Integrative redescription of Sprostoniella micrancyra Cezar, Luque and Amato, 1999 (Monopisthocotylea: Capsalidae) and the phylogenetic position of Sprostoniella Bychowsky and Nagibina, 1967

Abstract

Purpose The present study provides an integrative redescription of Sprostoniella micrancyra Cezar, Luque and Amato, 1999 (Monopisthocotylea: Capsalidae), a parasite of the Atlantic spadefish, Chaetodipterus faber (Broussonet, 1782) (Actinopterygii: Ephippidae) off the southeastern Brazilian coast. An additional specimen of Sprostoniella lamothei Pérez-Ponce de Léon and Mendoza-Garfias, 2000 collected from Parapsettus panamensis (Steindachner, 1876) in Peru was included for comparative molecular assessments. Methods S. micrancyra specimens were examined using light microscopy, histology, and scanning electron microscopy, with morphological preparations carried out following standard processing protocols. Genomic DNA was extracted from both Sprostoniella species, and partial sequences of the 28S rDNA and mitochondrial cox 1 genes were generated. Phylogenetic relationships were inferred using Maximum Likelihood and Bayesian inference. Results Morphological observations of S . micrancyra revealed several previously unreported features, including the presence of a pair of accessory haptoral sclerites, a pair of anchors, a haptor with one central loculus, and the absence of a vaginal opening, contrasting with the original description. Scanning electron microscopy confirmed haptoral organization and detailed the structure of adhesive discs and peduncle musculature, while histology elucidated the organization of reproductive and attachment structures and muscular systems. Phylogenetic analyses of ribosomal and mitochondrial markers recovered the two Sprostoniella species as a monophyletic clade. Conclusion Our results expand current knowledge of S. micrancyra and underscore the importance of integrative approaches to clarify the taxonomy and evolutionary relationships of capsalids.

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