Ultimate legs are a pair of modified rear legs unique to

centipede Centipedes (from Neo-Latin , "hundred", and Latin , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', "lip", and Neo-Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, ...

s. Although they do not aid in locomotion, ultimate legs are used for a variety of uses, and their morphology varies accordingly.

Sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

is frequently present.

Usage

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. The presence of spines on the ultimate legs of some species also serves a defensive role- as

Lewis Lewis may refer to: Names * Lewis (given name), including a list of people with the given name * Lewis (surname), including a list of people with the surname Music * Lewis (musician), Canadian singer * " Lewis (Mistreated)", a song by Radiohe ...

& Kronmüller (2015) put it, "a predator approaching from behind would come into contact with a battery of spines."

As a means of sound production

Members of the genus '' Alipes'', as well as some other centipedes,

stridulate Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mech ...

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. 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.

For suspension

Scolopendra dehaani hanging from a camera tripod

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.

In contact with other centipedes

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. During mating, ''

Scutigera coleoptrata ''Scutigera coleoptrata'', also known as the house centipede, is a species of centipede that is typically yellowish-grey and has up to 15 pairs of long legs. Originating in the Mediterranean region, it has spread to other parts of the world, wh ...

'' raise and lower their ultimate legs, along with their antennae.

References

{{Reflist Myriapod anatomy Centipedes