proboscis

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Orange-tip butterfly (Anthocharis cardamines), with long proboscis for feeding.

proboscis

anatomy

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July 13, 2026

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Orange-tip butterfly (Anthocharis cardamines), with long proboscis for feeding. — Orange-tip butterfly (Anthocharis cardamines), with long proboscis for feeding.

The term "proboscis" refers to a long, flexible snout or trunk, most famously associated with elephants. It can also describe any elongated, tubular structure used for feeding or sensing, particularly in invertebrates like butterflies. In some contexts, it can even refer to the human nose, especially if it is prominent.1

In insects, the proboscis is part of the mouth structure, often a segmented beak. This beak encloses piercing stylets that enter plant tissue, forming a sucking tube to draw up fluids. The proboscis monkey of Borneo is named for the male's distinctively long, pendulous nose.23

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circulatory system
Hemichordata
…and have a short, conical proboscis, which gives them their common name. The vascular system of the Enteropneusta is open, with two main contractile vessels and a system of sinus channels. The colorless blood passes forward in the dorsal vessel, which widens at the posterior of the proboscis into a…
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…and have a short, conical proboscis, which gives them their common name. The vascular system of the Enteropneusta is open, with two main contractile vessels and a system of sinus channels. The colorless blood passes forward in the dorsal vessel, which widens at the posterior of the proboscis into a…
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Diptera
Importance
…flies) have developed a piercing proboscis used only against other insects.
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…flies) have developed a piercing proboscis used only against other insects.
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gastropod
The head
…frequently is prolonged into a proboscis that extends well in front of the tentacles. Carnivorous species often have a proboscis capable of great extension, either invaginable or contractile.
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…frequently is prolonged into a proboscis that extends well in front of the tentacles. Carnivorous species often have a proboscis capable of great extension, either invaginable or contractile.
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Lepidoptera
Evolution and paleontology
…and were replaced by the proboscis formed from the galeae of the maxillae, which broadened the food base exploitable by the species to include not only sap and other plant juices but nectar and fruit juices as the flowering plants evolved. Various groups, however, independently lost the proboscis and concentrated…
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…and were replaced by the proboscis formed from the galeae of the maxillae, which broadened the food base exploitable by the species to include not only sap and other plant juices but nectar and fruit juices as the flowering plants evolved. Various groups, however, independently lost the proboscis and concentrated…
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locomotion
Fossorial invertebrates
Worms with a protrusible proboscis (a tubular extension of the oral region) generally burrow by the contract–anchor–extend method. Contraction of the circular muscles in the posterior half of the body drives the body fluids forward, causing the proboscis to evert (turn outward) and forcing it into the soil. When…
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Worms with a protrusible proboscis (a tubular extension of the oral region) generally burrow by the contract–anchor–extend method. Contraction of the circular muscles in the posterior half of the body drives the body fluids forward, causing the proboscis to evert (turn outward) and forcing it into the soil. When…
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spiny-headed worm
A proboscis, or snout, which bears hooks, gives the group its name. There are about 1,150 recorded species, all of which parasitize vertebrates (usually fish) as adults and arthropods (usually insects or crustaceans) as juveniles. The adults are usually less than 1 cm (0.4 inch) long,…
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A proboscis, or snout, which bears hooks, gives the group its name. There are about 1,150 recorded species, all of which parasitize vertebrates (usually fish) as adults and arthropods (usually insects or crustaceans) as juveniles. The adults are usually less than 1 cm (0.4 inch) long,…
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