Heestand Saucier, E.; France, S.C.; Watling, L. (2021). Toward a revision of the bamboo corals: Part 3, deconstructing the Family Isididae. Zootaxa 5047(3): 247-272.
Bamboo corals are distinguished from most other octocorals by an articulated skeleton. The nodes are proteinaceous and
sclerite-free while the internodes are composed of non-scleritic calcium carbonate. This articulation of the skeleton was
thought to be unique and a strong synapomorphy for the family Isididae. Our phylogeny, based on the amplification of
mtMutS and 18S, shows an articulating skeleton with sclerite-free nodes has arisen independently at least five times during
the evolutionary history of Octocorallia rather than being a synapomorphy characteristic of a monophyletic bamboo
coral clade. The family Isididae is currently composed of four subfamilies (Circinisidinae, Isidinae, Keratoisidinae,
and Mopseinae). Not only is the family polyphyletic, but our genetic analyses suggest also the subfamily Isidinae is
polyphyletic based on current taxonomic classifications, and Mopseinae is not monophyletic. The type, Isis, is found
outside of the well-supported Calcaxonia – Pennatulacea clade where the other members of Isididae cluster. The current
classification of the family Isididae does not reflect the evolutionary history of an articulated skeleton. To better reflect
the evolutionary history of these taxa we propose that three of the four the subfamilies, the genus Isidoides, and genera
within the subfamily Isidinae, be elevated to family level to produce a classification with five families with a bamboo-like
skeleton: Chelidonisididae, Isididae, Isidoidae, Keratoisididae, and Mopseidae.
