Experimental infections of Lymnaea truncatula with Fasciola hepatica were performed to study the consequences of the presence of predators (sciomyzid larvae or zonitid snails) on the characteristics of larval F. hepatica development in surviving snails. Controls consisted of infected snails that were not subjected to predators. Compared to controls, the survival rate at day 30 post-exposure, the duration of cercarial shedding, and the number of cercariae shed by surviving snails were significantly lower when predators were present in snail breeding boxes, whatever the type of predator used. In contrast, the prevalences of Fasciola infections in snails, and the length of time between exposure and the onset of cercarial shedding showed no significant variation. The progressive development of a stress reaction in surviving snails against predators during the first 30 days of experimental exposure to F. hepatica would influence snail survival during the cercarial shedding period and, consequently, the number of cercariae shed by the snails.

By means of scanning electron microscopy, aspects of the attachment of Moniliformis dubius (Acanthocephala) to the intestinal wall of the rat are described together with various changes in the structure and form of the mucosa. Attachment of the parasite results in the formation of a distinct pit around the everted proboscis and a crater around the neck. Contact between the anterior region of the trunk of the worm and the intestine of the host appears to lead to villous fusion so that characteristic grooves are formed in the mucosal tissue. Evidence was also obtained to suggest that host goblet cells may become exhausted during the course of an infection with Moniliformis.

Two hundred one-day-old male white leghorn chikens (Gallus domesticus) divided into 4 groups were inoculated with a single dose of 500, 1000, 2000 or 4000 filariform larvae of Ancylostoma caninum. Larval recoveries were made from different tissues at intervals from 4 hours to 72 hours after infection. Larval migration in the heart took place within 4 hours in all the groups except group A with 500 larvae and in thoracic muscle at 8 hours. Larvae also migrated into liver, lungs and neck muscle within 12 hours and into leg muscle at 18 hours. No larvae were recovered from the muscles after 72 hours of infection. Larvae did not migrate into kidney, spleen and central nervous system throughout the experimental period.

Lobatostoma hanumanthai n.sp. is described from the intestine of the carangid Trachinotus blochi from Bay of Bengal. It anatomical characters are compared with previously described species in the genus. This is the first record of an aspidogastrean from marine fishes of the Indian region.

Aim of the study was to get in-depth information on Aelurostrongylus abstrusus first-stage larvae (L1s) survival at different temperatures and to assess the capability of these larvae to develop into the third infective stage (L3s). Faeces of a naturally infected cat were split into two aliquots: the first was divided in subsamples assigned to four groups (F1–F4); from the second aliquot, L1s were extracted by Baermann technique, suspended in water and divided into four groups (W1–W4). Groups were stored at different temperatures (F1/W1 −20 ± 1°C; F2/W2 +4 ± 1°C; F3/W3 +14 ± 1°C; and F4/W4 +28 ± 1°C) and L1s vitality assessed every seven days. The capability of L1s stored in water to develop into L3s in snails was evaluated at the beginning and every 21 days. The L1s of W2 and F2 groups remained viable for a longer period (231 and 56 days, respectively) compared to those of other groups. The capability of L1s to moult into L3s in snails showed a decreasing trend; the group W2's L1s maintained the capability to moult into L3s for the longest time (day 189) compared to the other groups. The time of survival of A. abstrusus L1s is influenced by temperature. However, the species seems to be more resistant to temperature variations than other feline lungworms, and this may explain its wider distribution across Europe.

The localization and distribution of cholinergic, serotoninergic (5-HT, serotonin) and peptidergic components of the nervous system of adult Cephalochlamys namaquensis (Cestoda: Pseudophyllidea) have been determined using enzyme histochemical and immunocytochemical techniques interfaced with light and confocal scanning laser microscopy. All three classes of neuroactive substance showed a similar pattern of staining, occurring extensively throughout the central and peripheral nervous systems of the parasite. There were some minor regional differences in staining, suggesting specific roles for certain classes of neurone, and nerve cell bodies were most evident following immunostaining for serotonin. The general overlap in the distribution of staining may be indicative of some co-localization of neurotransmitter and/or neuromodulatory substances.

Deaths due to infection with Streptocara crassicauda (Creplin, 1829) occurred in three ornamental flocks of water fowl in Hampshire. On two occasions larvae of the worm were found in Gammarus sp. in the running water to which the flocks had access. Lesions were almost entirely in the oesophagus and pharynx, and death was usually due to necrosis, and consequent impaction, of the oesophagus It appears that the worm is capable of establishing itself in southern England.

The parasitological and histopathological effects of immunosuppression in guinea-pigs (Cavia porcellus) experimentally infected with Schistosoma haematobium were studied. A total of 16 guinea-pigs were divided into four groups (four per group): non-immunosuppressed, non-infected group (NN); immunosuppressed, non-infected group (IN); immunosuppressed, infected group (II); non-immunosuppressed, infected group (NI). The IN and II groups were immunosuppressed with 5 mg/kg prednisolone while the II and NI animals were infected with 200–300 S. haematobium cercariae. Excretion of eggs in urine/faeces, worm burden and histopathology of some vital organs of the guinea-pigs were studied. Eggs of S. haematobium were observed in the urine of the NI and II groups from 9 weeks post-infection and in faeces from 10 and 13 weeks post-infection for the NI and II groups, respectively. However, II animals excreted more viable eggs in urine and faeces than those of the NI group. Worm recovery at 14 weeks post-infection showed that NI and II guinea-pigs had more female worms than male worms and a greater proportion of worm recovery for NI animals was of immature worms. Significant differences (P < 0.05) existed between female, male and immature worm burden of the two groups but not in their total worm burden (P>0.05). Histological changes, which were notably reactions to adult S. haematobium worms, were observed in the organs of the NI and II groups but these changes were seen more in the organs of the immunosuppressed, infected (II) than in the non-immunosuppressed, infected (NI) guinea-pigs. The results suggest that immunosuppression before infection increased worm survival and had a moderate effect on liver and bladder histology of S. haematobium infected guinea-pigs.

1. Six species of nematodes were recovered from Hertfordshire birds.

2. Porrocaecum ensicaudatum and Syngamus trachea are discussed, S. skrjabini El'perin, 1938 being considered a synonym of the latter.

3. The survey produced one new host record and two new records for this country.

An in vitro study was carried out to determine efficacy of Indian isolates of the nematode-trapping fungi Arthrobotrys musiformis and Duddingtonia flagrans to capture infective larvae of Haemonchus contortus. These fungi have previously been screened and selected for their survival in the gastrointestinal tract of sheep without losing growth and nematode capturing potential. Following the feeding of chlamydospores of these two fungi alone or in combination in sheep experimentally infected with Haemonchus contortus, coprocultures were set up to enumerate the infective third stage larvae. The number of larvae captured from faeces of fungus-fed sheep was significantly higher compared with fungus-unfed controls irrespective of the fungus used. The fungal combination produced no antagonistic effect and thus can be used as efficiently as the fungi alone in the biological control of animal parasitic nematodes.

In the paper “Acuariid, capillariid and hymenolcpidid parasites of the dasyurid marsupial Antechimis stuartii Macleay, 1841, from southeastern Australia” by I. Beveridge and I. K. Barker, which appeared in part no. 4 (December) of volume 49, 1975, the descriptions of spiruroid larvae and of Capillaria rickardi sp.n. on page 223 should have appeared before that of Hymenolepis aklei sp.n. on page 220.

From morphological, biological and experimental data it is concluded that the attempt to merge Necator suillus in the synonymy of N. americanus is utterly unjustified.

Rana temporaria tadpoles which had been naturally infected by larvae of Polystoma integerrimum were kept in the laboratory under conditions precluding the continuous re-infection which occurs in nature. One tadpole was seen to have two larvae attached to the skin of the ventral surface of the body, which were moving towards the posterior end. The tadpole measured 7·9 mm. in body length and 20·8 mm. in total length, and its stage of development corresponded to stage 5 in the table of development and metamorphosis compiled by Rugh (1951); it was collected in mid-May and had been kept for twelve days under laboratory conditions. The tadpole was fixed and dissected: the bladder had not developed, and the gills showed no indication of atrophy; the alimentary canal was long and heavily coiled, and filled with food. In addition to the two larvae observed on the skin, one larva was found in the branchial chamber, two were in the cloacal tube, seven occupied the cloacal chamber and two had travelled up the right ureter to the kidney; the alimentary canal was free of larvae. All fourteen larvae were gyrodactyloids.

Twelve batches of the mollusc Cernuella (Cernuella) virgata (Mollusca: Helicidae) were deposited monthly directly on faeces containing first-stage larvae of Neostrongylus linearis, so that they were naturally infected. Every two weeks the molluscs were examined to study the larval development of N. linearis. No correlation was found between the number of first-stage larvae of N. linearis on the faeces and the number of total larvae and third-stage larvae which developed in the snails. However, a negative correlation was found between temperature and the days needed to reach the different larval stages. Thus, the molluscs harboured third-stage larvae from mid-spring to mid-autumn, the period of time which carries the greatest risk of infection for the definitive hosts.

The effects of infection with plerocercoids of Spirometra mansonoides on tissue glycogen deposition of rats was determined. Hypophysectomized rats infected for two days had higher liver glycogen concentrations than controls and this effect was greatest after one week. Elevated liver glycogen associated with plerocercoid infection was observed in fed animals both at the beginning and at the end of the light period as well as after an overnight fast. Glycogen phosphorylase (1,4αD glucan: orthophosphate α glucosyltransferase EC 2.4.1.1.) was inhibited but glucose-6-phosphatase (EC 3.1.3.9) was unaffected in the livers of infected hypophysectomized rats. While this effect is similar to actions of both growth hormone and insulin, plerocercoid infection had no influence on glycogen of cardiac or skeletal muscle at any time. Plerocercoid infection had no effect on the glycogen concentration of any tissue of intact rats.

The isoenzymes of acid and alkaline phosphatases and their histochemical localization were studied by polyacrylamide disc gel electrophoresis in four species of trematodes: Gigantocotyle explanatum from the liver and Gastrothylax crumenifer from the rumen of water buffalo (Bubalus bubalis) and Echinostoma malayanum and Fasciolopsis buski from the small intestine of the pig (Sus scrofa). Both acid and alkaline phosphatases were present in the tegument, gastrodermis, suckers, testes, ovary, eggs, vitellaria and uterus but alkaline phosphatase activity was demonstrated only in the parenchyma and excretory ducts. Polyacrylamide gel electrophoresis revealed two to four isoenzymes for both acid and alkaline phosphatase.

We have investigated the capacity of irradiated larvae of each of six different isolates of Schistosoma mansoni to protect mice against challenge infections from the homologous or a different isolate. The isolates differed in respect of their geographic origins, and in the lengths of time they had been maintained in the laboratory. All isolates induced significant protection against unattenuated challenge infections, and neither the degree of geographic disimilarity between vaccinating and challenge parasites, nor the numbers of laboratory cycles, appeared to influence the degree of protection induced by irradiation-attenuated larvae.

The callitrichid primates, Callithrix jacchus jacchus (the marmoset) and Saguinus labiatus (the tamarin) were inoculated with infective larvae of Brugia malayi and B. pahangi. Microfilaraemia at low levels developed in 3 out of 4 C. j. jacchus infected with B. malayi and living or dead adult worms found in all 4. Only one of 4 C. j. jacchus became microfilaraemic (mf + ve) when given B. pahangi and adults were found in two. Of 4 S. labiatus given B. pahangi one became very lightly mf + ve and adults were found in 3. It is concluded that these animals are not suitable hosts for chemotherapeutic experiments.

Two species of nematodes were recovered from the Meller's chamaeleon from Nyasaland, which died at the London Zoo. They comprised ten females and eight males of Foleyella candezi from the axilla and peritoneal cavity, and two adult females of Abbreviata sp. from the gut. Specific determination was not possible for the latter species, owing to the paucity of the material.

The females are thread-like and very slightly flattened dorso-ventrally. They have an average length of 94.8 mm. and range from 73 to 124 mm. The width is more or less uniform, average 0.5 mm. but becomes narrow at 1 mm. from the tip of the tail. The anterior end is bluntly rounded and in some specimens has a slightly bulbous appearance when observed from the lateral aspect. This is due to a slight narrowing at the junction of the oesophagus and intestine.

The tail is more attenuated than the anterior end and it is slightly curved ventrad and marked by a shallow groove running ventrally from the anus to the tip where it is flanked by two minute papillae-like structures.

The shallow stoma is somewhat oval in shape and surrounded by ten minute papillae, six of which form an inner circle and four an outer circle. The mid-dorsal and mid-ventral papillae of the inner circle are more conspicuous than the others.