6533b82dfe1ef96bd1291529

RESEARCH PRODUCT

Considerations on the taxonomy and morphology of Microcotyle spp.: redescription of M. erythrini van Beneden & Hesse, 1863 (sensu stricto) (Monogenea: Microcotylidae) and the description of a new species from Dentex dentex (L.) (Teleostei: Sparidae)

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AbstractBackgroundMicrocotyle erythrinivan Beneden & Hesse, 1863 (Platyhelminthes: Monogenea) and other closely related species of the genus are often considered as cryptic. Records in hosts other than the type-host with no species confirmation by molecular analyses have contributed to this situation.MethodsGill parasites of five sparid fishes,Boops boops(L.),Pagellus erythrinus(L.),P. acarne(Risso), Dentex dentex(L.) andPagrus pagrus(L.), from the Western Mediterranean off Spain were collected. Specimens ofMicrocotylespp. were characterised both molecularly and morphologically. Partial fragments (domains D1-D3) of the28SrRNA gene and the cytochromecoxidase subunit 1 (cox1) gene were amplified and used for molecular identification and phylogenetic reconstruction. Principal components analysis was used to look for patterns of morphological separation.ResultsMolecular analyses confirmed the identity of three species:M. erythriniexP. erythrinusandPa. pagrus;M. isyebiBouguerche, Gey, Justine & Tazerouti, 2019 exB. boops; and a species new to science described herein,M. whittingtonin. sp. exD. dentex.The specific morphological traits and confirmed hosts (P. erythrinusandPa. pagrus) are delimited here in order to avoid misidentifications ofM. erythrini(sensu stricto).Microcotyle erythrini(s.s.) is mostly differentiated by the shape of its haptor, which is also longer than in the other congeners. New morphological and molecular data are provided forM. isyebifrom the Spanish Mediterranean enlarging the data on its geographical range.Microcotyle whittingtonin. sp. is described fromD. dentexand distinguished from the remaining currently recognised species of the genus by the number and robustness of the clamps.ConclusionsNew diagnostic morphological traits useful to differentiateMicrocotylespp. are suggested: (i) haptor dimensions including lobes; (ii) the thickness of the clamps; (iii) the size and shape of spines of the genital atrium; (iv) the extension of the posterior extremities of vitelline fields; and (v) the shape of egg filaments. The use of new morphological approaches may allow considering these species ofMicrocotyleas being pseudocryptic. The use of representative undamaged specimens that have been genetically confirmed as conspecific is considered crucial to avoid abnormally wide morphological ranges that prevent species differentiation.