Morphological and molecular variability of the sea anemonePhymanthus crucifer(Cnidaria, Anthozoa, Actiniaria, Actinoidea)

Abstract

The shallow water sea anemonePhymanthus cruciferexhibits three distinct morphotypes, characterized by the presence or absence of protuberances on the marginal tentacles, as well as intermediate forms. The taxonomic status of the different morphotypes and the diagnostic value of protuberances on the tentacles have been debated for this species and the family Phymanthidae. We analysed the external and internal anatomy, cnidae and three mitochondrial molecular markers for representatives of each of the three morphotypes. In addition, we address the putative monophyly of the family Phymanthidae based on molecular data. With the exception of the protuberances, our morphological and molecular results show no differences among the three morphotypes; thus, we consider this feature to be intraspecific variability withinP. crucifer. Furthermore, molecular data reveal that the family Phymanthidae is not monophyletic. In addition, we discuss several diagnostic morphological features of the family Phymanthidae.

Comparison of cnidae sizes between the two morphotypes of the giant Caribbean sea anemone Condylactis gigantea (Actiniaria: Actiniidae)

“…Regarding statistical analyses of the size of cnidae, significant variability was found between specimens within each morphotype, as have been also observed in other studies (e.g. Allcock et al, 1998;Watts et al, 2000;González-Muñoz et al, 2015Garese, Carrizo, & Acuña 2016). However, the comparison between the green and pink/purple morphotypes reveals no statistical variation, agreeing with previous morphological revisions which suggest that there are no other morphological differences between the morphotypes, besides the variability in the tentacular tip coloration (González-Muñoz et al, 2012).…”

“…Allcock, Watts, & Thorpe, 1998;Manchenko, Dautova, & Latypov, 2000;Watts, Allcock, Lynch, & Thorpe, 2000), while other attempts did not find statistical support to clearly separate species or morphotypes based on cnidae size differences (e.g. Solé-Cava & Thorpe, 1987;Chintiroglou & Karalis, 2000;González-Muñoz et al, 2015;González-Muñoz, Garese, Tello-Musi, & Acuña, 2017).…”

Universal target‐enrichment baits for anthozoan (Cnidaria) phylogenomics: New approaches to long‐standing problems

“…We will also design separate octocoral-and hexacoral-specific bait In fact, a 0.5% divergence level at an extended mitochondrial barcode (mtMutS+igrI+COI) was proposed as a conservative criterion for species delimitation (McFadden, Brown, Brayton, Hunt, & van Ofwegen, 2014;McFadden et al, 2011). Similarly, low divergence estimates at mitochondrial barcoding markers have been found among hexacoral congeners (Brugler, Opresko, & France, 2013;Gonz alez-Muñoz et al, 2015;Shearer & Coffroth, 2008). Thus, these UCE and exon loci are promising for resolving species boundaries, although the level of intraspecific variation has yet to be determined.…”

Species Delimitation in Sea Anemones (Anthozoa: Actiniaria): From Traditional Taxonomy to Integrative Approaches

“…This has typically been seen with allozymes markers (Solé-Cava and Thorpe, 1992;Monteiro et al, 1997;Manchenko et al, 2000;Schama et al, 2005); although analyses using high-throughput sequencing technologies have reached quite similar conclusions (Reitzel et al, 2013;Spano et al, 2018). Phylogenetic approaches using single or concatenated genes are less consistent, detecting both high and low levels of differentiation among closely related lineages (Acuña et al, 2007;Gomes et al, 2012;Pereira et al, 2014;Canales-Aguirre et al, 2015;González-Muñoz et al, 2015;Mallien et al, 2018). In terms of phylogenetic informativeness, the fragments12S rDNA and 18S rDNA have proved to be more proficient to recover well-supported nodes compared to 16S rDNA, 28S rDNA and other barcode markers, such as COI and ITS (Daly et al, 2010;Dohna and Kochzius, 2016).…”

“…Likewise, body structures such as marginal projections not only become noticeable in adult individuals but also may vary due to environmental or ontogenetic factors (Francis, 1973;Bigger, 1980;Ayre and Grosberg, 1995). While the morphology of the musculature may seem less problematic, critically important features such as the sphincter muscle have not been exempted from controversies (England, 1987;Rodríguez and López-González, 2008;González-Muñoz et al, 2015). Relationship between the number of records for a species and its number of synonymous names.…”