Morphological and molecular characterization ofMonticelli, 1907 (Monopisthocotylea, Monogenea) from the gilthead seabreamLinnaeus (Teleostei, Sparidae) from the southwestern Mediterranean and notes on host specificity of the genusDiesing, 1850.

Abstract

Incomplete original descriptions, the unavailability or poor conditions of specimens and the lack of detailed redescriptions have caused the validity of several species of the genusDiesing, 1850 to be questioned. To date, seven of the recognized species were described upon one or two specimens, hindering study of intraspecific variations. This was made worse by considering few morphoanatomical differences sufficient to erect new species. Amongspp. occurring in Mediterranean waters,was first described from the gilt-head bream(Sparidae) off Italy. Although beautifully illustrated for a paper from that century, morphometric data forfrom the type-hostremain unavailable. Previous records ofprovided either morphometrical or molecular data, and its validity was questioned. We provide a redescription ofbased on newly collected specimens from thefrom the southwestern Mediterranean (off Algeria) using integrative taxonomy. Analysis of1 sequences offrom, compared to sequences from other sparid hosts, mainly, revealed a divergence not exceeding 2%, suggesting a stenoxenic specificity for this monogenean. Given thatis the type-host for, we were tempted to suggest a synonymy betweenandWe refrained from doing so becausewas first described from the Atlantic coast off Brest, France. Morphological data forfromare warranted assessing the host specificity ofand whether there might be a species complex within individual sparid fish species.