Caulerpa wysorii sp. nov., a denuded Caulerpa (Chlorophyta) resembling C. sertularioides when ‘dressed’

ABSTRACT

Routine DNA barcoding with the chloroplast gene tufA identified novel records of an unknown and denuded (i.e. lacking branchlets) Caulerpa species previously reported from the Florida Middle Grounds. tufA barcoding not only confirmed the matching molecular identity of this taxon with several newly collected denuded specimens from shallow habitats of the Yucatán shelf, but also with a set of plumose specimens previously collected from mesophotic depths of the West Florida shelf and recorded as Caulerpa sertularioides. Sequencing of two additional, faster-evolving DNA markers, i.e. nuclear ITS and the newly tested chloroplast-encoded rpoA, each confirmed conspecificity of the above morphotypes and the molecular separation of the new taxon from C. sertularioides and filiform species found in the region, namely C. cupressoides f. denudata and C. fastigiata. In light of our sequencing results and review of the early taxonomic history of filiform Caulerpa, we propose the description of Caulerpa wysorii sp. nov. for this new species that exhibits two distinct morphotypes in currently available collections, i.e. filiform or plumose assimilators. We also subsume C. tongaensis within the broadly distributed C. fastigiata, whose lectotype is also designated herein. In addition to Caulerpa wysorii sp. nov., we discovered yet another unknown denuded species from the Campeche Banks represented by a single specimen thus far.

KEYWORDS:

• Caulerpa cupressoides
• C. denudata
• C. fastigiata
• C. longiseta
• C. nuda
• C. tongaensis
• Cryptic species
• Endemic
• Mesophotic
• rpoA

Acknowledgements

We are thankful to Jo Wilbraham at BM for providing an image of A. Schott #369 and Patrick Frödén at LD for providing a picture of Harvey’s specimen 95. We also thank Barrett Brooks at US for bringing Sylvia Earle’s collections to our attention and discussion on filiform ‘spaghetti’ Caulerpa in the region. We also thank A.D.R. de N’Yeurt at USP Fiji for discussion of C. fastigiata and Denis Lamy, Lionel Kervran and Line Le Gall at PC for locating type specimens of C. fastigiata for lectotypification. We acknowledge L. dos Santos for assistance with PCR product cloning and W.E. Schmidt at UL for specimen information, pictures and discussion. This is SMS contribution #1151.

SUPPLEMENTARY MATERIAL

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

Additional information

Funding

TS acknowledges support from a Smithsonian G. E. Burch postdoctoral fellowship (2016–2019) and visiting professorship at UFRGS (current). SGAD thanks the Naturalis Biodiversity Center in Leiden and the Prince of Songkla University grant no. SCI610575S. LEMC and ACMG express their thanks for the fellowship granted under the program COFAA and EDI and Instituto Politécnico Nacional for the financial support (SIP20180489 and SIP20180491). BMD thanks project PNUD 3254 for the collection of Cuban specimens and Yusimí Alfonso of the Acuario Nacional de Cuba, where the specimen of C. cupressoides f. denudata is preserved. SF greatly acknowledges support from the National Science Foundation (DEB-0315995, DEB-1754504) and the Coastal Water Consortium of the BP/The Gulf of Mexico Research Initiative (GoMRI-I) for funding research cruises allowing mesophotic specimen collections.