Clathrina curacaoensis, Cóndor-Luján & Louzada & Hajdu & Klautau, 2018

Subclass Calcinea View in CoL

The phylogenetic affinities inferred from our ITS and C-LSU trees were congruent with the classification proposed by Klautau et al. (2013) using ITS, and by Voigt & Wörheide (2016) using C-LSU. With the addition of new sequences ( C. curacaoensis sp. nov. and B. tenuispinata ), we supported the monophyly of the genera Clathrina and Borojevia as obtained in other recent studies ( Azevedo et al., 2017; Voigt et al., 2017).

According to Klautau et al. (2016), ‘ the development of a peduncle and of parasagittal spicules probably appeared only once in the evolution of Clathrina ’ as former guanchas ( C. blanca , C. hispanica , C. ramosa ) clustered in a monophyletic clade in their phylogenetic tree (fig. 16, p. 38). In this study, C. curacaoensis sp. nov., a species with parasagittal spicules (but without peduncle), did not group with the referred species (former guanchas), indicating that at least parasagittal spicules appeared independently more than once in Clathrina .

In Calcinea View in CoL , the molecular information obtained from both DNA markers (ITS and C-LSU) certainly contributed to the identification of species. DNA similarity (p distance) and tree topology (well-supported monophyletic clades) were appropriate approaches for delimiting species and genera, as pointed out by Azevedo et al. (2017) using ITS sequences. It was also possible to test whether or not the morphological variation observed among some conspecific specimens corresponded to true interspecific polymorphism/plasticity. Azevedo et al. (2017) suggested that trichoxeas do not seem to be reliable characters to differentiate species in Clathrina View in CoL as specimens of C. mutabilis View in CoL with and without trichoxeas clustered together in their ITS tree ( Fig. 18 View Figure 18 , p. 338). We confirmed this result adding sequences of Curaçaoan specimens of C. mutabilis View in CoL in the phylogenetic tree, and we also found the same pattern in another species, C. lutea View in CoL .