Research Article |
Corresponding author: Daniel Suárez ( danielsura94@gmail.com ) Academic editor: Oana Teodora Moldovan
© 2018 Daniel Suárez, Sonia Martín, Manuel Naranjo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Suárez D, Martín S, Naranjo M (2018) First report of the invasive alien species Caenoplana coerulea Moseley, 1877 (Platyhelminthes, Tricladida, Geoplanidae) in the subterranean environment of the Canary Islands. Subterranean Biology 26: 67-74. https://doi.org/10.3897/subtbiol.26.25921
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The blue land planarian Caenoplana coerulea Moseley, 1877 is reported for the first time in the hypogean environment. Seven individuals of C. coerulea were collected in the most humid branch of an abandoned water mine in Gran Canaria (Canary Islands). Due to its character of generalist predator, it should be considered a threat for the endemic subterranean fauna.
Caenoplana coerulea , invasive alien species, top predator, water mine, hypogean
The endemic diversity of terrestrial planarians (Platyhelminthes, Tricladida, Geoplanidae) in oceanic islands is considerably scarce; they have limited powers of dispersal because they cannot survive long periods of immersion in water (
In the Canary Islands the blue land planarian Caenoplana coerulea Moseley, 1877 has been discovered recently in the islands of Gran Canaria and Tenerife although, to date, no record had been yet published (data from the Canarian Government). Caenoplana coerulea is an eastern Australian species that lives in areas with high humidity (
Between September 2017 and March 2018, we surveyed the hypogean fauna of an abandoned water mine called “La Federica”, in the east of Gran Canaria (27.9829°N; -15.4647°W, ca. 345 m) (Figure
The temperature, relative humidity and carbon dioxide inside the cave were measured with a Xintest HT-2000 Datalogger, and oxygen was measured with an Uyigao ua6070b Datalogger. The captured specimens of C. coerulea were preserved in 70% ethanol. Specimens were observed under a binocular lens for external morphological characterization. In addition, to confirm the identification, one specimen was sequenced. DNA was extracted using QIAGEN DNeasy Blood and Tissue Kit. COI was amplified using LCO1490/HCO2980 primers (
Nineteen individuals of C. coerulea were observed during the surveys and seven of them were collected and stored in ethanol (Table
Number of specimens of C. coerulea observed and collected during the survey of “La Federica” mine.
Date | Number of specimens observed (collected) | Temperature of the mine (°C) | Relative humidity of the mine (%) |
---|---|---|---|
9-IX-2017 | 6 (1) | 21.2 | 86 |
13-X-2017 | 5 (0) | 21.0 | 84 |
4-XI-2017 | 2 (2) | 20.9 | 86.5 |
8-XII-2017 | 2 (2) | 22.7 | 74 |
16-XII-2017 | 3 (2) | 21.8 | 83 |
3-III-2018 | 1 (0) | Not measured | Not measured |
The mine has two principal sectors; the western one showed high levels of CO2 (>10,000 ppm) and a low O2 concentration (<19.5%), while the eastern one had CO2 and O2 levels similar to those on the surface. The specimens in the eastern sector were seen under rocks and around roots in the most humid branch of the mine (Figure
Among the endemic potential prey of C. coerulea in the mine there is a millipede of the genus Dolichoilus Verhoeff, 1900 as well as two undescribed weevil species of the genera Oromia Alonso-Zarazaga, 1987 and Laparocerus Schoenherr, 1834. Those weevil are, to date, exclusive to this mine. During the surveys, the exoskeletal remains of a Laparocerus adult was found under a rock close to an individual of C. coerulea, indicating that it may have been consumed by the planarian. Also, another C. coerulea individual was photographed consuming a woodlouse (Figure
The external morphology fitted with the description given by
The mine “La Federica” is located in an area with high potential for subterranean fauna (
Introduced invertebrates are not very frequent in subterranean environments on the Canary Islands (
Check-list of the subterranean fauna in the mine “La Federica” (Gran Canaria, Canary Islands). Abbreviations: Y – Yes; N – No; ? – Doubtful.
Class/Order | Species | Troglobiont | Endemism | Potential prey |
---|---|---|---|---|
Class Arachnida | ||||
Order Schizomida | ||||
Stenochrus portorricensis Chamberlin, 1922 | Y | N | N | |
Order Araneae | ||||
Tegenaria pagana C.L. Koch, 1840 | N | N | N | |
Dysdera n. sp. 1 | Y | Y | N | |
Dysdera n. sp. 2 | Y | Y | N | |
Scotophaeus n. sp. | Y | Y | N | |
Setaphis gomerae (Schmidt, 1981) | N | Y | N | |
Troglohyphantes roquensis Barrientos & Fernández-Pérez, 2018 | Y | Y | N | |
Eidmanella pallida (Emerton, 1875) | N | N | N | |
Pholcus ornatus Bösenberg, 1895 | N | Y | N | |
Order Pseudoscorpiones | ||||
Microcreagrina cavicola Mahnert, 1993 | Y | Y | N | |
Class Chilopoda | ||||
Order Lithobiomorpha | ||||
Lithobius sp. | N | N | N | |
Class Diploda | ||||
Order Julida | ||||
Dolichoiulus cf. longungis Enghoff, 2012 | Y | Y | Y | |
Order Polyxenida | ||||
Polyxenus sp. | N | N | Y | |
Class Malacostraca | ||||
Order Isopoda | ||||
Porcellio sp. | N | N | Y | |
Class Insecta | ||||
Order Zygentoma | ||||
Canariletia holosterna Molero, Gaju, López, Oromí & Bach, 2014 | Y | Y | ? | |
Order Blattodea | ||||
Symploce microphthalma Izquierdo & Medina, 1992 | Y | Y | N | |
Order Hemiptera | ||||
Meenoplous roddenberryi Hoch & Naranjo, 2012 | Y | Y | ? | |
Collartida n. sp. | Y | Y | ? | |
Order Diptera | ||||
Phlebotomus sp. | N | N | Y | |
Megaselia sp. | N | N | Y | |
Order Coleoptera | ||||
Calathus angularis Brullé, 1839 | N | Y | ? | |
Parazuphium n. sp. | Y | Y | ? | |
Oromia n. sp. | Y | Y | Y | |
Laparocerus n. sp. | Y | Y | Y |
This work has been supported by the project “Fauna subterránea del Barranco de los Cernícalos” funded by the Cabildo de Gran Canaria. We are very grateful to Octavio Fernández (GE-Tebexcorade-La Palma) for elaborating the topography of the mine as well as to Pedro Oromí (Universidad de La Laguna) for revising the manuscript. Brent Emerson and Heriberto López (IPNA-CSIC) provided assessment during the laboratory phase. We are also grateful to the referees Marta Álvarez-Presas and Kathryn Hall for their constructive suggestions that improved the quality of the manuscript.