title: Alveus, gen. nov. (Bacillariaceae, Bacillariophyta), a heavily silicified diatom found in warm water oceans.
abstract: Scanning electron microscope images of complete and damaged frustules of Nitzschia marina Grun. revealed an unusual chambered structure of the valve. This structure is not present in any existing nitzschioid genus and warrants an independent generic status for this taxon, which is therefore separated into Alveus gen. nov. Generic and emended specific definitions are provided and presented in the context of their relationship to other genera within the family Bacillariaceae. Deep relief of the inner surface of Alveus valves is similar to that of genera Fragilariopsis, Denticulopsis, Neodenticula, and Crucidenticula. It differs from all these diatoms in the alveolar striation. This heavily silicified diatom was found in samples from the US Joint Global Oceanographic Flux Studies cruise TT007 stations 2 and 4, (9 degrees and 5 degrees N respectively, 140 degrees W) in the equatorial Pacific. Presently, this uncommon species is restricted to warm waters. It is very common in the surface sediments of the equatorial Pacific and Indian Ocean and in the tropical and subtropical Atlantic. The sedimentary record of Alveus marinus goes back to the Middle Late Miocene (approximately 8 Ma years).
authors.affiliation: Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Kaczmarska
authors.forename: G A
authors.initials: GA
authors.lastname: Fryxell
mesh_terms: D001419:Bacteria / Q000145:classification / Q000166:cytology / Q000648:ultrastructure*; D017377:Diatoms / Q000166:cytology / Q000648:ultrastructure; D017348:Microscopy, Electron, Scanning Transmission; D010140:Pacific Ocean; D009626:Terminology as Topic; D014871:Water Microbiology