Unidentified Nematode Research Articles

Diversity of metazoan parasites of the Mozambique tilapia, <i>Oreochromis mossambicus</i> (Peters, 1852), as indicators of pollution in the Limpopo and Olifants River systems

Aquatic systems are affected by a variety of anthropogenic activities that decrease water quality through the introduction of organic and inorganic pollutants. To investigate the relationship between fish parasite communities and water quality, metazoan parasites were examined in 140 specimens of the Mozambique tilapia (Oreochromis mossambicus) sampled in three lakes in the Limpopo Province, namely the Luphephe-Nwanedi Dams (regarded as unpolluted), the Flag Boshielo Dam (regarded as moderately polluted) and a return water dam on a mine site (regarded as polluted). The monogenean parasites Cichlidogyrus halli, digenean larval stages of Clinostomum and Diplostomum spp. and a gryporynchid cestode were found in or on O. mossambicus in all the sampled sites. The distribution of monogeneans (Cichlidogyrus sclerosus, Cichlidogyrus dossoui, Cichlidogyrus tilapiae, Scutogyrus longicornis and three Enterogyrus spp.), metacercarial stages of two digeneans (Neascus and Acanthostomum spp.) and nematodes (an unidentified nematode, Contracaecum sp., Paracamallanus cyathopharynx and Procamallanus laevionchus) was limited to the unpolluted and moderately polluted lakes. Larval stages of Diplostomum sp. were present in O. mossambicus collected from the unpolluted and polluted sites. The variability of the calculated infection indices (prevalence, mean abundance and mean intensity) and the parameters of species richness and diversity suggest that the structure of parasite communities are affected by the pollution levels of the water. The unpolluted reference site had the highest species richness and the highest overall parasite abundance values.

On the pathogens of the spruce bark beetle Ips typographus (Coleoptera: Scolytinae) in the Western Carpathians

Pathogens of spruce bark beetle Ips typographus were compared at eleven sites in Slovakia (the Western Carpathians). Seven different pathogen species were recorded: protozoan species Chytridiopsis typographi, Gregarina typographi, Malamoeba scolyti, nematodes of the genus Neoparasitylenchus and one unidentified nematode species. Presence of the entomopathogenic fungus Beauveria bassiana was also observed as well as parasitization by hymenopteran parasitoids. High infection rate of G. typographi and the nematode Neoparasitylenchus was detected in almost all sites and lethal impact of M. scolyti by massive infections was observed. The beetles from seven sites were screened for endosymbiotic bacteria Wolbachia, however, with no positive result.

Diet and nematode infection in Proceratoprhys boiei (Anura: Cycloramphidae) from two Atlantic rainforest remnants in Southeastern Brazil

Proceratophrys boiei is an endemic cycloramphid anuran inhabiting the leaf litter of Atlantic rainforests in Southeastern Brazil. We analyzed the whole digestive tract of 38 individuals of Proceratophrys boiei collected in two Atlantic Rainforest areas in the state of Rio de Janeiro, Brazil, to study the diet composition and the helminth fauna associated with this species. The main food items in P. boiei's diet were Coleoptera, Orthoptera and Blattaria. Five nematode species were found: Aplectana delirae, Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp. (larval stage only) and an unidentified nematode. Overall prevalence was 71% and mean infection intensity was 7.3 ± 5.8 neatodes per individual.

Gastrointestinal Parasites and Associated Pathological Lesions in Starving Free-Ranging African Elephants

Past events of drought in different ecosystems in Kenya have been linked to mass deaths of elephants (Loxodonta africana). However, it is possible that other factors such as parasitism could be acting in synergy with drought and result in mortality. During the severe drought of 2009 in the Laikipia-Samburu ecosystem in Kenya, 38 young elephants (5–8 years old) died. Necropsy of 11 fresh elephant carcasses revealed pathological lesions on the intestinal mucosa and haemorrhages which were linked to parasitism. A nematode, Grammocephalus clathratus, from the bile duct, a trematode, Protofasciola robusta, from the duodenum and a complex of unidentified nematodes from the lower gut were isolated from the elephants. The carcasses were overly emaciated and the intestinal system was devoid of digesta. It is likely that starvation and dehydration could have triggered a vicious cycle of host malnourishment, a result of combined inadequate food and nutritional deprivation by intestinal parasites which lead to emaciation, pathology and death.

First record of Neoxysomatium brevicaudatum through the non-invasive sampling of Anguis fragilis: complementary morphological and molecular detection

Relatively few studies have examined the parasite fauna of British reptiles, partly due to the cryptic nature and low population density of these hosts. Here we examined 12 populations of the slow worm Anguis fragilis which, unlike other UK lizards, occurs at locally high population densities. Morphological examination of non-invasively collected faecal samples revealed the presence of Neoxysomatium brevicaudatum and a second unidentified nematode species. Although previously unrecorded from slow worms in the UK, N. brevicaudatum was present in 38% of animals (mean intensity 70.9, range 1-686). Morphological identification was confirmed by sequencing the 18S ribosomal gene. The use of the species-specific, cytochrome oxidase I mitochondrial gene primers proved an efficient alternative to conventional, microscope screening for parasites, although the original identification of N. brevicaudatum was dependent upon morphological characters. Sequencing also identified the second, smaller nematode as belonging to the Rhabdiasidae family: this species was even more common at a prevalence of 83% (mean intensity 102.8, range 1-2000). While increasing our knowledge of the UK macroparasite fauna, this work demonstrates the benefits of a combined morphological-molecular approach.

Helminth Parasites of Golden Shiner Notemigonus crysoleucas (Pisces: Cyprinidae) from Ontario and Nova Scotia, Canada

Helminth parasite communities of golden shiner Notemigonus crysoleucas (Pisces: Cyprinidae) were characterized in north central (Lake Opeongo, Ontario, Canada) and far eastern (Vinegar Lake, Nova Scotia, Canada) localities within its natural range. Membership included 9 generalists (Allocreadium lobatum, Clinostomum complanatum, Apophallus brevis, Pliovitellaria wisconsinensis, Proteocephalus sp., Rhabdochona cascadilla, Camallanus oxycephalus, an unidentified nematode, and Pomphorhynchus bulbocolli) and 6 specialists (Octomacrum microconfibula, Dactylogyrus parvicirrus, Gyrodactylus sp., Phyllodistomum sp., Paradilepis sp. A, and Paradilepis sp. B). Infracommunity richness was 2.6 ± 1.2 in Ontario and 1.0 ± 0.8 in Nova Scotia. Component community richness was 13 in Ontario and 6 in Nova Scotia. The two helminth communities were made up of similar proportions of generalists and specialists. We suggest that comparable studies on the helminth communities of golden shiner from similar lakes more central in this host's North American range could examine whether there is decay in richness particularly when approaching the periphery of a host's range. This is the first report of helminth parasites from N. crysoleucas in Nova Scotia.

Helminths of the American bullfrog, Lithobates catesbeianus (Shaw, 1802), from Pawnee Lake, Lancaster, Nebraska, USA with a checklist of its helminth parasites

The American bullfrog, Lithobates catesbeianus, is one of the most intensively studied host species. However, most of the records related to the parasites of this anuran are scattered through the literature. The purpose of our study is twofold: 1) to list the helmiths of this host from Pawnee Lake, Lancaster Co., Nebraska, USA, and 2) To compile all published records and those contained by several scientific collections to construct a checklist of helminth parasites associated with the American bullfrog through its range in both native and introduced geographical areas. Twenty-seven specimens of L. catesbeianus were collected and examined for helminth parasites; 20 frogs were infected. Nine species of helminths were collected: 4 digeneans: Haematoloechus coloradensis, H. parviplexus, Gorgoderina attenuata, and Glypthelmins quieta, and 5 nematodes: Rhabdias ranae, Spinitectus gracilis, Cosmocercoides variabilis, Spiroxys sp., and an unidentified ascarid nematode. Pawnee Lake represents a new locality record for S. gracilis. The digenean H. parviplexus had the highest prevalence and mean abundance (33.3% and 3, respectively). As a result of our study, the number of helminth taxa known for this host is 159 (75 digeneans, 4 monogeneans, 10 cestodes, 7 acanthocephalans, and 63 nematodes); these records come from 6 countries (Canada, Cuba, Japan, Korea, United Kingdom, and USA). Although well documented, the helminthological record of this host species could increase after further inventory work in poorly sampled regions.

Identification and isozyme characterisation of Meloidogyne spp. infecting horticultural and agronomic crops, and weed plants in Florida

Abstract A total of 327 root samples collected from horticultural and agronomic crops, and weeds associated with these crops in Florida crop production regions, were examined. Isozyme phenotypes, esterase (EST) and malate dehydrogenase (MDH) phenotypes were used to characterise and identify the species of Meloidogyne present in these samples. At least 26 females from each sample were examined using polyacrylamide gel electrophoresis. Sixteen major bands of EST activity were found, corresponding to 12 phenotypes. A species-specific EST phenotype was consistently associated with each of the Meloidogyne spp. identified: Meloidogyne arenaria, M. floridensis, M. graminicola, M. hapla, M. incognita, M. javanica, M. mayaguensis and M. partityla. Two unique EST phenotypes, which have not been described, were found associated with three unidentified nematode populations. Five bands of MDH activity and four phenotypes were also found among the populations. During this study, new host records were determined for M. floridensis and M. mayaguensis, two recently reported Meloidogyne spp. in Florida. Plant species found as new hosts of M. floridensis were Cucumis sativus, Phaseolus sp., Solanum melongena and one weed species, Emilia sonchifolia, and the M. incognita-resistant peach rootstock ‘Flordaguard’. New hosts for M. mayaguensis were Carica papaya, Capsicum annuum var. Longum, and six weed plants, including Eclipta prostrata, Fatoua villosa, Panicum sp., Poinsettia cyathophora, Solanum americanum and also one unidentified weed species belonging to the family Acanthaceae. To our knowledge, Florida is the only geographic area of North America where M. floridensis and M. mayaguensis have been detected.

Nemerteans as hosts for symbionts: a review

Nemerteans utilize other animals as hosts in a variety of well‐studied, symbiotic relationships, but relatively little is known concerning nemerteans as hosts for other organisms. Only three haplosporidians, one microsporidian, two gregarines, three ciliates, five mesozoans, one mite and one copepod have been identified to species from nemerteans, whereas 34 nemertean species (one Archinemertea, 17 Heteronemertea, 15 Hoplonemertea, one Bdellonemertea) have been recorded as hosts. The majority of recorded nemertean symbionts are endoparasitic protozoans and orthonectids. Among the Haplosporidia, there are three species of Haplosporidium. The hyperparasite, Nosemoides vivieri, from an unidentified gregarine, is the only known microsporidian associated with a nemertean. Within the phylum Apicomplexa, besides the two species of gregarines from three species of nemerteans, there are 11 other species of nemerteans with unidentified gregarines. One species of nemertean has been found with an unidentified coccidian parasite. ‘Sporozoan‐like’ parasites, however, are known from three other species of nemerteans, two of which are pelagic polystiliferans. Two endosymbiotic and one ectosymbiotic species of ciliates have been identified from three species of nemerteans. At least five species of mesozoans (Orthonectida) infect nine species of nemerteans. Unidentified cestode, trematode and nematode juveniles, using nemerteans as intermediate hosts, have been recorded rarely and have not been linked to any life cycles. An ectosymbiotic mite and a copepod from two species of nemerteans are likely incidental associates. The nature of the host–symbiont relationships has been rarely reported. Castration of hosts by haplosporidians and orthonectids, and tissue damage by an unidentified coccidian and some gregarines, are known to occur. The suitability of nemerteans as hosts for parasites, hypersymbioses and approaches for future studies of parasite prevalence and host–parasite relationships are discussed.

Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) and other nematode genera associated with insects from Pinus pinaster in Portugal

AbstractInsects associated with maritime pine, Pinus pinaster, in Portugal were collected and screened for the presence of Bursaphelenchus species. Nematodes were identified using Internal Transcribed Spacers‐Restriction Fragment Length Polymorphism (ITS‐RFLP) analysis of dauer juveniles and morphological identification of adults that developed from dauer juveniles on fungal cultures or on cultures in pine wood segments at 26°C. Several associations are described: Bursaphelenchus teratospicularis and Bursaphelenchus sexdentati are associated with Orthotomicus erosus; Bursaphelenchus tusciae, B. sexdentati and/or Bursaphelenchus pinophilus with Hylurgus ligniperda and Bursaphelenchus hellenicus with Tomicus piniperda, Ips sexdentatus and H. ligniperda. An unidentified Bursaphelenchus species is vectored by Hylobius sp. The previously reported association of Bursaphelenchus xylophilus with Monochamus galloprovincialis was confirmed. The association of Bursaphelenchus leoni with Pityogenes sp. is not definitively established and needs further studies for clarification. Other nematode genera besides Bursaphelenchus were found to be associated with the insects sampled, including two different species of Ektaphelenchus, Parasitorhabditis sp., Parasitaphelenchus sp., Contortylenchus sp. and other unidentified nematodes. The Ektaphelenchus species found in O. erosus is morphologically similar to B. teratospicularis found in the same insect; adults of both the species are found in cocoon‐like structures under the elytra of the insects.

Distribution and relative importance of cereal stem borers and their natural enemies in the semi-arid and cool-wet ecozones of the Amhara State of Ethiopia

The distribution and relative importance of lepidopteran and coleopteran stem borers and their natural enemies on maize and sorghum were studied in cereal growing zones of the Amhara State of Ethiopia from 2003 to 2004. Sorghum is the major crop in semi-arid eastern and maize in the cool-wet western zones of the Amhara state. Four administrative zones, 10 districts and 88 localities in the semi-arid ecozone (SAE) and four zones, 19 districts and 71 localities in the cool-wet ecozone (CWE) were chosen for the study. In SAE, the species composition was 91% Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), 8% Busseola fusca (Fuller) (Lepidoptera: Noctuidae) and 1% Sesamia calamistis Hampson (Lepidoptera: Noctuidae). In the CWE, maize and sorghum are grown in different ecozones and thus B. fusca was the dominant species on sorghum, whereas 61% B. fusca and 39% S. calamistis were recorded on maize. Borer density generally increased with crop growth stage. C. partellus parasitism by C. flavipes Cameron (Hymenoptera: Braconidae), which occurred only in SAE, varied among districts ranging from 5% to 39%. In the CWE, unidentified nematodes parasitized medium-sized B. fusca larvae during the wet months. Population of native parasitoids was very low. The coleopteran borer, Rhynchaenus niger (Horn) (Coleoptera: Rhynchophoridae), attacked sorghum plants in both regions. Sorghum yields were negatively related to plant damage variables and positively to larval parasitism and plant growth variables. On maize, plant damage was too low to affect yields. Taylor’s power law indicated aggregated distribution for C. partellus and B. fusca larvae and pupae combined.

Preliminary studies of the helminth parasites of <i>Limicolaria Aurora</i> in Ile-Ife, Nigeria

Specimens of Limicolaria aurora collected from Ile-Ife area were surveyed for infection with parasitic helminthes. The snails were picked from bushes and dissected and examined in the laboratory. Four different helminth parasites comprising of 3 nematodes and a digenetic trematode were observed in L. aurora . The nematodes include the larvae of Angiostrongylus. cantonensis , the unidentified Nematode I and another unidentified nematode (Nematode II). Prevalences were 25.3% for A. cantonensis , 4.7% for Nematode I and 2.0% for Nematode II. The mean intensities of infection for the three nematodes were 12.4 ± 3.7, 1.3 ± 0.1 and 3.0 respectively. The trematode, which is yet unidentified has a prevalence of 80.7% and mean intensity of 53.7 ± 7.5. Key Words: Limicolaria aurora, Angiostrongylus. cantonensis , prevalence, trematode. Ife Journal of Science Vol.6(2) 2004: 105-107

Helminth community structure in Rattus leucopus (Gray) (Muridae) from Australia, Papua New Guinea and Papua

This study describes the helminth community in 28 Rattus leucopus, from Australia, Papua New Guinea and Papua (formerly Irian Jaya), and compares the community in Australian R. leucopus with those known from two other Australian endemics, R. sordidus and R. fuscipes. In total, 28 parasite species were found: one acanthocephalan, five cestodes, one trematode and 21 nematodes as well as two lots of unidentified spirurid nematode larvae. The diversity of helminths in R. leucopus was high but equitable; the reciprocal of Simpson's Index was 1.75. The distribution of prevalence of helminth species was not indicative of a core-satellite structure. No species occurred at a prevalence >30% and more than half the species occurred at prevalences of <10%. Only 10% of the helminth species identified were unique to R. leucopus. Helminth community structure in R. leucopus differed from that observed in R. sordidus and the community in R. fuscipes was markedly different from those in R. leucopus and R. sordidus. Determinants of the diversity of the helminth community in R. leucopus include the time intervals between the three waves of migration of Rattus spp. to Australia, biogeographic factors related to immigration and adaptive radiation of the host genus, and associated with coevolution, speciation and host switching of the helminths.

The Earthworm Lumbricus terrestris as a Possible Paratenic or Intermediate Host of the Pig Parasite Ascaris suum

Published reports suggest that some species of earthworms may serve as paratenic hosts or even intermediate hosts for the pig parasite, Ascaris suum. This study was conducted to determine whether infective As. suum eggs could hatch and the larvae remain infective within the earthworm, Lumbricus terrestris. Pig feces containing infective As. suum eggs were fed to earthworms that were then allowed to purge their intestines and eliminate ascarid eggs. Although exposed earthworms were examined using direct dissection, agar, and digestion techniques, no As. suum larva was recovered from the earthworms. Twenty-five exposed earthworms were administered to each of 3 helminth-free pigs, but no As. suum larva was isolated from the liver, the lungs, or the small intestine on days 4, 7, and 11 postinoculation. No intermediate or paratenic host role for L. terrestris in the As. suum life cycle was demonstrated. Unexpectedly, unidentified nematode larvae were isolated from both the earthworms and the lungs of the earthworm-fed pigs. These earthworms were imported from Canada and were usually sold to anglers for fish bait, suggesting that the human-mediated transport of intermediate or paratenic hosts may introduce parasites to new geographic regions.

Nematode infections of the eye: toxocariasis and diffuse unilateral subacute neuroretinitis.

In many parts of the world, parasitic infections of the eye are a major cause of blindness. The parasites Toxocara canis, Onchocerca volvulus, Taenia solium, Ancylostoma caninum, and Cysticercus celulosae all have been responsible for blinding ocular infections. The nematodes T. canis and Toxocara cati are parasitic roundworms that infect dogs (toxocarosis), other canidae, and cats. Ocular toxocariasis is an uncommon worldwide infection caused by the nematode larvae of T. canis, commonly found in dogs. Human transmission is usually via geophagia, the ingestion of food contaminated with Toxocara eggs, or contact with infected puppies, often resulting in devastating ocular or systemic effects. Ocular toxocariasis is typically a monocular disease of young children, and its clinical findings include posterior and peripheral retinochoroiditis, optic papillitis, and endophthalmitis. The inflammatory response created by ocular involvement may result in epiretinal membrane formation, traction retinal detachment, and combined traction-rhegmatogenous retinal detachment. Diffuse unilateral subacute neuroretinitis is another ocular parasitic infection that usually results in severe visual loss. Evidence suggests that diffuse unilateral subacute neuroretinitis is caused by a solitary unidentified nematode of two different sizes, but to date, only a small number of nematodes have been recovered from eyes affected with the infection. Diffuse unilateral subacute neuroretinitis occasionally can affect the fellow eye.

A Preliminary Life Table of the Armoured Ground Cricket, Acanthoplus speiseri Brancsik (Orthoptera: Tettigoniidae, Hetrodinae), a Pest of Grain Crops in Zambia

The development of a single cohort of the armoured ground cricket, Acanthoplus speiseri Brancsik was followed in the environs of the University of Zambia campus, Lusaka and a preliminary life table of the grain pest constructed. The pest's total generation mortality was influenced by: failed egg eclosion, failed ecdysis, cannibalism/predation and parasitism. The egg stage had the highest percent real mortality (98.57%) and sub-mortality k-value, indicating that this was the main contributor to the total generation mortality. The rest of the developmental stages suffered lower mortalities, although that of the 6th instar was comparatively higher. A mermithid nematode, Mermis sp., and another unidentified nematode species caused 2.61% sub-mortality in the 6th nymphal instar. The constructed preliminary life table of A. speiseri is analysed and the possible causes of the observed high mortalities in the egg and 6th instar stages are discussed.

Composition of Helminth Communities in Montane and Lowland Populations of the Western Fence Lizard, Sceloporus occidentalis from Los Angeles County, California

Abstract Five hundred seventy-two Sceloporus occidentalis from Los Angeles County, California, were examined for helminths: 200 from the San Gabriel Mountains (montane, ca. 1584 m elevation) and 372 from the Puente Hills (lowland, ca. 150 m elevation). The component helminth community of the montane fence lizard population consisted of four species: two species of cestodes, Mesocestoides sp. and Oochoristica scelopori and two species of nematodes, Physaloptera retusa and Spauligodon giganticus. The component helminth community of the lowland fence lizard population contained three species: Mesocestoides sp., Physaloptera retusa and unidentified nematode acuariid larvae. The two helminth communities are dissimilar in composition.

EFFECT OF GONADAL INFECTION BY NEMATODE PARASITE ON THE FECUNDITY OF THE SEA BREAM LETHRINUS NEBULOSUS IN RAS MOHAMED MARINE PARK (NORTHERN RED SEA)

The sea bream Lethrinus nebulosus was sampled during the spawning season of 1996 (May-July) in Ras Mohamed Marine Park. Out of 119 specimens collected (46 females and 73 males), 11 females (23.9 %of examined females) were found to be parasitized by unidentified nematode. This parasite is found to be specific for fish ovary, causing a reduction in the absolute fecundity of the infected females compared with normal ones (averaged 4.97 x 105 and 7.54 x 10 5 eggs/female, respectively).In all infected females, 2-4 nematode worms of 30-40cm in length / each ovarian lobe, were coiled together in a mass occupying the ovarian lumen and seemed to block the oviduct preventing egg releasing. Histological examination showed that ovaries of heavily infected females did not contain mature ova with a depression of the vitellogensis process. All infected ovaries were characterized by certain degrees of atresia depending upon the level of infection. The synchronization between reproduction of the fish and the parasite, and the parthenogenetic nature of the parasite are thought to increase the biological potential of the parasite to colonize and infect other host individuals and possibly other populations.

Helminth infracommunities in Litoria genimaculata (Amphibia: Anura) from Birthday Creek, and upland rainforest stream in Northern Queensland, Australia

The helminth fauna of Litoria genimaculata, a rainforest frog from northern Queensland, was quantified from 53 adult male frogs collected at monthly intervals between April 1990 and March 1991. The helminth fauna of this species was depauperate (6 species: Mesocoelium sp., Parapolystoma bulliense, Austraplectana sp., Onchocercidae gen. sp., Cosmocerca sp. and an unidentified nematode larva). The most commonly encountered species was P. bulliense, but the intestinal infracommanity was dominated by the digenean Mesocoelium sp. Fifty-five per cent of frogs were infected with only 1 helminth species and only 1 frog had more than 2 species, resulting in low diversity values. These results support previous studies which indicate that amphibians have depauperate helminth communities.

FMRFamide-related peptides (FaRPs) in nematodes: occurrence and neuromuscular physiology.

The occurrence of classical neurotransmitter molecules and numerous peptidic messenger molecules in nematode nervous systems indicate that although structurally simple, nematode nervous systems are chemically complex. Thus far, studies on one nematode neuropeptide family, namely the FMRFamide-related peptides (FaRPs), have revealed an unexpected variety of neuropeptide structures in both free-living and parasitic species. To date 23 nematode FaRPs have been structurally characterized including 12 from Ascaris suum, 8 from Caenorhabditis elegans, 5 from Panagrellus redivivus and 1 from Haemonchus contortus. Ten FaRP-encoding genes have been identified in Caenorhabditis elegans. However, the full complement of nematode neuronal messengers has yet to be described and unidentified nematode FaRPs await detection. Preliminary characterization of the actions of nematode neuropeptides on the somatic musculature and neurones of A, suum has revealed that these peptidic messengers have potent and complex effects. Identified complexities include the biphasic effects of KNEFIRFamide/KHEYLRFamide (AF1/2; relaxation of tone followed by oscillatory contractile activity) and KPNFIRFamide (PF4; rapid relaxation of tone followed by an increase in tone), the diverse actions of KSAYMRFamide (AF8 or PF3; relaxes dorsal muscles and contracts ventral muscles) and the apparent coupling of the relaxatory effects of SDPNFLRFamide/SADPNFLRFamide (PF1/PF2) to nitric oxide release. Indeed, all of the nematode FaRPs which have been tested on somatic muscle strips of A. suum have actions which are clearly physiologically distinguishable. Although we are a very long way from understanding how the actions of these peptides are co-ordinated, not only with those of each other but also with those of the classical transmitter molecules, to control nematode behaviour, their abundance coupled with their diversity of structure and function indicates a hitherto unidentified sophistication to nematode neuromuscular intergration.