International Journal of Marine Science, 2016, Vol.6, No.16 1
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Figure 2 Diagrammatic transverse (A-H) and surface (I-K)
views of
Montipora
corallites and associated coenostial
structures. (A) simple papillae with exsert corallite, (B)
compound papillae with exsert corallite, (C) simple papillae
with immersed corallite, (D) tuberculae with exsert corallite, (E)
tuberculae with immersed corallite, (FH) foveolate, tuberculate
and glabrous corallites (respectively), (I) corallites with thecal
and reticulum papillae, (J) corallites with thecal tuberculae, (K)
corallites with reticulum tuberculae forming ridges(to Veron,
Wallace, 1984)
or specialized radial corallites. Corallites of
Anacropora
are immersed or protrude slightly from
undifferentiated coenosteum.
Axial corallites start growing from the base of a
colony and grow upwards with different rates,
diversely orienting in space according to the genetic
ability of each species in certain environments.
Growing fixed on branch ends in different directions;
they form branched and branched -lamellar colonies,
and never form massive colonies. Radial corallites bud
from the lateral surface of axial corallites at different
angles and with different spacings, and have different
corallite shapes. Their growth taken together forms
that diversity of colony shapes which is typical for
Acropora
. Various forms of corallites and their
terminology are shown in the Figure 4, 5.
Figure 4 Radial corallite shapes of
Acropora
and their
nomenclature (to Wallace, 1978)
Figure 5 The appearance of corallites
Acropora
. 1-tubular,
2-nariform, 3-tube, pressed 4-loaded with simulate (spines) on
cenosteume
4 Identification Signs
Acropora
skeleton structure is much simpler
compared to other genera. They have no columella
orvarious septal reinforcements. A simple structure
consisting of three septal cycles develops in the
calices. Every element of these septal cycles is
connected with trabecular lobes. Radial elements,
passing through one or several concentric theca, form
a row of trabecules, closely connected to synapticula.
Three complete septal sets develop in a small number
of corallites. Usually one or both directive septa and
several metasepta, located symmetrically to the main
ones, are well developed. Septa are developed better,
as a rule, in axial corallites.
When describing and identification species, the
following features are usually used: characteristics of
axial corallites, corallite shapes, development of septal
apparatus in calices, sizes of outer and inner diameters,
wall thickness, morphology of main septa, septa of the
first and second orders. That is why it is appropriate to
provide a schematic illustration of axial and radial
corallites with an indication of the main skeletal
elements and the locations of measurements (Figure 6).
