Lost and found: Totton’s Minyaspis faroni revived and molecular evidence of paraphyly of Oxynaspis and Minyaspis

ABSTRACT

The stalked barnacles Minyaspis faroni associated with antipatharians known from the southern Red Sea have been recently recorded in the northern Red Sea. Two genera of oxynaspids, Oxyaspis and Minyaspis, differ morphologically in the coverage of the capitulum. In Oxyaspis, the capitulum is covered by calcified plates, whereas in Minyaspis, the plates are reduced, and there is an uncalcified area between plates. Molecular analyses revealed that species with reduced plates do not cluster in the same clade, whereas species with full coverage and uncalcified capitula are found in the same clade. Our analysis indicates that the reduction of opercular plates in the epibiotic barnacles has occurred more than once in the barnacle evolutionary pathway. The reduction in shell plates’ number, size, shape and thickness is an adaptive character of epibiotic symbiosis. This mode of life, common in thoracican barnacles, leads to adaptive morphological changes. Hence, the morphology of shell plates is not a homologous feature but reflects parallel evolution.

KEYWORDS:

• Lepadomorpha
• Minyapsis
• Red Sea
• parallel evolution

Acknowledgements

This project was initiated by Dr Itzchak Brickner, known by his colleagues and friends as Itzik. He passed away before the completion of this study. He collected the material and studied and described the morphology of the mouth parts and cirri of barnacles. Figure 7 was prepared by him. We thank Dr Marzia Bo of the University of Genoa for identification of the antipatharians. We thank Dr Yaakov Langzam of the Electron Microscopy Unit, and Dr Irit Shoval of the Microscope unit, Scientific Equipment Center at Bar Ilan University for help in preparing the SEM and light microscopy figures. We thank Yael Laure for editing this manuscript for publication.

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No potential conflict of interest was reported by the authors.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

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Funding

The authors reported there is no funding associated with the work featured in this article.