species from south and south-eastern Australia (Ectocarpales, Phaeophyceae): a DNA barcoding approach

Abstract

Defining species in the brown algal genus Colpomenia is a challenging endeavour because of their morphological similarity, overlapping phenotypic variation, the absence of conspicuous diagnostic characters, and often lack of reproductive structures crucial for their identification. Thus, the use of molecular tools has become widely used to study Colpomenia taxonomy and evolution. The following four Colpomenia species are described along the Australian coast: C. claytoniae M.Boo, K.M.Lee, G.Y.Cho & W.Nelson, C. ecuticulata M.J.Parsons, C. peregrina Sauvageau, and C. sinuosa (Mertens ex Roth) Derbès & Solier. The objective of this study was to assess the diversity of Colpomenia species in southern and south-eastern Australia by using DNA barcoding techniques and single-marker species delimitation methods. We generated 44 new COI-5P DNA sequences from nine different populations across three Australian states (South Australia, Victoria and Tasmania), and applied 13 variations of four species delimitation methods (ABDG, SPN, PTP, GMYC). Our results recognised three Colpomenia species in the region, namely, C. sinuosa, C. claytoniae, and C. peregrina. Colpomenia sinuosa is the most widely distributed species in Australia. Colpomenia peregrina and C. claytoniae presented high levels of intraspecific genetic divergence. We did not find C. ecuticulata, although it has been previously reported from nearby our sampling area.

Filogeografia e diversidade do gênero Colpomenia (Ectocarpales, Phaeophyceae) no Brasil e Austrália

“…Cho & W.Nelson (Guiry and Guiry 2021). Within Australia C. sinuosa is also the most geographically widespread Lee et al 2013;Martins et al 2021). Morphological variation between Colpomenia species in Australia proposed by were tested by who recognized C. sinuosa and C. peregrina as distinct species by circumscribing them using morphometric and statistical analyses.…”

“…Molecular techniques are revealing that macroalgal species generally comprise complexes of cryptic and quasi-cryptic species. Some molecular studies have detected cryptic diversity and possible cryptic speciescomplexes within Colpomenia, such as within C. sinuosa Lee et al 2013), C. peregrina (McDevit and and C. claytoniae (Martins et al 2021).…”

“…Therefore, the objectives of this study were (Martins et al 2021). Morphological variation between putative Colpomenia species in Australia proposed by were tested by (Martins et al 2021).…”

“…Therefore, the objectives of this study were (Martins et al 2021). Morphological variation between putative Colpomenia species in Australia proposed by were tested by (Martins et al 2021). In a worldwide approach, the existence of two major global lineages were proposed within C. sinuosa: a northern and a southern hemisphere lineages ).…”

“…identified four major C. peregrina lineages. Lastly,Martins et al (2021) detected three major C. claytoniae lineages occurring in Australia. All these studies suggested the occurrence of possible cryptic species within Colpomenia cryptic complex species and in other macroalgae cases frequently makes defining species problematic, Martins et al 2021 or even impossible based on morphological characters alone.…”