Primnoidae Duchassaing & Michelotti, 1864

Horvath, Elizabeth Anne, 2019, A review of gorgonian coral species (Cnidaria, Octocorallia, Alcyonacea) held in the Santa Barbara Museum of Natural History research collection: focus on species from Scleraxonia, Holaxonia, Calcaxonia - Part III: Suborder Holaxonia continued, and suborder Calcaxonia, ZooKeys 860, pp. 183-306 : 187-189

Genus Primnoidae Duchassaing & Michelotti, 1864

Gorgonia (part) Valenciennes, 1855: 12.

Swiftia Duchassaing & Michelotti, 1864: 13. Kükenthal 1924: 236. Deichmann 1936: 185-186. Bayer 1956: F206. Grasshoff 1977: 161. Muzik 1979: 167. Bayer 1981: 945. Breedy et al. 2015: 329.

Stenogorgia Verrill, 1883: 29 [= Swiftia , des. by Deichmann 1936: 186]. Grieg 1887: 5, 18. Studer (and Wright) 1887: 64. Studer 1901: 51. Nutting 1909: 723; 1910c: 6. Jungersen 1917: 1186. Bielschowsky 1918: 45. Kükenthal 1924: 347 ( Stenogorgia synonymy).

Platycaulos Wright & Studer, 1889: 61, 146-147. Nutting 1912: 94. Bayer 1981: 945.

Callistephanus Wright & Studer, 1889: 62, 148. Nutting 1912: 96. Bayer 1981: 945.

Allogorgia , Verrill, 1928: 8.

Thesea (pars) Verrill, 1869: 428.

Filigorgia Stiasny, 1937: 307.

Type species.

Gorgonia exserta Ellis & Solander, 1786: 87 (non Thesea exserta Duchassaing & Michelotti, 1860); [= Stenogorgia Verrill, 1883].

Diagnosis.

Colonies chiefly in one plane, with lax branching (dichotomous or pinnate-like); branches/branchlets tend to curve upwards; in some species, anastomoses possible (fan-like); in others, minimal branching or none. Polyps widely scattered, or crowded; often lateral or biserial, forming prominent conical or cylindrical mounds; on tips of branchlets, two polyps always opposed; conical anthostele seldom retracted; generally, polyps retractile. Anthocodiae commonly tall, exsert. Coenenchyme thin to moderate, somewhat rough/granular, outer layer filled not only with spinous rods or spindles, but with capstans having warts more or less conspicuously modified as double disks; some capstans quite foliate; inner layer mostly restricted to areas between longitudinal canals, containing only small capstans. Mound margins, base of tentacles, with numerous rows of conspicuous, stout spindles as bar-like rods, characteristic for species in the genus (fingerbiscuit shaped; see Bayer et al. 1983, pp 72-73, pl 19, figs 184-185). Axis is horny, flexible, somewhat flattened. Colony colors generally red, red-orange, pink or white.

Etymology.

Deichmann (1936) stated that the definition of the genus Swiftia corresponded exactly with Stenogorgia Verrill, 1883; the problem discussed there stemmed from a misinterpretation of G. exserta Ellis & Solander, 1786 by Verrill (also by Kükenthal 1924). See remarks, following.

Remarks.

The stout, anthocodial rods (seen at mound margins and bases of tentacles), are definitive for this genus. Examinations of multiple specimens (several different species) within this genus usually revealed the appearance of these rods; when present, looking much like the fingerbiscuit sclerite form shown in Bayer et al. (1983) for the genera Clavularia Blainville, 1830 and Ptilosarcus Verrill, 1865 (neither of these gorgonian genera), where sclerites are described as minute, flattened rods (rods here have a bit of depth). Further examinations (multiple species) revealed that some individual colonies of species in the genus did not have these conspicuous rod forms (having only spindles and capstans). Other colonies displayed spinous spindles and/or capstans and anthocodial rods; some few species had only the fingerbiscuit rods, numerous throughout all tissue structures. The rod form is not always easy to obtain in a sclerite array; some specimens without rods may actually have them, but they may be quite small, not very numerous and very widely scattered. A trend observed is that colonies further north in the Pacific (Alaska) have very obvious rods, while specimens of some of the same species collected in California (specifically central and southern California) may have rods, but infrequently. By way of comparison, in several species from the genus examined from waters in/near New Zealand, some had only rods, and no other form of sclerite. It appeared that colder, temperate to subpolar species had the rods (to the exclusion of all others) but species from warmer, albeit temperate water, tended to display a minimal number or complete absence of rods. Examination of many more specimens, collected in both hemispheres from poles to equator, could reveal further insight into the appearance of this key sclerite form. To further clarify questions surrounding location ranges for each of the Swiftia species discussed, Appendix 2: Map A1 shows the distributional range of each and Appendix 1: Table A1 shows key features used to distinguish one species from another.

Regarding use of the generic name Swiftia , Muzik (1979) stated: "(t)o preserve the generic name Swiftia a petition to" the International Commission on Zoological Nomenclature "(ICZN) must be made;" uncertain as to whether this was ever done. "For a full explanation, see Challenger Reports 31: 146 and Deichmann 1936: 185" ( Muzik 1979). The complete explanation can be found in Deichmann (1936) and Muzik (1979: 168); they serve to confirm the confusion that had developed, through the work of previous investigators, regarding generic status for the species discussed below. In Madsen (1970: 5), "A total of about a dozen gorgonarian species referred or referable to Swiftia (syn. Stenogorgia ) from widely scattered localities in all three oceans have been recorded, but only a few of them are sufficiently described." In the WoRMS Database (Cordeiro et al. 2018), status of this genus has been accepted, but Breedy et al. (2015: 329) stated that a "thorough review is needed in order to clarify taxonomic problems related to Swiftia ." This paper attempts to clarify some of the issues related only to those species that are found in, near, or extending geographically slightly south or north of the California Bight.

Figures

Map A 1. Distribution of species in genus Swiftia seen in, or immediately adjacent to, the California Bight. Range extensions are not definitive, but illustrative of the geographic distribution of specimens housed in SBMNH collection.