acorn worm


Also found in: Dictionary, Medical, Wikipedia.

acorn worm:

see HemichordataHemichordata
, small phylum of marine invertebrates closely related to both the echinoderms (phylum Echinodermata) and chordates (phylum Chordata). Acorn worms, class Enteropneusta, are the most common hemichordates.
..... Click the link for more information.
.

acorn worm

[′ā‚kȯrn ‚wərm]
(invertebrate zoology)
Any member of the class Enteropneusta, free-living animals that usually burrow in sand or mud. Also known as tongue worm.
References in periodicals archive ?
The number of cysts varied among acorn worm individuals.
To observe the relationship between the parasitic copepod and acorn worm host in situ, we examined histological sections of the infected tissues of acorn worms and found that cysts in the genital wing of the infected acorn worm were enclosed by the hypertrophied epithelium and connective tissues of the host (Fig.
Enteropneusts - or acorn worms - are marine animals closely related to starfish and sea urchins.
It's astonishing how similar Spartobranchus tenuis fossils are to modern-day acorn worms, except that they also formed fibrous tubes.
Tergivelum cinnabarinum is the name given to a vibrant scarlet-orange acorn worm -- cinnabarinum is Latin for cinnabar which is a red colored mineral.
It is only 10 years since the first species of deep sea torquaratorid acorn worm was found in the Pacific Ocean; now we have three new species from the Atlantic it seems different species will be found throughout the deep sea.
A new deep-sea species of epibenthic acorn worm (Hemichordata, Enteropneusta).
Morphology of a new deep-sea acorn worm (class Enteropneusta, phylum Hemichordata): A part-time demersal drifter with externalized ovaries.
An anatomical description of a miniaturized acorn worm (Hemichordata Enteropneusta) with asexual reproduction by paratomy.
The largest oocytes cause an outward bulge of the epidermis but are not externalized in epidermal pouches as they are in acorn worms of the genus Allapasus (the latter were described by Holland et al.
The 1984-1987 survey: Examples of the acorn worms and brachiopods collected are included in Fig.
Acorn worms are themselves part of the hemichordates, a group of marine animals closely related to today's sea stars and sea urchins.