The Brown Alga Delmarea attenuata Does Not Occur in New England

Abstract

Delamarea attenuata (Kjellman) Rosenvinge is a species of brown algae restricted to cold waters of the North Atlantic and the North Pacific. This monotypic genus is distinguished by its unbranched cylindrical parenchymatous axes with a surface layer of large, loosely connected vesicular pigmented cells called paraphyses (Hariot 1889; Kawai and Kurogi 1980; Rosenvinge and Lund 1947). Ovate unilocular sporangia or elongate plurilocular sporangia are typically produced on separate thalli but sometimes on the same thallus (Pedersen 1984). The family Delamareaceae has been recognized by Zinova (1953), primarily on the unique structure of the paraphyses. The order Delamareales was established by Lund (1959), but Pedersen (1974, 1984) argued against ordinal recognition, placing the Delamareaceae within the Dictyosiphonales. Evidence from gene-sequencing analyses, which have included Delamarea, currently places the Dictyosiphonales within a broadly circumscribed Ectocarpales (Draisma et al. 2001). This note is to point out that an error has persisted in the literature regarding the alleged occurrence of this distinctive species in New England (Guiry and Guiry 2007; Sears 1998, 2002; Taylor 1957). Taylor (1957) reported it to occur from both ‘‘southern Massachusetts and Ile Miquelon’’ off the south coast of Newfoundland. The latter location is correct in that Hariot (1889) first described Delamarea from there (as D. paradoxa Hariot). Later, Rosenvinge (1893) recognized that Kjellman’s (1883) Scytosiphon attenuatus, described from Spetsbergen, was a taxonomic synonym that had priority over Hariot’s binomial. Taylor’s (1957) record of Delamarea attenuata from Massachusetts is here questioned. Taylor cited Doty’s (1948) report of Scytosiphon attenuatus from Woods Hole, Massachusetts. It is RHODORA, Vol. 110, No. 942, pp. 231–234, 2008 E Copyright 2008 by the New England Botanical Club