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a genus of green algae found in tropical and subtropical seas. The genus includes 21 species. An adult organism of this genus consists of a lobed, rhizoidal base, a cylindrical stalk, and a cap formed by a verticil of connate and unconnate game tangia. In the rhizoidal portion of the single-celled thallus there is one giant nucleus with a developed nucleolus. After the cap is almost completely formed, the nucleus divides repeatedly, and numerous nuclei migrate through the stalk into the gametangia, which are separated by septa. The contents of the gametangia divide into numerous thick-walled cysts, in which meiosis then occurs. In the autumn, after the decomposition of the thallus, the cysts are released and then hibernate; in the spring they germinate, forming biflagellate gametes. The gametes copulate, forming a zygote which during the first year grows into a branched rhizoid with a vertical axis. The latter dies, while the remaining basal portion which contains the nucleus hibernates; the next spring it starts a new vertical axis, which forms one or several sterile verticils on the top. Each verticil of gametangia is preceded by one sterile verticil which drops off. Under laboratory conditions, the life cycle of Acetabularia can be reduced to six months. Acetabularia is a favorite research subject in investigating the interaction between the nucleus and protoplasm.

Kursanov, L. I., and N. A. Komarnitskii. Kurs nizshikh rastenii, 3rd ed. Moscow, 1945. Pages 84–86.


References in periodicals archive ?
Agardh Dasycladaceae Neomeris annulata Dickie * * Polyphsaceae Acetabularia pussilla M.
The roles of light and the nucleus in the regulation of reproductive onset in Acetabularia acetabulum.
One of the most carefully analyzed examples of this is the formation of whorls in the algae Acetabularia and its relatives.
It has demonstrated, for instance, the differences between the tolerance for artificial and natural plant extracts by unicellular algae (Acetabularia Acetabulum).
Even more curious is the survival and productive activity of the chloroplasts of some chlorophycaceous algae (Acetabularia, Udotea, Halimeda) consumed by opisthobranch mollusks (Elysia, Bosellia) within the cells of the animal's digestive gland.
These trends were even more evident for Acetabularia acetabulum [ILLUSTRATION FOR FIGURE 5 OMITTED].
The view of development as a process of self-organization has inspired Goodwin's empirical work on morphogenesis in the unicellular green alga, Acetabularia acetabulum.
By 1930, and based on his studies with algae, especially Acetabularia (Figure 2c), Danish-German biologist Joachim Hammerling, proposed that the development of organisms is fully determined by DNA and that, additionally, there are certain substances responsible for defining an organism's form in its initial stages (Haemmerling, 1963).
timida did not find any algal transcripts, although the data set was small and donor algal (Acetabularia) genome sequences were only partially available (Wagele et al., 2011), so matches might have easily been missed.
In addition to its role in ecosystem primary productivity, it and its relatives (Udotea sp., Acetabularia sp., Halimeda sp.) can be responsible for much of the calcium carbonate mud deposited in back-reef areas when present in abundance.
Garcia E, Reyes R (1996) Bioconcentration of mercury in Acetabularia calyculus: Evidence of a polypeptide in whole cells and anucleated cells.
NC3: Laguna Nichupte, canal de entrada norte, 200 m de SEMARNAP (Cancun), fondo rocoso con algas (Acetabularia, Halimeda opuntia y Laurencia sp.) y esponjas, 0.1-2 m, 20 II 1999, SISV y JRBZ.