Streptocaulus gracilis Fraser, 1937b

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, Zootaxa 4487 (1), pp. 1-83 : 63-64

Streptocaulus gracilis Fraser, 1937b

Streptocaulus gracilis Fraser, 1937b: 6 , pl. 2, fig. 10.

Holotype. USNM 43293 : Puerto Rico, off northeast coast, 18°30’20”N, 65°57’00”W, Johnson-Smithsonian Deep- Sea Expedition Sta. 9, 0 1 February 1933, 240–280 fm (439–512 m), R/ V Caroline, one colony, ca. 9 cm high, in fairly good condition, without gonophores, coll . Paul Bartsch, labelled “ type ” and “ holotype ”; ethanol.

Schizoholotype. BCPM 976-00946-001, Puerto Rico, one colony fragment, 1.3 cm high, in good condition, without gonophores; slide (slide is broken lateral to mount).

Type locality. Puerto Rico: off northeast coast, 18°30’20”N, 65°57’00”W, 240–280 fm (439–512 m) (Johnson- Smithsonian Deep-Sea Expedition Sta. 9; Bartsch, 1933).

Current status. Valid.

Remarks. The name-bearing type of Streptocaulus gracilis (USNM 43293), designated by Fraser (1937b) as a holotype, is listed in the NMNH database as a syntype. Examination of the type material confirms the existence of a single specimen, i.e., the holotype.

The single location record of the species as cited in Fraser’s original account, from the slope north of Puerto Rico (18°33’15”N, 65°56’45”W, 240 fathoms), does not match that of type material (USNM 43293) in the current online database record of the NMNH (syntype, N of St. Thomas, U.S. Virgin Islands, centroid latitude 18.5583, longitude -65, Johnson-Smithsonian Deep-Sea Expedition Sta. 98, 549 m). Neither of these locations appears to be correct. A label in the vial with the holotype specimen indicates that it was collected at Johnson-Smithsonian Deep- Sea Expedition Station 9, not Station 98. According to Bartsch (1933), Stn 9 was occupied at 18°30’20”N, 65°57’00”W, 240–280 fm (439–512 m) on 0 1 February 1933. He reported that at Station 98, sampling gear did not touch bottom and only pelagic animals were collected. A slide of S. gracilis exists in the RBCM (BCPM 976- 00946-001), but no collection data are provided with it. The species was not listed in Arai (1977). Collection data recorded above correspond with those of Station 9 in Bartsch (1933).

Streptocaulus gracilis , held to be valid in WoRMS, was described from a single specimen. Its trophosome was said by Fraser (1937b) to be a “Colony 8 cm in height…”, and the record in the NMNH database (USNM 43293) lists a specimen count of “1.” That specimen is the holotype, and material on a slide at the RBCM (BCPM 976- 00946-001) represents a fragment of the holotype (i.e., a schizoholotype).

Ramil & Vervoort (1992: 175) suggested that Streptocaulus gracilis may be referable to family Plumulariidae rather than Aglaopheniidae based on trophosomal morphology. If so, it warrants assignment to a genus other than the aglaopheniid taxon Streptocaulus Allman, 1883 . The gonosome of S. gracilis is unknown.