When looks can be deceiving: a new cryptic land planarian species of Choeradoplana Graff, 1896 (Platyhelminthes: Geoplanidae) from Argentina

Abstract

A new species of the genus Choeradoplana found in the east-central region of Argentina is herein described, Choeradoplana malaria sp. nov. This new entity shows a striking similarity regarding the pigment pattern with other land planarian species of this genus, viz. Choeradoplana langi, Choeradoplana gladismariae, and Choeradoplana minima. Besides, the internal anatomy of Ch. malaria sp. nov. is remarkably similar to that of Ch. gladismariae, a species recorded in southeastern Brazil, some 2300 km distant from the new species. Although there are minimal differences in the colour pattern of the dorsum, both species can be differentiated by some anatomical and histological details, such as the thickness of the cutaneous musculature, the width of the creeping sole, and some features related to the reproductive system. This low morphological disparity between both species fits within the term ‘cryptic species’. These subtle differences were also corroborated in a phylogenetic analysis using Cox-1 gene sequences. Likewise, species delimiters reinforced the identity of the new taxon herein proposed and allowed us to differentiate Ch. malaria sp. nov. from Ch. gladismariae at the genetic level.

http://zoobank.org/urn:lsid:zoobank.org:pub:DF432618-A85B-4C99-8E64-EC9C581B0714

Key words:

• cryptic species
• Geoplaninae
• land flatworms
• Neotropical region

Acknowledgements

The authors are grateful to the authorities of the natural reserve Reserva Natural Punta Lara (Ensenada, Buenos Aires) and especially to the park managers for providing support during fieldwork. We also acknowledge the park managers of the natural reserve Reserva Natural Isla Martín García (Buenos Aires) for allowing us to perform samplings. We thank Víctor Hugo Merlo Álvarez for helping us during sampling. We thank Fernando Carbayo and two anonymous reviewers whose valuable suggestions and comments helped us to improve the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental material

Supplemental material for this article can be accessed here: https://doi.org/10.1080/14772000.2023.2296078.

Data availability statement

The new DNA sequences included in this study will be available on GenBank. All other datasets generated and/or analysed during the current study are available from the corresponding author (LN) upon reasonable request.

Associate Editor: Dr Jesus Hernández-Orts

Additional information

Funding

This work was partially financed by the Universidad Nacional de La Plata under Grant 11/N935, CONICET under Grant PIP11220200101531CO, and ANPCyT under Grant PICT 2019-1143.