Non-blue Haslea species (Bacillariophyceae: Naviculaceae) in the benthic marine flora of Guam (Mariana Islands, Western Pacific Ocean).

Abstract

In recent years the taxonomy of Haslea has been in flux. We describe several Haslea taxa from Guam, including four new species, in light of these recent findings. Four delicate, fusiform Haslea species are described from a variety of benthic habitats on coral reefs. These species, H. fusiformis comb. nov. and H. alexanderi, H. apoloniae and H. guahanensis spp. nov. are distinguished by stria density, foramen (‘areola’) shape, and cell size from each other and from similar taxa. A key to all these taxa is provided. In addition, an arcuate species is described as Haslea arculata sp. nov. The presence of a bilayered wall is shown for all these taxa. We compare the morphology of specimens reported as H. howeana from Guam with Navicula tsukamotoi, recently described from Okinawa, and with ‘Navicula cf. howeana’ from Puerto Rico. We provide the first account of the complex cingulum of N. tsukamotoi. We conclude that our specimens match N. tsukamotoi and that H. howeana should be returned to Navicula, but we leave open the question of conspecificity.

Keywords:

• biodiversity
• copulae
• coral reefs
• diatoms
• Mariana Islands
• Naviculales

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Acknowledgements

Claire Perez was supported by an internship from the Islands of Opportunity Louis Stokes Alliance for Minority Participation (LSAMP) program, funded by the National Science Foundation. The microscopes in the U. Guam Microscopy Teaching and Research Laboratory were purchased with grants from the National Institute of General Medical Sciences, Minority Opportunities in Research (MORE) Division, Research Initiatives in Scientific Excellence (RISE) program (2003–2010). Culture, sequencing and SEM work conducted at UT Austin were generously supported by the Jane and Roland Blumberg Centennial Professorship in Molecular Evolution awarded to Dr. Edward Theriot. We thank Anton Igersheim, then at Naturhistorisches Museum Wien, for the loan of Grunow’s material, and Maria Schefter for continuous support in the field work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed https://doi.org/10.1080/0269249X.2020.1761887.

ORCID

Christopher S. Lobban http://orcid.org/0000-0003-1596-0656