Colloblast
Colloblasts are unique, multicellular structures found in ctenophores.[1] They are widespread in the tentacles of these animals and are used to capture prey. Colloblasts consist of a collocyte containing a coiled spiral filament, internal granules and other organelles.[2]
Like the cnidocytes of cnidarians, colloblasts are discharged from the animals’ tentacles, and are used to capture prey. However, unlike cnidocytes, which are venomous cells, colloblasts contain adhesives which stick to, rather than sting the prey.
Form, function, and occurrence
[edit]Colloblasts were first described in 1844.[3]
The apical surface of colloblasts consist of numerous cap cells that secrete eosinophilic granules[1] that are thought to be the source of adhesion.[4] 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.[5] Colloblasts are found in all ctenophores except those of the order Beroida, which lack tentacles, and the species Haeckelia rubra, which use cnidocytes from cnidarian prey.[5]
References
[edit]- ^ a b Leonardi, N..D.; Thuesen, E.V.; Haddock, S.H.D. (2020). "A sticky thicket of glue cells: A comparative morphometric analysis of colloblasts in 20 species of comb jelly (Phylum Ctenophora)". Ciencias Marinas. 46 (4): 211–225. doi:10.7773/cm.v46i4.3118.
- ^ Harrison, Frederick W.; Kohn, Alan J. (1996-12-06). Microscopic Anatomy of Invertebrates, Mollusca II. ISBN 978-0-471-15447-1.
- ^ Mari-Luz, Hernandez-Nicaise (1984). "9.7: The integument of the tentacles: the colloblast". In Bereiter-Hahn, Jürgen; Matoltsy, A. Gedeon; Richards, K. Sylvia (eds.). Biology of the Integument Invertebrates. Berlin, Heidelberg: Springer. p. 107. ISBN 9783642515934.
- ^ Franc, J.-M. (1978). "Organization and function of ctenophore colloblasts: An ultrastructural study". Biological Bulletin. 155 (3): 527–541. doi:10.2307/1540788. JSTOR 1540788.
- ^ a b Pang, K.; Martindale, M.Q. (2008). "Comb jellies (ctenophora): A model for basal metazoan evolution and development". Cold Spring Harbor Protocols. 2008 (12). pdb.emo106. doi:10.1101/pdb.emo106. PMID 21356709.