The Opecoelidae sperm model and its contribution to phylogeny: Spermatozoon ultrastructural particularities of Allopodocotyle pedicellata (Plagioporinae, Digenea, Platyhelminthes)

Records of opecoeline species Pseudopecoelus cf. vulgaris and Anomalotrema koiae Gibson & Bray, 1984 (Trematoda, Opecoelidae, Opecoelinae) from fish of the North Pacific, with notes on the phylogeny of the family Opecoelidae

“…The family Opecoelidae Ozaki, 1925 is a large group of trematodes parasitic in marine and freshwater fish. The modern taxonomic model of this family, based on morphological (Cribb, 2005; Bakhoum et al , 2017) and genetic data (Bray et al , 2016; Martin et al , 2018b, c), distributes opecoelids between six subfamilies: Opecoelinae, Helicometrinae, Opecoelininae, Opistholebetinae, Stenakrinae and Plagioporinae s. lato . Plagioporinae s. lato is the most problematic group of opecoelids from the taxonomic point of view, as phylogenetic reconstructions demonstrate the polyphyly of this subfamily (Andres et al , 2014; Shedko et al ., 2015; Bray et al , 2016; Fayton and Andres, 2016; Faltýnková et al , 2017; Fayton et al ., 2017; Martin et al , 2017, 2018b; Rima et al , 2017; Fayton et al , 2018).…”

Ultrastructure of the spermatozoon of Macvicaria obovata (Digenea: Opecoelidae), a parasite of Sparus aurata(Pisces: Teleostei) from the Gulf of Gabès, Mediterranean Sea

“…In this sense, eight species from the Opecoelidae were spermatologically investigated. The latter belong to three of the five subfamilies: Helicometra epinepheli and Helicometra fasciata (Helicometrinae), Opecoeloides furcatus and Poracanthium furcatum (Opecoelinae), Allopodocotyle pedicellata, Nicolla testiobliquum, Nicolla wisniewskii and Podocotyloides magnatestis (Plagioporinae) (Miquel et al 2000;Levron et al 2003Levron et al , 2004Quilichini et al 2007aQuilichini et al , 2007bQuilichini et al , 2011bDiagne et al 2016;Bakhoum et al 2017).…”

A comparative study of the ultrastructural characteristics of the mature spermatozoa of two fellodistomidsTergestia clonacanthaandT. laticollisand contribution to the phylogenetic knowledge of the Gymnophalloidea

“…Overall, the authors found a similar general pattern. Table 1 shows that the same spermatozoon type (according to Bakhoum et al [ 7 ]) has usually been found for species of the same genus: type III for Holorchis micracanthum [ 3 ] and H. pycnoporus [ 12 ]; type V for Prosorhynchus aculeatus and [ 18 ] P. longisaccatus [ 26 ]; type V for the Diplodiscidae Diplodiscus amphichrus [ 10 ] and D. subclavatus [ 5 ]; type V for Fasciola gigantica [ 22 ] and F. hepatica [ 21 ]; type II for Lecithochirium microstomum [ 23 ] and L. musculus [ 23 ]; type III for the Lepocreadiidae Bianium arabicum [ 30 ] and B. plicitum [ 30 ]; type IV for the Opisthorchiidae Opisthorchis felineus [ 32 ] and O. viverrini [ 13 ]; type IV for the Opecoelidae Allopodocotyle pedicellata [ 6 ] and A. tunisiensis [ 15 ], and type III for the Opecoelidae Nicolla testiobliquum [ 27 ] and N. wisniewskii [ 28 ]. Nevertheless, some differences have been observed between spermatozoa of species belonging to the same genus like the Notocotylidae Notocotylus neyrai [ 20 ] (undefined type) and N. noyeri [ 24 ] (type IV) concerning the location of the external ornamentation; the Opecoeloidea Helicometra epinepheli [ 29 ] (type III) and Helicometra fasciata [ 16 ] (undefined type) concerning especially the presence/absence of external ornamentation; and the Zoogonidae Lecithostaphylus parexocoeti [ 4 ] (undefined type) and L. retroflexus [ 14 ] (type IV) concerning the location of the external ornamentation.…”

“…Some families have never been studied, while some genera have already been the subject of several studies. Among these genera, we considered: the Aephnidiogenidae Holorchis [ 3 , 12 ], the Bucephalidae Prosorhynchus [ 18 , 26 ], the Dicrocoeliidae Dicrocoelium [ 1 , 8 ], the Diplodiscidae Diplodiscus [ 5 , 10 ], the Fasciolidae Fasciola [ 21 , 22 ], the Hemiuridae Lecithochirium [ 23 ], the Lepocreadiidae Bianium [ 30 ], the Notocotylidae Notocotylus [ 20 , 24 ], the Opecoelidae Allopodocotyle [ 6 , 15 ], Helicometra [ 16 , 29 ] and Nicolla [ 27 , 28 ], the Opisthorchiidae Opisthorchis [ 19 , 32 ], and the Zoogonidae Lecithostaphylus [ 4 , 14 ].…”