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.     

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.     

Coryphogonimus aglaos n. g., n. sp. (Digenea: Prosthogonimidae) from the Australian bush rat,Rattus fuscipes (Rodentia: Muridae), with notes on other prosthogonimids from Australian mammals

Coryphogonimus aglaos n. g., n. sp. (Digenea: Prosthogonimidae) is described from the liver of the Australian bush rat, Rattus fuscipes (Rodentia: Muridae). The new genus is distinguished from other prosthogonimids by the possession of the following combination of characters: oral and ventral suckers well developed; caeca terminating in front of testes; genital pore opening dorsal to oral sucker; vitelline follicles restricted to caecal region; uterus extending posterior to testes; and uterus without an egg reservoir. A single specimen of an as yet undetermined Coryphogonimus species is recorded from the Australian water rat, Hydromys chrysogaster (Rodentia: Muridae). A new host, Sminthopsis macroura (Marsupialia: Dasyuridae), is recorded for Coelomotrema antechinomes. Attention is drawn to the apparent rarity of the six known mammal prosthogonimids.     

Steganoderma (Steganoderma) valchetensis n. sp. (Digenea: Zoogonidae) from the relict fish Gymnocharacinus bergi (Osteichthyes: Characidae) in Argentina

A new species of Steganoderma (Steganoderma) (Digenea: Zoogonidae) was found in the digestive tract of the southernmost, endemic and scale-less characid, Gymnocharacinus bergi, inhabiting thermal headwaters of the Valcheta Creek in northern Patagonia, Argentina. Steganoderma valchetensis n. sp. is included in the subgenus Steganoderma because of having a sessile ventral sucker and caeca reaching to the testes. This new species can be distinguished from other species of this genus on the basis of body-length, sucker-ratio, the length of the cirrus-sac, the morphology of the seminal vesicle and gonads, and the location of the vitelline follicles and genital pore. The taxonomic status of the species of Steganoderma, parasitising the freshwater fishes of Patagonia, in southern Argentina, and Chile, is also discussed.     

Redescription of Synthesium pontoporiae n. comb. with notes on S. tursionis and S. seymouri n. comb. (Digenea: Brachycladiidae Odhner, 1905)

Synthesium pontoporiae n. comb. is redescribed, together with Synthesium tursionis and Synthesium seymouri n. comb.; the parasites were obtained from stranded and accidentally caught cetaceans. The sucker ratio (ratio between widths of the oral and ventral suckers) in S. pontoporiae was 1:1.8-3.0 (mean 1:2.2); in S. tursionis was 1:0.8-1.2; and in S. seymouri was 1:0.5-0.7. Synthesium pontoporiae differed from its congeners by additional diagnostic characters, including: oval to lobed testes; small cirrus with pyriform proximal region and flexible, tubular distal region formed by evagination of ejaculatory duct; and vitellarium in small follicles extending from the level of the seminal vesicle to the posterior extremity of the body and not forming dendritic radial bunches. Data on the morphology of adult S. pontoporiae and S. tursionis were inferred from confocal laser microscopical observations.     

Dactylomyza gibsoni n. g., n. sp. (Digenea: Opecoelidae) from Schuettea woodwardi (Waite) (Monodactylidae) from off Western Australia

An opecoelid digenean, Dactylomyza gibsoni n. g., n. sp. is described and figured from Schuettea woodwardi (Waite), a monodactylid from off the coast of Western Australia. The new genus conforms to the concept of the opecoelid subfamily Opecoelinae. The resemblance of the new genus to three other opecoelid genera, Pseudopecoeloides Yamaguti, 1940, Opecoeloides Odhner, 1928 and Poracanthium Dollfus, 1948, is discussed. Dactylomyza n. g. is distinguished from these morphologically similar worms on the basis of its median genital pore, ventral sucker appendages, uroproct and the absence of an accessory sucker. Pseudopecoeloides equesi Manter, 1947 is transferred to the new genus as Dactylomyza equesi (Manter, 1947) n. comb.     

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.     

Allassogonoporus callosciuri n. sp. (Digenea: Allassogonoporidae) from the plantain squirrel Callosciurus notatus (Boddaert) (Rodentia: Sciuridae) in Borneo

A new digenean, Allassogonoporus callosciuri n. sp. from the plantain squirrel Callosciurus notatus from the Malaysian state of Sarawak, Borneo, is described. The new species differs from: A. amphoraeformis by the size of the ventral sucker and the position of the vitellarium and uterus; and from A. marginalis by the smaller oral sucker, the position of the testes and vitellarium; from A. vespertilionis by the position of the vitellarium, testes and ovary; from A. asymmetrica by the position of the testes and uterus. Gilford's (1955) and Dubois' (1963) opinions on the synonymy of Allassogonoporus and Myotitrema is supported. No representatives of the family Allassogonoporidae have been reported previously from sciurids or South-East Asia.     

<Emphasis Type="Italic">Allassogonoporus dromiciops</Emphasis> n. sp. (Digenea: Allassogonoporidae) from <Emphasis Type="Italic">Dromiciops gliroides</Emphasis> (Marsupialia: Microbiotheriidae) in Patagonia,Argentina

A new species of Allassogonoporus Olivier, 1938, from a naturally infected specimen of Dromiciops gliroides, is described. Adults of A. dromiciops n. sp. were recovered from the small intestine. This new species can be distinguished from all other species of the genus by having: the largest body and eggs, a lobed testes and ovary, a Y-shaped excretory vesicle and vitelline follicles beginning at the level of the posterior margin of the oral sucker. This is the first record of a species of Allassogonoporus in South America and the first record of a digenean parasitising D. gliroides.     

Paraoistosomum novaeguineae n. gen., n. sp. (Digenea) from a New Guinea crocodile: a surprising relative of the enigmatic Oistosomum caduceus Odhner, 1902

Paraoistosomum novaeguineae n. gen., n. sp. is described based on specimens from the kidneys of a New Guinea crocodile Crocodylus novaeguineae collected in Papua New Guinea. The body shape and the topology of most internal organs of the new species are strongly reminiscent of Oistosomum caduceus Odhner 1902, the sole member of Oistosomum, a genus of unclear phylogenetic relationships and systematic position described from the Nile crocodile in Sudan in 1902 and never reported since then. At the same time, the new species has a number of significant differences from Oistosomum caduceus. Among them are much shorter intestinal ceca, a relatively larger ventral sucker, ovary anterolateral to ventral sucker (posterolateral in O. caduceus ), vitellaria arranged in 2 clusters of loosely organized follicles at the level of ventral sucker (2 narrow long lateral fields in O. caduceus ), much longer esophagus, and other characters. Most importantly, the new species has the genital pore situated at the anterior body end adjacent to the oral sucker, whereas O. caduceus has the genital pore in front of the ventral sucker. These dramatic differences suggest establishment of a new genus for the species from Papua New Guinea. The anatomy of P. novaeguineae n. gen., n. sp. suggests that these genera may not belong to the Plagiorchiidae, the current familial allocation of Oistosomum. Scarcity of material and lack of molecular data do not permit clarification of this problem at the present time.     

Two new opecoelids (Digenea) in the flatfish Pseudorhombus jenynsi (Bleeker) from Shark Bay,Western Australia

The first marine fish digeneans recorded from Shark Bay, Western Australia are described from the flatfish Pseudorhombus jenynsi. Macvicaria dampieri n. sp. differs from the other members of the genus in its undivided, straight, saccular seminal vesicle, and the definition of the genus is extended to include this feature. The following new combinations are made: Macvicaria branchiostegi (Yamaguti, 1937) [originally Plagioporus] and M. cynoglossi (Madhavi, 1975) [originally P.]. Cainocreadium alanwilliamsi n. sp. is distinguished by the variable anterior extent of its excretory vesicle, which reaches to a level ranging between the posterior margin of the ventral sucker and just into the forebody, and by its relatively short forebody.     

Bilatorchis papillogenitalis n.g., n.sp. (Paramphistomidae: Orthocoelinae), a parasite of the red lechwe (Kobus leche Gray, 1850) from Zambia

Summary Bilatorchis papillogenitalis n.g., n.sp. from the red lechwe, Kobus leche Gray, 1850, from Zambia is described and illustrated. It is assigned to the subfamily Orthocoelinae Price & McIntosh, 1953 and distinguished from other members of the subfamily by the lateral and symmetrical position of the testes in the posterior third of the body between the caecal ends and the acetabulum, the intertesticular position of the ovary and Mehlis' gland and the limited extent of the caeca which end only at the level of the anterior border of the testes. A new type of genital atrium, papillogenitalis type is proposed for B. papillogenitalis, Calicophoron papillosum, Carmyerius parvipapillatus and, possibly, Orthocoelium parvipapillatum. The genus Cochinocotyle Gupta & Gupta, 1970 is moved to the subfamily Orthocoelinae.Supported by a scholarship grant under the 4th Education Project of the Philippines with the World Bank.Supported by a scholarship grant under the 4th Education Project of the Philippines with the World Bank.     

Preptetos cannoni n. sp. (Digenea: Lepocreadiidae) from Siganus lineatus (Teleostei: Siganidae) from the southern Great Barrier Reef,Australia

Preptetos cannoni n. sp. is described from Siganus lineatus from Heron Island on the southern Great Barrier Reef, Australia. Morphological features that are diagnostic of this species include: a genital pore that is sinistral to the ventral sucker and vitelline follicles that reach anteriorly to at least the bifurcation of the intestine. This is the first report of a species of the genus Preptetos from Australian waters and from fishes of the genus Siganus.     

Resurrection and emendation of Pseudoparamacroderoides Gupta & Agrawal, 1968 (Digenea: Macroderoididae), description of a new species from Vietnam,and comments on the systematics of macroderoidid genera

We herein resurrect and emend Pseudoparamacroderoides Gupta & Agrawal, 1968 (Digenea: Macroderoididae) and describe a new species, Pseudoparamacroderoides dongthapensis n. sp., from adult specimens infecting the intestine of a riverine catfish, Mystus mysticetus Roberts, (Siluriformes: Bagridae) in the Mekong River, Vietnam. Pseudoparamacroderoides (Pseudoparamacroderoides seenghali Gupta & Agrawal, 1968 [type species]; Pseudoparamacroderoides vittati Kakaji, 1969 [= Ps. vittatusi]; Pseudoparamacroderoides raychaudhurii Agarwal & Kumar, 1983; and Pseudoparamacroderoides keni Agarwal & Agarwal, 1984) differs from other macroderoidid genera by having the combination of a subspherical oral sucker that lacks distinctly-enlarged circumoral spines; caeca that extend posteriad beyond the testes without forming a cyclocoel; testes that are approximately ≤1/3 maximum body width in diameter; a cirrus sac that is claviform, slightly dorsal to and predominantly lateral to the ventral sucker (cirrus sac partially dorsolateral to dextral or sinistral margin of ventral sucker); symmetrical vitelline fields that extend posteriad to the middle of the post-testicular space (not restricted to the inter-gonadal space) and that remain separate (not confluent) anteriorly and posteriorly; and an excretory vesicle that is I-shaped (with or without anterior swelling) and wholly post-ovarian, inter-testicular, or median to the posterior testis. Pseudoparamacroderoides dongthapensis n. sp. differs from its congeners by having an elongate hindbody (>2× forebody length) and an excretory vesicle that is approximately half as long as the body and that extends anteriad beyond the anterior testis. This is the first record of a species of Pseudoparamacroderoides from beyond the Indian sub-continent, from M. mysticetus, and from the Mekong River or from Vietnam. A diagnostic key to macroderoidid genera and a key to Pseudoparamacroderoides spp. are provided.

     

Megalophallus deblocki n. sp. (Digenea: Microphallidae) from Rostrhamus sociabilis (Vieillot) (Aves: Accipitridae) in Paraguay

A new species in the little-known digenean fauna of Paraguayan birds is described in detail, especially in relation to its terminal genitalia. The new form, Megalophallus deblocki n. sp., is a microphallid from the intestine of the snail kite Rostrhamus sociabilis (Vieillot). It is differentiated in detail from its congeners, but differs mainly in having a substantially larger phallus (e.g. in relation to the ventral sucker), a smaller ventral sucker and smaller eggs. Comments are included on the functional morphology of the terminal genitalia.     

<Emphasis Type="Italic">Petasiger islandicus</Emphasis> n. sp. (Digenea: Echinostomatidae) in the horned grebe <Emphasis Type="Italic">Podiceps auritus</Emphasis> (L.) (Aves: Podicipedidae) from Iceland

Petasiger islandicus n. sp. is described and figured from a demographically isolated population of the horned grebe Podiceps auritus auritus (L.) in Lake Myvatn (Iceland). This new species belongs to the group of species with 19 collar spines which possess a large elongate-oval cirrus-sac, well-developed pars prostatica and massive bulb-like cirrus. Within this group, P. islandicus appears most similar to P. oschmarini Kostadinova & Gibson, 1998, a form with similar body dimensions described from the same host, but differs in having a larger head collar, collar spines, oral sucker, pharynx, testes and sucker-width ratio, and a smaller cirrus-sac, cirrus and eggs. Two Nearctic species resemble P. islandicus in general morphology but differ as follows: P. pseudoneocomense Bravo-Hollis, 1969 has a larger body and collar width, notably shorter collar spines, smaller testes and sucker-width ratio, and a shorter but much wider cirrus-sac which is also smaller relative to the ventral sucker and almost entirely anterior to it; and P. caribbensis Nassi, 1980 has a smaller body, shorter collar spines and a seminal vesicle which is small in relation to the cirrus-sac, vitelline fields reaching anteriorly to the level of the genital pore and the intestinal bifurcation is located more anteriorly.     

Strzeleckia major n. g., n. sp. and S. minor n. sp. (Digenea: Hasstilesiidae) from Antechinus swainsonii (Marsupialia: Dasyuridae) in Australia

Strzeleckia major n. g., n. sp. and S. minor n. sp. are described from the dusky antechinus Antechinus swainsonii (Marsupialia: Dasyuridae) from the Kosciusko National Park in southern New South Wales, Australia. The two species were found together in the same individual host animals but occupy different sites in the intestine. The new genus is placed within the Hasstilesiidae, where it differs from the only other genus, Hasstilesia, by being more elongate and in having larger suckers, tandem testes, the ovary between rather than opposite the testes, and in having the caeca not reaching the posterior end of the body. It is suggested that the life-cycles of these species are similar to those of other hasstilesiids. Pupillid snails may act as sole intermediate hosts.     

Parvatrema chaii n. sp. (Digenea: Gymnophallidae) from mice experimentally infected with metacercariae collected from surf-clam, Mactra veneriformis

Parvatrema chaii n. sp. (Digenea: Gymnophallidae) is described using the worms recovered from experimentally infected mice in Korea. The metacercariae were collected from surf-clams, Mactra veneriformis, from a tidal flat in Sochon-gun, Chungchongnam-do. The metacercariae were elliptical (0.262 x 0.132 mm), and the genital pore had an anterior arch of 16-17 sensory papillae in scanning electron microscopic view. Adult worms were ovoid to foliate (0.275-0.303 by 0.140-0.150 mm), and their characteristic features included the presence of lateral lips, short esophagus, genital pore located some distance anterior to the ventral sucker, club-shaped seminal vesicle, a compact to slightly lobed vitellarium, elliptical eggs (0.018-0.020 by 0.010-0.013 mm), and absence of the ventral pit. This gymnophallid is classified as a member of the genus Parvatrema because of the location of the wide genital pore some distance from the ventral sucker, and the absence of the ventral pit. It differs from previously reported Parvatrema species, including the type species, P. borinquenae. In particular, the morphologies of the vitellarium and the genital pore with an anterior arch of 16-17 sensory papillae are unique features. Therefore, we propose it as a new species, Parvatrema chaii n. sp. (Digenea: Gymnophallidae).     

Catatropis chilinae n. sp. (Digenea: Notocotylidae) from Chilina dombeiana (Gastropoda: Pulmonata) and notes on its life-cycle in Patagonia,Argentina

A new species of Catatropis from a freshwater pulmonate snail of the family Chilinidae, which is endemic to South America, is described. Naturally infected Chilina dombeiana were collected from several localities in Andean Patagonia. The characteristics of the larval stages are presented. Experimentally reared adults, located in the distal portion of the intestinal caeca, were recovered from chickens and ducks. Adults of Catatropis chilinae n. sp. can be distinguished from all other species in having 9-11 (10) ventral glands, a cirrus-sac extending between the first third and the middle of the body, a metraterm slightly shorter or equal to the cirrus-sac, vitelline follicles reaching forward to the middle of the body, lobed testes, and a genital pore closely posterior to the caecal bifurcation. Eggs bear polar filaments only at the anopercular end. Rediae have only one or two cercariae. Shed cercariae are trioculate with a long tail and encyst in the environment, and metacercariae become infective 72 hours after encystment. This species is widely distributed between 40°10 S and 43°09 S and it is the first Catatropis species recorded for the Chilinidae and for Argentina.     

On the morphology of Acanthostomum spiniceps (Looss, 1896) and A. absconditum (Looss, 1901) (Digenea: Cryptogonimidae: Acanthostominae) with particular reference to the juvenile stage

The morphology of juvenile and adult stages of Acanthostomum spiniceps and A. absconditum, from bagrid fish of the river Nile in Egypt, was studied with both light and scanning electron microscopy. In early juveniles, circumoral spines are absent and the entire body surface is covered with tegumental spines. Late juveniles show gradual differentiation of the circumoral tegument into a collar of spines associated with a reduction in density of tegumental spines at the posterior extremity of the body. Genital primordia appear when juveniles are about 1.75 mm long. The distributions of tegumental spines on adult A. spiniceps and A. absconditum are similar. Spines are denser on the dorsal and ventral surfaces of the anterior and middle parts of the body and less dense towards the posterior end. The tegumental fold surrounding the ventral sucker of A. absconditum has spines while the fold of A. spiniceps lacks them. The most important morphological features differentiating both species are the number of circumoral spines, body shape, ratio of body length to width, sucker sizes, and the presence or absence of spines on the ventral sucker.