{{Short description|Pair of modified rear legs unique to centipedes}} {{Infobox anatomy|Type=Modified leg|Name=Ultimate legs|Image=Ultimate leg collage 2.jpg|Function=Varied: defensive postures, mating rituals, anchoring|Origin=Legs|synonym=|synonyms=Anal legs, caudal legs, terminal legs}}
'''Ultimate legs''' are a pair of modified rear legs unique to centipedes. Although they do not aid in locomotion, ultimate legs possess a variety of uses, and their morphology varies accordingly.
Sexual dimorphism is frequently present.<ref name="Kenning2019">{{Cite journal |last1=Kenning |first1=Matthes |last2=Schendel |first2=Vanessa |last3=Müller |first3=Carsten H. G. |last4=Sombke |first4=Andy |date=2019-01-14 |title=Comparative morphology of ultimate and walking legs in the centipede Lithobius forficatus (Myriapoda) with functional implications |journal=Zoological Letters |volume=5 |issue=1 |page=3 |doi=10.1186/s40851-018-0115-x |issn=2056-306X |pmc=6330759 |pmid=30656061 |doi-access=free }}</ref><ref name="Kronmuller2015">{{Cite journal |last1=Kronmüller |first1=Christian |last2=Lewis |first2=John G. J. |date=2015-06-30 |title=On the function of the ultimate legs of some Scolopendridae (Chilopoda, Scolopendromorpha) |url=https://zookeys.pensoft.net/article/5542/ |journal=ZooKeys |language=en |issue=510 |pages=269–278 |doi=10.3897/zookeys.510.8674 |pmid=26257548 |issn=1313-2970|pmc=4523778 |bibcode=2015ZooK..510..269K |doi-access=free }}</ref><ref name="Kenning2017">{{Cite journal |last1=Kenning |first1=Matthes |last2=Müller |first2=Carsten H. G. |last3=Sombke |first3=Andy |date=2017-11-14 |title=The ultimate legs of Chilopoda (Myriapoda): a review on their morphological disparity and functional variability |journal=PeerJ |language=en |volume=5 |article-number=e4023 |doi=10.7717/peerj.4023 |pmid=29158971 |issn=2167-8359|pmc=5691793 |doi-access=free }}</ref><ref name="Sombke2021">{{Cite journal |last1=Sombke |first1=Andy |last2=Müller |first2=Carsten H. G. |date=Apr 2021 |title=When SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes |journal=Frontiers in Zoology |language=en |volume=18 |issue=1 |page=17 |doi=10.1186/s12983-021-00402-3 |issn=1742-9994 |pmc=8056527 |pmid=33879192 |doi-access=free }}</ref>
== Usage == [[File:Centipedes warning postures.jpg|thumb|250x250px|Warning postures of ''Scolopendra spinosissima'' and ''S. galapagoensis'']]
=== As a defence against predators === In many species, ultimate legs are used in warning postures to scare off predators. The ultimate legs are raised, splayed, and sometimes waved back and forth.<ref name="Kenning2019" /><ref name="Kronmuller2015" /> The presence of spines on the ultimate legs of some species also serves a defensive role- as Lewis & Kronmüller (2015) put it, "a predator approaching from behind would come into contact with a battery of spines."<ref name="Kronmuller2015" />
=== As a means of sound production === Members of the genus ''Alipes'', as well as some other centipedes, stridulate their leaf-like ultimate legs, possibly as a way to warn off predators, or as a distraction by encouraging the predator to focus on the legs, which would then be autotomized to help the centipede escape.<ref name="Kronmuller2015" />
In some of those species, including ''Alipes grandidieri'' and ''Rhysida immarginata togoensis'', the legs continue to stridulate for over half a minute after being detached.<ref name="Kronmuller2015" />
=== For suspension === [[File:Scolopendra dehaani hanging from a camera tripod.jpg|thumb|274x274px|''Scolopendra dehaani'' hanging from just its ultimate legs.]] Some species use their ultimate legs to hang or anchor themselves from trees or other desired objects. This has been recorded as playing a role in predation; the centipede suspends itself in the air and swings back and forth to capture prey.<ref name="Kronmuller2015" />
=== In contact with other centipedes === [[File:Courtship ritual (centipedes).jpg|thumb|''Scolopendra galapagoensis'' interlocking ultimate legs before mating.]] Before mating, many species of Scolopendrid centipedes interlock ultimate legs. A similar behaviour has been recorded in ordinary meetings, wherein each centipede grasps the other's trunk with its ultimate legs. This possibly serves as a way to defuse aggression, and in some species may be held for several minutes.<ref name="Kronmuller2015" />
During mating, ''Scutigera coleoptrata'' raise and lower their ultimate legs, along with their antennae.<ref name="Kenning2017" />
== References == {{Reflist}}
Category:Myriapod anatomy Category:Centipedes