Steganoderma szidati n. sp. (Trematoda: Zoogonidae) from Galaxias maculatus (Jenyns) and G. platei Steindachner in Patagonia,Argentina

Steganoderma szidati n. sp. is described from the intestine of two freshwater fishes, Galaxias maculatus and G. platei (Galaxiidae), from Andean lakes in Patagonia, Argentina. This freshwater zoogonid species fits in the genus Steganoderma (sensu Bray, 1987) because of the length of the caeca and the position of the vitelline follicles. The new species is characterised by possesing 6-13 vitelline follicles situated between the anterior margin of the ventral sucker and the poterior margin of the testis. The gonads are in the anterior hindbody and the ovary is anterior to the right testis. The cirrus has two conspicuous spines at its distal end, and the seminal vesicle always exhibits a constriction. The excretory vesicle never reaches the level of the posterior margin of the testes.     

A new species of Mesocoelium (Digenea: Mesocoeliidae) found in Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia

Mesocoelium lanfrediaesp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella marina (Amphibia: Bufonidae) and is described here, with illustrations provided by light, scanning electron microscopy and molecular approachs. M. lanfrediae sp. nov. presents the typical characteristics of the genus, but is morphometrically and morphologically different from the species described previously. The main diagnostic characteristics of M. lanfrediae sp. nov. are (i) seven pairs of regularly-distributed spherical papillae on the oral sucker, (ii) ventral sucker outlined by four pairs of papillae distributed in a uniform pattern and interspersed with numerous spines, which are larger at the posterior margin and (iii) small, rounded tegumentary papillae around the opening of the oral sucker, which are morphologically different from those of the oral sucker itself, some of which are randomly disposed in the ventrolateral tegumentary region of the anterior third of the body. Addionally, based on SSU rDNA, a phylogenetic analysis including Brachycoeliidae and Mesocoeliidae taxa available on GenBank established the close relationship between M. lanfrediae sp. nov. and Mesocoelium sp.     

The Lepocreadiidae (Digenea) of fishes from the north-east Atlantic: a review of the genusLepidapedon Stafford, 1904

The genusLepidapedon is subdivided into several species groups and subgroups of species based on the vitelline distribution and the length of the excretory vesicle. The species in each of the subgroups are listed and keys to the species in most subgroups are given. The following north-eastern Atlantic species are described or redescribed:Lepidapedon rachion fromMelanogrammus aeglefinus, Gadus morhua, Aspitrigla cuculus, Merlangius merlangus andPollachius pollachius; L. cambrensis fromEnchelyopus cimbrius; L. sommervillae n. sp. fromTrachyrincus scabrus, T. murrayi andCoryphaenoides guentheri; L. elongatum fromGadus morhua; L. gaevskayae fromCoryphaenoides (Nematonurus) armatus; L. discoveryi n. sp. fromCoryphaenoides (Nematonurus) armatus; L. arlenae n. sp. fromTrachyrincus scabrus andT. murrayi; L. mariannae n. sp. fromGaidropsarus argentatus; Lepidapedon spp. innom (Elongatum-group) fromCoryphaenoides guentheri andCoryphaenoides (Chalinura) leptolepis; L. desclersae n. sp. fromLepidion eques; L. beveridgei fromCoryphaenoides (Nematonurus) armatus andC. (Chalinura) mediterraneus; andL. zubchenkoi fromCoryphaenoides (Chalinura) leptolepis andC. (C.) profundicolus. The phylogeny, host-specificity and zoogeography of the genus are briefly discussed.     

The Psilostomidae Looss, 1900 (<Emphasis Type="Italic">sensu stricto</Emphasis>) (Digenea: Echinostomatoidea): description of three new genera and a key to the genera of the family

Three new psilostomid genera, Byrdtrema n. g., Longisaccus n. g. and Macracetabulum n. g., each with a single species, are described from ducks, Aix sponsa (L.) and Bucephala albeola (L.) in North America. Byrdtrema n. g. and Macracetabulum n. g. possess a bipartite seminal vesicle and share this character with four psilostomid genera, Grysoma Byrd, Bogitsh & Maples, 1961, Neopsilotrema Kudlai, Pulis, Kostadinova & Tkach, 2016, Psilostomum Looss, 1899 and Psilotornus Byrd & Prestwood, 1969. Byrdtrema n. g. differs from Macracetabulum n. g. in the shape of the body (elongate vs elongate-oval); the position of the ventral sucker (in first third of body vs just pre-equatorial); the shorter forebody; as well as in the smaller size of the eggs in relation to body length. Both new genera differ from (i) Grysoma by the nature of the vitellarium (large, compact follicles with small vitelline cells vs weakly defined follicles with large vitelline cells, respectively) and the smaller size of the eggs in relation to body length; (ii) Psilostomum in the posterior extend of the cirrus-sac in relation to ventral sucker (slightly posterior vs more posterior), the location of the genital pore (at the level of oesophagus vs just postbifurcal), the shorter length of uterine and longer post-testicular fields in relation to body length, and the anterior limits of vitellarium (at the level of ventral sucker vs posterior to ventral sucker); (iii) Psilotornus by the presence of a muscular pharynx (vs absent or rudimentary) and the location of the cirrus-sac (antero-dorsal to ventral sucker or more posterior vs entirely anterior to ventral sucker) and ovary (in hindbody vs in forebody). Byrdtrema n. g. differs from Neopsilotrema in the shape of the body (elongate vs subspherical to elongate-oval) and ventral sucker (elongate-oval vs subspherical to transversely oval), the shorter forebody and smaller eggs in relation to body length. Macracetabulum n. g. differs from Neopsilotrema by the shape of the ventral sucker (elongate-oval vs subspherical to transversely oval), the anterior limits of vitellarium (level of middle of ventral sucker vs level of intestinal bifurcation or anterior testis); and the slightly smaller size of eggs in relation to body length. Among the psilostomid genera, Longisaccus n. g. shows close affinities to Psilochasmus Lühe, 1909 in the presence of the long cirrus-sac and tubular internal seminal vesicle but can be clearly distinguished from the latter by the absence of the retractile tail-like process. In combination with molecular data, the above differences justify the recognition of three new genera. A key to the genera of the Psilostomidae is provided.     

Rhipidocotyle genovi n. sp. (Digenea: Bucephalidae) from the intestine ofGaidropsarus mediterraneus (L.) (Gadiformes: Gadidae) from the Black Sea

Rhipidocotyle genovi n. sp. is described from the fishGaidropsarus mediterraneus (L.) (Gadiformes: Gadidae) in the Black Sea. Morphological features characteristic of this species include: an anterior sucker with seven prominent muscular appendages; a pharynx rather posterior in position; ovary and testes relatively anterior in position, usually anterior to the pharynx; a long (in relation to body length) sucker, cirrus-sac and excretory vesicle; the presence of a pre-oral lip; and contiguous vitelline fields which form an arch. The new species is distinguished fromR. galeata, R. lamberti andBucephalus marinum. This is the first member of the genus whose adults are recovered from Black Sea marine fishes. Metacercariae, which encyst in large numbers in the musculature and fins of the blenniid fishesBlennius tentacularis, B. sanguinolentus, B pavo, B. sphinx andB. zvonimiri and exhibit a similar morphology to the adult, are described.     

Description and molecular characteristics of Morishitium polonicum malayense Urabe,Nor Hashim & Uni,n. subsp. (Trematoda: Cyclocoelidae) from the Asian glossy starling,Aplonis panayensis strigata (Passeriformes: Sturnidae) in Peninsular Malaysia

We describe Morishitium polonicum malayense n. subsp. from Asian glossy starlings (Aplonis panayensis strigata) (Horsfield, 1821) (Passeriformis: Sturnidae) caught in Malaysia. The trematodes had parasitized the air sacs and the thoracic and body cavities of 40 out of 67 (59.7%) birds examined. The specimens each had an oral sucker, a postpharyngeal genital pore, and tandem testes, but lacked a ventral sucker. The morphological characteristics of our specimens were similar to those of M. polonicum polonicum (Machalska, 1980) from Poland. However, the anterior extremity of vitelline follicles of the present specimens sometimes extended to the level of pharynx. The oral sucker width, oral sucker width/pharynx width ratio, and intertesticular space metrics differed from those of M. p. polonicum. The maximum-likelihood trees based on the cytochrome c oxidase subunit I (COI) and the internal transcribed spacer 2 (ITS2) sequences indicated that the species from the present study formed a sister group with M. p. polonicum from the Czech Republic. The p-distances of COI and ITS2 sequences between the present specimens and M. p. polonicum from the Czech Republic were 6.9–7.5% and 0.6%, respectively. These genetic divergences indicate the border for intra- or interspecific variation of digeneans. The definitive host species and geographical distribution of the current specimens were distinct from those of M. p. polonicum from Europe. We thus concluded that the present specimens are ranked as a new subspecies of M. polonicum, namely M. polonicum malayense n. subsp.     

Lepidapedon spp. (Digenea: Lepocreadiidae) from deep-sea gadiform fishes of the NW Atlantic Ocean,including four new species

Five species are described from fishes in deep waters of the northwestern Atlantic Ocean: Lepidapedon gaevskayae n. sp. from Coryphaenoides (Nematonurus) armatus; L. merretti n. sp. from Phycis chesteri; L. zubchenkoi n. sp. from Coryphaenoides (Chalinura) leptolepis; L. beveridgei n. sp. from C. (N.) armatus; and Lepidapedon sp. innom. from Antimora rostrata. The genus Lepidapedon is discussed and divided into groups of species distinguished by the vitelline distribution and the extent of excretory vesicle. The new species are placed in their appropriate groups and differentiated from the other species in the group.     

A new species of Parspina Pearse, 1920 (Digenea: Cryptogonimidae) from Pimelodella gracilis (Valenciennes) (Siluriformes: Heptapteridae) in the Paraná River basin, Argentina, and a key to the genus

A new species of cryptogonimid belonging to the genus Parspina Pearse, 1920 is described from the intestine of Pimelodella gracilis (Valenciennes) in the Paraná River basin, Argentina. Parspina pimelodellae n. sp. is characterised by having: (i) a body length/width ratio of 1:3.6–5.3 at the level of the ventral sucker; (ii) 21 oral spines; (iii) an oral sucker larger than the ventral sucker, with a sucker width ratio of 1:0.6–0.7; (iv) a postcaecal region of 16–19% of the body-length; (v) a compact, transversely elongate ovary, anterior to and well separated from the testes; (vi) small, branched vitelline follicles, extending from the level of the ventral sucker to the anterior margin of the ovary; and (vii) a large seminal vesicle situated posterodorsal to the ventral sucker. A key to the species of Parspina is presented.     

Morphological and molecular data for larval stages of four species of Petasiger Dietz, 1909 (Digenea: Echinostomatidae) with an updated key to the known cercariae from the Palaearctic

Recent molecular phylogenetic studies on fish tapeworms of the genus Caryophyllaeus Gmelin, 1790 (Cestoda: Caryophyllidea), parasites of cyprinid fishes in the Palaearctic Region, have revealed unexpected phenotypic plasticity that seems to be related to definitive hosts. In the present paper, Caryophyllaeus brachycollis Janiszewska, 1953 is redescribed and its two morphotypes are circumscribed on the basis of newly-collected specimens. Morphotype 1 from barbels [Barbus spp. including the type-host Barbus barbus (L.); Barbinae] and chubs (Squalius spp.; Leuciscinae) is characterised by a more robust body with spatulate scolex, which is only slightly wider than a very short neck region, and the anterior position of the testes and vitelline follicles, which begin immediately posterior to the scolex. Specimens of Morphotype 2 from breams (Abramis spp., Ballerus spp. and Blicca spp.; Abraminae), which have been previously misidentifed as Caryophyllaeus laticeps (Pallas, 1781), possess a more slender body with a flabellate scolex, which is much wider than a long neck, and the first testes begin at a considerable distance posterior to the first vitelline follicles. Despite conspicuous differences in the scolex morphology and the anterior extent of the testes and vitelline follicles, both morphotypes are identical in the morphology of the posterior end of the body, in particular that of the cirrus-sac, which is large, thick-walled, elongate-pyriform, and contains a long cirrus, and in the distribution of the vitelline follicles, which surround medially vas deferens near the cirrus-sac. A specimen of Morphotype 1 from B. barbus from the Argens River, France, is designated as neotype of C. brachycollis. The presence of phenotypic plasticity in morphological characteristics previously used for differentiation of species of Caryophyllaeus may confound species identification, which is crucial for biodiversity, ecological and evolutionary studies. To avoid these potential problems, combination of morphological and molecular data is strongly recommended.     

Morphology of the early zoeal stages of Macropipus tuberculatus (Roux, 1830) (Crustacea, Brachyura, Portunidae)

The first three zoeal stages of the portunid crab Macropipus tuberculatus (Roux, 1830) are described and illustrated from laboratory-reared material obtained from one ovigerous crab captured in the western Mediterranean Sea. Zoeae of M.tuberculatus can be distinguished from other known polybiinid species from the northeastern Atlantic and Mediterranean waters by a combination of meristic and morphometric features, especially by the number of setae in the outer lobe of the maxilla endopod. Larval morphology presents additional evidence supporting the split of the genus Macropipus into the genera Liocarcinus and Macropipus sensu stricto based on adult characters.      

An almost complete skeleton of Metailurus parvulus (Carnivora, Felidae) from the late Miocene of Kerassia (Northern Euboea, Greece)

We describe a partial skeleton of Metailurus parvulus from the Turolian site of Kerassia 1 (Northern Euboea, Greece). The material, which consists of a mandible, the anterior and posterior limb-bone elements, some sternal bones and some vertebrae, is the most complete known of this species. The dental material is compared to specimens from Pikermi and Chomateri (Greece), and China. The limb-bones available offer us the possibility to discuss the status of some previously described specimens from Pikermi. The limb proportions indicate that M. parvulus had elongated posterior limbs relative to the anterior ones, which reflects developed jumping skills. M. parvulus had moderately developed cursorial abilities, intermediate between open and closed habitat felids, and probably frequented primarily relatively open woodlands.     

Descriptions of two new silversides, Hypoatherina golanii and Hypoatherina lunata, from the Indo-West Pacific (Atheriniformes: Atherinidae)

Two new atherinid fishes, Hypoatherina golanii and Hypoatherina lunata, are described based on specimens collected from the wide range of the Indo-West Pacific. The former species is known from the Red Sea and was confused with Hypoatherina barnesi because it has a somewhat wide midlateral band and overlapping meristic counts. Hypoatherina golanii is distinguished from its congeners by the midlateral scales with an indented posterior margin, posterior margin of anterior predorsal scales with a spatular outgrowth, posterior margin of axillary scales without a distinct projection, and posterior end of maxilla not slanted downward. Hypoatherina lunata is distributed in the waters of southern Japan (Okinawa and Kagoshima prefectures) and Indonesia (North Sulawesi, Maluku, and Papua), but was confused with Hypoatherina woodwardi. Hypoatherina lunata is distinguished from its congeners in having a distinct crescent marking in front of the eye and the anus usually situated anterior to the tip of the pelvic fin.     

Zoogonidae (Digenea) from southern Great Barrier Reef fishes with a description of Steganoderma (Lecithostaphylus) gibsoni n. sp.

Two species of the Zoogonidae are recorded from Heron Island on the southern Great Barrier Reef. Steganoderma (Lecithostaphylus) gibsoni n. sp. is described from the intestine of Abudefduf whitleyi (Pomacentridae). The new species is distinguished by the combination of the following: pedunculate ventral sucker, caeca extending well past testes, presence of two-chambered internal seminal vesicle, vitelline follicles extending only to anterior margin of testes, and testes close to ventral sucker. Zoogonus pagrosomi Yamaguti, 1939 is recorded from Lethrinus atkinsoni (Lethrinidae). This species has been recorded previously only from a sparid from Japan. A new combination, Steganoderma (Lecithostaphylus) fugus (Zhang, Qiu & Li, 1986), is made.     

Systematics of Alloteuthis (Cephalopoda:Loliginidae) based on molecular and morphometric data

Alloteuthis is a group of small, slender loliginid squids of minor fisheries importance. There are three nominal Alloteuthis species—A. media (Linnaeus), A. subulata (Lamarck) and A. africana Adam. Two of these species (A. media and A. subulata) have largely overlapping ranges in the Mediterranean and northeastern Atlantic, while A. africana is found along the west coast of Africa. Despite the low level of species diversity, Alloteuthis taxonomy and systematics are confused, and assignment of specimens to species can be difficult. To clarify Alloteuthis systematics, we gathered morphometric data and DNA sequence data from two mitochondrial loci and a nuclear locus from Alloteuthis specimens collected from several localities. Analyses of the morphometric data suggest that head width is the main variable allowing separation of A. africana from the other two species, and central club sucker size separates A. media from A. subulata. One easily diagnosable character often used to distinguish Alloteuthis species—relative fin length—appears to be of little taxonomic value. Only three specimens assignable to A. subulata both morphologically and genetically were found, all from the Adriatic; possible reasons for this apparent rarity are discussed. Gene tree parsimony and coalescent-based methods were used to estimate species relationships from the molecular data, and both supported a sister-species relationship between A. media and A. subulata. Analyses of molecular variation (AMOVA's) revealed significant genetic differentiation between Atlantic and Mediterranean A. media. This study highlights the importance of 1) sampling multiple individuals, locations and loci for species-level phylogenetic studies, 2) using morphometric analyses to reveal taxonomically meaningful morphological characters and 3) accounting for the stochastic nature of the coalescent process when estimating species phylogenies for closely related taxa.     

A new species of Pseudopecoelus von Wicklen, 1946 (Digenea: Opecoelidae) from the orange roughy Hoplostethus atlanticus Collett, 1889 (Trachichthyidae) from off southeastern Australia

A new species, Pseudopecoelus sewelli, is described from the deep-sea fish Hoplostethus atlanticus from off southeastern Australia. It is an elongate form with considerable variation in such important characters as the anterior vitelline extent, the sucker ratio and the egg-size. The features distinguishing this species from five related forms are combinations of the sucker ratio, egg-size, lobation of gonads, presence or absence of a cirrus-sac and the position of the genital pore.     

Saturnius minutus n. sp. and S. dimitrovi n. sp. (Digenea: Hemiuridae) from Mugil cephalus L. (Teleostei: Mugilidae), with a multivariate morphological analysis of the Mediterranean species of Saturnius Manter, 1969

Three species of the bunocotyline genus Saturnius Manter, 1969 are described from the stomach lining of mugilid fishes of the Mediterranean and Black Seas. Two of the species are new: S. minutus n. sp. occurs in Mugil cephalus off the Mediterranean coast of Spain; and S. dimitrovi n. sp., a parasite of M. cephalus off the Bulgarian Black Sea coast and the Spanish Mediterranean coast, was originally described as S. papernai by Dimitrov et al. (1998). In addition, S. papernai Overstreet, 1977 is redescribed from M. cephalus off the Spanish Mediterranean coast and from Liza aurata and L. saliens off the Bulgarian Black Sea coast. The three species are distinguished morphometrically using univariate and multivariate analyses. These results were verified using Linear Discriminant Analysis which correctly allocated all specimens to their species designations based on morphology (i.e. 100% successful classification rate) and assigned almost all specimens to the correct population (locality). The following variables were selected for optimal separation between samples: the length of the forebody, ventral sucker and posterior testis, the length and width of the posteriormost pseudosegment, and the width of the muscular flange at ventral sucker level.     

Siphoderina hustoni n. sp. (Platyhelminthes: Trematoda: Cryptogonimidae) from the Maori snapper Lutjanus rivulatus (Cuvier) on the Great Barrier Reef

A new cryptogonimid trematode, Siphoderina hustoni n. sp., is reported, collected off Lizard Island, Queensland, Australia, from the Maori snapper Lutjanus rivulatus (Cuvier). The new species is moderately distinctive within the genus. It is larger and more elongate than most other species of Siphoderina Manter, 1934, has the shortest forebody of any, a relatively large ventral sucker, a long post-testicular zone, and is perhaps most recognisable for the substantial space in the midbody between the ventral sucker and ovary devoid of uterine coils and vitelline follicles, the former being restricted to largely posterior to the ovary and the latter distributed from the level of the anterior testis to the level of the ovary. In phylogenetic analyses of 28S ribosomal DNA, the new species resolved with the other nine species of Siphoderina for which sequence data are available, all of which are from Queensland waters and from lutjanid and haemulid fishes. Molecular barcode data were also generated, for the ITS2 ribosomal DNA and cox1 mitochondrial DNA markers. The new species is the first cryptogonimid known from L. rivulatus and the first metazoan parasite reported from that fish in Australian waters.

     

Crossing barriers of zoogeographical regions: Molecular evidence of vicariance of the only cestode parasite of loaches (Cobitidae) in the Indomalayan region,Paracaryophyllaeus lepidocephali (Cestoda: Caryophyllidea), and its redescription

Tapeworms of the genus Paracaryophyllaeus Kulakovskaya, 1961 (Cestoda: Caryophyllidea) are specific parasites of loaches (Cypriniformes: Cobitoidea) and occur almost exclusively in the Palaearctic region. The only exception and example of vicariance over the borders of two zoogeographical regions is Paracaryophyllaeus lepidocephali (Kundu, 1985), an insufficiently known species described from the Indomalayan region, with uncertain generic allocation. In the present paper, the species is redescribed based on new material collected from the type host, Lepidocephalichthys guntea, in West Bengal, India. Molecular data reveal this species as a member of Paracaryophyllaeus, within which it is the most closely related to P. cf. gotoi from Misgurnus anguillicaudatus in China and Japan on the basis of large subunit of ribosomal nuclear DNA (28S rDNA). Generic position of P. lepidocephali examined herein is also confirmed by morphology including cross sections, in particular, by a small, cylindrical body, medullary testes with testicular fields crossing the anterior margin of the cirrus sac, medullary vitelline follicles, with some follicles paramuscular, a shallow common genital atrium, short vagina and uterus not extending anteriorly beyond the cirrus sac. It differs from all Palaearctic congeners but Paracaryophyllaeus vladkae Scholz, Oros and Aydogdu, 2014 by the testicular field crossing the anterior margin of the cirrus sac. It differs from P. vladkae by more anterior position of the first vitelline follicles compared to the first testes. This species is a unique example of a fish tapeworm crossing the borders of the Palaearctic and Indomalayan zoogeographical regions.