New species of Galene and Howella gen. nov. (Halymeniaceae, Rhodophyta) from the mesophotic zone off Bermuda

ABSTRACT

The mesophotic zone off the coast of Bermuda has been explored for macroalgae beginning with the R/V Seahawk cruises of the 1980s and most recently on the Nekton XL Catlin cruise of the R/V Baseline Explorer in 2016. In this paper, we present two new members of the Halymeniaceae discovered on these missions based upon a combined ML analysis of mitochondrial (COI-5P), plastid (rbcL) and nuclear genes (LSU), as well as morphological and anatomical characteristics. Howella gorgoniarum gen. et sp. nov. grows conspicuously on the base of soft corals, and represents one of the three species in the new genus. Two species of the non-monophyletic Thamnoclonium, T. latifrons Endlicher & Diesing and T. lemannianum Harvey from South Africa and Australia, are moved to Howella based upon their molecular phylogenetic placements. First collected offshore of Bermuda in 1960 and misidentified as Halymenia hancockii, Galene leptoclados sp. nov. represents the first species in its genus collected outside of the western Pacific.

KEYWORDS:

• COI-5P
• Galene leptoclados sp. nov.
• Howella gorgoniarum gen. et sp. nov.
• LSU
• rbcL
• Thamnoclonium
• Western Atlantic

Acknowledgements

We thank crew and divers aboard the 1980s’ R/V Seahawk cruises including Drs Chuck Amsler, Paulette Peckol and Rick Searles. The XL Catlin Deep Ocean Survey, Nekton’s mission to the Northwest Atlantic and Bermuda aboard the R/V Baseline Explorer (BEX), allowed for the 2016 collections. Our work on the BEX would have been impossible without the assistance of Capt. Larry Bennett and his crew, Brownies Global Logistics, Triton Submersibles and pilots, and the technical divers of Global Underwater Explorers led by Dr. Todd Kincaid. Christopher Flook of the Bermuda Institute of Ocean Sciences (BIOS) and Roger Simmons of the Bermuda Aquarium, Natural History Museum and Zoo (BAMZ) provided logistical support while in Bermuda. A specimen loan of Halymenia hancockii from MICH was kindly arranged by Dr. Michael Wynne. This is contribution no. 274 to the Bermuda Biodiversity Project (BBP) of BAMZ, Department of Environment and Natural Resources, and Nekton contribution No. 14.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

Field work for this project was supported by the National Undersea Research Program of the U.S. National Oceanic and Atmospheric Administration (NOAA SU-0683-2), and by the Nekton Foundation, Oxford, England with the support of XL Catlin and the Garfield Western Foundation. The genetic work at UNB was supported by Discovery and Accelerator grants to GWS from the Natural Sciences and Engineering Research Council of Canada, as well as funding from the Canada Foundation for Innovation, the New Brunswick Innovation Foundation and the Nekton Foundation.