Wednesday, September 20, 2017

Branching ↔ Plates of branchlets


Branching corals show amazing diversity and there are an equally wide range of terms used to describe them.  Generally the term branching describes colonies that have secondary branches, i.e. branches coming off the first branch.  Forms that don’t have secondary branches are grouped with the digitate, columnar forms discussed below.

(Photo)

The branches may form into a number of arrangements, including large plates made up of small branchlets (e.g. p. 1-5 in the Coral Finder).

Branching corals take many forms - fingers, needles, blades and plates of branchlets - to name a few. Clockwise from top left: Acropora, Seriatopora, Pocillopora & Acropora.

(Photos of bushy, bottlebrush, corymbose, compact, plate of branchlets)

The tips of the branches can be used to differentiate between similar genera such as those within the Pocilloporidae family; branches tapered to a needle point are more common to Seriatopora (p.2 of the Coral Finder), whereas Stylophora branches are sub-rounded or blunt (p.2 of the Coral Finder).

(Photos of seriatopora and stylophora tips)

The branches are described as faceted when they form angular cross-sections (e.g. Paraclavarina, p. 5 of the Coral Finder).

(Photos of Paraclavarina)