taxonID	type	description	language	source
650B6949FFB4FFF8F7BD3421A8801799.taxon	description	(FIG. 2; TABLE 3) Ty p e - h o s t: S c o r p i s g e o r g i a n a Va l e n c i e n n e s (Perciformes: Scorpididae), banded sweep. Type-locality: Off Point Peron, Western Australia. Voucher material: One hologenophore, mounted dorsolaterally, from S. georgiana collected off Garden Island (32 ° 12 ′ 46 ″ S, 115 ° 40 ′ 13 ″ E), Western Australia (WAM V 8938).	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFB9FFF4F61A3590AADF1764.taxon	diagnosis	Diagnosis: Body elongate, subcylindrical. Forebody short, less than one-fifth body length. Tegument smooth in forebody, textured with fine projections in hindbody. Oral sucker unspecialized, terminal, opening antero-ventrally, roughly spherical. Ventral sucker larger than oral sucker, roughly spherical, pedunculate, papillate with 7 – 9 small, round papillae either side of aperture. Prepharynx very short. Pharynx unspecialized, smaller than oral sucker, subspherical. Oesophagus short, constricted. Intestine bifurcates at approximately 45 ° in forebody. Caeca thin, unite with excretory vesicle to form uroproct close to posterior extremity. Testes two, ellipsoidal, smooth, tandem, usually separate, intercaecal, situated more than 50 % of body length from anterior extremity; post-testicular zone less than 25 % of body length. Cirrus-sac well developed, exceptionally long, highly sinuous, extends well into hindbody, occupies more than 33 % of body length. Internal seminal vesicle long, sinuous, broad, narrowing anteriorly. Pars-prostatica indistinct. Ejaculatory duct exceptionally long, tightly sinuous. Cirrus sometimes everted. Genital atrium short, simple. Genital pore sinistro-submedial, bifurcal or immediately post-bifurcal, small, often indistinct. Ovary smooth, roughly spherical, medial, anterior to and separated by short distance from anterior testis, situated about 50 % of body length from anterior extremity. Seminal receptacle uterine. Laurer’s canal present, short, opening dorsal to ovary, widening proximally into small, receptacle-like chamber. Oviduct short. Oötype prominent. Uterus sinuous, preovarian, intercaecal, ascending dorsal to cirrus-sac. Metraterm thin to indistinct. Mehlis’ gland prominent, extensive, antero-dorsal to ovary. Vitellline reservoir smaller than and antero-dorsal to ovary. Vitelline follicles numerous, regular, restricted to hindbody, distributed laterally and ventrally, sparse dorsally, interrupted at level of ovary and each testis. Eggs operculate, tanned, unembryonated in utero, without polar protuberances or filaments. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal or dorso-subterminal. In the digestive tract of herbivorous, marine fishes of the genus Kyphosus (Kyphosidae) in southern Australian waters. Type-species: Holsworthotrema enboubalichthys sp. nov. Other species: Holsworthotrema chaoderma sp. nov. ZooBank registration LSID: http: // www. zoobank. org / urn: lsid: zoobank. org: act: 30 C 5014 D- 2 AF 3 - 447 E- 900 A- 5861 F 640397 A Etymology: The new genus is named in honour of and in gratitude to Dr William (Bill) and Carol Holsworth. The Holsworth foundation has generously supported Ph. D. candidatures of SBM and DCH, has directly enabled this study, and has contributed to various other student projects undertaken at the Marine Parasitology Research Laboratory, The University of Queensland. R e m a rk s: T h e t w o n e w s p e c i e s f o r w h i c h w e propose Holsworthotrema occur in sympatry with S. longistipes in phylogenetically related and ecologically similar host fishes. They are clearly closely related to that species, differing at 9, 16 to 17, and 8 to 9 base-positions in the ITS 2, 28 S and 18 S rDNA regions, respectively. The two new species also share several morphological features with S. longistipes, including an elongate body, short forebody, specialized tegument, pedunculate ventral sucker, long cirrus-sac extending well into the hindbody, long seminal vesicle, entire ovary, preovarian uterus, uterine seminal receptacle and vitelline follicles restricted to the hindbody and not reaching to the level of the posterior margin of the ventral sucker. However, several important morphological distinctions are also apparent such that these two new species should be allocated to a distinct genus. Most importantly, the caeca form a uroproct in the new species but terminate blindly in S. longistipes, a distinction always considered of generic significance among the Opecoelidae (Cribb, 2005), and usually also among digeneans more generally. Additionally, in the new species the uterus runs dorsal vs. ventral to the cirrus-sac, the cirrus-sac and ejaculatory duct are much longer and prominently sinuous, the ventral sucker is larger than the oral sucker vs. smaller, the ventral sucker peduncle is relatively short and broad vs. exceptionally long and thin, and the ventral sucker has papillae. The two new species are also similar morphologically to another stenakrine concept, Pseudopecoelina Yamaguti, 1942. Species of that genus do have a uroproct and essentially differ from the new species only in that the ventral sucker lacks papillae and is sessile vs. pedunculate, and in that the cirrus-sac and ejaculatory duct, although long and tubular, are never as long as in the new species and are simple vs. strongly sinuous. There has been no suggestion of any tegument specializations in species of Pseudopecoelina, although none has been examined with SEM. Species of Pseudopecoelina are known only from shallow-water carnivorous fishes in the Tropical Indo-West Pacific. The type-species, P. dampieriae Yamaguti, 1942, is known only from the firetail dottyback Labracinus cyclopthalmus (Müller & Troschell) (Perciformes: Pseudochromidae) [as Dampieria hellmuthi (Bleeker)] in Japanese waters (Yamaguti, 1942). Therefore, it seems likely that the two new species will prove to be more closely related to S. longistipes than to species of Pseudopecoelina.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFB8FFF4F7B63761AC4D10D1.taxon	description	(FIGS 3, 4; TABLE 3) Type-host: Kyphosus cornelii (Whitley) (Perciformes: Kyphosidae), western buffalo bream. Ty p e - l o c a l i t y: O f f G a r d e n I s l a n d (3 2 ° 1 2 ′ 4 6 ″ S, 115 ° 40 ′ 13 ″ E), seaward side, Western Australia. Other localities: Off Point Peron (32 ° 15 ′ 59 ″ S, 115 ° 41 ′ 03 ″ E), Rockingham, Western Australia. Type-material: Holotype (WAM V 8939) and 14 paratypes (WAM V 8940 – 8953), including two ventral mounts (WAM V 8950, V 8950) and two hologenophores (WAM V 8952, V 8953).	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFBCFFF0F7ED3712AD051718.taxon	description	(FIGS 5, 6; TABLE 3) Type-host: Kyphosus gladius Knudsen & Clements, 2013 (Perciformes: Kyphosidae), gladius sea chub. Ty p e - l o c a l i t y: O f f Po i n t Pe r o n (3 2 ° 1 5 ′ 5 9 ″ S, 115 ° 41 ′ 03 ″ E), Rockingham, Western Australia. Other host – locality combinations: Kyphosus sydneyanus (Günther), silver drummer, Thomson Bay (31 ° 59 ′ 51 ″ S, 115 ° 32 ′ 59 ″ E), off Rottnest Island, Western Australia. Type-material: Holotype (WAM V 8954) and 11 paratypes (WAM V 8955 – V 8965), including one ventral mount (WAM V 8964) and one hologenophore (WAM V 8965).	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA3FFEEF4A03547AA7F1700.taxon	diagnosis	Diagnosis: Body elongate, subcylindrical. Forebody short, about one-sixth body length. Tegument smooth, thin. Oral sucker unspecialized, terminal. Ventral sucker, unspecialized, larger than oral sucker, pedunculate. Prepharynx short. Pharynx unspecialized, smaller than oral sucker. Oesophagus relatively long. Intestine bifurcates in forebody or dorsal to ventral sucker. Caeca blind, extending well beyond testes near to posterior extremity. Testes two, smooth, ellipsoidal, medial, separate; post-tesicular zone occupies about one-quarter total body length. Cirrus-sac well developed, short, broad oval, mostly dorsal to ventral sucker, may protrude slightly beyond ventral sucker into hindbody. Seminal vesicle internal, occupying most of cirrus-sac, broad proximally, becoming looped distally. Pars prostatica indistinct. Ejaculatory duct short. Common genital atrium short, simple. Genital pore pre-bifurcal, sinistro-submedial. Ovary smooth, medial, anterior to and separated from anterior testis, situated aboutone-halfbodylengthfromanteriorextremity. Seminal receptacle canalicular, smaller than and antero-dorsal to ovary. Laurer’s canal present, short, opens dorsal to ovary. Mehlis’ gland present. Uterus preovarian, intercaecal, approaches genital atrium ventral to cirrus-sac. Vitelline follicles dense, restricted to hindbody, extending from near to posterior extremity to well beyond ovary anteriorly but not reaching level of ventral sucker, distributed dorsally, laterally and ventrally, becoming confluent ventrally in post-testicular zone and preovarian zone. Eggs oval, operculate, unembryonated in utero. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal. In mesopelagic north-west Atlantic fishes, known only from Congridae (Anguilliformes). Type and only species: Abyssopedunculus brevis (A n d r e s & O v e r s t r e e t, 2 0 1 3) c o m b. n o v. (s y n. Podocotyloides brevis). ZooBank registration LSID: http: // www. zoobank. org / urn: lsid: zoobank. org: act: 8337048 F- 1 E 99 - 4 C 54 - 8 C 02 - D 651 BC 00 A 341 Etymology: The generic name is composed from Latin abyss, the deep, and pedunculus, a peduncle or stem. The name is chosen because the concept is distinguishable among plagioporine (s. l.) type taxa in deep-sea fishes by a pedunculate ventral sucker. The genus is to be treated as feminine. Remarks: Podocotyloides Yamaguti, 1934 was recently revised by Martin et al. (2018 c). Genuine species are known mostly from Indo-West Pacific shallow-water fishes of the Haemulidae (Perciformes) and resolve to clade B in the major marine Plagioporinae (s. l.) clade. Abyssopedunculus brevis resolves among the deep-sea taxa and was described based on material from Conger esculentus (Anguilliformes: Congridae) collected at a depth of 200 m off Puerto Rico (Andres & Overstreet, 2013). Thus, it cannot be considered to belong in Podocotyloides. Morphologically, it differs most obviously from genuine Podocotyloides species in that its excretory vesicle reaches only to the level of the ovary vs. the level of the ventral sucker, its cirrus-sac is short and oval vs. long, tubular and sigmoid, its ejaculatory duct is short and simple vs. long and provided with petalloid appendages, and its metraterm is indistinct vs. well developed and provided with a prominent sphincter. Among the taxa represented in the deep-sea + freshwater clade, A. brevis is distinct in that it has both a pedunculate ventral sucker and a canalicular seminal receptacle.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA2FFEDF6143792AC9C1616.taxon	diagnosis	Diagnosis: Body oval to elongate-oval, dorso-ventrally flattened. Forebody about one-quarter to one-third body length. Tegument smooth, relatively thick. Oral sucker unspecialized, terminal or subterminal. Ventral sucker unspecialized, larger than oral sucker. Prepharynx short. Pharynx unspecialized, smaller than oral sucker. Oesophagus unspecialized. Intestine bifurcates in forebody. Caeca blind, extending near to posterior extremity. Testes two, smooth or irregularly lobed, medial, usually contiguous; post-tesicular zone about one-tenth to over one-quarter body length. Cirrus-sac well developed, short, claviform, not extending into hindbody. Seminal vesicle internal, broad. Pars prostatica present. Ejaculatory duct relatively long. Common genital atrium short, simple. Genital pore pre-bifurcal, sinistro-submedial. Ovary irregularly lobed, medial to dextro-submedial, anterior to and contiguous with anterior testis, separated from ventral sucker. Seminal receptacle canalicular, smaller than ovary. Laurer’s canal present, short, opens dorsal to ovarian complex. Mehlis’ gland present. Uterus preovarian, usually intercaecal. Vitellarium follicular, dense, extending from near to posterior extremity to level of intestine bifurcation or beyond, may be interrupted at level of ventral sucker, may become confluent in post-testiuclar zone or forebody. Eggs oval, operculate, unembryonated in utero, <80 µm long. Excretory vesicle tubular, extends to level of ovary. In Indo-West Pacific marine fishes of several orders, mainly from the mesopelagic zone. Ty p e - s p e c i e s: M e s o b a t h y l e b o u r i a l a n c e o l a t a (Price, 1934) comb. nov. [syn. Podocotyle lanceolata, Neolebouria lanceolata (Price, 1934) Reimer, 1987]. Other species: Mesobathylebouria acanthogobii (Yamaguti, 1951) comb. nov. [syn. Plagioporus acanthogobii, Neolebouria acanthogobii (Yamaguti, 1951) Gibson, 1976]; M. lobata (Yamaguti, 1934) comb. nov. [syn. Lebouria lobata, Neolebouria lobata (Yamaguti, 1934) Gibson, 1976]; M. tinkerbellae (Thompson & Margolis, 1987) comb. nov. (syn. Neolebouria tinkerbellae); M. tohei (Yamaguti, 1970) comb. nov. [syn. Plagioporus tohei, Neolebouria tohei (Yamaguti, 1970) Gibson, 1976]. ZooBank registration LSID: http: // www. zoobank. org / urn: lsid: zoobank. org: act: 9752 A 24 C-CBFD- 48 F 9 - AEA 3 - A 349 CDBAE 7 F 4 Etymology: The generic name is composed from Greek meso, middle, and bathos, deep, combined with the genus Lebouria Nicoll, 1909, named after Dr Marie Lebour and the stem for Neolebouria, but now a junior synonym of Peracreadium Nicoll, 1909. The name is chosen because these species are morphologically similar to those of Neolebouria and are generally found in fishes from the lower epipelagic to mesopelagic zone. The genus is to be treated as feminine. Remarks: Neolebouria currently comprises 11 species [plus N. maorum (Allison, 1966) Gibson, 1976 incertae sedis], but these must be considered to represent at least two genera because N. georgiensis Gibson, 1976, the type-species, and N. lanceolata do not resolve together in molecular phylogenetic analyses (Faltýnková et al., 2017; Martin et al., 2017). Neolebouria georgiensis is almost certainly congeneric with N. antarctica (Szidat & Graefe, 1967) Zdzitowiecki, 1990 and N. terranovaensis Zdzitowiecki et al., 1993. These three species are known only from Antarctic and sub-Antarctic waters, in notothenioid perciform fishes (Artedraconidae, Bathydraconidae, Channichthyidae and Nototheniidae) and also species of Paraliparis (Scorpaeniformes: Liparidae) (Gibson, 1976; Zdzitowiecki, 1987, 1991, 1997; Zdzitowiecki et al., 1993; Palm et al., 2007). As per Martin et al. (2017), we consider one other nominal species, Neolebouria merretti Gibson & Bray, 1982, to be more convincingly congeneric with N. georgiensis than N. lanceolata. It is known from an ipnopid (Aulopiformes) collected at 2985 – 3311 m deep south-west of the Canary Islands (Gibson & Bray, 1982). These four species have large (1800 – 4800 µm long), robust bodies, thick tegument, medial and irregularly lobed gonads and large eggs, greater than 80 µm long. In N. georgiensis, N. merretti and N. terranovaensis the cirrus-sac reaches to about the level of the posterior margin of the ventral sucker or a little beyond into the hindbody, although in N. antarctica it is much shorter. The original descriptions for N. georgiensis and N. merretti are highly detailed (Gibson, 1976; Gibson & Bray, 1982) and thus two potentially significant characters serve to convincingly unite these species. First, in each species, the entirety of the oesophagus, and also the anterior part of the caeca in N. merretti, is surrounded by especially dense gland cells, and second, the seminal vesicle is broad and dilate proximally but then becomes long, thin, coiled and duct-like prior to the pars-prostatica and ejaculatory duct. We propose Mesobathylebouria for N. lanceolata and four of the remaining six species of Neolebouria: N. acanthogobii, N. lobata, N. tinkerbellae and N. tohei. Collectively, these five species occur in a broad range of fishes from mainly the lower epipelagic to mesopelagic zone, but not including notothenioids, other Antarctic / sub-Antarctic fishes or indeed other perciform fishes: Anguilliformes (Nettastomatidae, Congridae), Aulopiformes (Ipnopidae), Lophiformes (Chaunacidae), Ophidiiformes (Ophidiidae), Polymixiiformes (Polymixiidae), Scorpaeniformes (Hoplichthyidae, Triglidae) and Stomiiformes (Phosicthyidae) (Martin et al., 2017 and references therein). Four of these species have Indo-Pacific distributions, N. acanthogobii and N. lobata are both known from off Japan and Mozambique, N. tohei is known from Hawaii and N. tinkerbellae is known from off British Columbia, whereas N. lanceolata is known from the Gulf of Mexico and the Caribbean and also from off Mozambique. Species included here in Mesobathylebouria can be distinguished most objectively from those retained in Neolebouria (s. s.) by smaller eggs, measuring less than 80 µm long. These species are also less robust and some have a dextro-submedial ovary or smooth testes. In N. lanceolata the cirrus-sac almost reaches to the posterior margin of the ventral sucker, but in the other four species it is either entirely anterior to the ventral sucker or overlaps only the anterior portion. Two nominal Neolebouria species are unaccounted for, N. leiognathi (Wang et al., 1992) Bray, 2002 and N. pentacerotis Machida & Araki, 2002. Neolebouria leiognathi is known from the deep pugnose ponyfish Secutor ruconius (Perciformes: Leiognathidae), a small coastal fish, off China (Wang et al., 1992). It has almost equal suckers, a neatly trilobed ovary, eggs greater than 90 µm long and possibly a medial genital pore. It is unlikely to belong in either Neolebouria or Mesobathylebouria, but its placement elsewhere is difficult. Few opecoelids are known from leiognathids and none bear particular resemblance to N. leiognathi. The original description is lacking in detail and thus, for the present, we consider N. leiognathi a species incertae sedis. Neolebouria pentacerotis is known from the Japanese armourhead Pentaceros japonica (Perciformes: Pentacerotidae), a lower epipelagic to mesopelagic fish, collected at depth in Japanese waters (Machida & Araki, 2002). It has exceptionally small eggs, 27 – 33 µm long, and thus is consistent with the concept of Choerodonicola Cribb, 2005, species of which are known only from perciform fishes, including in Japanese waters. Choerodonicola may be polyphyletic (Martin et al., 2018 a), based on sequence data available for two species: one, C. arothokoros Martin et al., 2018, in which the ovary is entire and the other, C. renko Machida, 2014, in which it is lobed. In the type-species, C. choerodontis (Yamaguti, 1934) Cribb, 2005, the ovary has an intermediate, irregularly lobed condition. Of the two sequenced representative species, N. pentacerotis is probably more closely related to C. renko Machida, 2014, which is known from two Japanese sparids: the yellowfin seabream Dentex abei Iwatsuki et al. and the yellowback seabream D. hypselosomus Bleeker, which reportedly range from depths of 50 to 200 m (Iwatsuki et al., 2007). Thus, we propose Choerodonicola pentacerotis (Machida & Araki, 2002) comb. nov. It is distinguishable within the genus by a distinct interruption in the vitelline field at the level of the ventral sucker; C. interruptus (Manter, 1954) Martin et al., 2018 also has an interrupted vitelline field, but the interruption is at the level of the testes in that species and it is known only from a labrid (Perciformes) endemic to New Zealand.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA0FFECF62831DFAC9C1220.taxon	diagnosis	Diagnosis: Body elongate-oval to elongate, dorso-ventrally flattened, large. Tegument smooth. Forebody short, occupies less than one-fifth total body length. Oral sucker unspecialized. Ventral sucker larger than oral sucker, sessile to protuberant. Pharynx unspecialized. Prepharynx short. Oesophagus unspecialized. Intestine bifurcates in forebody or dorsal to ventral sucker. Caeca unite to form cyclocoel near posterior extremity. Testes two, smooth, medial, usually separate. Cirrus-sac well developed, extending into hindbody. Seminal vesicle, internal. Pars-prostatica present. Ejaculatory duct long. Common genital atrium simple. Genital pore pre-bifurcal, sinistro-submedial to sinistral. Ovary smooth, medial, smaller than, anterior to and usually separate from testes. Seminal receptacle canalicular. Laurer’s canal present. Uterus preovarian. Vitelline follicles restricted to hindbody, extending anteriorly beyond ovary, sometimes reaching posterior margin of ventral sucker. Eggs operculate, unembryonated in utero. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal. In demersal and bathydemersal, mesopelagic, northern Atlantic marine fishes of Gadiformes (Lotidae, Macrouridae, Moridae, Phycidae) Type and only genus: Bathycreadium Kabata, 1961. Remarks: The Bathycreadiinae is proposed for Bathycreadium. Analyses of molecular data available for B. brayi demonstrate that it is phylogenetically distinctive among the deep-sea and freshwater clade and consistently resolves as sister to the freshwater taxa (Fig. 1). Bathycreadium currently comprises six species, five of which are known only from mesopelagic gadiform fishes in the north Atlantic, collected from depths between 340 and 665 m [no depth reported for B. elongata (Maillard, 1970) Bray, 1973]. These species agree closely in morphology, most significantly in that in each the caeca form a cyclocoel. Among opecoelids with a canalicular seminal receptacle, only one other genus, Nicolla Wisniewski, 1934, is defined for species with a cyclocoel. The two concepts are distinguished by the presence vs. absence of vitelline follicles in the forebody. Nicolla comprises both freshwater and marine species. Sequence data generated from specimens identified as the type-species, N. skrjabini (Iwantitzky, 1928) Dollfus, 1960 [= N. ovata (Pigulewsky, 1931) Wisniewski, 1934], a freshwater form, indicate that it resolves external to all other freshwater plagioporine taxa, thus providing a link between the freshwater genus concepts and that of Bathycreadium. Nicolla skrjabini is separated by relatively long branch lengths from the remaining freshwater taxa represented in the analyses, but B. brayi is separated by even greater distinction (Fig. 1). Moreover, like the other freshwater taxa, species of Nicolla have a short excretory vesicle, reaching only to the testes, as opposed to the ovary in species of Bathycreadium. Therefore, considering the ecological, morphological and phylogenetic distinctions relative to the freshwater taxa, we think it is most informative to recognize Bathycreadium in a separate subfamily. The sixth species of Bathycreadium, B. mullii Abdel-Gaber et al., 2018, probably does not belong in the genus. It was recently described based on specimens recovered from Mullus surmeletus (Perciformes: Mullidae) in the south-east Mediterranean (Abdel-Gaber et al., 2018), a frequently reported combination for both Opecoeloides furcatus (Bremser in Rudolphi, 1819) Odhner, 1928 and Poracanthium furcatum Dollfus, 1948, two elongate opecoeline taxa in which the caeca form a uroproct in the former and unite and open via a common anus in the latter.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA0FFEAF4A132BFA9601247.taxon	diagnosis	Diagnosis: Body oval, fusiform, pyrifrom or elongate-oval, dorso-ventrally flattened, medium to large. Tegument smooth. Forebody less than one-half body length. Oral sucker unspecialized or funnel-shaped. Ventral sucker larger than oral sucker, sessile to protuberant. Pharynx unspecialized. Prepharynx short. Oesophagus unspecialized. Intestine bifurcates in forebody or dorsal to ventral sucker. Caeca blind, terminate near posterior extremity. Testes two, smooth or lobed, medial or diagonal, separate or contiguous. Cirrus-sac usually well developed, may be absent, restricted to forebody or overlapping ventral sucker or extending into hindbody. Seminal vesicle, usually internal, sometimes naked, usually long, thin and sinuous distally. Pars-prostatica present, may be inconspicuous. Ejaculatory duct often short. Common genital atrium simple. Genital pore bifurcal or pre-bifurcal, sinistro-submedial. Ovary smooth to regularly or irregularly lobed, medial to dextro-submedial, smaller than and anterior to testes, contiguous with or separate from anterior testis, separate from ventral sucker. Seminal receptacle canalicular. Laurer’s canal present. Mehlis’ gland present. Uterus preovarian. Vitellarine follicles always extending beyond testes posteriorly, entering forebody or restricted to hindbody, may be distributed ventrally and dorsally or absent dorsally. Eggs oval, operculate, unembryonated in utero, without filaments or protuberances. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal. In Antarctic, sub-Antarctic and deep-sea, especially bathypelagic, fishes, several families. Type-genus: Podocotyle Dujardin, 1845 Other genera: Bathypodocotyle gen. nov., Buticulotrema Dronen & McEachran, 1993; Halosaurotrema gen. nov.; Macrourimegatrema Blend et al., 2004; Neolebouria Gibson, 1976; Tellervotrema Gibson & Bray, 1982. Remarks: Dollfus (1959) proposed the Podocotylidae and Podocotyloidea, but most subsequent authors have considered Podocotyle, the type-genus, to belong in the Opecoelidae. Nevertheless, as per the principle of coordination, Dollfus (1959) also established the subfamily name, the Podocotylinae. Here, this subfamily concept is resurrected for Podocotyle, as well as Bathypodocotyle, Buticulotrema, Halosaurotrema and Neolebouria, each of which is represented in phylogenetic analyses by a single species and together form a strongly supported clade (Fig. 1). We also include Macrourimegatrema and Tellervotrema in this concept. These genera comprise two and three species, respectively, none of which are represented by sequence data. Collectively, podocotyline taxa are almost all known from deep-sea and / or temperate to polar fishes. Species of Bathypodocotyle, Buticulotrema, Macrourimegatrema and Tellervotrema occur in gadiform fishes, specifically of the Macrouridae and mainly in the north Atlantic; one species is known from the north Pacific (Gibson & Bray, 1982; Blend et al., 2004, 2007; Kuramochi, 2009). The sole species of Halosaurotrema is known from a north Atlantic halosaurid (Notocanthiformes) (Bray & Campbell, 1996), and species of Neolebouria, as recognized here, are known mainly from Antarctic and sub-Antarctic notothenioid perciform fishes; two are also known from a liparid (Scorpaeniformes), and a third is known only from an Atlantic ipnopid (Aulopiformes) (Gibson, 1976; Gibson & Bray, 1982; Zdzitowiecki, 1987, 1991, 1997; Zdzitowiecki et al., 1993; Palm et al., 2007). The many, ecologically diverse species of Podocotyle probably represent multiple distinct lineages, but five nominal species, and one unnamed species discussed by Blend et al. (2017), are known only from deep-sea fishes in the north-west Atlantic: four, P. harrissae Bray & Campbell, 1996, P. nimoyi Blend, Dronen, & Armstrong, 2016, P. pearsei Manter, 1934 and the unnamed species are from macrourids, one, P. shistotesticulata Bray & Campbell, 1996, is from a morid, another gadiform fish, and one, P. bathyhelminthos Blend & Dronen, 2015, from an ophidiid (Ophidiiformes) (Manter, 1934; Bray & Campbell, 1996; Blend & Dronen, 2015 b; Blend et al., 2016, 2017). These species are almost certainly closely related to species of Bathypodocotyle and Tellervotrema, differing from the former by a lobed vs. entire ovary and from the latter by restriction of the vitelline field to the hindbody. Perhaps most compellingly, like species of Bathypodocotyle and Tellervotrema, all six species of Podocotyle have a short cirrus-sac (in P. bathyhelminthos it may protrude a little into the hindbody) and a short to exceptionally short ejaculatory duct. Podocotyle atomon, the only sequenced representative of the genus, is known from a variety of fishes, mainly from the north Atlantic, Arctic and north Pacific, including Gadiformes (Gadidae), but also Anguilliformes, Gasterosteiformes, Perciformes, Pleuronectiformes, Scorpaeniformes and Sygnathiformes. It resolved as sister to B. margolisi in the phylogenetic analyses (Fig. 1) and is more consistent with the type species, P. angulata Dujardin, 1845, than with the Podocotyle species from deep-sea macrourids. Podocotyle angulata is also known from fishes of the Anguilliformes, Gasterosteiformes and Pleuronectiformes in the north Atlantic. Morphologically, the taxa included here in the Podocotylinae are mostly highly conserved, distinguished from one-another mainly by the distribution of the vitelline follicles, lobation and arrangement of the gonads, and relative lengths of the forebody and hindbody. Thus, similar to the distinctions made for Podocotyle above, the concept of Halosaurotrema differs from that of Neolebouria (s. s) in hindbody length and arrangement of the gonads, Bathypodocotyle differs from Neolebouria (s. s) and Tellervotrema mainly in restriction of the vitelline follicles to the hindbody, and Neolebouria (s. s) and Tellervotrema essentially differ only in the presence vs. absence of a dorsal vitelline field and perhaps in the regularity and degree of ovary lobation. Specialized conditions serve to distinguish two genera: species of Macrourimegatrema have a funnel-shaped oral sucker, and, most significantly, species of Buticulotrema lack a cirrus-sac. Buticulotrema is, therefore, usually considered to belong to the Opecoelininae, but the concept of that subfamily is dubious. Species of Buticulotrema bear no significant resemblance to those of Opecoelina, the type-genus, or Bartoliella Aken’Ova, 2003, the only other nominal genus. Neither includes species known from bathypelagic fishes and both concepts require the caeca to unite and open into a common anus, whereas in species of Buticulotrema the caeca are blind. Sequence data have not yet been generated from specimens related to species of either Opecoelina or Bartoliella, but it seems unlikely that these will prove to be closely related to those of Buticulotrema. The concept of the Podocotylinae can be distinguished from the Bathycreadinae by blind caeca vs. caeca forming a cyclocoel and from the Opecoelinae and Stenakrinae by a canalicular vs. uterine seminal receptacle. Distinction from the Plagioporinae (s. s), i. e. the freshwater clade, is more subtle, but we think two characters provide a potentially reliable basis. In the Podocotylinae, the excretory vesicle is longer, always reaching to the level of the ovary vs. at most to the level of the testes. Second, in some freshwater plagioporine taxa, the uterus becomes extracaecal and / or post-testicular, whereas in the Podocotylinae it is (almost) always intercaecal and preovarian. Only in one species from deep-sea fishes, Podocotyle nimoyi, is the uterus not strictly preovarian. In this species it extends to between the ovary and the anterior testis and partially dorsal to the anterior testis, but it does not enter the post-testicular zone. Additionally, a short cirrus-sac with a seminal vesicle becoming long or even duct-like distally and, in particular, a short ejaculatory duct occupying less than half the length of the cirrus-sac, appears to unite several podocotyline taxa, specifically species of Bathypodocotyle, Neolebouria, Tellervotrema and some Podocotyle.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA6FFE9F622324EA9F11204.taxon	diagnosis	Diagnosis: Body elongate-oval, dorso-ventrally flattened, large. Tegument smooth. Oral sucker, unspecialized, terminal or subterminal. Ventral sucker unspecialized, larger than oral sucker, may be protuberant. Prepharynx short. Pharynx unspecialized, slightly smaller than oral sucker. Oesophagus unspecialized. Intestine bifurcates in forebody. Caeca blind, extending beyond testes near to posterior extremity. Testes two, smooth, round or wedge shaped, medial, contiguous; post-tetsicular zone occupies at least one-quarter total body length. Cirrus-sac well developed, short, retrorse oval, restricted to forebody or overlapping anterior portin of ventral sucker. Seminal vesicle internal, occupying most of cirrus-sac, sinuous, broad proximally, becoming long, sinuous and narrow, almost duct-like, distally. Pars prostatica prominent. Ejaculatory duct exceptionally short. Common genital atrium simple. Genital pore pre-bifurcal, sinistro-submedial. Ovary smooth, medial or dextro-submedial, contiguous with anterior testis. Seminal receptacle canalicular, smaller than ovary, retrorse. Laurer’s canal present, opens dorsal to ovary. Mehlis’ gland present. Uterus preovarian, intercaecal. Vitellarium follicular, dense, restricted to hindbody, becoming confluent in post-testiuclar zone, extending near to posterior extremity. Eggs oval, operculate, unembryonated in utero. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal. In mesopelagic and bathypelagic north Atlantic and north Pacific fishes of the Macrouridae (Gadiformes). Type-species: Bathypodocotyle margolisi (Gibson, 1995) comb. nov. (syn. Allopodocotyle margolisi). Other species: Bathypodocotyle enkaimushi (Blend et al., 2015) comb. nov. (syn. Allopodocotyle enkaimushi). ZooBank registration LSID: http: // www. zoobank. org / urn: lsid: zoobank. org: act: 097 A 860 F- 3892 - 413 A- 805 E- 790 D 00548435 Etymology: The generic name is composed from Greek bathos, deep and the existing opecoelid genus Podocotyle, itself from podo-, relating to the foot and kotyle, a cup. The name is chosen because the new genus is comprised of deep-sea taxa previously recognized in Allopodocotyle, which itself is based on similarity to the concept of Podocotyle. Remarks: Allopodocotyle is loosely defined, accommodates many species and is evidently polyphyletic. The genus currently comprises about 24 species from a broad range of marine fishes, united, among typically ‘ plagioporine’ genera, by an entire ovary and restriction of the vitelline follicles to the hindbody (Cribb, 2005). The type-species, A. plectropomi (Manter, 1963), Pritchard, 1966, and its most convincing congeners, are known from Indo-West Pacific groupers (Perciformes: Serranidae: Epinephelinae). Sequence data have been published, by Bray et al. (2016), for four species considered to belong in Allopodotyle: A. epinepheli (Yamaguti, 1942) Pritchard, 1966, A. margolisi and two species identified only to genus. Data for A. epinepheli and one of the unidentified species, both collected from Indo-West Pacific groupers, resolve together in the large marine Plagioporinae (s. l.) clade. We consider these data to represent the phylogenetic position of genuine Allopodocotyle species. Allopodocotyle margolisi is phylogenetically distant from these taxa and is known from the Mediterranean grenadier Coryphaenoides mediterraneus (Giglioli) (Gadiformes: Macrouridae), collected at 1745 – 2195 m deep from the Rockall Trough in the north-east Atlantic (Gibson, 1995). Compared with A. epinepheli, A. plectropomi and also A. serrani (Yamaguti, 1952) Pritchard, 1966, another convincing species known from Indo-West Pacific groupers, A. margolisi is most distinguishable by the configuration of its terminal genitalia. It has a short cirrus-sac not extending into the hindbody and an exceptionally short ejaculatory duct vs. a relatively long cirrus-sac extending well into the hindbody with a long ejaculatory duct occupying at least half the length of the cirrus-sac. Allopodocotyle margolisi can further be distinguished from these species in that it has medial and contiguous vs. diagonal and separate testes and in that the vitelline follicles extend anteriorly to the posterior margin of the ventral sucker vs. only to the level of the ovary or a little beyond. One other nominal species of Allopodocotyle agrees more closely in its morphology and ecology with A. margolisi than with species from Indo-West Pacific groupers: A. enkaimushi has an exceptionally short ejaculatory duct and cirrus-sac, medial and contiguous testes, and vitelline follicles restricted to the hindbody but extending anteriorly to the posterior margin of the ventral sucker. It is also known from macrourids, collected at depths between 681 and 1061 m off Japan (Blend et al., 2015). We propose Bathypodocotyle for these two species. We think that these species are probably closely related to other taxa known from deep-sea macrourid fishes, specifically species of Macrourimegatrema, Tellervotrema and some species of Podocotyle, as well as species of Neolebouria (s. s). However, none of these concepts can adequately accommodate the taxa included here in the new genus: Macrourimegatrema is defined for species with a funnel-shaped oral sucker and a more elongate body, species of Tellervotrema and Podocotyle have lobed ovaries, and species of Tellervotrema and Neolebouria have vitelline follicles entering the forebody.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
650B6949FFA5FFE9F6143267ADF417E1.taxon	diagnosis	Diagnosis: Body pyriform. Tegument smooth. Oral sucker unspecialized, subterminal, subspherical. Ventral sucker unspecialized, larger than oral sucker, transversely ellipsoidal. Prepharynx short. Pharynx unspecialized, slightly smaller than oral sucker. Oesophagus distinct, unspecialized. I n t e s t i n e b i f u r c a t e s i n f o r e b o d y. C a e c a b l i n d, extending near to posterior extremity. Testes two, irregularly lobed, diagonal, contiguous, filling much of hindbody; post-tesicular zone very short, roughly equal to post-caecal zone. Cirrus-sac well developed, overlapping ventral sucker, not extending into h i n d b o d y. S e m i n a l v e s i cl e i n t e r n a l, o c c u p y i n g about one-half cirrus-sac, broad proximally, narrowing abruptly prior to pars prostatica. Pars prostatica narrow, continuous with ejaculatory duct. Common genital atrium simple. Genital pore pre-bifurcal, sinistro-submedial. Ovary irregularly lobed, dextro-submedial, contiguous with anterior testis. Seminal receptacle canalicular, smaller than ovary. Laurer’s canal present, opens dorsal to ovary. Mehlis’ gland present. Uterus preovarian. Vitellarium follicular, distributed length of caeca, becoming confluent dorsally in forebody. Eggs operculate, unembryonated in utero. Excretory vesicle tubular, extends to level of ovary. Excretory pore terminal. In bathypelagic halosaurid fishes (Notocanthiformes) of the north Atlantic. Type and only species: Halosaurotrema halosauropsi (B r a y & C a m p b e l l, 1 9 9 6) c o m b. n o v. (s y n. Gaevskajatrema halosauropsi). ZooBank registration LSID: http: // www. zoobank. org / urn: lsid: zoobank. org: act: 3 C 89 E 842 - E 7 C 6 - 482 D- B 24 A- 21 F 536 D 9 EF 86 Etymology: Halosaurotrema is named for the host family of the only species, the Halosauridae. The name is derived from Greek halos, salt, sauros, lizard and trema for trematode. Remarks: Gaevskajatrema halosauropsi requires a new genus. It was described based on material recovered from Halosauropsis macrochir (Günther) (Notocanthiformes: Halosauridae) collected between 1908 and 2570 m deep in the north Atlantic (Bray & Campbell, 1996); it is the only opecoelid known from a notocanthiform fish. Conversely, G. perezi (Mathias, 1926) Gibson & Bray, 1982, the type-species, and G. pontica (Koval, 1966), Machkevsky, 1990, the only other member of the genus, are known from shallow-water wrasses (Perciformes: Labridae) from the eastern Mediterranean to the Black Sea and from off Roscoff, north-western France (Gibson & Bray, 1982). Phylogenetic analyses show that G. perezi and G. halosauropsi are only distantly related, with the type-species resolving among the Opistholebetinae (Martin et al., 2018 b). The morphological characters considered to be most important for defining Gaevskajatrema are caeca terminating lateral to the testes and vitelline follicles not extending beyond the testes posteriorly. Strictly, G. halosauropsi exhibits both conditions, but not in a form consistent with that seen in G. perezi. In that species, the caeca are short such that the post-caecal zone occupies more than one-quarter of body length, and there is an appreciable post-testicular zone from which the vitelline follicles are excluded. In G. halosauropsi, the caeca and vitelline follicles reach near to the posterior extremity, as is typical for most opecoelids, but the hindbody is relatively short and the testes large, such that the post-testicular zone is roughly equivalent to the post-caecal and post-vitelline zones. Furthermore, in G. halosauropsi the ovary and testes are irregularly lobed vs. smooth and the excretory vesicle extends to the level of the ovary vs. the posterior testis. Thus, we propose Halosaurotrema gen. nov. and H. halosauropsi comb. nov. The new concept is similar to Neolebouria (s. s), but differs in general body shape, the relatively short hindbody and post-testicular zone, and in that the testes are diagonal and the ovary dextro-submedial vs. all gonads medial.	en	Martin, Storm Blas, Huston, Daniel Colgan, Cutmore, Scott Christopher, Cribb, Thomas Herbert (2019): A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society 186: 385-413
