Fragilariforma horstii sp. nov. (Bacillariophyceae) a new araphid species from the northern United States of America
Morales EA, Manoylov KM, Bahls LL. 2012. Fragilariforma horstii sp. nov. (Bacillariophyceae) a new araphid species from the northern United States of America. Nova Hedwigia (Stuttgart, Germany). 141:141-154
A new taxon, namely Fragilariforma horstii E. Morales, Manoylov & Bahls, is described from rivers in the northern United States of America. Light (LM) and scanning electron microscopy (SEM) data reveal that the taxon has several features congruent with taxa currently placed in Fragilariforma D. M. Williams & Round such as uniseriate striae recessed between thickened costae, simple round areolae, spines on the costae at the valve face/mantle junction, a portula along a stria, developed apical pore fi elds, and ligulate, open girdle bands. However, the taxon also exhibits unique features that justify its separation at the species level from any currently known taxon within Fragilariforma: 1) the spines are subtended by a siliceous ring having short extensions projecting onto the valve face, 2) there is a portula lacking a labiate internal structure, and 3) the girdle bands lack perforations. Among Fragilariforma spp. producing a cruciform shape, the new species is distinguished by the tapering and narrowly rounded apices and the much higher stria density. The new taxon is circumneutral to acidophilous and oligo- to mesotraphentic. A discussion is presented about the morphology and ecology of this taxon in the light of pertinent literature.
- Type
- Journal Article
- Authors
- Morales, Eduardo; Manoylov, Kalina; Bahls, Loren
- Units
- GLAC
- Keywords
- Aquatic Studies, araphid diatoms, Bacillariophyceae, Fragilariforma horstii sp. nov.