Synthecium gracile Fraser 1937
Creators: name: Calder, Dale R.
name: Choong, Henry H. C.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Hydrozoa
Leptothecata
Syntheciidae
Synthecium
Synthecium gracile

description: Synthecium gracile Fraser, 1937b
? Sertularella cylindrica var. pusilla Ritchie, 1910: 817, pl. 77, fig. 9.
Cyclonia gracilis Stechow, 1921b: 230.
? Hincksella cylindrica Blackburn, 1937: 173, fig. 2.
Synthecium gracile Fraser, 1937b: 2, pl. 1, fig. 2 [invalid junior primary homonym of Synthecium gracile Coughtrey, 1875]. Hincksella gracilis.— Vervoort & Watson, 2003: 245.
? Hincksella pusilla.— Vervoort & Watson, 2003: 245.
Holotype. USNM 43286: Puerto Rico, N of Salinas Point, Johnson-Smithsonian Deep-Sea Expedition Sta. 26, 18°30’30”N, 66°23’05”W, 0 7 February 1933, 60– 73 m, R/ V Caroline, one colony on a hydroid stem, ca. 6 mm high, in fair condition, without gonophores, coll. Paul Bartsch, labelled “ type ”; ethanol.
Paratype. BCPM 976-00962-001: Puerto Rico, north coast, Johnson Hydro Sta. 26 (Johnson-Smithsonian Deep-Sea Expedition Sta. 26), 0 7 February 1933, one colony overgrowing another hydroid, in poor condition, without gonothecae, labelled “co-type”; dry sometime in the past, 60% IPA.
Type locality. Puerto Rico: 18°30’30”N, 66°23’05”W, 33–40 fm (60–73 m) (Bartsch 1933, Sta. 26; Fraser 1937b).
Current status. Invalid.
Remarks. Synthecium gracile was described by Fraser (1937b) from a specimen collected during the Johnson- Smithsonian Deep-Sea Expedition. The single colony at the NMNH (USNM 43286) was designated by him as the holotype, although it is currently listed as a syntype in the NMNH online database. Material in the Fraser Hydroid Collection at the RBCM (BCPM 976-00962-001), from the same location and labelled “co-type”, constitutes a paratype. Another specimen of S. gracile at the RBCM (BCPM 976-00963-001: slide), collected from “Cerros Island” (Cedros Island, Mexico) during the Allan Hancock Pacific Expeditions (Fraser 1938a), is not type material.
The nomenclature of S. gracile Fraser, 1937b is fraught with homonymy. The name is a junior primary homonym of S. gracile Coughtrey, 1875 (established as S. gracilis, but corrected to S. gracile by Thompson 1879). Homonymy no longer exists between the two names because S. gracile Fraser is now assigned to Hincksella Billard, 1918, while S. gracile Coughtrey is referred to Amphisbetia L. Agassiz, 1862. However, the name of Fraser’s species then becomes a junior secondary homonym of Hincksella gracilis (Stechow, 1921b) (originally Cyclonia gracilis).
Vervoort & Watson (2003: 245) considered Fraser’s hydroid to be a briefly described and poorly illustrated species of doubtful identity, likely conspecific with Hincksella pusilla (Ritchie, 1910) from the Mergui Archipelago, Indian Ocean. It is listed by WoRMS as a synonym of H. cylindrica (Bale, 1888), in common with Vervoort (1968), Calder (1991), and others. However, Galea & Ferry (2015) presented evidence that H. cylindrica is a species restricted to Australia, and concluded that the species of warm waters in the western Atlantic (including Cyclonia gracilis Stechow, 1921b) is identical with H. pusilla. With Fraser’s species currently held to be a probable synonym (for a recent synonymy list, see Galea 2010), it seems unnecessary to provide a replacement name for it here.
description: Published as part of Calder, Dale R. & Choong, Henry H. C., 2018, Names of hydroids (Cnidaria, Hydrozoa) established by Charles McLean Fraser (1872 - 1946), excluding those from Allan Hancock Expeditions, pp. 1-83 in Zootaxa 4487 (1) on pages 49-50, DOI: 10.11646/zootaxa.4487.1.1, http://zenodo.org/record/1456161