Shallow Octocorals of the SAB

Octocorals are recorded in all the world’s oceans and at all depths. The diversity of the group is highest in the tropical western Pacific, but the Atlantic is rich in octocoral species as well. Worldwide, there are approximately 335 genera of octocorals from 45 valid families (Bayer, 1981; Williams, 1995). The growing number of new species recorded and revisions within the families makes it difficult to arrive at an exact number of species, but it is estimated at over 2800 worldwide (Bayer, 1981; Williams, 1995; Williams, 2001). This work covers 26 species (approximately 1%) from 11 families known from the South Atlantic Bight (to a depth of 200 m). It is intended to assist scientists, managers, educators and students to properly identify, through the use of keys, species notes, and images, the octocorals present from depths less than 200 m in the South Atlantic Bight.

Prior work
The taxonomy and classification of western Atlantic octocorals were first treated extensively by Deichmann (1936), who included all shallow and deep-water species known at the time and described several new species. Her work was a continuation of A. E. Verrill’s study of fauna collected on the Blake Expedition of 1877-1878, a manuscript he was unable to complete before his death. Nearly 30 years later, Bayer (1961) presented an updated taxonomic treatment of western Atlantic tropical and subtropical shallow water octocorals and then produced a key (Bayer,1981) to the non- pennatulacean genera of world-wide Octocorallia. Subsequently, Williams (1995) published a world key to the pennatulacean octocorals, which complemented Bayer’s (1981) key, and between the two a complete work was established that set the standard for the modern classification of the Octocorallia. In the shadow of these important taxonomic works, the rationale for developing a regional key to the octocorals of the South Atlantic Bight was based on the following: a) Since the publishing of Deichmann’s 1936 western Atlantic key, many new species have been described, 4 of which are included in the present work, and octocoral classification has changed significantly; b) although Bayer (1981) and Williams (1995) contain modern classifications, they treat worldwide genera and do not have species diagnoses; c) Bayer (1961) and Deichmann (1936) included many species that do not occur in the shallow South Atlantic Bight, creating the necessity of a regional, user-friendly guide.
Bayer (1961) did not include a key to the species or descriptions of the former Paramuriceidae (now Plexauridae) as they occurred too deep in the West Indian region. These species do occur in shallow water (<200m) in the South Atlantic Bight and are included in this key. Also included are four range extensions not previously recorded in shallow water at this latitude range. Future collections will undoubtedly reveal new species, although none are described in this work.
This document relies heavily on the prior work of F. M. Bayer and the reader is encouraged to refer to his work when identifying difficult specimens. In particular, his illustrations of octocoral sclerites are unparalleled and, in the absence of scanning electron microscope imagery, are the only quality reproductions of the sclerites of many species. Since the identification of some octocoral species relies on sclerite morphology, his skillful illustrations are a valuable resource.
Unless otherwise noted, all references, key characteristics, diagnoses, etc. in this document are applicable to octocoral species in the shallow South Atlantic Bight and do not necessarily represent world species.

The following abbreviations have been used: GML- Grice Marine Laboratory, College of Charleston, Charleston, SC; NMNH - National Museum of Natural History (Smithsonian Institution); SAB - South Atlantic Bight; SCDNR – South Carolina Department of Natural Resources; SERTC – Southeastern Regional Taxonomic Center, Charleston, SC; USNM - United States National Museum, used for previously cataloged material.

Introduction