One new and four previously described species of Triacanthinella Bychowsky & Nagibina, 1968 (Monogenea) were collected from the tripodfishes Triacanthus biaculeatus and Tripodichthys blochii off Peninsular Malaysia. Triacanthinella lumutensis n. sp. from Tripodichthys blochii off Lumut, Selangor is similar to Triacanthinella principalis Bychowsky & Nagibina, 1968 in having morphologically similar types of haptoral sclerites and copulatory organ, but differs in possessing a longer copulatory tube. Also re-described are T. principalis Bychowsky & Nagibina, 1968, T. gracilis Bychowsky & Nagibina, 1968 and T. aspera Bychowsky & Nagibina, 1968 from both Triacanthus biaculeatus and Tripodichthys blochii, plus Triacanthinella longipenis Bychowsky & Nagibina, 1968 from Tripodichthys blochii and Triacanthinella tripathii Bychowsky & Nagibina, 1968 based on its type-material. In the new species, the filament loop of the anchors is associated with a sheath-like sclerite which envelops the anchor point. Such sclerites were also observed in the present specimens of Triacanthinella principalis, T. aspera, T. longipenis and T. gracilis but were not mentioned in the original descriptions. The generic diagnosis of Triacanthinella is amended and a key to the recognised species is presented. The specific names of two of the previously described species are emended from the neuter form to T. principalis and T. gracilis.
Numerous specimens of Ancyrocephaloides triacanthi Yamaguti, 1938 and A. chauhani Bychowsky & Nagibina, 1975 were collected from two triacanthid fishes, Triacanthus biaculeatus and Tripodichthys blochii, off Peninsular Malaysia. The two monogenean species are redescribed and considered to be the only valid species of Ancyrocephaloides Yamaguti, 1938. Examinations of these worms revealed new features, e.g. the presence of exudates (both net-like and bundle-like) and superficial grooves in the anchors in both species, which necessitated re-descriptions of the two species and amendments to the generic diagnosis. Both species have relatively small anchors with two lateral superficial grooves along the shaft and point, peduncular glands and four large, pyriform secretory reservoirs in the peduncular-haptoral region, each with a single tubular extension to an associated anchor, and net-like structures (exudate) attached to the anchors. The net-like structures are one of the external manifestations of the secretion produced in the peduncular glands and stored in the pyriform secretory reservoirs. When released within the gill-tissue of the host, the exudate is in the form of bundles which extend within the gill-filament. The small anchors convey secretions from the secretory reservoirs via lateral superficial grooves into the gills as the anchors pierce the host tissue for attachment. The secretion coagulates as left and right thread-like bundles of exudate within the gill tissues and is only apparent as nets when it is released into the surrounding water. The recurved point of the anchor and position of the point of exudation allow the nets to remain attached to the anchor point, even after the detachment of the anchors from the gill tissue. This exudate possibly acts somewhat like a 'belay device' or 'safety belt', preventing the parasite from being washed away by the respiratory current during the onset of its leech-like locomotion, as well as assist the relatively small anchors in attachment.
Two known and two new species of Diplectanocotyla Yamaguti, 1953 (D. gracilis Yamaguti, 1953, D. megalopis Rakotofiringa & Oliver, 1987, D. langkawiensis n. sp. and D. parva n. sp.) were collected from Megalops cyprinoides (Megalopidae) off Langkawi, Kedah and Matang, Perak, Peninsular Malaysia. All four species possess similar types of sclerotised male and female reproductive structures and similar soft anatomical features. The squamodisc sclerites of all four species have spine-like projections with varying degrees of visibility and shapes (sharp-pointed to triangular). In D. megalopis and D. langkawiensis n. sp. the spines are sharp-pointed and distinct on sclerites from rows 5-6 onwards. In D. gracilis and D. parva n. sp. the sclerite spines are triangular, lightly sclerotised and occur on almost all of the sclerites. D. parva n. sp. has comparatively the smallest set of anchors, bars, squamodiscs and squamodisc suckers. The anchors and bars of the other three species are almost similar in overall size, and the main distinguishing feature is the relative lengths of the inner and outer roots of the ventral anchors. In D. gracilis the outer root is very much smaller than the inner root and they are disposed almost at a right angle to each other. In D. megalopis the outer root is usually about half the length of the inner root and the roots are inclined at c.60 degrees to each other. In D. langkawiensis n. sp. the roots are inclined at c.40 degrees degrees and the outer root is of a similar length or only slightly shorter than the inner root. The openings of the two squamodisc suckers of all four Diplectanocotyla species are surrounded by tiny scale-like spines. Bifid tegumental spines are found in the posterior region of all four species, differing only in their extent: in D. parva n. sp. the tegumental spines are only distributed in the peduncular region and not beyond, whilst in the other three species the tegumental spines extend from the posterior level of the testis to the end of the peduncle. An amended diagnosis of Diplectanocotyla and a key to its species are appended.
Two new and two previously described species of diplectanid monogeneans (Heteroplectanum flabelliforme n. sp., Diplectanum sumpit n. sp., D. jaculator Mizelle & Kritsky, 1969 and D. toxotes Mizelle & Kritsky, 1969) were collected from archerfish Toxotes jaculatrix off the Island of Langkawi, Kedah and off Perak, Malaysia. The reproductive systems and squamodiscs of D. jaculator and D. toxotes are described for the first time. D. sumpit n. sp. differs from D. toxotes and D. jaculator in a having a small curved copulatory tube with a distinct accessory piece, compared to the long, tubular copulatory tube of D. jaculator and the slender tube of D. toxotes. D. sumpit n. sp. also differs from D. toxotes in having a larger ventral bar and larger squamodiscs. H. flabelliforme n. sp. differs from all known Heteroplectanum species in the shape and size of the squamodiscs, the arrangement of the sclerites in the squamodiscs, the extremely large ventral bar and the short, curved, non-spinous copulatory tube.
Septesinus gibsoni n. g., n. sp. (Monocotylidae: Heterocotylinae) is described from the gills of the dwarf whipray Himantura walga (Müller & Henle) collected in marine waters off Sarawak (Borneo), Malaysia. Septesinus n. g. is distinguished from other genera in the Monocotylidae by a combination of characters, including a haptor with one central and seven peripheral loculi, the presence of a highly sinuous ridge surmounting all haptoral septa, four rounded accessory structures on the dorsal surface of the haptor, and the anterior region with two pairs of anteromedian and three pairs of anterolateral gland-duct openings. Septesinus n. g. is accommodated in the Heterocotylinae. Septesinus gibsoni n. sp. is described and fully illustrated, and a key to the genera of Heterocotylinae is provided. The composition of the ridges surrounding the mouth of a number of heterocotyline species and their usefulness as a taxonomic character are examined. The identity of four specimens of Monocotyle Taschenberg, 1878, also recovered from the gills of this host species, is discussed.
Sundapolystoma chalconotae. n. g., n. sp. (Polystomatidae, Polystomatinae) is proposed for a new polystomatid from the urinary bladder of Rana chalconota (Schlegel) in Peninsular Malaysia. This is the first species of polystomatid to be described from the amphibians of Peninsular Malaysia and the second for the Southeast Asian region. This new genus, as exemplified by S. chalconotae, differs from other polystomatids, and in particular Parapolystoma Ozaki, 1935 (P. bulliense (Johnston, 1912) Ozaki, 1935 and P. johnstoni Pichelin, 1995), in having a tubular uterus and a single diffuse testis. P. crooki Vande Vusse, 1976 is similar to S. chalconotae in having a similar type of uterus and testis, and is re-assigned as Sundapolystoma crooki (Vande Vusse, 1976) n. comb. S. chalconotae differs from S. crooki in having anchors with a longer outer root rather than a longer inner root and 7-8 genital spines compared to 9-13 in S. crooki.
This is a catalogue and discussion of the known dactylogyridean monogenean genera of siluriform fishes of the Old World. Of a total of 38 nominal genera, only 19 are considered valid. Seventeen of these 19 genera are currently in the Ancyrocephalidae (containing the Ancyrocephalinae and Ancylodiscoidinae), whilst the other two (Neocalceostoma and Neocalceostomoides) are in the Neocalceostomatidae. The 17 genera are Anchylodiscus, Ancylodiscoides, Bagrobdella, Bifurcohaptor, Bychowskyella, Chauhanellus, Cornudiscoides, Hamatopeduncularia, Mizelleus, Paraquadriacanthus, Pseudancylodiscoides, Protoancylodiscoides, Quadriacanthus, Schilbetrema, Schilbetrematoides, Synodontella and Thaparocleidus. Clariotrema Long, 1981 and Neobychowskyella Ma, Wang & Li, 1983 are considered synonyms of Bychowskyella Akhmerov, 1952, Anacornuatus Dubey, Gupta & Agarwal, 1992 is considered a synonym of Quadriacanthus Paperna, 1961, Mizellebychowskia Gupta & Sachdeva, 1990 is considered a synonym of Neocalceostoma Tripathi, 1959 and Hargitrema Tripathi, 1959 is treated as a synonym of Hamatopeduncularia Yamaguti, 1953. It is proposed that the Ancylodiscoidinae be raised to family status within the order Dactylogyridea to accommodate these 17 'ancyrocephalid' genera from siluriforms, together with Malayanodiscoides and Notopterodiscoides from notopterids. A key and the diagnostic characteristics of the 19 recognised dactylogyridean genera from catfishes plus two from notopterids, together with a list of species and synonyms, are included. New combinations made in this work are Thaparocleidus avicularia (Chen, 1987) n. comb., T. calyciflorus (Chen, 1987) n. comb., T. choanovagina (Luo & Lang, 1981) n. comb., T. dissimilis (Chen, 1988) n. comb., T. leiocassis (Reichenbach-Klinke, 1959) n. comb., T. meticulosa (Chen, 1987) n. comb., T. parasoti (Zhao & Ma, 1999) n. comb., T. persculpus (Chen, 1987) n. comb., T. valga (Chen, 1987) n. comb. and T. wulingensis (Yao & Wang, 1997) n. comb. [all from Silurodiscoides] and Bychowskyella glyptothoraci (Ma, Wang & Li, 1983) n. comb. [from Neobychowskyella].
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.
Three species of Opisthomonorcheides Parukhin, 1966 are reported for the first time from Indonesian waters: O. pampi (Wang, 1982) Liu, Peng, Gao, Fu, Wu, Lu, Gao & Xiao, 2010 and O. ovacutus (Mamaev, 1970) Machida, 2011 from Parastromateus niger (Bloch), and O. decapteri Parukhin, 1966 from Atule mate (Cuvier). Both O. pampi and O. ovacutus can now be considered widespread in the Indo-Pacific region, with earlier records of these species being from Fujian Province, China and Penang, Malaysia, respectively. We redescribe O. decapteri from one of its original hosts, Atule mate, off New Caledonia, and report this species from Jakarta Bay, Indonesia, extending its range throughout the Indian Ocean into the south-western Pacific. All three species possess a genital atrium that is long, sometimes very long, and a genital pore that is located in the forebody. This validates the interpretation that the original description was erroneous in reporting the genital pore in the hindbody, well posterior to the ventral sucker. These observations verify the synonymy of Retractomonorchis Madhavi, 1977 with Opisthomonorcheides. A major discrepancy between the species of Opisthomonorcheides is that some are described with the uterus entering the terminal organ laterally and some with it entering terminally; this feature needs further analysis. Based on the length of the genital atrium and the posterior extent of the vitellarium, the 27 species of Opisthomonorcheides considered valid can be divided into four groups. Among the 53 host records analysed, the families Carangidae (53% of records), Stromateidae (17%) and Serranidae (5.7%) are the most common; the reports are overwhelmingly from members of the Perciformes (91%), with further records in the Clupeiformes (5.7%), Gadiformes (1.9%) and Pleuronectiformes (1.9%). Two fish genera (Parastromateus Bleeker and Pampus Bonaparte) dominate the recorded hosts, with the black pomfret Parastromateus niger harbouring six species, the silver pomfret Pampus argenteus (Euphrasen) harbouring six, and the Chinese silver pomfret P. chinensis (Euphrasen) two. A host-parasite checklist is presented. We discuss the host-specificity of members of the genus, questioning some records such as that of O. decapteri in a deep-sea macrourid. We also comment on the morphological similarity, but phylogenetic distance, between the various Pomfret species, advancing the possibility that a series of host misidentifications has occurred. Sequences of the ITS2 rDNA gene generated for O. pampi and O. ovacutus are briefly discussed and molecular data are lodged in the GenBank database.
: Baracktrema obamai n. gen., n. sp. infects the lung of geoemydid turtles (black marsh turtle, Siebenrockiella crassicollis [type host] and southeast Asian box turtle, Cuora amboinensis ) in the Malaysian states of Perak, Perlis, and Selangor. Baracktrema and Unicaecum Stunkard, 1925 are the only accepted turtle blood fluke genera having the combination of a single cecum, single testis, oviducal seminal receptacle, and uterine pouch. Baracktrema differs from Unicaecum by having a thread-like body approximately 30-50× longer than wide and post-cecal terminal genitalia. Unicaecum has a body approximately 8-12× longer than wide and terminal genitalia that are anterior to the distal end of the cecum. The new genus further differs from all other accepted turtle blood fluke genera by having a cecum that is highly convoluted for its entire length, a spindle-shaped ovary between the cirrus sac and testis, a uterine pouch that loops around the primary vitelline collecting duct, a Laurer's canal, and a dorsal common genital pore. Phylogenetic analysis of the D1-D3 domains of the nuclear large subunit ribosomal DNA (28S) revealed, with high nodal support and as predicted by morphology, that Baracktrema and Unicaecum share a recent common ancestor and form a clade sister to the freshwater turtle blood flukes of Spirorchis, paraphyletic Spirhapalum, and Vasotrema and that, collectively, these flukes were sister to all other tetrapod blood flukes (Hapalorhynchus + Griphobilharzia plus the marine turtle blood flukes and schistosomes). Pending a forthcoming emended morphological diagnosis of the family, the clade including Spirorchis spp., paraphyletic Spirhapalum, Vasotrema, Baracktrema, and Unicaecum is a likely placeholder for "Spirorchiidae Stunkard, 1921 " (type genus Spirorchis MacCallum, 1918 ; type species Spirorchis innominatus Ward, 1921 ). The present study comprises the 17th blood fluke known to infect geoemydid turtles and the first proposal of a new genus of turtle blood fluke in 21 yr.
Opisthioglyphe sharmai n. sp. is described from the gall bladder of the Malayan box turtle, Cuora amboinensis, and the black marsh turtle, Siebenrockiella crassicollis, in Malaysia. The new species is morphologically similar to Opisthioglyphe ranae and some other members of the genus parasitic in amphibians and reptiles. Opisthioglyphe sharmai n. sp. is easily differentiated from all other members of the genus by the cirrus sac extending posterior to the ventral sucker, while in all previously known species the cirrus sac is entirely or mostly preacetabular with the base of the structure not reaching beyond mid-line of the ventral sucker. Despite the overall stable morphology, O. sharmai n. sp. is characterized by highly variable arrangement of testes, from tandem to opposite. It is only the second representative of the genus described from turtles and the first species of Opisthioglyphe parasitic in gall bladder, while all previously described members of the genus are parasitic in the intestine of their hosts.
Freshwater snails, Stenomelania denisoniensis (Brot) from Tinaroo Dam, North Queensland, Australia were found to be infected with a heterophyid cercaria identified as Procerovum sp. The tail of the cercaria has finfolds which are bilateral anteriorly and dorso-ventral posteriorly, features which separate it from other genera in the Haplorchis-group. This group is differentiated from the cercariae of all the other heterophyid genera by the presence of the penetration glands that extend to the posterior end of the body lateral to the excretory bladder. This paper presents a full description of the cercaria, together with comparisons with other known species of Procerovum.
Parapleurogonius brevicecum gen. et sp. n. is described from the freshwater turtle, Kachuga trivittata, in Selangor, Malaysia. Parapleurogonius is most closely related to Pleurogonius Looss, 1901, but from which it can be distinguished by the termination of the ceca at or just overlapping the anterior border of the testes and the pretesticular position of the excretory pore. Additionally, Parapleurogonius is described from a freshwater turtle, whereas Pleurogonius is only known from marine hosts.
A description of sensory receptors of Trichobilharzia brevis is given. They are compared with the five Schistosomatidae described by Richard (1971), namely, Trichobilharzia ocellata, schistosoma mansoni, S. bovis, S; haematobium and S. rodhaini. All these species display very similar chaetotaxic characters. In the study of the cercaria of Haplorchis pumilio, comparison with the few Opisthorchioidea cercarial sensory organs already known has enabled the authors to characterise the chaetotaxy for this superfamily.
Three-dimensional (3D) models of the marginal hooks, dorsal and ventral anchors, bars and haptoral reservoirs of a parasite, Sundatrema langkawiense Lim & Gibson, 2009 (Monogenea) were developed using the polygonal modelling method in Autodesk 3ds Max (Version 9) based on two-dimensional (2D) illustrations. Maxscripts were written to rotate the modelled 3D structures. Appropriately orientated 3D haptoral hard-parts were then selected and positioned within the transparent 3D outline of the haptor and grouped together to form a complete 3D haptoral entity. This technique is an inexpensive tool for constructing 3D models from 2D illustrations for 3D visualisation of the spatial relationships between the different structural parts within organisms.