cirrus

1. Meteorol a thin wispy fibrous cloud at high altitudes, composed of ice particles

2. a plant tendril or similar part

3. Zoology

a. a slender tentacle or filament in barnacles and other marine invertebrates

b. a hairlike structure in other animals, such as a filament on the appendage of an insect or a barbel of a fish

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

cirrus

[′sir·əs]

(invertebrate zoology)

The conical locomotor structure composed of fused cilia in hypotrich protozoans.

Any of the jointed thoracic appendages of barnacles.

Any hairlike tuft on insect appendages.

The male copulatory organ in some mollusks and trematodes.

(vertebrate zoology)

Any of the tactile barbels of certain fishes.

(zoology)

A tendrillike animal appendage.

cirrus (Ci)

Thin, separated or detached clouds appearing in all seasons. They are often feathery, fibrous, or tufted in appearance. They are high clouds, which occur at above 20,000 ft (6 km) height. Cirrus clouds are composed of thin crystals or needles of ice, not droplets of water. These clouds are represented on the weather map by symbols like

and

. The former means that the amount of cirrus is not increasing, whereas the latter means that it is a dense cirrus cloud but it does not form an anvil of a cumulonimbus cloud.

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References in periodicals archive

The observations of the present study confirm that the cirri of treated specimens are arrested in the flexed position (Jorgensen, 1975, 1983), eliminating direct cirri particle interaction while the frontal and lateral cilia continue to beat.

We cannot determine whether the particle-delivery mechanism involves direct particle contact with the cirri. However, at the observed proximity of the particle with the cirrus ([less than] 1 [micro]m), the question of 'hydromechanical' versus 'mechanical' becomes irrelevant, as any intervening water is essentially a mechanical coupler.

Both the eulamellibranch, Dreissena polymorpha and the filibranch Mytilus edulis species have homorhabdic gills and complex cirri, and capture small particles in the near-field when cirral movements cause particles to be deflected onto the frontal surface.

The structure of the latero-frontal cirri on the gills of certain lamellibranch molluscs and their role in suspension feeding.

Studies on the gill of Mytilus edulis: the eu-laterofrontal cirri. Proc.

The Role of Latero-Frontal Cirri in Particle Capture by the Gills of Mytilus edulis

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