acorn worm

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Related to acorn worms: Hemichordata, Lancelets

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.
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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 ?
Abundance patterns of brachiopods and acorn worms in particular were similar since both groups were absent early on 1984, begun to increase and reached high numbers around the mid rainy season of 1984, became scarcer during 1985 and early 1986, and increased slightly during the dry season of 1986-1987.
The acorn worms (Enteropneusta) were represented by 16 specimens found mainly during the rainy season (Fig.
For histological observations, 10 infected acorn worms were anesthetized with 0.
In most cases, the infected acorn worms contained one (60%, n = 74) or two (33%, n = 41) cysts.
The fossils, Spartobranchus tenuis, are a member of the acorn worm group.
Hemichordates are a type of marine animal split into two groups: the acorn worm, which live in burrows, and the pterobranchs, which live in a tubular structure anchored to the ocean floor.
There is much interest in the acorn worms from the point of view of understanding the early evolution of the vertebrates.
A reddish-purple acorn worm with large lips either side of its head region reminded researchers of floppy-eared Star Wars character Yoda while pupurata is Latin for purple and describes its colorful hue.
Previously we had sequenced this acorn worm multiple times, but to further verify this sequence, genomic DNA was extracted from S.
This result suggests that early hemichordates were enteropneust-like, with pterobranchs arising from acorn worm ancestors (Rychel and Swalla, 2007; Brown et al.
Here, we use ribosomal DNA sequence and morphology to characterize an acorn worm from the Russian Kara Sea as new genus and species: Coleodesmium karaensis within the family Torquaratoridae.
In the autumn of 2011, a single acorn worm was recovered from a Sigsbee trawl during cruise 59 of the RN Akademik Mstislav Keldysh.