PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 117(4):447-487. 2004. Studies on western Atlantic Octocorallia (Coelenterata: Anthozoa). Part 5: The genera Plumarella Gray, 1870; Acanthoprimnoa, n. gen.; and Candidella Bayer, 1954 Stephen D. Cairns and Frederick M. Bayer Department of Zoology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, D.C. 20013-7012, U.S.A., e-mail:
[email protected] Abstract. — The nine western Atlantic species belonging to three genera, Plu-marella, Acanthoprimnoa, and Candidella, are described and illustrated. Four new species of Plumarella are described, as well as one new species of Acan-thoprimnoa; the genus Acanthoprimnoa is also described as new, differentiated from Plumarella by lacking tubercles on the undersurfaces of its sclerites. Two western Pacific species are transferred to Acanthoprimnoa: A. serta and A. cristata. Three varieties are recognized of the common Plumarella pourtalesii, one previously described as a variety {P. p. robusta) and another proposed herein (P. p. var. obtusa). A dichotomous key and table of comparisons is provided for the species and forms of Plumarella, as are a table of comparisons for the two Atlantic species of Acanthoprimnoa, and an indented key to the eleven genera of western Atlantic Primnoidae. Specimens of these genera were found to be extremely common at lower shelf and upper slope depths primarily in the temperate western Atlantic; over 1500 specimens were examined in this study, including types of all included species. This is the fifth in a series of revisions (Cairns 2001; Cairns & Bayer 2002, 2003, 2004) of the western Atlantic deep-water octocorals, and the fourth dealing with the Primnoidae, a family consisting of about 205 species and 32 genera worldwide, of which approximately 33 species and 1 1 genera occur in the western Atlantic. Bay-er's revision of western Atlantic Calyptro-phora (2001) should also be considered as the first unnumbered part of this series, which also deals with primnoids. In order to facilitate identification at the generic lev-el within this family a key is provided be-low for those 1 1 genera that occur in the western Atlantic. Two genera occur twice in the key since they have both dichoto-mous and pinnate branching. In this part we review the genera Plumarella and Candi-della, as well as describe a new genus, Acanthoprimnoa, separated from Plumar-ella on the basis of its lacking tubercles on the undersurfaces of its sclerites. Specimens of Plumarella and Acanthoprimnoa are ex-tremely common at shelf and upper slope depths (137-1 160 m) in the western Atlan-tic, occurring there opportunistically as weeds do on dry land. Ironically, species of these two genera were previously known from only 1 1 stations and as many speci-mens from the western Atlantic; this report lists approximately 1425 specimens from 145 localities. The third genus, Candidella, is known from deeper water (514-2139 m), and occurs farther north (New England Sea-mounts) as well as in the eastern Atlantic. Indented Key to the 1 1 Western Atlantic Genera of Primnoidae (fraction indicates number of western Atlantic species/total number of species; genera in bold face treated in this part) I. Colonies unbranched or extremely sparsely branched: Primnoella (4/14)
Localities extracted from OCR text.
Specimen codes extracted from OCR text.
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