Species accounts

No common name

Priapulus caudatus

ORDER

Priapulimorphida

FAMILY Priapulidae

TAXONOMY

Priapulus caudatus Lamarck, 1816.

OTHER COMMON NAMES None known.

PHYSICAL CHARACTERISTICS

The body is large, up to 8 in (200 mm). This species is the typical priapulan. Its body is strongly tubular and ringed with many annulations. The introvert can be quite long when extended, reaching as much as a third of the length of the trunk. At the posterior end are a pair of caudal appendages.

DISTRIBUTION

Circumpolar Northern Hemisphere to Mediterranean Sea in eastern Atlantic Ocean and California in eastern Pacific Ocean.

HABITAT

Soft muddy bottoms. BEHAVIOR

The hydrostatic skeleton is used for movement. The introvert and anterior part of the trunk act as an anchor in the sediment. Once anchored, the animal pulls itself through the sediment by peristaltic contraction of body wall muscles.

FEEDING ECOLOGY AND DIET

Most probably a detritus feeder when young and a predator as an adult.

REPRODUCTIVE BIOLOGY

Sexes are separate. Gonadal products are released freely into the water, where fertilization occurs. A loricate larva lives in the bottom mud. As the larva grows, it sheds the cuticular covering and gradually grows into a juvenile.

CONSERVATION STATUS Not listed by the IUCN.

SIGNIFICANCE TO HUMANS None known. ♦

Reproductive Biology

No common name

Tubiluchus corallicola

ORDER

Priapulimorphida

FAMILY Tubiluchidae

TAXONOMY

Tubiluchus corallicola van der Land, 1968.

OTHER COMMON NAMES None known.

PHYSICAL CHARACTERISTICS

Generally less than 0.1 in (5 mm) long. The introvert is moderately short, making up less than one fourth of the total body length in extended individuals. The trunk is not annulated and is covered with small spines. The single caudal appendage is very long, usually much longer than the trunk.

DISTRIBUTION

Bermuda, Curacao, Bonaire, and Barbados.

HABITAT

Poorly sorted coral sands in shallow tropical waters. BEHAVIOR

In laboratory dishes, the animals always use their muscular caudal appendage to maintain contact with the substrate.

FEEDING ECOLOGY AND DIET

Most likely ingests small organic particles or may eat other small meiofaunal organisms.

REPRODUCTIVE BIOLOGY

Copulation is probable with internal fertilization. Females produce only up to 20 eggs. Release of embryos has not been observed, but larvae can be collected from the sediment and reared in the laboratory.

CONSERVATION STATUS Not listed by the IUCN.

SIGNIFICANCE TO HUMANS None known. ♦

Resources

Periodicals

Kirsteuer, E., and J. van der Land. "Some Notes on Tubiluchus corallicola (Priapulida) from Barbados, West Indies." Marine Biology 7 (1970): 230-8.

van der Land, J. "Systematics, Zoogeography, and Ecology of the Priapulida." Zoologische Verhandelingen 112 (1970): 1-118.

Les Watling, PhD

Phylum Loricifera Number of families 2

Thumbnail description

Group of microscopic, bilateral symmetrical animals characterized by a body with five sections: a protrusive mouth cone; a head (introvert) with up to nine rows of scalids (in the adults); a neck with trichoscalids; a thorax; and an abdomen with a lorica consisting of plates or plicae (folds)

Illustration: Bucket-tailed loriciferan (Rugiloricus cauliculus). (Illustration by Barbara Duperron)

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