Radiole

Quick meaning: Radiole is a noun meaning (zoology) The spine of a sea urchin.

Meaning

(zoology) The spine of a sea urchin.

More Meanings

1. (zoology) A heavily ciliated feather-like tentacle occurring in clusters on the crowns of certain tubeworms, especially those of the order Canalipalpata (fan-head worms), used for feeding and respiration.

Example Sentences

Family Sabellidae [...] Head with a characteristic crown of 2 groups of pinnate projections called radioles [...], which sometimes bear eyes, and project from the tube when the worm is feeding.

The anterior segments of sabellid and serpulid worms are modified in two important ways: the head has a crown of pinnate radioles arranged in two spirals or semicircles above the mouth, and some of the anterior segments form a thoracic region [...]. In the Serpulidae, one (sometimes two) of the radioles is modifed as an operculum, which blocks the mouth of the tube when the worm retreats.

The radioles of the second size are about 8 millims. in length and 2 millims. in width, very much compressed and flattened, rounded at the end and finely striated longitudinally. They are articulated in a single row to the small tubercles round the edge of the areola, and in their natural attitude they lean over the naked part of the areola and cover the muscles and the head of the large radiole like a frill.

Fabricia bikinii, n. sp. [...] The tentacular crown is composed of three pairs of symmetrical radioles; in addition there are shorter, entire, paired filamentous processes, or palpi, at the ventral end of the crown [...]. Each radiole has 6 to 8 pairs of slender filaments that arise along the basal half of the radiole; these filaments extend distally not quite as far as the radioles to which they are attached.

Word Forms

• radioles

Related Words

Related dictionary entries include rotula, spatangid, urchin, scrobicula, echinometrid, spatangoid.

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