Subclass
OCTOCORALLIA (=ALCYONARIA)
Order Alcyonacea
Suborder Holaxonia
Octocorals with unspiculated axis and often a soft,
chambered central core.
When using sclerites alone, it is sometimes difficult to distinguish
between the two families of Holaxonia represented in the SAB.
The SAB Plexauridae have a much more diverse assemblage of sclerite
morphology as a whole than the SAB Gorgoniidae, but there are
some genera (i.e. Thesea) that contain spindles that
initially resemble those in the Gorgoniidae. Spindle size and
degree of loculation surrounding the axis must also be considered
while attempting to place holaxonian specimens in the correct
family.
Family Plexauridae
Members of the families Paramuriceidae and Muriceidae
were reclassified in Bayer 1981 to be included in the Plexauridae.
Members of this family occurring in the SAB have an unspiculated,
horny axis and a hollow, axial core that is surrounded by a loculated
cortex. Generally the calyces have a strong armature of sclerites.
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1a. – Colonies with prominent cylindrical calyces,
distinctly separated, usually on one or two sides of branch and
generally not crowded ..................................................................2
left: Scleracis guadalupensis;
right: Bebryce parastellata
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1b. – Colonies
with spiny, shelf-like or dome-like calyces, not cylindrical, scattered
entirely around branches and crowded ....................................3
left: Thesea nivea;
right: Muricea pendula
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