The description of Gyrodactylus mulli sp. n. (Monogenea: Gyrodactylidae) from the Black Sea blunt-snouted mullet Mullus barbatus ponticus

A new species Gyrodactylus mulli sp. n. is described from the thorax fins of blunt-snouted mullet Mullus barbatus ponticus by the collections of B. E. Bychowsky made in 1947 near Karadag on the Black Sea. Gyrodactylus mulli sp. n. differs from G. alviga Dmitrieva et Gerasev, 2000 (described from blunt-snouted mullet too) in having another morphotype of the marginal hooks. The new species differs from G. proterorhini Ergens, 1967, which has the identical type of the marginal hooks, in having longer membrane of the ventral connective bar, longer point of the anchors, shorter marginal hooks, and lesser size of the cirrus.     

Gyrodactylus gvozdevi n. sp. (Gyrodactylidae: Monogenea) from Noemacheilus dorsalis (Kessler) in Kazakhstan

Gyrodactylus gvozdevi n. sp. (Gyrodactylidae: Monogenea) is described from the skin of the freshwater fish Noemacheilus dorsalis (Kessler) (Cobitidae: Cypriniformes) from Kazakhstan. This species is most closely related to G. pseudonemachili Ergens & Bykhovsky, 1967 in the shape and size of the anchors and both the ventral and dorsal bars, but can be distinguished from it by the shape and size of the hookproper of the marginal hooks.     

Gyrodactylus sommervillae n. sp. (Monogenea) from Abramis brama (L.) and Rutilus rutilus (L.) (Cyprinidae) in Oxfordshire,UK

Gyrodactylus sommervillae n. sp. (Monogenea) is described from the skin, fins and gills of Abramis brama (L.) and Rutilus rutilus (L.) from Blenheim Palace Lake, Oxfordshire, UK. G. sommervillae n. sp. closely resembles G. aphyae Malmberg, 1957, G. kearni Ergens, 1990 and G. lamberti Ergens, 1990 in the approximate shape of the marginal hook sickle and the anchors, but can be separated on the precise shape of the marginal hooks and the ventral bar.     

Seasonal variations of the opisthaptoral hard parts of Gyrodactylus derjavini Mikailov, 1975 (Monogenea: Gyrodactylidae) on brown trout Salmo trutta L. parr and Atlantic salmon S. salar L. parr in the River Sandvikselva,Norway

Seasonal variations in the size and shape of the marginal hooks, anchors and ventral bar of the opisthaptor of Gyrodactylus derjavini Mikailov, 1975 were studied. The G. derjavini specimens were collected from brown trout Salmo trutta L. parr and Atlantic salmon S. salar L. parr in the River Sandvikselva, southeastern Norway. Samples were taken at roughly monthly intervals during a 13-month period. The marginal hooks, anchors and ventral bars showed considerable seasonal variation in size, but varied very little in shape. The size increased when the water temperature decreased and vice versa.     

Morphometric comparison of three members of the Gyrodactylus nemachili-like species group (Monogenea: Gyrodactylidae) on Barbatula barbatula L. in the Czech Republic, with a reinstatement of G. papernai Ergens & Bychowsky, 1967

The Gyrodactylus nemachili-like species complex, parasitising stone loach Barbatula barbatula L. in the Czech Republic, was investigated based on the detailed morphometric analysis of its haptoral hard parts. The existence of two species, G. jiroveci Ergens & Bychowsky, 1967 and G. pseudonemachili Ergens & Bychowsky, 1967 was confirmed. A standard discriminant analysis of the morphometric data showed a clear separation between specimens of G. jiroveci and another species or variant. Based on the morphology of the haptoral hard parts, this third species was more similar to G. jiroveci than to G. pseudonemachili. The differences between G. jiroveci and the third species were mainly in the morphology of the marginal hook sickle, but included the total length of the marginal hook, the length of the hamulus point, the length of the marginal hook sickle, the width of the ventral bar, and the width of the dorsal bar. Based on comparison with the original material, the third species was identified as G. papernai Ergens & Bychowsky, 1967, which has recently been considered a synonym of G. jiroveci. These analyses provided sufficient evidence for the restoration of G. papernai as a valid taxon. Partial sequences of the internal transcribed spacer rRNA genes (ITS rDNA) verified the validity of all three Gyrodactylus species studied.     

A new gyrodactylid species from Cobitis granoei (Rendahl) (Cobitidae) in central China

Gyrodactylus granoei n. sp. (Monogenea: Gyrodactylidae) is described from the fins and body surface of the spine loach, Cobitis granoei (Rendahl) (Cobitidae), in central China. It resembles a suite of species from cyprinid and cobitid fishes that have short, compact hamuli, a ventral bar with no obvious anterolateral projections, a linguiform posterior membrane, a male copulatory organ with small hooks in multiple rows, a simple cylindrical dorsal bar, and short marginal hooks, with an expanded sickle heel. Of these, the new species resembles most closely Gyrodactylus micracanthus Hukuda, 1940 from Misgurnus anguillicaudatus (Cantor) (Cobitidae), but it is identified by the length of the hamuli and the morphology of dorsal and ventral bars. When searched using BLAST, sequence data (829 bp) spanning the ITS1, 5.8s, and ITS2 region did not return an identical match; close similarity (82-88%) was found with sequenced members of the subgenus Gyrodactylus. It is suggested that the new species is part of a freshwater lineage that has radiated successfully among cyprinid fishes in North America, Europe, and Asia, and some of their predator and amphibian neighbors.     

Gyrodactylus anarhichatis n. sp. and G. microanchoratus n. sp. (Monogenea: Gyrodactylidae) from the Atlantic wolf-fish Anarhichas lupus (Anarhichadidae) off the coast of Norway

The gyrodactylid monogeneans Gyrodactylus anarhichatis n. sp. and G. microanchoratus n. sp. are reported from the skin and fins of wild Atlantic wolf-fish Anarhichas lupus L. caught off the coast of northern Norway. G. anarhichatis n. sp. is also reported from farmed Atlantic wolf-fish and spotted wolf-fish A. minor Olafsen. G. anarhichatis n. sp. most closely resembles G. corti Mizelle & Kritsky, 1967, but is also similar to G. perlucidus Bychowsky & Poljansky, 1953 and G. errabundus Malmberg, 1970, while G. microanchoratus n. sp. differs from most other Gyrodactylus spp. by having marginal hooks longer than anchors and a peculiar lump on the marginal hook sickle toe pointing towards the sickle point.     

Seasonal variations of opisthaptoral hard parts of Gyrodactylus salaris Malmberg, 1957 (Monogenea: Gyrodactylidae) on parr of Atlantic salmon Salmo salar L. in the River Batnfjordselva,Norway

Seasonal variations in size and shape of the marginal hooks, the anchors and the ventral bar of the opisthaptor of Gyrodactylus salaris Malmberg, 1957 were studied. The G. salaris specimens were collected from parr of Atlantic salmon Salmo salar L. in the River Batnfjordselva, north-western Norway. Samples were taken at roughly monthly intervals during a two-year period. The marginal hooks, the anchors and the ventral bar showed considerable seasonal variation in size, but varied only slightly in shape. The variation in 12 of the 14 characters measured showed a significant regression to the variation in the water temperature. The total length of the marginal hooks of G. salaris can be considerably longer than the previously reported maximum of 40 m for the species.     

Gyrodactylus longidactylus n. sp., a monogenean from Pomatoschistus lozanoi (de Buen) (Gobiidae) from the North Sea

Gyrodactylus longidactylus n. sp., a gyrodactylid monogenean parasitising the gills of Pomatoschistus lozanoi (de Buen, 1923) in the North Sea is described. It is a species with rather small anchors which are only connected to a ventral bar which lacks a ventral bar membrane. The marginal hooks have long handles, which are always longer than the total length of the anchor. The pharynx has long pharyngeal processes. Measurements, drawings of the opisthaptoral hard parts, penis and pharynx, and SEM micrographs of this monogenean are presented. G. longidactylus n. sp. is the first monogenean species described from P. lozanoi.     

The family Tetraonchidae (Monogenea): its structure and position among the monogeneans

The muscle fascicles of the haptor in Tetraonchus monenteron have been described. The muscle connection of the fan-shaped dorsal bars with dorsal anchors is shown. When these muscle fascicles are contracted the dorsal anchors works as pincers. The division of tetraonchids into two genera based on types of copulatory organs, morphology of bars and haptor ans associations with different groups of fishes is restored. Different authors based on ciliated cells and chaetotaxy of the oncomiracidium and comparative spermiogenetic of T. monenteron include the tetraonchids with 16 marginal hooks into the order Dactylogyroidea. In the same time, based on the analysis of the onthogenesis of the dactylogyrid's haptor they postulate, that the haptor of these worms originally had 2 pairs of anchors and only 14 marginal hooks. The present paper contains data indicating that different representatives of the Dactylogyridea have 14-18 marginal hooks. Author put forward a suggestion, that some group of dactylogyrids originally did not have the anchors.     

Two new species of Gyrodactylus von Nordmann, 1832 (Monogenea: Gyrodactylidae) parasitizing Girardinichthys multiradiatus (Cyprinodontiformes: Goodeidae), an endemic freshwater fish from central Mexico

Gyrodactylus mexicanus n. sp. and Gyrodactylus lamothei n. sp. are described from the fins and skin of Girardinichthys multiradiatus, an endemic freshwater fish from central Mexico. Gyrodactylus mexicanus is compared to other Gyrodactylus species that parasitize Fundulus spp., the phylogenetically closest group to the Goodeidae from North America. Gyrodactylus mexicanus is distinguished by having large anchors with well-developed superficial roots, enlarged hooks with a proximally disrupted shank (ligament), and a ventral bar with 2 poorly developed anterolateral projections and a small medial process. Gyrodactylus lamothei is distinguished from G. mexicanus and from other species of Gyrodactylus on the North American continent by having anchors with a sclerite on the superficial root and robust hooks with a straight shaft and a recurved point.     

Policlithrum ponticum sp. n. (Monogenea: Gyrodactylidae: Polyclithrinae) from Mugil cephalus from the Black Sea and problems of suprageneric systematics of the gydrodactylids

Polyclithrum ponticum sp. n. is described and P. mugilini Rogers, 1967 is redescribed. Both monogenean species are parasites of Mugil cephalus in the Black Sea. The new species differs from P. mugilini, P. alberti and P. boegeri by the lesser size of anchors, while it is distinguished from P. corallense by the larger size of these structures. P. ponticum sp. n. differs from all formerly described species by the greater length of dorsal connective bar. In both species from the Black Sea, "ear-like" structures situated near the external roots of anchors are described for the first time. It is suggested, that these structures take part in longitudinal, two-lobe folding of the haptor. The process of opening the haptor is probably performed by the additional bars of the haptor (bars 2 and 3 after: Rogers, 1967), joined to each other and with the anchors. The fifth pair of additional bars (Ernst e. a., 2000) derives from the "beard" of ventral connective bar and is united with its basal part. The sixth pair of additional bars (Ernst e. a., 2000) is considered as a typical "ribs" of the haptor, and therefore the "ribs" are represented by three pairs. Differences between marginal hooks of P. ponticum sp. n. and P. mugilini are insignificant, that probably depends on the presence of "ribs" of the haptor. Based on the subdivision of marginal hooks into two groups, the presence of additional supporting structure in the haptor, and the presence of the seminal receptacle, it is suggested that the subfamily Polyclithrinae Rogers, 1967 should include the genera Polyclithrum Rogers, 1967, Swingleus Rogers, 1969, Macrogyrodactylus Mamlberg, 1959, and probably Fundulotrema Hargis, 1955. Based on such characters as the lack of the anchors, the presence of suckers in the haptor, and ovipositing of eggs, it seems to be expedient to use the following taxa in systematics of gyrodactylids: Isancistrinae Fuhrmann, 1928 (genera Isancistrum, Anacanthocotyle); Gyrdicotylinae Vercammen-Grandjean, 1960 (Gyrdicotyle) and Ooegyrodactylinae Harris, 1983 (genera Phanerothecium, Ooegyrodactylus, Nothogyrodactylus, Hyperopletes).     

Gyrodactylus gemini n. sp. (Monogenea: Gyrodactylidae), a parasite of Semaprochilodus taeniurus (Steindachner) from the Venezuelan Amazon

Gyrodactylus gemini n. sp. (Monogenea, Gyrodactylidae) is described from the surface of the body and fins of the fish Semaprochilodus taeniurus (Steindachner) imported into Britain from the Venezuelan Amazon. The new species differs from other species of the genus, including those described from South and Central America, by having: (i) stout hamuli with straight shafts and diverging roots; (ii) marginal hooks with the sickle length larger than the width; (iii) a dorsal bar without a medial constriction; (iv) a rectangular ventral bar with short processes; (v) a triangular ventral bar membrane; and, most obviously, (vi) at least two generations which can develop two embryos simultaneously. This is the first known species of the genus Gyrodactylus from the Venezuelan Amazon and the first record of the subgenus Gyrodactylus (Gyrodactylus) from South America.     

A new diplectanid (Monogenea) genus and species from the gills of the black snook, Centropomus nigrescens (Perciformes: Centropomidae) of the Pacific coast of Mexico

Cornutohaptor nigrescensi n. sp. (Diplectanidae) is described from the gills of the black snook, Centropomus nigrescens (Perciformes: Centropomidae) from the Pacific coast of Mexico. Cornutohaptor n. gen. is proposed for this new species and is characterized by possessing 2 intestinal ceca terminating blindly; a germarium looping right intestinal cecum; bilobed testis; 2 seminal vesicles; 7 pairs of hooks, each with protruding thumb; a grooved ventral bar and coiled male copulatory organ (MCO); an accessory piece comprising a "baglike structure" with an appendage; dorsal bars associated parallelly to body midline; and no adhesive accessory organs on the haptor. Cornutohaptor differs from all confamilial genera by including species with anchors with straight and deep root longest, hook pair 1 reduced in size, MCO with counterclockwise rings, and by the morphology of the accessory piece. Cornutohaptor nigrescensi most closely resembles species of Murraytrema Price, 1937, Lobotrema Tripathi, 1937, and Murraytrematoides Yamaguti, 1958, because of the absence of squamodiscs or lamellodiscs on the haptor and tegumental scales on the posterior portion of the body. Cornutohaptor differs from these genera in the position and number of haptoral bars (2 bars in Lobotrema spp., dorsal bars transversally associated in Murraytrema and Murraytrematoides spp.) and in having a coiled MCO (copulatory organ is a comparatively straight, poorly sclerotized tube in Murraytrematoides spp.). This is the first diplectanid described from a centropomid along the Pacific coast of Mexico.     

Gyrodactylus longipes n. sp. (Monogenea: Gyrodactylidae) from farmed gilthead seabream (Sparus aurata L.) from the Mediterranean

Gyrodactylus longipes n. sp. (Monogenea, Gyrodactylidae) is described from the gills of farmed juvenile gilthead seabream (Sparus aurata L.) from two sites located in Italy and Bosnia-Herzegovina and represents the second species of Gyrodactylus to be described from S. aurata. Gyrodactylus orecchiae Paladini, Cable, Fioravanti, Faria, Di Cave et Shinn, 2009 was the first gyrodactylid to be described from S. aurata, from populations cultured in Albania and Croatia. In the current study, G. longipes was found in a mixed infection with G. orecchiae on fish maintained in Latina Province, Italy, thus extending the reported distribution of the latter throughout the Mediterranean. The morphology of the opisthaptoral hard parts of G. longipes is compared to those of G. orecchiae, using light and scanning electron microscopy. Gyrodactylus longipes is characterised by having larger, elongated ventral bar processes and long, triangular-shaped toe region to their marginal hook sickles which, by comparison, are rhomboid in G. orecchiae. The marginal hook sickles of G. longipes are almost double the size of G. orecchiae which allows for their rapid discrimination from each other in mixed infections. A comparison of the DNA sequence of the ribosomal internal transcribed spacer 1 and 2 regions (ITS1 and ITS2) of G. longipes with the corresponding sequence from G. orecchiae and with those available in GenBank, supports the separate species status of G. longipes. Part of this study necessitated an overview of the existing Gyrodactylus fauna from Italy and Bosnia-Herzegovina; a summary from each country is provided here to assist future investigations.     

<Emphasis Type="Italic">Gyrodactylus thlapi</Emphasis>n. sp. (Monogenea) from <Emphasis Type="Italic">Pseudocrenilabrus philander philander</Emphasis> (Weber) (Cichlidae) in the Okavango Delta,Botswana

A new species of Gyrodactylus von Nordmann, 1832 and the first monogenean reported from Botswana is described from the cichlid Pseudocrenilabrus philander philander,bringing the number of gyrodactylids described from the African Continent to 18. Gyrodactylus thlapi n. sp. can be readily discriminated from the other described species almost exclusively by the shape of its hamuli, which have short roots and large, elongate ventral bar attachment points with the dorsal bar attachment point, demarcating the junction between the hamulus shaft and the root, positioned at the anterior terminus of the attachment plane. The marginal hooks of G. thlapi n. sp., which most closely resemble those of G. groschafti Ergens, 1973, are compared and discussed.     

A special technique for studying haptoral sclerites of monogeneans

The marginal hooks and anchors have been digested from the haptors of the monogeneans Gyrodactylus salaris and Discocotyle sagittata. These structures then can be measured and drawn more accurately than those surrounded by haptoral tissue. The technique also facilitates the study of isolated hooks with SEM. The results of studies using this digestion technique are presented.     

Neotropical Monogenoidea. 33. Three new species of Ancistrohaptor n. g. (Dactylogyridae,Ancyrocephalinae) on Triportheus spp. (Teleostei,Characidae) from Brazil,with checklists of ancyrocephalines recorded from neotropical characiform fishes

Three new species of Ancistrohaptor n. g. are described from the gills of three species of Triportheus (Characidae) collected from the environs of Manaus, Amazonas, Brazil: A. falcatum n. sp. from T. elongatus; and A. falciferum n. sp. and A. falcunculum n. sp. from T. angulatus, T. albus and T. elongatus. Ancistrohaptor n. g. is proposed for species possessing overlapping gonads, a dextral or dextroventral vaginal aperture, a coiled (counter-clockwise) male copulatory organ, two accessory pieces in the copulatory complex, and a haptor armed with two pairs of anchors (ventral anchor with elongate shaft), dorsal and ventral bars and 14 hooks; hook pair 1 (ventral) anterior to ventral bar, pairs 2–4 (ventral) lying bilaterally anterior to ventral anchor bases, pair 5 (ventral) associated with distal end of ventral anchor shafts, and pairs 6 and 7 (dorsal) bilateral about midway along haptoral length. Parasite-host and host-parasite lists of the Ancyrocephalinae from neotropical Characiformes are provided.     

A new species of Heterosentis Van Cleave, 1931 (Acanthocephala, Arhythmacanthidae), a parasite of pinguipedid fishes in the southwest Atlantic

A new species of arhythmacanthid acanthocephalan, Heterosentis martini n. sp., parasitic in the Argentinean sandperch Pseudopercis semifasciata (Cuvier) (Perciformes, Pinguipedidae) from the coasts of Argentina is described. Heterosentis martini n. sp. differs from all congeneric species by having 10 longitudinal rows of hooks in the proboscis, each with 7-8 hooks, consisting of 1 medium apical and 3 larger sub-apical hooks with root, and 3-4 smaller, basal, curved hooks with rudimentary roots and spines in both ventral and dorsal regions of the body. The most similar species, Heterosentis heteracanthus (Linstow, 1896) Van Cleave, 1931, and Heterosentis brasiliensis Vieira, Felizardo and Luque, 2009, also have 10 longitudinal rows of hooks, but H. heteracanthus differs from the new species by having only 3-5 (more frequently 4) hooks in each row, with only the anterior hook large and bearing a developed root. Heterosentis brasiliensis differs from the new species by possessing 2 sub-apical hooks in each row (instead of 3), similar body length but shorter proboscis, and trunk spines restricted to the ventral surface of body.