Authors

C Bouguerche¹; F Tazerouti¹; D Gey²; J L Justine³;  ¹ Laboratoire de Biodiversité et Environnement : Interactions – Génomes, Université des Sciences et de la Technologie Houari Boumediene, Algiers, Algeria;  ² Service de Systématique Moléculaire (UMS 2700), Muséum National d’Histoire Naturelle, Paris, France;  ³ Institut Systématique Évolution Biodiversité (ISYEB), Muséum National d’Histoire Naturelle, Paris, France

Discussion

The monogenean Microcotyle erythrini is atypical because it has been recorded from several fish host species in the Mediterranean Sea and Atlantic Ocean, in contrast to many species which are considered strictly host-specific. This could indicate a true lack of specificity or that several cryptic species are involved. During an ongoing survey of monogenean gill parasites of marine fishes off the Algerian coast, specimens of a species resembling M. erythrini were collected from bogues, Boops boops. A comparison with published descriptions and with museum specimens of M. erythrini did not yield any clear morphological difference. However, sequences of cytochrome c oxidase subunit I (COI) differed by 16.3% from that of M. erythrini (collected from the type-host Pagellus erythrinus), indicating that the species was different. The species was then described as a new species, Microcotyle isyebi. We collected a second Microcotyle species from the gill filaments of the bluespotted seabream Pagrus caeruleostictus (Sparidae). An analysis of the COI gene of this species revealed minor intraspecific variations (1.4%), an order of magnitude lower than the distance between it and other Microcotyle species (10–15 %). This species was distinguished from M. erythrini based on morphological (size of clamps, number of testes) and molecular (COI) differences and was described as a new species, Microcotyle visa. Additionally, a species of Paramicrocotyle sp. included in the molecular analysis was nested within a robust Microcotyle + Paramicrocotyle clade; we considered that Paramicrocotyle Caballero & Bravo-Hollis, 1972 is a junior synonym of Microcotyle van Beneden & Hesse, 1863 and transferred two species of Paramicrocotyle as Microcotyle danielcarrioni (Martinez & Barrantes, 1977) Bouguerche et al., 2019 and Microcotyle moyanoi (Villalba & Fernandes, 1986) Bouguerche et al., 2019. These results suggest that a molecular re-evaluation of other Microcotyle erythrini-like specimens from various fish hosts could reveal the existence of additional parasite biodiversity.

Key words: Integrative taxonomy; Barcoding; COI; monogeneans; helminths; Microcotyle.