RESUMO
During the examination of 913 fish specimens belonging to four families in the Campeche Bank (Gulf of Mexico), 23 gill ectoparasitic monogenean species were found, which belong to three families: Dactylogyridae, Microcotylidae and Diclidophoridae. The species Euryhaliotremaamydrum, E.carbuncularium, E.dunlapae, E.fajeravilae, E.fastigatum, E.longibaculum, E.paracanthi, E.tubocirrus, Haliotrematoidescornigerum, H.gracilihamus, H.heteracantha, H.longihamus, H.magnigastrohamus, H.striatohamus, Hamatopedunculariabagre, Neotetraonchusbravohollisae, and N.felis (all Dactylogyridae) were found on the hosts Lutjanussynagris, L.griseus, Ariopsisfelis, Bagremarinus, Archosargusrhomboidalis, and Haemulonplumieri. Additionally, Microcotylearchosargi, Microcotyle sp., and Microcotyloidesincisa (all Microcotylidae) were found on L.griseus and A.rhomboidalis; finally, Choricotyle sp. 1, Choricotyle sp. 2, and Choricotyle sp. 3 (all Diclidophoridae) were found on H.plumieri. The prevalence, abundance, mean intensity of infection, and supplementary taxonomic revisions for all monogeneans found are provided. Partial sequences of the 28S rRNA gene were also obtained for monogeneans of ariid, sparid, and haemulid host fishes to explore their systematic position within the Monogenea. New locality and host records for some previously described species of Euryhaliotrema, Hamatopeduncularia, Microcotyle, and Choricotyle from lutjanid, ariid, sparid, and haemulid hosts were reported. The present study adds evidence supporting the interoceanic occurrence of the same monogenean species (on lutjanids) on the west-east Atlantic and Pacific Oceans (= amphiamerican species). As previously suggested, there are at least, two possibilities to explain that parasite distribution: differentiation of morphological features in these monogeneans have resulted in only slight to insignificant morphological changes developing over the extended period of 3.2 mya (when the Isthmus of Panama was closing) and/or speciation is only evident at molecular level.
RESUMO
During a parasitological survey of perciform fishes from Lizard Island, Great Barrier Reef, Australia, we found the following gill monogenoidean species (Platyhelminthes): Euryhaliotrema lizardi n. sp. on Caesio caerulaurea Lacepède, 1801 (Caesionidae) (type host) and Haliotrema weberii n. sp. on Chromis weberi Fowler and Bean, 1928 (Pomacentridae) (type host), Chromis amboinensis (Bleeker, 1871), Chromis atripectoralis Welander and Schultz, 1951 and Caesio teres Seale, 1906. Euryhaliotrema lizardi n. sp. is characterized by having anchors with an elongated straight shaft and point as well as a vaginal canal with two loops before connecting to the seminal receptacle. Ha. weberii n. sp. is distinguished from other congeners by possessing a tubular male copulatory organ (MCO), partially straight. Two previously described dactylogyrids were also found: Haliotrematoides caesionis (Yamaguti, 1953) Kritsky, Yang and Sun 2009) on Caesio cuning (Bloch, 1791) and Ca. teres (new host record) and Haliotrematoides patellacirrus (Bychowsky and Nagibina, 1971) Kritsky, Yang and Sun 2009, on Ca. cuning (new host record). Finally, we provide the first report of a gastrocotylinean pre-adult on Ca. teres. We provide descriptions and illustrations of the new species and the gastrocotylinean pre-adult and include supplemental observations of Ht. caesionis and Ht. patellacirrus. The present findings expand the known spectrum of host species of Euryhaliotrema, Haliotrema and Haliotrematoides to include new caesionid and pomacentrid fishes.