Cladocarpus longipinna Fraser, 1945a

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 : 61

Cladocarpus longipinna Fraser, 1945a

Cladocarpus longipinna Fraser, 1945a: 22 , figs. 3a–d.

Holotype. USNM 43465: USA, Louisiana, R/V Pelican Sta. 13, Gulf of Mexico, 29°20’N, 88°16’W, 0 5 February 1938, one colony, ca. 7 cm high when extended, in good condition, with gonophores and antler-shaped phylactocarpia, labelled “ type ”; ethanol.

Type locality. USA, Louisiana: R/ V Pelican Sta. 13, 29°20’N, 88°16’W, 33 fm (60 m) ( Fraser 1945a).

Current status. Valid.

Remarks. Fraser (1945a) described Cladocarpus longipinna from a fragmentary colony (“Fragment of colony, 4 cm, was not branched;…”). The specimen, in collections at the NMNH (USNM 43465), was designated by him as the “ type ” of the species. While currently listed as a syntype in the current online database of the NMNH, a single colony is present and it is regarded here as the holotype. No other type specimens of C. longipinna are known to exist.

The specific name longipinna , derived from a combination of the Latin words longus (long) and pinna (feather), is taken to be a noun in apposition. Its ending therefore need not agree with the gender of the generic name with which it is combined (ICZN Art. 34.2.1). The name is misspelled (as both “ longispina ” and “ longispinna ”) on several labels accompanying the holotype, but the binomen is written as “ Cladocarpus longipinna ” on a small label in Fraser’s handwriting and in the published account of the species.

Cladocarpus longipinna is an obscure species known primarily from the original description and from the holotype colony. According to Fraser (1947a), it resembles C. septatus Nutting, 1900 , but differs in having a polysiphonic stem, longer and more slender hydrothecae with a greater number of small marginal cusps, and simpler phylactogonia. After examining the holotype, we question whether the hydrocaulus is truly polysiphonic. The species is currently recognized as valid ( Bouillon et al. 2006; Calder & Cairns 2009; WoRMS), although further study of its taxonomic status is warranted.