Moniezia Expansa Research Articles

Nahçivan Özerk Cumhuriyeti Şerur Bölgesindeki Koyunlarda Moniezia Türlerinin Yaygınlığı

Summary This study was carried out to determine the prevalence of Moniezia infection in sheep in Sherur Region of Nakhchivan Autonomous Republic. A total of 856 sheep and lambs of different ages were used in this study. The fecal samples were taken directly from the rectums 856 sheep and lambs which were 6 months-3 ages old. The fecal samples were examined under microscope following with Fulleborn’s flotation method. It was found that a rate of infection was 27.8% in Sherur Region. The prevalence was 35.2% in 6 monthsone year old sheep. Two Moniezia species, namely Moniezia expansa (65.5%) and Moniezia benedeni (34.5%) were identified in infected sheep. The prevalence of Moniezia species according to proglottides were found (69.3%) for Moniezia expansa and (30.7%) for Moniezia benedeni.

Generation and analysis of expressed sequence tags from a cDNA library of Moniezia expansa

The Moniezia expansa is a parasite of sheep that causes diarrhea and fleshless leading to stockbreeding losses. A genomic resource for large-scale molecular studies in this parasite is lacking. To study the gene expression including development, digestion and reproduction organs of M. expansa, a cDNA library had been constructed and expressed sequence tags (ESTs) had been analyzed, which were helpful for the development of a powerful microarray platform which are used to analyze gene expression in this species. cDNAs are useful resources in annotating genes and providing functional analysis of genes. In this study, a cDNA library from adult cestode of M. expansa was created and 2642 ESTs from 5′-ends of the cDNA clones representing 1081 unigenes were obtained. Cluster analysis of these ESTs allowed identification of 1081 unique sequences containing 351 contigs and 730 singletons. BLASTX searches identified 780 significant (E-value < 10 −5) hits and further Gene Ontology (GO) analysis was used to annotate these genes. All the EST sequences were deposited under dbEST in GenBank (GenBank: FE905224– FE905315, FE942104– FE942773, FE969189– FE969190, FF677548– FF677734, FF848124– FF848253). Although we only obtained 1081 unigenes, the set of ESTs identified represents a significant proportion of the M. expansa and provides molecular resource for the development of microarrays for gene expression studies concerning development, metabolism and reproduction.

Occurrence of Moniezia expansa (Rud, 1810) Blanchard, 1891 (Cestoda: Anoplocephalidae) in domestic pig ( Sus scrofa domestica Linnaeus, 1758) in Perú

The presence of Moniezia expansa (Rud, 1810) Blanchard, 1891, is reported in domestic pig ( Sus scrofa domestica Linnaeus, 1758). Four tapeworms were collected and identified as M. expansa. This is the first report of M. expansa collected in a domestic pig in Perú.

Parasitism and horn quality in male Spanish ibex (Capra pyrenaica hispanica) from Andalucía based on coprological analysis and muscle biopsy

A parasitological survey was performed on 51 adult male Spanish ibexes (Capra pyrenaica hispanica) from Málaga (Andalucía, Southern Spain) which were legally hunted during rutting season (October to December) in 2002 and 2003, in order to determine the health status of the ibex populations. Animals were classified according to horn quality and geographic location and their respective parasite levels were compared. Gastrointestinal and pulmonary (family Protostrongylidae) nematodes (order Strongylida), intestinal cestodes (family Anoplocephalidae: Moniezia expansa and M. benedeni) and intestinal coccidia (Eimeria spp) were detected by coprological analysis, and muscle protozoa (Sarcocystis spp) by muscle biopsy. A parasitism index (PI) was calculated for each animal and parasite group. A horn index (HI) was designed that classified animals into four categories: HI1 (good), HI2 (normal), HI3 (poor) and HI4 (very poor). There was a negative correlation (R = –0.262; P = 0.062) between the PI of lungworms (Protostrongylidae) and HI, high lungworm PIs corresponded with lower HI values (better horn characteristics). Linear correlations between arcsine transformed parasite counts and one principal component analysis (PCA) of horn measures were calculated. There was a correlation (R = 0.30; P = 0.03) between lungworm larval shedding (Protostrongylidae) and PCA for horn quality. High larval counts corresponded with high PCA values (better horn quality). The possibility of rut stress affecting dominant males is proposed as a predisposing factor for the observed trend.

Parasitic helminth load in urban waste-water of Kenitra City, Morocco

Waste-waters of Kenitra City are rejected without any preliminary treatment in the receiving medium (Sebou River, Fouarat Lake). A small fraction is used to irrigate crops in the peri-urban area of Kenitra City. The parasitological characterization revealed an average parasitic helminth egg concentration of 25.07 per liter (±10.6). Nematodes have an average concentration of 19.79 (±12.4) eggs/L while cestodes have 5.27 (±8.6) eggs/L. However, the eggs and larvae of strongyloides were 11.02 (±2.4) eggs/L and 1.74 (±2.6) larve/L respectively. Most of the other idenitifed eggs were Ascaris sp. (13.04 ±8.6 eggs/L), Trichuris sp. (2.82 ±4.2 eggs/L), Nematodirus sp. (0.66 ±2.1 eggs/L), Enterobius vermicularis (1.64 ±3.6 eggs/L), Ancylostoma sp. (1.63 ±1.4 eggs/L) and strongyloides (11.02 ±10.5 eggs/L). Hymenolepis sp. (1.53 ±9.6 eggs/L), Moniezia expansa (1.91 ±6.6 eggs/ L) and Tænia sp. (1.82 ±2.7 eggs/L) were the observed cestodes. Eggs concentration varied between districts and the sampling seasons. The parasitological quality of the waste-water was much below the World Health Organization and the Morocco Ministry of the Environment Standards for re-use in agriculture (&#8804 1 viable nematode egg per liter). We recommend that these waste-waters be processed before they are recycled in the Sebou River and Fouarat Lake or used for agriculture. Keywords: waste-waters, parasitic eggs of helminths, Sebou, Fouarat, Kenitra City, Morocco.Nigerian Journal of Parasitology Vol. 29 (1) 2008 pp. 20-28

Observations on oribatid mites (Acari: Oribatida) serving as intermediate hosts of Moniezia expansa (Cestoda: Anoplocephalidae) in Iran

Preliminary observations on oribatid mites, intermediate hosts of tapeworms of the family Anoplocephalidae, based on mites collected from soil and grass samples from Mazandaran province in the north of Iran, showed that Galumna iranensis Mahunka and Akrami, 2001, Galumna karajica Mahunka and Akrami, 2001 and Scheloribates fimbriatus Thor, 1930 harbored cysticercoids. Therefore, it is likely that they may act as natural vectors of anoplocephalids. Subsequently these mite species were used for artificial infection with Moniezia expansa eggs. Fully developed cysticercoids were recovered only in S. fimbriatus, 35 days after incubation at 28 ± 1°C and 90 ± 5% RH. The percentage of infection was 70.8, and average and maximum number of cysticercoids per mite was 1.9 and 6.0, respectively. No mite eggs were found in infected mites.

Prevalence and seasonal incidence of larval and adult cestode infections of sheep and goats in eastern Ethiopia

A study on the prevalence and seasonal incidence of cestode parasite infections of sheep and goats was carried out in eastern Ethiopia for 2 years (May 2003-April 2005). During this period, viscera including liver, lungs, heart, kidneys and the gastro-intestinal tract were collected from 655 sheep and 632 goats slaughtered at four abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga. At the abattoirs the abdominal, thoracic and pelvic cavities as well as the muscle surfaces of all animals were visually examined for the presence of larval (cystic) stages of cestode parasites. The viscera were transported within 24 h to the parasitology laboratory of Haramaya University and were examined for larval and adult cestodes following standard procedures. The most prevalent metacestodes (larval cestodes) were Cysticercus ovis (Taenia ovis), Cysticercus tenuicollis (T. hydatigena) and hydatid cysts (Echinococcus granulosus). In sheep, the overall prevalence was 26% for C. ovis, 79% for C. tenuicollis, and 68% for hydatid cysts. Similarly, for goats, the corresponding prevalence was 22%, 53% and 65%, respectively. The difference between sheep and goats in prevalence of C. tenuicollis was significant. The high prevalence of hydatid cysts in both sheep and goats indicates that cystic echinococcosis/hydatidosis is a public health problem in these regions which requires implementation of control measures, including public health education, strict meat inspection and control of stray dogs. The results of the survey also implies that infections of small ruminants with these metacestodes are responsible for condemnation of substantial quantities of affected organs and muscles and therefore of direct economic importance. Intestinal infections with adult tapeworms of Moniezia expansa, Avitellina centripunctata and Stilesia globipunctata, and bile duct infections with Stilesia hepatica were also common in both sheep and goats. In sheep, the overall prevalence of these tapeworms were 61%, 20%, 24% and 39%, respectively. Similarly, the overall prevalence of these parasites in goats was 53%, 21%, 27% and 36%, respectively.

Genetic markers to distinguish Moniezia expansa from M. benedeni (Cestoda: Anoplocephalidae) and evidence of the existence of cryptic species in Australia

Multilocus enzyme electrophoresis (MEE) was used to genetically compare Moniezia spp. collected from sheep and cattle in southern Australia. Fifteen enzyme loci were established for the genetic characterisation of individual specimens of Moniezia, which represents a significant increase in the number of loci that was previously available for these cestodes. Another four enzyme loci were also identified as providing potential genetic markers. There were no differences in staining activity or banding patterns of different body regions of individual cestodes. Fixed genetic differences between Moniezia expansa and Moniezia benedeni were detected at 10 (77%) loci. Individuals that lacked the diagnostic morphological characters (i.e. the arrangement pattern of the interproglottidal glands) could be assigned to either morphospecies based on their MEE profiles. Genetic differences were also detected among individuals of the two morphospecies. One specimen of M. expansa had fixed genetic differences at 33% of enzyme loci when compared to all other specimens of M. expansa. Fixed genetic differences were also detected between the two groups of M. benedeni at 12 of 13 (92%) enzyme loci. This magnitude of genetic difference was greater than that detected between the two morphospecies. This provides evidence for the existence of cryptic species in the genus Moniezia.

Effects of condensed tannin from Acacia mearnsii on sheep infected naturally with gastrointestinal helminthes

The effect of tannins on endoparasite control in hair sheep was investigated using 20 entire lambs of the Santa Inês breed. At the beginning of the experiment these animals were 6-months old and weighed 22.5 kg ± 4.7. The treatments used were (10 animals each): GT (animals receiving 18 g of Acácia negra containing 18% of condensed tannin/animal/week) and GC (animals not receiving tannin). The experiment lasted 84 days, with animals kept on an Andropogon gayanus pasture. Faeces were collected weekly, with weighing and blood collection carried out fortnightly. At slaughter, the adult worms were harvested for identification and counting. Although the GT animals weighed more than the GC lambs at slaughter, these differences were not significant ( P > 0.05). In general, the values for haemoglobin, hematocrit, total protein, urea, phosphorus and calcium in the serum were within normal levels and no significant differences between groups were observed. For faecal egg count (FEC), lower values were observed throughout the experiment in the group receiving tannin, but these differences were only significant in the eighth week. There was a lower output of eggs by regression for GT compared with GC ( P < 0.05). The species identified, in decreasing order of worm count, were: Trichostrongylus colubriformis, Haemonchus contortus, Oesophagostomum columbianum, Cooperia sp., Strongyloides papillosus, Trichuris globulosa and Moniezia expansa. The total worm count and number of each species of worm were lower for GT compared with GC for T. colubriformis and Cooperia sp. ( P < 0.05). Condensed tannin (CT) from A. negra had an antiparasitic effect, thereby representing an alternative for worm control in sheep.

Infections of Moniezia expansa (Rudolphi, 1810) in Sheep During the Wet and Dry Seasons on St. Croix, U.S. Virgin Islands

The sheep tapeworm, Moniezia expansa, occurred in 100% of lambs and wethers during the wet warm season (15 Jun–15 Dec) on the U.S. Virgin Island of St. Croix in 1999. In total, 924 mm of precipitation was measured during this period. In the early dry season and mid-dry season, the percentage of lambs and wethers infected was 25 and 44%, respectively. In total, 424 mm of rainfall was measured during this period (16 Dec 1999–15 Jun 2000). During the transition from wet to dry seasons, prevalence was lower in ewes (peaking at 29.6%) than in offspring. In lambs and wethers, prevalence increased to 58% and then declined to 44.4%. Temperature averaged 25°C during the wet season and 29.4°C during the dry season. Eggs per gram of feces (EPG), determined by the modified McMaster method, followed a similar pattern, peaking at 1,698 EPG in the wet season, 2,008 EPG in the early dry season, and 939 EPG in the mid-dry season. Infections were heavier and of greater duration in the wet season. The study started in September 1999 and ended in August 2000.

Influence of protein supplementation on the resistance and resilience on young hair sheep naturally infected with gastrointestinal nematodes during rainy and dry seasons

Thirty, 4-month-old entire Santa Ines lambs were grazed on an Andropogon gayanus pasture, during a 34-week period (rainy season weeks 0–20 and dry season weeks 21–34) and allocated in two treatment groups ( n = 15) each with different protein supplementation: high protein (HP—19% CP) and low protein (LP—11% CP). These were subdivided into those receiving anthelmintic treatment (c) ( n = 7) and without anthelmintic treatment (i) ( n = 8). The objective was to evaluate the effects of supplementation with protein on resistance and resilience to natural helminth infection of hair breed lambs. Lamb weight, blood collection and faecal egg counts (FEC) were carried out monthly. The lambs were slaughtered after 34 weeks, when worm burdens, worm length and eosinophil cell counts were taken. The sheep on treatments HPc and HPi were heavier in live weight than those from LPi and LPc ( P < 0.05) at the end of the rainy period. The HPc group finished heavier ( P < 0.05) than the other groups in the dry season, which had no significant differences between them. The predominant species of nematode found was T. colubriformis followed by H. contortus, Trichuris globulosa and Moniezia expansa. Animals on HPi had lower FEC than LPi ( P < 0.05). The number of worms was lower for both HP groups ( P < 0.05) with worm length shorter in the HPc group ( P < 0.05) compared with all other groups. The number of eosinophils was higher in animals in the LPi group, which also showed anaemia and lower plasma urea at the end of the dry season. Diet supplementation with high protein was able to improve resilience and resistance to natural infection by endoparasites during the rainy season. In the dry season there was a decrease in both of these traits, which were intimately linked to the quality of available forage under tropical conditions.

Tapeworm control in sheep

SIR, – It may be a common belief among vets that the sheep tapeworm, Moniezia expansa , is not associated with significant disease in lambs. Although farmers have historically treated animals for ‘cosmetic’ reasons when lambs go to market, routine tapeworm control does not generally occur.

Variations saisonnières des helminthes gastro-intestinaux chez la chèvre du plateau central du Burkina Faso

Des nécropsies pendant une année de 60 chèvres ont permis d’identifier les parasites de la cavité abdominale, du foie et du tube digestif. Au total, 10 nématodes, 4 cestodes et 2 trématodes ont été identifiés. Cysticercus tenuicollis a été trouvé dans la cavité péritonéale, Dicrocoelium hospes dans le foie, et Gongylonema verrucosum et des paramphistomes dans l’ensemble réseau-rumenfeuillet. Dans la caillette, il y avait Haemonchus contortus et Trichostrongylus colubriformis. L’intestin grêle abritait T. colubriformis, T. vitrinus, Strongyloides papillosus, Gaigeria pachyscelis, Avitellina centripunctata, Stilesia globipunctata et Moniezia expansa. Quant au gros intestin, il hébergeait Oesophagostomum columbianum, Skrjabinema ovis, Trichuris ovis et Trichuris globulosa. Les plus prévalents de ces parasites ont été T. colubriformis (98,3 p. 100), Oesophagostomum columbianum (88,3 p. 100), les larves L4 (85 p. 100), puis les adultes (65 p. 100) d’Haemonchus contortus, T. vitrinus (41,7 p. 100), Avitellina centripunctata (30 p. 100) et Cysticercus tenuicollis (30 p. 100). L’abondance moyenne des nématodes a globalement été faible à l’exception de celle des larves d’H. contortus dans la caillette et des adultes de T. colubriformis dans l’intestin grêle à la fin de la saison pluvieuse, et pendant la période sèche et froide. Cette période serait idéale pour l’application du deuxième déparasitage stratégique annuel des chèvres de la région.

Internal parasites of free-ranging guanacos from Patagonia

In the winter of 2000, a greater than 80% reduction in the guanaco population located in Cabo Dos Bahı́as Wildlife Reserve, Chubut, Argentina, was evident due to massive mortality attributed to starvation. Twelve guanacos were necropsied and samples were analyzed at the Parasitology Laboratory of Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral. Fecal analysis revealed developmental stages of Nematodirus sp., Marshallagia sp., Trichuris sp. and Eimeria spp. Histopathological analysis showed the presence of Sarcocystis sp. in muscle and fascia cysts. Other parasites recovered included Dictyocaulus filaria, Trichuris tenuis and Moniezia expansa. Of these, D. filaria and M. expansa possibly reflect interactions with domestic sheep. This is the first time that T. tenuis has been reported in guanacos.

Gene organization and expression of a neuropeptide Y homolog from the land planarian Arthurdendyus triangulatus.

Neuropeptide Y is one of the most widespread regulatory peptides within the vertebrate nervous system and shares the C-terminal motif [FY]-x(3)-[LIVM]-x(2)-Y-x(3)-[LIVMFY]-x-R-x-R-[YF] with pancreatic polypeptide, peptide YY, and fish pancreatic peptide Y. All four peptides are believed to have arisen from a single ancestral gene through successive gene duplication events in vertebrates. The origin of this peptide family may date back further still; similarly sized peptide transmitters with an identical C-terminal motif have been identified in molluscs and flatworms and designated neuropeptide F (NPF). Cloning of the npf gene from the parasitic flatworm Moniezia expansa identified some unusual features within the peptide precursor organization but, at the same time, provided support for an evolutionary relationship of npf and npy genes through the presence of a single intron at a conserved position. To extend the analysis of the evolutionary relationships between invertebrate NPF and vertebrate NPY family peptides, the NPF precursor from the turbellarian Arthurdendyus triangulatus was characterized. Sequence analysis revealed the npf transcript to be 362 base pairs in length encoding a single open reading frame of 81 amino acids. The precursor comprises a signal peptide followed by the mature peptide of 36 amino acids in length, terminating in the typical invertebrate GRPRF motif, followed by a carboxyterminal glycyl extension. The NPF precursor of A. triangulatus shows significant similarities to the vertebrate NPY peptides. Indeed, the N-terminus of A. triangulatus prepro-NPF corresponds more closely to that of the vertebrate peptide homologs than to that of other invertebrate NPFs isolated to date. Immunocytochemical localization studies have demonstrated NPF immunoreactivity throughout the nervous system of A. triangulatus, particularly in association with muscular structures. The data support an early evolutionary origin for this peptide transmitter family within the nervous system of basal bilaterians.

The NMR-derived Conformation of Neuropeptide F from Moniezia expansa

The solution structure of neuropeptide F (NPF), from the flatworm (platyhelminthes) Moniezia expansa, has been determined by 1H NMR spectroscopy at 800MHz in 60%/40% CD3OH/H2O. NPF is the most abundant neuropeptide in platyhelminthes. The secondary structure of NPF contains an alpha helix from residues Lys14 to Ile31, while the N terminus, consisting of residues Pro−2 to Asn13, and the C-terminus, consisting of residues Gly32 to Phe36, are in a random conformation. The structure was calculated by a simulated annealing protocol, and the conformational data are compared to the porcine neuropeptide Y (NPY), a peptide hormone and neurotransmitter. The exact function of NPF is unknown, but structural similarity with porcine NPY indicates that its mode of action is similar. These structural data can serve as a starting point in the design of new antiparasitic drugs.

Enantioselective binding of albendazole sulphoxide to cytosolic proteins from helminth parasites.

The pharmacological effect of the active albendazole metabolite, albendazole sulphoxide (ABZSO), depends on its sustained presence at the site of parasite location and its binding to helmith beta-tubulin. ABZSO is found in the plasma and tissues of albendazole-treated animals in two enantiomeric forms: (+)ABZSO and (-)ABZSO. Knowledge of enantioselectivity in drug action is necessary, since any difference in target proteins affinity between enantiomers may have implications on the pharmacological effect of this anthelmintic molecule. The binding of ABZSO to mammalian and helminth parasites cytosolic proteins, as well as the differential binding of both enantiomers, were studied. Cytosolic proteins from Moniezia expansa (cestode), Ascaris suum (nematode), Fasciola hepatica (trematode), rat liver and brain as well as purified porcine brain tubulin were used. Drug analysis was performed by HPLC using both C18 and chiral columns. ABZSO protein binding was quantitatively different between parasite species (4.17, 2.5 and 1.07 ng/mg for cestode, nematode and trematode, respectively); this binding to helminth cytosolic proteins was enantioselective. Enantiomeric ratios of (-)ABZSO/(+)ABZSO as a percentage were: 43/57 (Ascaris), 36/64 (Moniezia) and 91/9 (Fasciola). Conversely, the binding of ABZSO to mammalian cytosolic proteins showed no enantioselectivity. The overall binding affinity of ABZSO for mammalian cytosolic proteins was lower than that observed in helminth proteins. The characterization of the comparative binding pattern of ABZSO enantiomers to cytosolic proteins from helminth parasites and mammalian tissues may contribute to understanding the pharmacological properties of this chiral anthelmintic molecule.

Epidemiology of gastrointestinal helminthiasis of rift valley goats under traditional husbandry system in Adami Tulu District, Ethiopia

The prevalence, mean intensity, relative density of helminth species and the effects of environmental factors, sex and maturity of host on seasonal dynamics in relative density of helminthes ova in Rift Valley goats were investigated from July 1997 to June 1998. Ten nematode and three cestode species were identified. Haemonchus contortus was the most prevalent followed by Strongloides papillosus and Trichostrongylus sp. with prevalence rate of 66.5%, 36.1% and 30.4% and mean intensities and relative densities of 1139.9, 503.7, 434.8 and 344.9, 82.8, 60.1, respectively. Moniezia expansa showed 32.2% prevalence rate and 545.2 and 79.6 mean intensity and relative density, respectively. Mixed infestation was common to Rift Valley goats. About 2.8%, 6.2%, 15.8%, 21.6% and 23.7%, of the examined goats harbored multiple infestations varying from five to one species, respectively. Maturity and sex of hosts influenced seasonal variations in relative density of helminthes species. Female hosts harbored higher relative densities (p

Epidemiological studies on gastrointestinal helminths of dromedary ( Camelus dromedarius) in semi-arid lands of eastern Ethiopia

A total of 752 dromedaries were examined and 75% were found to be harbouring nematode eggs. The mean EPG was 1831 and the range was from 100 to 21,200. The prevalence rates in the four-age groups examined were 59.6% (3–7 years), 72.4% (8–12 years), 76.1% (13–17 years) and 83.9% (18–22 years). The prevalence rate for females and males were 77.6 and 64.8%, respectively and for long dry, short rainy, short dry and long rainy seasons were 66, 80, 69 and 82.6%, respectively. The mean EPG of faeces was significantly ( P<0.01) higher for older animals compared to other group of younger animals (3–7 years), for females compared to males, and for rainy compared to dry season. Sixteen dromedary gastrointestinal organs were used for identification and counts of helminths. Among the adult worms identified, from the abomasum, Haemonchus longistipes had a 94% prevalence rate. From the small intestine Trichostrongylus colubriformis, Trichostrongylus probolurus, Impalaia tuberculata and Strongyloides papillosus were identified with prevalence rates of 75, 25, 63 and 20%, respectively. Moreover, cestodes such as Moniezia benedeni, Moniezia expansa, Avitellina spp. and Stilesia globipunctata with prevalence rates of 31, 13, 25 and 19%, respectively, were identified. I. tuberculata was identified for the first time in this country from a dromedary. The pathological lesions were more pronounced in higher infestations. Infestation level over approximately 1000 of H. longistipes and 15,000 in mixed infection of T. colubriformis and I. tuberculata, caused gross lesions of ulcerated and hyperaemic mucosa, and the odour of the fluid were fetid. The microscopic lesions observed were sloughing of epithelium, necrosis of glands, atrophy and loss of villi, haemorrhages and cellular infiltration mainly of eosinophiles and lymphocytes.

A confocal microscopical study of the musculature of adult Schistosoma mansoni.

Using the filamentous actin marker, FITC-conjugated phalloidin, the major muscle systems of adult male and female schistosomes have been examined. The body wall musculature comprises an outer sheath of circular fibres, within which there is a compact layer of short, spindle-shaped longitudinal fibres and a lattice-like arrangement of inner diagonal fibres. Within the oral sucker and acetabulum 3 fibre types, circular, radial and longitudinal can be distinguished. The wall of the oesophagus is lined by a grid-like array of circular and longitudinal fibres, whereas the walls of the intestinal caeca contain only comparably broad circular fibres. Within the female reproductive system, only circular fibres are present in the oviduct, vitelline duct and uterus. In contrast, the wall of the ootype displays closely arranged circular and longitudinal muscle fibres. Antisera to previously identified myoactive compounds (serotonin [5-hydroxytryptamine, 5-HT], neuropeptide F [Moniezia expansa] and GYIRFamide [Bdelloura candida, Dugesia tigrina]) were used as neuronal markers in a preliminary study of the spatial inter-relationships of specific nerve fibres and various muscle systems. Serotoninergic fibres innervate both suckers and also constitute a subtegumental nerve net. In males they provide innervation to the dorso-ventral muscle fibres of the gynaecophoric canal, and in females they innervate the circular and longitudinal muscle fibres of the ootype. Neuropeptide F and the FMRFamide-related peptide, GYIRFamide are both localized within nerve plexuses associated with the dorso-ventral fibres of the gynaecophoric canal, and are evident in the innervation of the ventral and oral sucker.