Recent collecting cruises conducted in the Northwestern Gulf of Mexico at 40- to 90-m depth revealed a diverse deepwater flora that is dominated by members of the Cryptonemiales complex. In this article, we describe two species new to science, Platoma chrysymenioides sp. nov. (Schizymeniaceae) and Sebdenia integra sp. nov. (Sebdeniaceae). Chloroplast-encoded rbcL sequence analyses corroborate morphological and nuclear small subunit ribosomal RNA gene data that the red algal orders Cryptonemiales and Rhodymeniales are closely related. The allied order Nemastomatales is strongly supported to include the Nemastomataceae and Schizymeniaceae, but the phylogenetic position of the Sebdeniaceae and Tsengiaceae remains equivocal. The Cryptonemiales, Rhodymeniales, Nemastomatales, Sebdeniaceae, and Tsengiaceae form a well-supported monophyletic assemblage—the Cryptonemiales complex—within the Rhodophyta.

Depth range
40- 90 m

Mesophotic “mentions”
0 x (total of 8019 words)

Classification
* Presents original data
* Reports new species
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'

Fields
Evolution
Taxonomy

Focusgroups
Algae (Macro, Turf and Crustose Coralline)

Locations
USA - Gulf of Mexico

Platforms
Dredging / trawling
Remotely Operated Vehicle (ROV)