Could polyp pulsation be the key to species boundaries in the genus Ovabunda (Octocorallia: Alcyonacea: Xeniidae)?

Evaluating the genus Cespitularia MilneEdwards & Haime, 1850 with descriptions of new genera of the family Xeniidae (Octocorallia, Alcyonacea)

“…Members of the octocoral family Xeniidae form a major faunistic component on shallow Indo-Pacific coral reefs (e.g., Alderslade 2001, Janes 2013, McFadden et al 2014, Halàsz et al 2014, 2015). They play a significant ecological role in coral reef ecosystems, exhibiting a rapid colonization rate (e.g., Tilot et al 2008, Wild and Naumann 2013) as well as invasive capabilities (Ruiz-Allais et al 2014).…”

“…The number of pinnule rows and the number of pinnules in the outermost row have been considered taxonomically diagnostic (e.g., Hickson 1931a, Reinicke 1997, Halàsz et al 2014). However, Halàsz et al (2015) and subsequently McFadden et al (2017) demonstrated that this character is not informative for species delineation among members of the xeniid genus Ovabunda Alderslade, 2001. The taxonomic literature on Xeniidae also considers several other morphological characters to be informative, such as colony shape, dimensions and coloration, as well as polyp retractability and pulsation in the live state (e.g., Reinicke 1997, Halàsz et al 2014, 2015).…”

Molecular operational taxonomic units reveal restricted geographic ranges and regional endemism in the Indo‐Pacific octocoral family Xeniidae

“…These challenges arise in part because much of the early literature on the group is poorly illustrated and species descriptions may not correctly describe the type specimens on which they are based, making it difficult to put names on morphospecies without direct comparison to the original type material (Benayahu, van Ofwegen, & McFadden, ; Halàsz, ; Halàsz, McFadden, Aharonovich, Toonen, & Benayahu, ). In addition, recent taxonomic studies have suggested that morphological features of polyps and sclerites that have traditionally been used to diagnose and distinguish species of xeniids from one another are often unreliable and incongruent with genetically determined species boundaries (Benayahu, van Ofwegen, & McFadden, ; Halàsz, Reynolds, McFadden, Toonen, & Benayahu, ; Halàsz et al., ; McFadden, Brown, et al., ; McFadden et al., ). Although scanning electron microscopy has identified new morphological characters (e.g.…”

“…Although scanning electron microscopy has identified new morphological characters (e.g. the crystalline microstructure of skeletal elements; Alderslade, ; Aharanovich & Benayahu, ) that help to discriminate genera reliably (Benayahu, van Ofwegen, & McFadden, ), identification of new morphological characters to discriminate species—especially ones that can be observed in the field—is an ongoing challenge (Halàsz et al., ; McFadden et al., ).…”

“…Although approximately 138 species of xeniids belonging to 19 genera are listed currently in the World Register of Marine Species (WoRMS Editorial Board, ), the true number remains unknown, and recent molecular genetic studies have suggested that some genera may be comprised of fewer species than have been described based on morphology (Halàsz et al., ; McFadden et al., ). Geographical ranges of species as reflected in the classical taxonomic literature may also be highly speculative.…”