Rediscovery of Polystoma stellai Pérez Vigueras, 1955 (Platyhelminthes, Monogenea) in Cuba

Abstract

The family Polystomatidae (Platyhelminthes, Monogenea) comprises parasitic flatworms with an affinity for infecting amphibians and reptiles. Among them, Polystoma stellai stands out as a particularly rare species documented in both Cuba and Florida (USA). Originally described in 1955 based on a single specimen, only one additional specimen has been collected since, and there exists no type or reference material for this species, resulting in a significantly limited understanding of its characteristics. Recently, a specimen of P. stellai was collected during a dissection of Osteopilus septentrionalis (Anura) by Biology students at Universidad de Oriente, Cuba. The studied material was collected more than 800 km from the area where the species was described. The newly collected specimen aligns with the original description of P. stellai; however, notable differences are observed, particularly in the reduced size of the body and certain structures compared to previously documented ones. We provide the first photos and detailed description of the hamulus, characterised by unequal hooks, one of which exhibits a distal flap. Given the available data, there arises a suspicion that the specimen previously recorded in Florida may belong to a distinct species of Polystoma. Furthermore, the position of P. stellai within Polystoma remains tentative due to some diagnostic characteristic of representatives of this genus have not been corroborated in this species.