The occurrence of macroparasites was studied from 543 stray cats in four urban cities from the west (Kuala Lumpur), east (Kuantan), north (Georgetown) and south (Malacca) of Peninsular Malaysia from May 2007 to August 2010. Five ectoparasites species were recovered namely, Ctenocephalides felis, Felicola subrostratus, Haemaphysalis bispinosa, Heterodoxus spiniger and Lynxacarus radovskyi. Two cats from Georgetown were infested with the dog louse, H. spiniger and this represented the first host record for this species in Malaysia. Up to nine species of helminths were recovered with overall high prevalences of infection of 83% in Kuantan, followed by 75.1% in Kuala Lumpur, 71.6% in Georgetown and 68% in Malacca. The helminth species comprised five nematodes, Toxocara malaysiensis, Toxocara cati, Ancylostoma braziliensis, Ancylostoma ceylanicum, Physaloptera praeputialis, two cestodes Taenia taeniaeformis, Dipylidium caninum and one trematode, Playtnosomum fastosum. The majority of helminths were present in the four study sites except for the absence of P. praeputialis in Kuala Lumpur. The prevalence and abundance of infections were analysed taking intrinsic (host age and sex) and extrinsic (season) factors into consideration. Levels of infection and infestation were mainly influenced by host age and to a lesser extent sex and season, whereas four nematode species exhibited significant interactions within the intestine of the cat host. The potential for transmission of some macroparasite species from stray cats to the human population in urban areas is discussed.
A gastrointestinal parasite survey of 411 stray and refuge dogs sampled from four geographical and climactically distinct locations in India revealed these animals to represent a significant source of environmental contamination for parasites that pose a zoonotic risk to the public. Hookworms were the most commonly identified parasite in dogs in Sikkim (71.3%), Mumbai (48.8%) and Delhi (39.1%). In Ladakh, which experiences harsh extremes in climate, a competitive advantage was observed for parasites such as Sarcocystis spp. (44.2%), Taenia hydatigena (30.3%) and Echinococcus granulosus (2.3%) that utilise intermediate hosts for the completion of their life cycle. PCR identified Ancylostoma ceylanicum and Ancylostoma caninum to occur sympatrically, either as single or mixed infections in Sikkim (Northeast) and Mumbai (West). In Delhi, A. caninum was the only species identified in dogs, probably owing to its ability to evade unfavourable climatic conditions by undergoing arrested development in host tissue. The expansion of the known distribution of A. ceylanicum to the west, as far as Mumbai, justifies the renewed interest in this emerging zoonosis and advocates for its surveillance in future human parasite surveys. Of interest was the absence of Trichuris vulpis in dogs, in support of previous canine surveys in India. This study advocates the continuation of birth control programmes in stray dogs that will undoubtedly have spill-over effects on reducing the levels of environmental contamination with parasite stages. In particular, owners of pet animals exposed to these environments must be extra vigilant in ensuring their animals are regularly dewormed and maintaining strict standards of household and personal hygiene.
Snapper had been cultured in Malaysia since 1980 due to the fry availability and the high demand. However, details on the caligids infestation were not properly documented. This study was carried out to determine the prevalence, mean intensity and site preference of Caligus rotundigenitalis (Caligidae, Siphonostomatoida) a parasitic copepod on cage cultured crimson snapper, Lutjanus erythropterus from Bukit Tambun, Penang, Malaysia. A total of 70 specimens of cultured snapper were examined based on different infestation sites such as head, body as well as operculum. The specimens were separated into three groups according to the size of the fish. C. rotundigenitalis was found to be the only species infesting L. erythropterus with the prevalence and the mean intensity of 81.4% and 5.6±4.4, respectively. There was a significant difference between the prevalence of site infestation of the body and inner operculum sites. The prevalence of C. rotundigenitalis was highest on inner operculum of the fish followed by the body and head. However, there was no significant difference in the distribution of C. rotundigenitalis over the different infestation sites derived from the three groups. The information obtained from this study can be used for more effective control measures of ectoparasitic copepod infestation in floating cages.
Infection with Chloromyxum careni Mutschmann, 1999 was found in the Asian horned frog Megophrys nasuta from Malaysia and Indonesia. Kidney was the only organ infected. Coelozoic plasmodia up to 300 μm were localized in Bowman's space, embracing the glomerulus from all sides, or rarely in lumina of renal tubules. Plasmodia are polysporic, containing disporic pansporoblasts. Myxospores observed by light microscopy are colorless, variable in shape and size, measuring 6.0-8.5 × 5.0-6.5 μm, composed of two symmetrical valves joined by a meridian suture, containing four pyriform polar capsules 3.0-4.0 × 2.5-3.0 μm and a single sporoplasm. Each valve possesses 14-24 (median 21) fine longitudinal ridges clearly visible only in scanning electron microscopy. Rarely, atypical spores with a markedly pointed posterior pole and only 6-10 surface ridges are present in plasmodia together with typical spores. Both small subunit (SSU) and large subunit (LSU) rRNA gene sequences possess extremely long GU-rich inserts. In all SSU and LSU rDNA-based phylogenetic analyses, C. careni clustered as a distinct basal branch to the Myxobolus+Myxidium lieberkuehni clade, out of the marine Chloromyxum clade containing Chloromyxum leydigi, the type species of the genus. These morphological and phylogenetic data suggest erection of a new genus for the C. careni lineage, but we conservatively treat it as a Chloromyxum sensu lato until more information is available.
Tetrarhynchobothrium tenuicolle Diesing, 1850 is redescribed from the type-specimens collected from Raja clavata Linnaeus in the Adriatic Sea. T. striatum (Wagener, 1854) is redescribed from voucher specimens from the type host, Myliobatis aquila Linnaeus, from the type-locality, off Naples, Italy. The two species are very similar in tentacular armature, but are provisionally maintained as independent species, since the armature of T. tenuicolle cannot be fully described and because all available specimens of T. striatum are immature, limiting comparisons of potential differences in segment anatomy. T. setiense Dollfus, 1969 is treated as a synonym of T. striatum. Zygorhynchus borneensis n. sp. is described from Himantura uarnacoides (Bleeker) and H. pastinacoides (Bleeker) off Sabah, Malaysia. The new species is distinguished from its congeners by the very small hooks present in the basal region and by the presence of a uterine pore. The metabasal tentacular armature of Didymorhynchus southwelli Beveridge & Campbell, 1988, described for the first time, is homeoacanthous and homeomorphous in form. However, it has a basal swelling with hook rows originating on the bothrial surface and terminating on the antibothrial surface of the tentacle.
Traditional studies on myxosporeans have used myxospore morphology as the main criterion for identification and taxonomic classification, and it remains important as the fundamental diagnostic feature used to confirm myxosporean infections in fish and other vertebrate taxa. However, its use as the primary feature in systematics has led to numerous genera becoming polyphyletic in subsequent molecular phylogenetic analyses. It is now known that other features, such as the site and type of infection, can offer a higher degree of congruence with molecular data, albeit with its own inconsistencies, than basic myxospore morphology can reliably provide.
Twenty Asian sea bass Lates calcarifer from a floating cage in Bt. Tambun, Penang were examined for the presence of parasitic gill copepod, Lernanthropus latis. The prevalence of L. latis was 100% with the intensity of infection ranging from 1 to 18 parasites per host or 3.75 of mean intensity. Female parasites having oblong cephalothorax and egg-strings were seen mainly on the entire gill of examined Asian sea bass. The infected gill of Asian sea bass was pale and had eccessive mucus production. Under light and scanning electron microscopies (SEM), L. latis was seen grasping or holding tightly to the gill filament using their antenna, maxilla and maxilliped. These structures are characteristically prehensile and uncinate for the parasite to attach onto the host tissue. The damage was clearly seen under SEM as the hooked end of the antenna was embedded into the gill filament. The parasite also has the mandible which is styliform with eight teeth on the inner margin. The pathological effects such as erosion, haemorrhages, hyperplasia and necrosis along the secondary lamellae of gill filaments were seen and more severe at the attachment site. The combined actions of the antenna, maxilla and maxilliped together with the mandible resulted in extensive damage as L. latis attached and fed on the host tissues.
In order to obtain basic data on parasitic infections of Bornean orangutans, Pongo pygmaeus morio (Owen, 1837), in Danum Valley, Sabah, Malaysia, fecal examinations were conducted. Based on a total of 73 fecal samples from 25 individuals, cysts of Entamoeba coli, Entamoeba spp., and Chilomastix mesnili, cysts and trophozoites of Balantidium coli, and eggs of Trichuris sp. or spp., unknown strongylid(s), Strongyloides fuelleborni, and an unknown oxyurid, plus a rhabditoid larva of Strongyloides sp., were found. Mature and immature worms of Pongobius hugoti Baruš et al., 2007 and Pongobius foitovae n. sp. (Oxyuridae: Enterobiinae) were recovered from fecal debris and described. Pongobius foitovae is readily distinguished from P. hugoti by having a much longer esophageal corpus, a longer and distally hooked spicule in males, and a more posteriorly positioned vulva in female. Presence of plural species of non- Enterobius pinworms is a remarkable feature of the orangutan-pinworm relationship, which may reflect speciation process of the orangutans, host switching, and coevolution by pinworms.
During a survey on fishes of the Tasik Kenyir Reservoir, Malaysia, 5 new Myxobolus spp. and 2 known Henneguya spp. were found. The specific locations for 2 Myxobolus spp. were the host's muscles, while 2 other Myxobolus spp. were found to develop in the host's kidney and gills, respectively. Of the species developing intracellularly in muscle cells, M. terengganuensis sp. nov. was described from Osteochilus hasselti and M. tasikkenyirensis sp. nov. from Osteochilus vittatus. M. csabai sp. nov. and M. osteochili sp. nov. were isolated from the kidney of Osteochilus hasselti, while M. dykovae sp. nov. was found in the gill lamellae of Barbonymus schwanenfeldii. Henneguya shaharini and Henneguya hemibagri plasmodia were found on the gills of Oxyeleotris marmoratus and Hemibagrus nemurus, respectively. Description of the new and known species was based on morphological characterization of spores, histological findings on locations of plasmodia and DNA sequence data.
Tor tambroides, a common and appreciated cyprinid fish of the Tasik Kenyir water reservoir in Malaysia, is one of the species selected for propagation. This fish was first successfully propagated in Malaysia by the Department of Agriculture, Sarawak, Malaysia, and the breeding program continued throughout the country. The gills were frequently infected by a Myxobolus species to be described as Myxobolus tambroides sp. n. The small, 50 to 70 μm, round plasmodia of this species is located intralamellarly. Plasmodia were filled with pyriform myxospores, 9.9 and 7.4 μm wide. In sutural view, the caudal end of the myxospores had a distinctive valvular groove, parallel with the suture. Plasmodia caused deformations on the affected and the neighbouring gill lamellae. The 18S rDNA sequence of M. tambroides sp.n. did not show a close relationship with any other Myxobolus spp., represented in the GenBank. This might be an emerging parasite likely to impact the propagation of this fish.
Epidermal pseudotumours from Hippoglossoides dubius and Acanthogobius flavimanus in Japan and gill lesions in Limanda limanda from the UK have been shown to be caused by phylogenetically related protozoan parasites, known collectively as X-cells. However, the phylogenetic position of the X-cell group is not well supported within any of the existing protozoan phyla and they are currently thought to be members of the Alveolata.Ultrastructural features of X-cells in fish pseudotumours are somewhat limited and no typical environmental stages, such as spores or flagellated cells, have been observed. The life cycles for these parasites have not been demonstrated and it remains unknown how transmission to a new host occurs. In the present study, pseudobranchial pseudotumours from Atlantic cod, Gadus morhua, in Iceland and epidermal pseudotumours from the northern black flounder, Pseudopleuronectes obscurus, in Japan were used in experimental transmission studies to establish whether direct transmission of the parasite is achievable. In addition, X-cells from Atlantic cod were sequenced to confirm whether they are phylogenetically related to other X-cells and epidermal pseudotumours from the northern black flounder were analysed to establish whether the same parasite is responsible for infecting different flatfish species in Japan.
Examination of 35 barramundi (Lates calcarifer) from aquaculture cages in Setiu Wetland, Malaysia, revealed a single fish infected with three Henneguya spp. (Cnidaria: Myxosporea). Characterization of the infections using tissue tropism, myxospore morphology and morphometry and 18S rDNA sequencing supported description of three new species: Henneguya setiuensis n. sp., Henneguya voronini n. sp. and H. calcarifer n. sp. Myxospores of all three species had typical Henneguya morphology, with two polar capsules in the plane of the suture, an oval spore body, smooth valve cell surfaces, and two caudal appendages. Spores were morphometrically similar, and many dimensions overlapped, but H. voronini n. sp. had shorter caudal appendages compared with H. calcarifer n. sp. and H. setiuensis n. sp. Gross tissue tropism distinguished the muscle parasite H. calcarifer n. sp. from gill parasites H. setiuensis n. sp. and H. voronini n. sp.; and these latter two species were further separable by fine-scale location of developing plasmodia, which were intra-lamellar for H. setiuensis n. sp. and basal to the filaments for H. voronini n. sp. small subunit ribosomal DNA sequences distinguished all three species: the two gill species H. setiuensis n. sp. and H voronini n. sp. were only 88% similar (over 1708 bp), whereas the muscle species H. calcarifer n. sp. was most similar to H. voronini n. sp. (98% over 1696 bp). None of the three novel species was more than 90% similar to any known myxosporean sequence in GenBank. Low infection prevalence of these myxosporeans and lack of obvious tissue pathology from developing plasmodia suggested none of these parasites are currently a problem for barramundi culture in Setiu Wetland; however additional surveys of fish, particularly at different times of the year, would be informative for better risk assessment.