Molecular and morphological diversity of Narragansett Bay (RI, USA) Ulva (Ulvales, Chlorophyta) populations. Issue 5 (16th September 2013)

• Record Type: Journal Article
• Authors: Guidone, Michele; Thornber, Carol; Wysor, Brian; O'Kelly, Charles J.; Dunton, K.
• Is Part Of: Journal of phycology. Volume 49:Issue 5(2013:Oct.)
• Page Start: 979
• Page End: 995
• Publication Date: 2013-09-16
• Subjects: Algae -- Periodicals; 579.8
• DOI: 10.1111/jpy.12108
• Languages: English
• ISSNs: 0022-3646

Abstract

<abstract abstract-type="main" id="jpy12108-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Macroalgal bloom‐forming species occur in coastal systems worldwide. However, due to overlapping morphologies in some taxa, accurate taxonomic assessment and classification of these species can be quite challenging. We investigated the molecular and morphological characteristics of 153 specimens of bloom‐forming <italic>Ulva</italic> located in and around Narragansett Bay, RI, USA. We analyzed sequences of the nuclear internal transcribed spacer 1 region (ITS1) and the chloroplast‐encoded <italic>rbc</italic>L; based on the ITS1 data, we grouped the specimens into nine operational taxonomic units (OTUs). Eight of these OTUs have been previously reported to exist, while one is novel. Of the eight OTUs, all shared sequence identity with previously published sequences or differed by less than 1.5% sequence divergence for two molecular markers. Previously, 10 species names were reported for <italic>Ulva</italic> in Rhode Island (one blade and nine tube‐forming species) based upon morphological classification alone. Of our nine OTUs, three contained blade‐forming specimens (<italic>U. lactuca, U. compressa, U. rigida</italic>), one OTU had a blade with a tubular stipe, and six contained unbranched and/or branched tubular morphologies (one of these six, <italic>U. compressa</italic>, had both a blade and a tube morphology). While the three blade‐forming OTUs in Narragansett Bay can frequently be distinguished by careful observations of morphological characteristics, and spatial/temporal distribution, it is much more difficult to distinguish among the tube‐forming specimens based upon morphology or distribution alone. Our data support the molecular species concept for <italic>Ulva</italic>, and indicate that molecular‐based classifications of <italic>Ulva</italic> species are critical for proper species identification, and subsequent ecological assessment or mitigation of <italic>Ulva</italic> blooms.</p> </abstract>