Ultimate legs

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Ultimate legs
Ultimate leg collage 2.jpg
Details
SynonymsAnal legs, caudal legs, terminal legs
OriginsLegs
FunctionVaried: defensive postures, mating rituals, anchoring
Anatomical terminology

Ultimate legs are a pair of modified rear legs unique to centipedes. Although they do not aid in locomotion, ultimate legs are used for a variety of uses, and their morphology varies accordingly.

Contents

Sexual dimorphism is frequently present. [1] [2] [3] [4]

Usage

Warning postures of Scolopendra spinosissima and S. galapagoensis Centipedes warning postures.jpg
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. [1] [2] 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." [2]

Scolopendra dehaani hanging from just its ultimate legs. Scolopendra dehaani hanging from a camera tripod.jpg
Scolopendra dehaani hanging from just its ultimate legs.

For suspension

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. [2]

In contact with other centipedes

Scolopendra galapagoensis interlocking ultimate legs before mating. Courtship ritual (centipedes).jpg
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. [2]

During mating, Scutigera coleoptrata raise and lower their ultimate legs, along with their antennae. [3]

As a means of sound production

Members of the genus Alipes stridulate their leaf-like ultimate legs, probably as a way to warn off predators. The legs continue to stridulate for up to half a minute if detached from the centipede. [2]

The ultimate legs of Rhysida immarginata togoensis emit a faint creaking or squeaking sound when detached and bent. [2]

Related Research Articles

<span class="mw-page-title-main">Centipede</span> Many-legged arthropods with elongated bodies

Centipedes are predatory arthropods belonging to the class Chilopoda of the subphylum Myriapoda, an arthropod group which includes millipedes and other multi-legged animals. Centipedes are elongated segmented (metameric) creatures with one pair of legs per body segment. All centipedes are venomous and can inflict painful stings, injecting their venom through pincer-like appendages known as forcipules or toxicognaths, which are actually modified legs instead of fangs. Despite the name, no centipede has exactly 100 pairs of legs; number of legs ranges from 15 pairs to 191 pairs, always an odd number.

<span class="mw-page-title-main">Myriapoda</span> Subphylum of arthropods

Myriapods are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial.

<i>Scutigera</i> Genus of centipedes

Scutigera is a centipede genus in the scutigeromorph family Scutigeridae, a group of centipedes with long limbs and true compound eyes. It compose of more than 30 species, including the most common and well-studied Scutigera coleoptrata.

<span class="mw-page-title-main">Chinese red-headed centipede</span> Subspecies of centipede

The Chinese red-headed centipede, also known as the Chinese red head, is a centipede from East Asia. It averages 20 cm (8 in) in length and lives in damp environments.

<span class="mw-page-title-main">Scolopendridae</span> Family of centipedes

Scolopendridae is a family of large centipedes.

<i>Scolopendra morsitans</i> Species of centipede

Scolopendra morsitans, also known as the Tanzanian blue ringleg or red-headed centipede, is a species of centipede in the family Scolopendridae. S. morsitans is the type species for the genus Scolopendra.

<i>Geophilus flavus</i> Species of centipede

Geophilus flavus is a terrestrial, soil-dwelling, species of centipede in the Geophilidae family. G. flavus occurs in a range of habitats across central Europe, North America, Australia and other tropical regions. Geophilomorph centipedes, like centipedes generally, are primary predators, hunting predominantly in underground soil burrows or above ground leaf litter. Their consumption behaviours are influenced by environment and seasonal factors. Given their lack of economic value and marginal medical significance, G.flavus remains largely understudied in mainstream research. Some recent studies have detailed the evolutionary development of G.flavus and Geophilidae generally, illustrating developed predatory features like forcipule venom glands.

<span class="mw-page-title-main">Scolopocryptopidae</span> Family of centipedes

Scolopocryptopidae is a family of blind centipedes in the order Scolopendromorpha. This family includes more than 90 species. Centipedes in this family are found mainly in the Americas and East Asia but have also been recorded in West Africa, New Guinea, and Fiji.

<span class="mw-page-title-main">Geophilidae</span> Family of centipedes

The Geophilidae are a polyphyletic, cosmopolitan family of soil centipedes in the superfamily Geophiloidea containing the mostly defunct clades Aphilodontidae, Dignathodontidae, Linotaeniidae, Chilenophilinae, and Macronicophilidae. These centipedes are found almost worldwide.

<span class="mw-page-title-main">Himantariidae</span> Family of centipedes

Himantariidae is a monophyletic family of centipedes in the order Geophilomorpha and superfamily Himantarioidea, found almost exclusively in the Northern Hemisphere. Centipedes in this family feature a short head with a concave labral margin bearing a row of denticles, a single dentate lamella and some pectinate lamellae on each mandible, second maxillae with strongly tapering telopodites and slightly spatulate claws, and a stout forcipular segment with short forcipules and a wide tergite; the ultimate legs usually have no pretarsus, and the female gonopods are distinct and biarticulate.

<span class="mw-page-title-main">Mecistocephalidae</span> Family of centipedes

Mecistocephalidae is a monophyletic family of centipedes in the order Geophilomorpha. It is the only family in the suborder Placodesmata. Most species in this family live in tropical or subtropical regions, but some occur in temperate regions. This family is the third most diverse in the order Geophiliomorpha, with about 170 species, including about 130 species in the genus Mecistocephalus.

<i>Geophilus</i> Genus of centipedes

Geophilus is a large, heterogeneous genus of soil centipedes in the family Geophilidae largely considered to be synonymous with Brachygeophilus. This genus is mostly Holarctic and characterized by a claw-shaped ultimate pretarsus, complete or nearly complete coxo-pleural sutures at the prosternum, and incomplete chitin-lines. Centipedes in this genus feature slightly elongate heads and labral intermediate parts with tubercles, the forcipules are usually poorly elongate with a single small tubercle at the base of each tarsungulum, and the anterior trunk metasternites usually have an anterior medial socket and a posterior transversally elongate pore-field. The generic name first appeared in Brewster's Edinburgh Encyclopaedia in 1814 as Geophilus electricus.

<i>Plutonium zwierleini</i> Species of centipede

Plutonium zwierleini, in the monotypic genus Plutonium, is one of the largest scolopendromorph centipedes in Europe, and one of the few potentially harmful to humans. Nevertheless, it has been rarely reported, only from the southern part of the Iberian and Italian peninsulas, Sardinia and Sicily.

<span class="mw-page-title-main">Schendylidae</span> Family of centipedes

Schendylidae is a family of centipedes in the order Geophilomorpha found in the Americas, the Palearctic region, Africa, Madagascar, Australia, and southeast Asia, and also on some Pacific islands.

Arrup is a genus of centipedes in the family Mecistocephalidae, native to Europe and Asia as far as Japan. Centipedes in this genus feature small telopodites on the second maxillae, the head and forcipular segment are elongate, the clypeus is almost completely areolate, and the poison glands in adult males are often deep inside the forcipules. These centipedes range from 1 cm to 5 cm in length. All species in this genus have 41 leg-bearing segments. Most are soil-dwellers but Arrup akiyoshiensis is a troglobiont.

Agnostrup is a genus of centipedes in the family Mecistocephalidae, native to Europe and Asia. Centipedes in this genus feature small telopodites without claws on the second maxillae and a robust basal denticle on the forcipular tarsungulum. These centipedes range from 2 cm to 3 cm in length. All species in this genus have 41 leg-bearing segments.

Anarrup is a genus of centipedes in the family Mecistocephalidae, native to Europe and Asia as far as Indonesia. Centipedes in this genus feature a clypeus with areolation and setae limited to a short anterior marginal band; the second maxillae have swollen and densely setose telopodites and a coxosternite divided mid-longitudinally. These centipedes range from 6 cm to 8 cm in length. All species in this genus have 41 leg-bearing segments.

Geophilus persephones is a species of soil centipede in the family Geophilidae discovered in 1999. This species is named after Persephone, the queen of the underworld in Greek mythology, and found in caves in the Gouffre de la Pierre Saint-Martin. It has elongated antennae and legs as well as abundant sensory setae, and like other geophilomorhps it lacks sight, has a flattened trunk, and is well adapted to underground life. This species was the first troglomorphic geophilomorph ever discovered and one of the only two in existence along with Geophilus hadesi. Known from a single male specimen measuring 16.2 mm in length, this species has only 29 pairs of legs, one of only two species in the Geophilidae family to have so few leg pairs.

Geophilus richardi is a species of soil centipede in the family Geophilidae found in France, Italy, and the Ionian Islands. Females of this species have 33 pairs of legs; males have 29 or 31. This species is one of only two in the family Geophilidae to include centipedes with as few as 29 leg pairs. This species grows up to 10 millimeters long, has no carpophagus pit or pore-fields, and has a gradually tapering, curved pretarsus of the second maxillae. G. richardi lacks typical ventral pores between 2–4mm. The sternites instead bear a small number of pores between 0.5–1mm that differ from micropores, which are unbounded by a cuticular ring. These are possibly the remnants of typical ventral pores, their smaller size being a byproduct of overall miniaturization.

Arthrorhabdus mjobergi is a species of centipede in the Scolopendridae family. It is endemic to Australia, and was first described in 1916 by German naturalist Karl Kraepelin from material collected by Swedish zoologist and explorer Eric Mjöberg. It is a relatively small species, averaging 38 millimetres in length, with a pale brownish-yellow body, reddish-brown head, and variably coloured last segment and back legs. Its notable characteristics include short, 17-segmented antennae, mouthparts with 4 or 5 large outward-facing teeth, body segments with distinct median indentations, and varied leg features such as bristles at the base of claws on the first 20 pairs and 2 to 5 spines on the last pair.

References

  1. 1 2 Kenning, Matthes; Schendel, Vanessa; Müller, Carsten H. G.; Sombke, Andy (2019-01-14). "Comparative morphology of ultimate and walking legs in the centipede Lithobius forficatus (Myriapoda) with functional implications". Zoological Letters. 5 (1): 3. doi: 10.1186/s40851-018-0115-x . ISSN   2056-306X. PMC   6330759 . PMID   30656061.
  2. 1 2 3 4 5 6 7 Kronmüller, Christian; Lewis, John G. J. (2015-06-30). "On the function of the ultimate legs of some Scolopendridae (Chilopoda, Scolopendromorpha)". ZooKeys (510): 269–278. Bibcode:2015ZooK..510..269K. doi: 10.3897/zookeys.510.8674 . ISSN   1313-2970. PMC   4523778 . PMID   26257548.
  3. 1 2 Kenning, Matthes; Müller, Carsten H. G.; Sombke, Andy (2017-11-14). "The ultimate legs of Chilopoda (Myriapoda): a review on their morphological disparity and functional variability". PeerJ. 5: e4023. doi: 10.7717/peerj.4023 . ISSN   2167-8359. PMC   5691793 . PMID   29158971.
  4. Sombke, Andy; Müller, Carsten H. G. (Apr 2021). "When SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes". Frontiers in Zoology. 18 (1): 17. doi: 10.1186/s12983-021-00402-3 . ISSN   1742-9994. PMC   8056527 . PMID   33879192.