=Graham E |title=The hatching larva of the priapulid worm Halicryptus spinulosus |journal=Frontiers in Zoology |date=2009 |volume=6 |issue=1 |pages=8 |doi=10.1186/1742-9994-6-8|doi-access=free |pmc=2693540}}</ref> lives in sulfide-rich, oxygen-poor sediments. During elevated sulfide levels it increasingly relies on anaerobic metabolism and turns black, due to a film of bacteria covering its cuticle.<ref>[https://www.int-res.com/articles/meps/48/m048p285.pdf Association of various types of epibacteria with Halicryptus spinulosus (Priapulida) ]</ref><ref>[https://www.int-res.com/articles/meps/86/m086p167.pdf Sulfide detoxification and tolerance in Halicryptus spinulosus (Priapulida): a multiple strategy]</ref><ref>[https://oceanrep.geomar.de/id/eprint/56272/1/Juterzenka_K_1991.pdf Epizoic bacterial growth on a benthic macro-invertebrate Halicryptus spinulosus (Priapulida)]</ref>
==See also== *{{Cite journal | last1 = Lemburg | first1 = C. | doi = 10.1007/BF00397931 | title = Ultrastructure of the introvert and associated structures of the larvae of Halicryptus spinulosus (Priapulida) | journal = Zoomorphology | volume = 115 | pages = 11–29 | year = 1995 | s2cid = 42437901 }}
==References== {{Reflist}}
==External links== {{Wikispecies}} {{ITIS|id=155158|taxon=''Halicryptus''}}
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Category:Priapulida Category:Ecdysozoa genera
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