A new species of Allogenus (Tricladida, Maricola, Uteriporidae) from South Georgia, Sub-Antarctica

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Volonterio, Odile, Brewin, Paul E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2013
• Subjects: Aquatic Science; Antarctic; Southern Ocean; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1017/s0025315413001628; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315413001628

South Georgia is a remote sub-Antarctic island, considered a marine biodiversity ‘hotspot’ in the Southern Ocean. During a survey along the north coast of South Georgia several marine planarians were found. One of the specimens was a new species of Allogenus (Uteriporidae), which is described here as Allogenus sluysi sp. nov. The new species has the characteristics of the genus and can be distinguished from the type and only known species, Allogenus kerguelensis , by its smaller size, blackish-brown pigmentation, presence of three retinal cells in each eye cup, position of its testes half-way between the ventral and dorsal body surfaces or at a slightly more ventral position, and by having an ejaculatory duct that opens centrally at the tip of the penis papilla. The presently known geographical distribution of Allogenus , the heterogeneous marine planarian species composition in South Georgia, and the distribution of these species in this region are in agreement with a previously proposed vicariance hypothesis, albeit that dispersal cannot be ruled out.