Cnidarians
bnsullivan | August 31, 2009
Scleractinian corals, also known as stony corals -- or just hard corals -- are the primary reef builders in the oceans. Their polyps secrete calcium carbonate to form a skeleton. A minority of species live as single polyps, but most stony coral species are colonial, and the structures they build 'grow' over time. They form a myriad of shapes: mounds, branches, fingers, plates, and encrustations.
In several previous posts I discussed and displayed photos of a number of so-called soft corals, all of which are octocorals, i.e., their polyps have eight tentacles. Stony corals are…
bnsullivan | August 24, 2009
The pretty creatures pictured here look like anemones, but they are not true anemones. They are Cerianthids, commonly referred to as 'tube anemones', which are taxonomically quite distinct from true anemones.
Cerianthids and true anemones do belong to the same phylum, Cnidaria, and the same class, Anthozoa, but tube anemones belong to the subclass Ceriantipatharia, a taxon that also includes the so-called 'black corals' (Antipatharia).
One of the visible features that distinguishes Cerianthid tube anemones from true anemones is the morphology of their tentacles. The macro photo below…