Porpita Lamarck, 1801

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 69-70

Genus Porpita Lamarck, 1801

Porpita Lamarck, 1801: 355 .

Type species. Porpita indica Lamarck, 1801 , a junior subjective synonym of Medusa porpita Linnaeus, 1758 [ Porpita porpita ], by monotypy.

Diagnosis. Porpitid hydroids with disc-shaped mantle and internal float; upper surface nearly flat or with central bulge, sail absent. Dactylozooids with capitate tentacles in three vertical rows.

Porpitid medusae with eight radial canals when mature; adults with one or two slender capitate marginal tentacles, young medusae lacking tentacles; algal symbionts usually present, aggregated in endodermal cells bordering radial canals.

Remarks. The widely used name Porpita Lamarck, 1801 (Hydrozoa) is a junior homonym of Porpita Soldani, 1789 (Protozoa) , as noted in an earlier work ( Calder 1988). Reversal of Precedence can be applied in this case under provisions of the current code (ICZN Art. 23.9), with Porpita Lamarck, 1801 being designated as both valid and a nomen protectum and Porpita Soldani, 1789 being relegated to a nomen oblitum. First, the senior homonym has not been used as a valid name in zoology after 1899 to my knowledge (ICZN Art. 23.9.1.1). Second, Porpita Lamarck, 1801 has been used in at least 25 works by more than 10 authors in the past 50 years (ICZN Art. 23.9.1.2) ( Brinckmann-Voss 1970, 1987; Herring 1971; Bouillon 1974, 1984b, 1985; Eldredge & Devaney 1977; Calder 1988, 1993; Petersen 1990; Cairns et al. 1991, 2002; Medel & López-González 1996; Schuchert 1996; Kelmo & Santa-Isabel 1998; Hoover 1998; Bullard & Hay 2002; Kirkendale & Calder 2003; Anderson et al. 2004; Oiso et al. 2005; Dunn et al. 2005; Shimabukuro et al. 2006; Bouillon et al. 2006; Gravier-Bonnet 2007; Daly et al. 2007).

More than 20 nominal species have been assigned at various times to this genus worldwide ( Calder 1988). Over the past century, most authors have recognized no more than three of these as valid: Porpita porpita ( Linnaeus, 1758) from the Indian Ocean, P. umbella (O.F. Müller, 1776b) from the Atlantic Ocean, and P. pacifica Lesson, 1826 from the Pacific Ocean. Moser (1925) and Totton (1954) have been followed here in regarding these three as conspecific, with the name P. porpita having priority. For reviews of the taxonomy and nomenclature of this genus, see Bigelow (1911) and Calder (1988).