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| Pleurobranchaea britannica Turani, Carmona, Barry, Close, Bullimore & Cervera, 2024 |
Abstract
In the north-eastern Atlantic and Mediterranean Sea, the pleurobranchid genus Pleurobranchaea Leue, 1813 is represented by two species, Pleurobranchaea meckeli (Blainville, 1825) and Pleurobranchaea morosa (Bergh, 1892). The former is a well-known species distributed from northern Spain to Senegal and the Mediterranean Sea, while the second is a poorly-described species. In this contribution, species delimitation analyses (ABGD and COI/16S p-distances) identified a third undescribed Pleurobranchaea species from samples collected in south-western UK waters and the Gulf of Cadiz (SW Spain). This new species, Pleurobranchaea britannica sp. nov., is also supported by several morphological synapomorphies. The British specimens constitute the first occurrence of the genus Pleurobranchaea in UK waters.
Key Words: Atlantic Ocean, Gulf of Cadiz, Mediterranean Sea, molluscan diversity, Pleurobranchaea britannica, Pleurobranchaeidae, southwest UK, systematics
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| A. Living specimens of Pleurobranchaea britannica sp. nov. collected on Survey CEND 0518, southwest England. Photo by Ross Bullimore (NHMUK 20230085); B. Two young individuals of P. sp. nov. from the Gulf of Cadiz, Spain (MNCN 15.05/200181; MNCN 15.05/200182); C. Specimen of P. meckeli from Morocco, Mediterranean Sea (MNCN 15.05/94845). |
Superorder Nudipleura Wägele & Willan, 2000
Order Pleurobranchida Gray, 1827
Superfamily Pleurobranchoidea Gray, 1827
Family Pleurobranchaeidae Pilsbry, 1896
Genus Pleurobranchaea Leue, 1813
Pleurobranchaea britannica sp. nov.
Diagnosis: Body oval, large, translucent with a minute cream/ochre pigmentation. Some specimens with opaque white specks irregularly spread all over mantle, oral veil, gill and posterior region of the foot not covered by the mantle. Rhinophores with dark spots on the front and white ones on the back. Gill bipinnate, with 15–18 pairs of pinnules and smooth rachis. Caudal spur absent. Outermost radular teeth bicuspid. Seminal receptacle short; bursa copulatrix at the end of the vagina and directly fused to it.
Etymology: The species name in Latin refers to the British waters where this species was initially found.
Martina Turani, Leila Carmona, Peter J. Barry, Hayden L. Close, Ross Bullimore and Juan Lucas Cervera. 2024. First Occurrence of the Genus Pleurobranchaea Leue, 1813 (Pleurobranchida, Nudipleura, Heterobranchia) in British Waters, with the Description of A New Species. Zoosystematics and Evolution. 100(1): 49-59. DOI: 10.3897/zse.100.113707