apical plate

apical plate

[′ap·i·kəl ′plāt]
(invertebrate zoology)
A group of cells at the anterior end of certain trochophore larvae; believed to have nervous and sensory functions.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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References in periodicals archive ?
excentricus is the ventrally displaced apical pore complex (APC) resulting in a relatively long suture between the second (2') and third (3') apical plate, and the hypotheca has a narrow second antapical plate 2'''' (Fraga et al., 2011).
The last segment apically is tripartite and consists of two lateral lobes, which are equipped with the sensory structures and the ventral one, that is, the apical plate [18].
We agree with Horiguchi & Pienaar (1991) in that Peridinium quinquecorne has only two intercalary plates, and that dorsal view observations have to be made carefully in order to prevent confusing the plate 2a with an apical plate, following Balech's (1980) criterion, that this plate does not touch the apical pore.
Despite a more than a doubling of the original sample of regular echinoids and inclusion of data inferred from apical plate crystallography, the representation of different modes of development has not changed substantially.
The names of the thecal plates were abbreviated according to the Kofoid tabulation system as follows: first apical plate (1'), first intercalary plate (la), second intercalary plate (2a), first precingular plate (1"), and second pre-cingular plate (2").
Aedeagus with toothed apical plate most similar to burnsi, although plate not as elongate relative to medial portion of aedeagus to anterior.
In these embryos, unlike the embryos of regular echinoids, secondary mesenchyme cells did not seem to exert the force to pull up the archenteron toward the inner surface of the apical plate. In fact, the archenteron cells were not stretched along the axis of elongation and were in close contact with each other.
The names of the thecal plates are abbreviated according to the Kofoid tabulation system as follows: 1'--first apical plate, la--first intercalary plate, 2a--second intercalary plate, 3a--third intercalary plate, 1"'--first postcingular plate, S.a.--anterior sulcal plate, S.s.--left sulcal plate, S.d.--right sulcal plate, S.m.--medium sulcal plate (see also Fig.
In fa ct, FMRFamide-LIR fibers also branched repeatedly under the apical plate in early embryonic stages of L.
It was about 8 [micro]m long and slightly curved, enclosed by the plate 2' and also touched apical plates 1', and 3'.