Colloblast
Encyclopedia
Colloblasts are a cell type found in ctenophores. They are widespread in the tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

s of these animals and are used to capture prey. Colloblasts consist of a coiled spiral filament that is embedded in the epidermis and an axial filament with a granular dome. The apical surface of these cells consist of eosinophilic
Eosinophilic
Eosinophilic refers to the staining of certain tissues, cells, or organelles after they have been washed with eosin, a dye.Eosin is an acidic dye; thus, the structure being stained is basic....

 granules that are thought to be the source of adhesion. On contact, these granules rupture, and release an adhesive substance onto the prey. The spiral filament absorbs the impact of the rupture preventing the ensnared prey from escaping.. Colloblasts are found in all ctenophores except those of the order Beroida, which lack tentacles, and the species Haeckelia rubra, which utilize cnidocyte
Cnidocyte
A cnidocyte, cnidoblast, or nematocyte is a type of venomous cell unique to the phylum Cnidaria . The cnidocyte cell provides a means for them to catch prey and defend themselves from predators. Despite being morphologically simple, lacking a skeleton and usually being sessile, cnidarians prey on...

s from cnidarian prey.

Like the cnidocyte
Cnidocyte
A cnidocyte, cnidoblast, or nematocyte is a type of venomous cell unique to the phylum Cnidaria . The cnidocyte cell provides a means for them to catch prey and defend themselves from predators. Despite being morphologically simple, lacking a skeleton and usually being sessile, cnidarians prey on...

s of cnidaria
Cnidaria
Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...

ns, colloblasts are discharged from the tentacles and are used for prey capture. However, unlike cnidocytes, which are venomous cells, colloblasts stick to, rather than sting their prey.

Colloblasts were first observed in 1844.
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