''Nephasoma rimicola'' is a marine invertebrate belonging to the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Sipuncula, the peanut worms. This worm occurs in the northeastern Atlantic Ocean.

Description

''Nephasoma rimicola'' grows to a maximum length of about . Like all peanut worms it has a cylindrical trunk and a narrower, retractable

anterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

section known as the introvert. The mouth is at the end of the introvert which can be extended to feed or retracted into the body at other times. In this species the trunk is about three times as long as it is wide with the introvert being a similar length. The introvert is retracted by a single, ventral pair of retractor muscles. Near its tip, the introvert has many hook-like spines arranged in six to ten rings, and the mouth is surrounded by well-formed tentacles; there are eight of these in juveniles but more develop as the worm grows, with sixteen being present in most adults and twenty in the largest individuals. The rings of hooked spines and the well-developed tentacles help to distinguish this species from the usually much smaller ''

Nephasoma minutum ''Nephasoma minutum'' is a marine invertebrate of the phylum Sipuncula, commonly known as peanut worms because of their shape when contracted. It is a cylindrical, unsegmented worm with a crown of tentacles around the mouth. These worms live in c ...

'' which occupies similar habitats.

Distribution

''Nephasoma rimicola'' occurs in the northeastern Atlantic Ocean. It has been found in northern Spain and in several shallow water locations around the British Isles, including west of the Isle of Wight, the estuary of the River Exe in north Devon and Milford Haven in south Pembrokeshire where it inhabits crevices in the rock. It also occurs off the coast of southern Spain in deeper water, between .

Ecology

Peanut worms are

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

s. The introvert is extended along the surface of the substrate and organic particles are gathered by the oral tentacles and moved to the mouth when the introvert is drawn in. The gut is long and J-shaped, with the anus on the dorsal surface of the front end of the trunk. The introvert is normally kept retracted except when the worm is feeding.

References

{{Taxonbar, from=Q1909918 Sipunculans Animals described in 1973