Abstract
All the currently known sponge species bearing placochelae or placochelae-like spicules (i.e. belonging to the genera Guitarra, Coelodischela, Tetrapocillon, Euchelipluma, and Hoplakithara) have been reviewed and their relationships delineated by cladistic analysis. A matrix of 18 taxa and 14 characters is included. The species Isodictya palmata and Esperiopsis fucorum were used as an outgroup, because they shared either monactines or diactines and smooth palmate isochelae with different members of the ingroup. Cladistic analysis using PAUP produced two equally parsimonious trees of 33 steps (CI=0.758). Strict, Semistrict and Majority Rule consensus trees displayed the same topology. The phylogeny of the trees was not totally resolved. The bootstrap 50% majority-rule consensus tree supported, to a greater or lesser extent, the previously detected monophyletic groups. A common linkage for the ingroup was found in 72% of instances. The genus Euchelipluma appeared as monophyletic in 75% of instances while the group which included the genus Guitarra did so in 66%. The monophyly of the species with sigmoid microscleres and without spiny isochelae (G. isabellae/sigmatifera/antarctica/dendyi and C. diatomorpha/massa) received 56% support as did the group of species with spiny isochelae, whereas monophyly of the group laplani/bipocillifera received 64% support and the genus Tetrapocillon 56%. According to our cladistic analysis, all the species bearing placochelae or derived forms should be allocated to Guitarridae. Within this family, the genus Euchelipluma appeared as monophyletic while Guitarra was paraphyletic. The single species of the genus Hoplakithara clearly belongs to theGuitarra (sigmatifera) group and thus becomes synonymous with Guitarra. G. solorzanoi is considered here a synonymy of G. laplani. A diagnosis for the 10 valid species of Guitarra known to date as well as for the two species of Coelodischela and the two of Euchelipluma is given.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.