Thelohanellus kitauei is a freshwater myxosporean parasite causing intestinal giant cystic disease of common carp. To clarify the life cycle of T. kitauei, we investigated the oligochaete populations in China and Hungary. This study confirms two distinct aurantiactinomyxon morphotypes (Aurantiactinomyxon type 1 and Aurantiactinomyxon type 2) from Branchiura sowerbyi as developmental stages of the life cycle of T. kitauei. The morphological characteristics and DNA sequences of these two types are described here. Based on 18S rDNA sequence analysis, Aurantiactinomyxon type 1 (2048 bp) and Aurantiactinomyxon type 2 (2031 bp) share 99.2-99.4 %, 99.8-100 % similarity to the published sequences of T. kitauei, respectively. The 18S rDNA sequences of these two aurantiactinomyxon morphotypes share 99.4 % similarity, suggesting intraspecific variation within the taxon, possibly due to geographic origin. Phylogenetic analyses demonstrate the two aurantiactinomyxon types clustered with T. kitauei. Regardless, based on 18S rDNA synonymy, it is likely that Aurantiactinomyxon type 1 and 2 are conspecific with T. kitauei. This is the fourth elucidated two-host life cycle of Thelohanellus species and the first record of T. kitauei in Europe.
Thirty snakehead fish, Channa micropeltes (Cuvier, 1831) were collected at Lake Kenyir, Malaysia. Muscle, liver, intestine and kidney tissues were removed from each fish and the intestine was opened to reveal cestodes. In order to assess the concentration of heavy metal in the environment, samples of water in the surface layer and sediment were also collected. Tissues were digested and the concentrations of manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) were analysed by using inductively-coupled plasma mass-spectrometry (ICP-MS) equipment. The results demonstrated that the cestode Senga parva (Fernando and Furtado, 1964) from fish hosts accumulated some heavy metals to a greater extent than the water and some fish tissues, but less than the sediment. In three (Pb, Zn and Mn) of the five elements measured, cestodes accumulated the highest metal concentrations, and in remaining two (Cu and Cd), the second highest metal accumulation was recorded in the cestodes when compared to host tissues. Therefore, the present study indicated that Senga parva accumulated metals and might have potential as a bioindicator of heavy-metal pollution.
The ciliated protozoan parasite Cryptocaryon irritans infecting marine fishes in Taiwan is described. Developmental characteristics and sequences of the ribosomal DNA regions such as part of 18 S, the entire first internal transcribed spacer, and part of 5.8 S of various Taiwan isolates of C. irritans were investigated. A total of 5 isolates was obtained from different fish-host species and localities, the majority from cultured fish species. C. irritans from Taiwan is able to shift its developmental characteristics, i.e. from non-adherent to adherent tomonts, from individualistic to aggregate-forming tomonts, from infection of the gills only to infection of the gills and body. Thus, it is not possible to classify strains of C. irritans on the basis of these parameters. Premature tomonts that developed from dead fishes were able to produce theronts that could infect fish host. Isolates from Pingtung and the USA had identical nucleotide sequences while an isolate from Malaysia was identical to an Israel isolate. Percentage variation among pairs of Taiwan isolates showed a higher degree of variation than isolate sequences listed in GenBank. Sequence analysis revealed highly aberrant isolates in Taiwan, and a phylogenetic tree distinguished a marine and a low-salinity variant. C. irritans from marine fishes in Taiwan, therefore, display some characteristics not previously reported. Since manipulation of salinity in brackishwater ponds and marine cage sites is not feasible, there is a need to develop new strategies for the control and prevention of cryptocaryoniasis.
A study of the anterior adhesive apparatus (head organs) of Bravohollisia gussevi Lim, 1995 was carried out using light and electron microscopy. The anterior adhesive apparatus or head organs in B. gussevi comprise 6 circular openings or apertures in the antero-lateral region, associated pits lined with specialized microvillous tegument that differ from the general body tegument, a bundle of ducts, and uninucleate gland cells located lateral to the pharynx. The uninucleate glands of the anterior adhesive apparatus (head organs) comprise 2 types of cells, one kind of cell producing rod-like bodies (S1) and the other oval bodies (S2). The S1 bodies are filled with numerous, less electron-dense vesicles in an electron-dense matrix, while S2 bodies have no vesicles but contain a more homogeneous electron-dense matrix. Interlinking band-like structures were observed between S1 bodies. Similar band-like structures were found between S2 bodies. The formation of S1 bodies was followed by transmission electron microscopy. However, the formation of S2 bodies was unclear and could not be resolved. Uniciliated structures were also observed around the openings of the anterior adhesive apparatus. Each uniciliated structure is usually associated with an opening of a gland cell producing granular, electron-dense, secretory bodies, which differ from the secretions produced by the lateral gland cells of the anterior adhesive apparatus.
To examine the phylogeographical pattern of Tetrancistrum nebulosi (Monogenea, Dactylogyridae) in the South China Sea, fragments of mitochondrial cytochrome c oxidase subunit I and NADH dehydrogenase subunit 2 genes were obtained for 220 individuals collected from 8 localities along the southeast coast of China and 1 locality in Terengganu, Malaysia. Based on these two genes, two and three distinct clades with geographic signals were revealed on the phylogenetic trees respectively. The divergence between these clades was estimated to occur in the late Pleistocene. Analysis of molecular variance and pairwise FSTsuggested a high rate of gene flow among individuals sampled from the Chinese coast, but with obvious genetic differentiation from the Malaysian population. Mismatch distribution and neutrality tests indicated that the T. nebulosi population experienced expansion in Pleistocene low sea level periods. Vicariance was considered to account for the genetic divergence between Chinese and Malaysian populations, while sea level fluctuations and mainland-island connections during glacial cycles were associated with the slight genetic divergence between the populations along the mainland coast of China and those off Sanya. On the contrary, oceanographic circulations and host migration could lead to genetic homogeneity of populations distributed along the mainland coast of China.
The ornamental fish trade provides a pathway for the global translocation of aquatic parasites. We examined a total of 1020 fish imported from Singapore, Malaysia, Thailand, or Sri Lanka to Australia (including freshwater and marine fish species) for monogenean ectoparasites. Fish were received following veterinary certification that they showed no clinical signs of pests and diseases from the exporting country and visual inspection at Australian border control. Australian import conditions require mandatory treatment for goldfish with parasiticides (e.g. trichlorfon, formaldehyde, sodium chloride) for the presence of gill flukes (Dactylogyrus vastator Nybelin, 1924 and Dactylogyrus extensus Mueller and Van Cleave, 1932) prior to export. Over 950 individual parasites were detected in five imported fish species, representing 14 monogenean species. Seven Dactylogyrus spp. including D. vastator and three Gyrodactylus spp. infected goldfish, Carassius auratus Linnaeus, 1758, from Malaysia, Singapore, and Thailand. Dactylogyrus ostraviensis Řehulka, 1988, infected rosy barb, Pethia conchonius Hamilton, 1822, from Singapore, Sri Lanka, and Thailand while two Trianchoratus spp. infected three spot gourami, Trichopodus trichopterus Pallas, 1970 and pearl gourami Trichopodus leerii Bleeker, 1852, from Sri Lanka. Urocleidoides reticulatus Mizelle & Price, 1964, infected guppy, Poecilia reticulata Peters, 1859, from Sri Lanka. The discovery of D. vastator in goldfish, as well as 13 other monogenean species, shows that pre-export health requirements, which include chemical treatment of goldfish, and inspection of all ornamental fish species did not prevent infection by monogeneans. Inspection prior to exportation and at border control must account for the highly cryptic nature of monogenean parasites and consider alternatives to current pre-export conditions and visual inspection at border control.
Culturing fishes in marine cages is a rapidly developing area of marine aquaculture. The Asian seabass Lates calcarifer (Bloch) is a fast growing good quality fish that is readily cultured in intensive systems in the South Asian region and in Malaysia in particular. Although several papers have been published to date on viral, bacterial, parasitic and fungal organisms causing diseases in the Asian seabass, the occurrence of a coccidian infection in this species has only recently been recorded. We collected sporulated and unsporulated oöcysts of a new species of Goussia Labbé, 1986, from the mucus covering the epithelium of the intestine of L. calcarifer. This paper provides a description of Goussia kuehae n. sp. Sporulated oöcysts of this species are ellipsoidal, 37-40 μm in length and 28-30 μm in width. The ellipsoidal sporocysts are relatively small, 15.2-17 × 5.7-8 μm, and located loosely in the oöcyst. There are residual bodies both in the oöcysts and the sporocysts. Goussia kuehae n. sp. differs from all known species of Goussia in the large size of the oöcysts and in having two types of oöcyst residuum.
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.
We describe new myxosporean species from Malaysian fishes cultured in pond farms and net-cages. Myxobolus omari sp. nov. and M. leptobarbi sp. nov. were found in the muscles of Pangasianodon hypophthalmus and Leptobarbus hoevenii, respectively, while plasmodia and spores of Thelohanellus zahrahae sp. nov. and Henneguya daoudi sp. nov. were detected in the gills of Barbonymus gonionotus and Trichogaster trichopterus, respectively. Plasmodia and spores found in these fishes differed from the known myxosporean species in respect of their morphology, tissue tropism and 18S rDNA structure. No major pathological changes were found, but in the future these species might pose a potential threat to more intensified fish culture.
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.
Hamatopeduncularia longiangusticirrata sp. nov. and H. petalumvaginata sp. nov. were collected from Arius maculatus and Nemapteryx caelata, respectively from Tanjung Karang, Peninsular Malaysia. Morphological and molecular investigations were carried out to ascertain the identity of the new species. The two new species differ from previously described Hamatopeduncularia species in the morphology of the male and female reproductive organs. Hamatopeduncularia longiangusticirrata sp. nov. possesses a long penis similar to H. elongata, H. longicopulatrix, H. brisbanensis, H. major and H. petalumvaginata sp. nov., but differs in having a thread-like tapering distal end and can be distinguished from H. brisbanensis and H. major in not having an accessory piece. Hamatopeduncularia longiangusticirrata sp. nov. is also unique in having an ornamented penis initial and a vaginal tube surrounded by fine hair-like structures. Hamatopeduncularia petalumvaginata sp. nov. possesses a simple penis without an accessory piece and a petaloid vaginal opening that resembles the arrangement of petals on a flower. Maximum likelihood trees were constructed from partial 28S and 18S rDNA sequences of the two new species and other ancylodiscoidids to reveal a strongly supported monophyletic branch consisting of the two new species for both markers. According to Lim's classification in 1996 of Hamatopeduncularia species penis type, H. petalumvaginata sp. nov. has been classified within the elegans-type and H. longiangusticirrata sp. nov. is proposed as the longiangusticirrata-type.
Haliotrema susanae sp. nov. is described from the gills of the pinecone soldierfish, Myripristis murdjan off Langkawi Island, Malaysia. This species is differentiated from other Haliotrema species especially those from holocentrids in having a male copulatory organ with bract-like extensions at the initial of the copulatory tube, grooved dorsal anchors and ventral anchors with longer shafts. The maximum likelihood (ML) analysis based on partial 28S rDNA sequences of H. susanae sp. nov. and 47 closely related monogeneans showed that H. susanae sp. nov. is recovered within a monophyletic clade consisting of only species from the genus Haliotrema. It is also observed that H. susanae sp. nov. forms a clade with H. cromileptis and H. epinepheli which coincides with a similar grouping by Young based on solely morphological characteristics. The morphological and molecular results validate the identity of H. susanae sp. nov. as belonging to the genus Haliotrema.
Ligophorus belanaki n. sp. and Ligophorus kederai n. sp. are described from Liza subviridis Valenciennes, 1836 and Valamugil buchanani Bleeker, 1854, respectively. Ligophorus kederai n. sp. has fenestrated ventral anchors, while in L. belanaki n. sp. the ventral anchor is not fenestrated. Ligophorus belanaki n. sp. is similar to L. careyensis, one of its coexisting congeners, in the overall shape and size of hard parts, but differs in having a flat median piece in the structure of the AMP (antero-median protuberance of the ventral bar), copulatory organ with non-ornamented initial part and longer vaginal tube, compared to raised median piece in the AMP, ornamented initial part and comparatively shorter vaginal tube in L. careyensis. Ligophorus kederai n. sp. is similar to L. fenestrum, a coexisting congener, in having fenestrated ventral anchors, but differs in having longer points and narrower base. Ligophorus fenestrum, unlike L. kederai n. sp., also possesses fenestrated dorsal anchors. The principal component analysis (PCA) scatterplots indicate that the two new and eight known Ligophorus species from Malaysian mugilids can be differentiated based on the morphometries of their anchors, ventral bars and copulatory organ separately and when combined together. Numerical taxonomy (NT) analyses based on Jaccard's Index of Similarity and neighbour-joining clustering, is used to facilitate comparison of these two new species with the 50 known Ligophorus based on morphological and metric characters. The two new species are different from each other and the other 50 species in the overall shapes and sizes of hard parts, as indicated by the NT analyses.
Sampling of a large number of elasmobranchs from coastal waters off Borneo revealed the presence of five new species of Dollfusiella Campbell & Beveridge, 1994 (Trypanorhyncha: Eutetrarhynchidae), namely D. angustiformis n. sp., D. hemispinosa n. sp., D. spinosa n. sp., D. imparispinis n. sp. and D. parva n. sp. Dollfusiella angustiformis n. sp. is described from the spiral intestines of four species of the dasyatid stingray genus Himantura Müller & Henle from both the Indonesian and Malaysian parts of Borneo. All the other species were obtained from Malaysian Borneo. Dollfusiella hemispinosa n. sp. is described from the spiral intestines of three species of Himantura, whereas D. spinosa n. sp. was obtained from several specimens of Pastinachus solocirostris Last, Manjaji & Yearsley (Dasyatidae) as well as from Taeniura lymma 1 (sensu Naylor et al., 2012) (Dasyatidae), Neotrygon kuhlii 2 (sensu Naylor et al., 2012) (Dasyatidae), and Glaucostegus cf. typus (sensu Naylor et al., 2012) (Rhinobatidae). Dollfusiella imparispinis n. sp. is described from the spiral intestine of a single specimen of Chiloscyllium punctatum Müller & Henle (Hemiscyllidae) from the South China Sea off Sarawak, whereas D. parva n. sp. was obtained from several species of Himantura. Specimens of the five novel taxa possess scoleces covered with enlarged microtriches, a morphological characteristic exhibited by several other congeners. However, the new species differ from all congeners by possessing unique patterns of oncotaxy as well as combinations of additional morphological features. The number of valid species within Dollfusiella is increased to 26. For this reason, a key for the species of Dollfusiella is provided. Furthermore, novel information on hosts and geographic distribution is provided for two previously described species of Dollfusiella, D. michiae (Southwell, 1929) and D. spinulifera (Beveridge & Jones, 2000). The latter species differs slightly from the original description and shows a much higher variability with regard to the lengths of the scolex and muscular bulbs and the number of testes. These variable characters subdivided specimens of D. spinulifera into relatively distinct groups. However, the specimens did not differ in their oncotaxy and are considered to represent a single variable species.
A total of 17 species of the genus Bifurcohaptor Jain, 1958 have been reported from two fish families namely Bagridae Bleeker, 1858 (Mystus vittatus (Bloch, 1794), M. tengara (Hamilton, 1822), M. keletius (Valenciennes, 1840), Hemibagrus nemurus (Valenciennes, 1840), Rita rita (Hamilton, 1822) and Sperata seenghala (Sykes, 1839)) and Sisoridae Bleeker, 1858 (Bagarius bagarius (Hamilton, 1822)). Out of these, only two species viz. B. indicus and B. giganticus are found valid in India, parasitizing gills of Mystus spp. and Bagarius sp. Taxonomic studies suggest, present specimen of B. indicus and B. giganticus, both are morphologically close to species described by Jain (1958), except morphometric variations and posses 7 pairs of marginal hooks instead of 6 pairs. Present manuscript delves with the characterization of B. indicus and B. giganticus reported from India, using molecular techniques. Partial mt COI nucleotide sequence based insilico protein analysis and partial 28S and ITS-1 rDNA based phylogenetic analysis, estimated by Neighbour-joining (NJ) and Minimum Evolution (ME) methods revealed that the species of the genus Bifurcohaptor are genetically distinct and valid. The grouping of Bifurcohaptor spp. with other representatives of family Dactylogyridae supports morphology based placement into family Dactylogyridae. Present and previous host-parasite information suggests both Bifurcohaptor spp. are species specialist however, the genus Bifurcohaptor is generalist at generic level.
The presently reported study provides a detailed morphological description of the female and the male of a new species of the genus Parabrachiella-Parabrachiella jarai sp. nov. The parasites were sampled from marine fish, silver sillago, Sillago sihama (Perciformes: Sillaginidae), captured in Malaysia in 1994 and Hong Kong in 1995. The new species bears some resemblance to Parabrachiella lata (Song et Chen, 1976) but differs from it in details of second antenna, mandible, and maxilliped. The genus Parabrachiella currently covers 67 species including those recently transferred from Neobrachiella Kabata, 1979. An amended generic diagnosis is proposed for Parabrachiella and Thysanote. Some members of Parabrachiella are herewith transferred to Thysanote and some Thysanote are now placed in Parabrachiella.
Both sexes of Brachiella malayensis n. sp. are described on the basis of specimens found in the nostrils of narrow-barred Spanish mackerel Scomberomorus commerson (Lacepède) collected off Besut, Malaysia. The female of this species closely resembles those of B. magna Kabata, 1968 and B. cybii Pillai, Prabha et Balaraman, 1982 but is distinguishable mainly by the body size and the proportions of the cephalosome, posterior processes and caudal rami. While examining the male, we noticed a systematic inconsistency in some lernaeopodid genera. The genus Brachiella Cuvier, 1830, represented by its type-species Brachiella thynni Cuvier, 1830, and two monotypic genera Charopinopsis Yamaguti, 1963 and Eobrachiella Ho et Do, 1984, represented by Charopinopsis quaternia (Wilson, 1935) and Eobrachiella elegans (Richiardi, 1880), respectively, share distinct synapomorphies in the embracing (vs. pinching) elongate male maxilliped and the female trunk with a pair of long, cylindrical ventroposterior processes (in addition to a pair of modified caudal rami), both of which are involved in their unique reproductive strategy. The latter two genera are herewith relegated to junior synonyms of Brachiella.
The Asian seabass is euryhaline, therefore it is interesting to describe the infestation and survival of caligids at varying salinity on the host. In this study, two different brackish water culture systems with monoculture and polyculture practices were investigated for the occurrence of Caligus spp. on Lates calcarifer. Polyculture practices mainly consisted of snapper (Lutjanus spp.), grouper (Epinephelus spp.) and seabass (L. calcarifer), while the monoculture was stocked with only seabass. A total of 777 Caligus spp. specimens were isolated from the sampling in 2009, consisting of three species; Caligus chiastos, Caligus epidemicus and Caligus rotundigenitalis. In 2011, the total specimen was increased to 3110 and two additional species were found; Caligus punctatus and one unknown species (Caligus sp.). A 98.6% of the total examination was represented by C. epidemicus. Constant presence of C. epidemicus was observed throughout the study, regardless the differences in between culturing practices and systems. This species was able to survive within wide salinity range, from 5 to 28 ppt. The other isolated species (C. chiastos, C. punctatus, C. rotundigenitalis and Caligus sp.) were only found infesting in polyculture cages with the salinity ranging from 25 to 28 ppt. Despite accounts for less than 2% of the total specimens, these species may able to produce a challenge for L. calcarifer polyculture farming activity due to their capability for host switching. The present study revealed the potential risk for cross-species transmission in polyculture practices.
Five species of adult nematodes, unidentifiable nematode larvae, and three species of acanthocephalans, were found in freshwater ornamental fishes newly imported into Germany from Brazil, Colombia, Indonesia, Malaysia, Nigeria, Peru, Sri Lanka and Thailand. The following species were identified: Adult Nematoda: Pseudocapillaria tomentosa, Capillariidae gen. sp., Dichelyne hartwichi sp. n., Procamallanus (Spirocamallanus) pintoi and Spinitectus allaeri; Acanthocephala: Pseudogorgorhynchus arii gen. et sp. n., Neoechinorhynchus sp. and Pallisentis sp. The nematode Dichelyne hartwichi sp. n. (male only) from the intestine of Chelonodon fluviatilis (Hamilton) from Thailand is characterised mainly by the presence of minute cuticular spines on the tail tip, length of spicules (510 microns) and arrangement of caudal papillae. The acanthocephalan Pseudogorgorhynchus arii sp. n. from the intestine of Ariopsis seemanni (Günther) from Colombia represents a new genus Pseudogorgorhynchus gen. n., differing from other genera of the Rhadinorhynchidae mainly in possessing a small proboscis armed with markedly few (18) hooks arranged in six spiral rows. Spinitectus macheirus Boomker et Puylaert, 1994 and Spinitectus moraveci Boomker et Puylaert, 1994 are considered junior synonyms of Spinitectus allaeri Campana-Rouget, 1961.
A new nematode species, Paraphilometroides nemipteri sp. n. is described from the female specimens collected from the dorsal fin and operculum of the marine perciforme fish, Nemipterus peronii off Kuala Terengganu coastal waters in Malaysia. It considerably differs from all other species in Philometridae in the structure of the head end (presence of wide dorsal and ventral cephalic cuticular alae supported by special inner transverse muscular formations) and, therefore, a new genus Paraphilometroides gen. n. has been erected to accommodate it. Additional characteristic features of P. nemipteri are the presence of cuticular bosses on the body, eight cephalic papillae in the outer circle and four small papillae in the inner circle, and the absence of caudal protrusions.