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One of a pair of elongated, often segmented appendages usually found near the mouth in invertebrate organisms such as mollusks, crustaceans, and insects, the functions of which include sensation, locomotion, and feeding. Also called palpus.

[French palpe, from New Latin palpus, from Latin, a touching; see pāl- in Indo-European roots.]

pal′pal (păl′pəl) adj.


(pælp) or


n, pl palps or palpi (ˈpælpaɪ)
1. (Zoology) either of a pair of sensory appendages that arise from the mouthparts of crustaceans and insects
2. (Zoology) either of a pair of tactile organs arising from the head or anterior end of certain annelids and molluscs
[C19: from French, from Latin palpus a touching]
ˈpalpal adj


(ˈpæl pəs)

n., pl. -pi (-pī).
an appendage attached to an oral part and serving as an organ of sense in insects, crustaceans, etc.
[1805–15; < New Latin; Latin palpus or palpum palm of the hand]
palp′al, adj.


A segmented organ extending from the mouthparts of arthropods, used for touch or taste.
References in periodicals archive ?
1 and 2); palpal formula 5/2; pronotum crossed by strong transverse impression (Figs.
2005, Galvis 2015, World Spider Catalog 2016), whose males can be recognized by their large palpal bulbs, with large proximal tegular lobes, embolus long with a wide spiral, and usually finger-like RTA (retrolateral tibial apophysis); while females can be recognized by their large epigynal windows, with a median septum, with short to long copulatory ducts (Zhang & Maddison 2015).
australis can be recognized by ventro-medial spurs in male palpal segments, and the copious, plumose, pale white setae on the female dorsum.
Other features separating Pantala from Tramea are the very short moveable hook and deep palpal crenations of the former species.
Ascoids simple and long, reaching or extending beyond apex of flagellomere; palpal segment 5 longer than 3+4 segments.
The new species belongs to Gonatopus group 4 (Olmi and Virla, 2014) by the pronotum crossed by a strong transverse furrow, the enlarged claw provided of one large subapical tooth and lamellae and by the palpal formula 6/3; it can be included in the key to the females of the Neotropical Gonatopus species of group 4 presented by Olmi and Virla (2014) by replacing the fnal couplets 12-14 as follows:
The formula of the palpotarsus (fT) for the two new species are both 4B (B=branched) and fp (formula of palpal seta) = B/N/N/N/B (N=naked).
Several individuals were photographed and, where possible, females distinguished from similarly coloured (brown) immature males by their larger size and lack of enlarged palpal tarsi.
Functional aspects of the male palpal organ in Dolomedes tenebrosus, with notes on the mating behavior (Araneae, Pisauridae).
A solar-powered supertrain that can travel close to the speed of sound is to be developed in the latest project by the billionaire PalPal founder Elon Musk.