The biodiversity and composition of endoparasites in fish obtained from the Antarctic and subantarctic zones are compared in this study. Several fish were collected in the summer from Antarctica (King George Island) and the Southern Pacific coast (Strait of Magellan and Almirante Montt Gulf). This database was complemented with published information on fish endoparasite communities from both zones, with specimens of fish sample size n ≥ 15. Thus, 31 fish species were analysed in this study, which altogether had 79 parasite species. Diversity indices were calculated for the parasite community of each fish species. Then they were compared between the Antarctic and subantarctic zones. Parasite species composition and host specificity (as the number of fish species used by a parasite species) were also analysed and compared between zones. The diversity indices and the abundance of parasites were significantly higher in the Antarctic than the subantarctic fish. Few parasite species (7.6%) were shared between fish from both zones, showing significant differences in parasite composition. Antarctic parasites were less host-specific than subantarctic parasites, which allowed the coexistence of several parasite species in the fish. The high parasite abundance in Antarctic fish could trigger sympatric speciation in certain parasitic lineages or the exploitation of new resources, resulting in more parasite species than those in subantarctic environments. The high abundance of Antarctic parasites implies different methods and rates of transmission than those of subantarctic parasites. In addition, more alternative fish hosts were used by the Antarctic than subantarctic parasites. This altogether indicates that host–parasite interaction dynamics significantly differ between the Antarctic and subantarctic systems.

The association between eosinophil count and cholelithiasis among people with Clonorchis sinensis infection is still uncertain. We conducted a cross-sectional study to investigate the associations among Clonorchis sinensis infection, eosinophil count and cholelithiasis. The study included 4628 participants from January to December 2018. The levels of eosinophil count were divided into four groups according to the quartiles of eosinophil count. Spearman's rank correlation was performed to assess the association between eosinophil counts and Clonorchis sinensis egg counts. Multiple regression analysis was performed to evaluate the relationships among C. sinensis infection, eosinophil count and cholelithiasis after adjusting for three models. The prevalence of C. sinensis infection was 38.72% (1792/4628), and the prevalence of cholelithiasis was 6.03% (279/4628). The infection rate of C. sinensis was higher in the cholelithiasis group than in the non-cholelithiasis group (63.08% vs. 37.16%, P < 0.001). Significant differences were found among various eosinophil count quartiles for C. sinensis infection, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GT), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA) and non-alcoholic fatty liver disease (NAFLD) (all P < 0.001). A significant positive correlation was found between eosinophil count and log-transformed C. sinensis egg count (r = 0.9477, P < 0.001). Multiple logistic regression analysis revealed that light and moderate intensities of C. sinensis infection were associated with cholelithiasis (P < 0.01 and P < 0.001, respectively), and C. sinensis infection with eosinophil count ranging from 0.05 to 0.5 × 109/l were associated with cholelithiasis (P < 0.05). In conclusion, our findings suggest that the light and moderate infections of C. sinensis with eosinophil count ranging from 0.05 to 0.5 × 109/l may be associated with a higher risk of cholelithiasis.

More than 65 species of the genus Microcotyle Van Beneden & Hesse, 1863, have been described to date, most of them infecting Perciformes. Among the scorpaenoids (Perciformes, formerly Scorpaeniformes) the species of the genus Microcotyle parasitize sebastids and scorpaenids worldwide. In this study, we provide new morphological and molecular data for Microcotyle spp. in sebastids and scorpaenids from the Western Mediterranean and north-east Atlantic. Specimens of Helicolenus dactylopterus (Delaroche, 1809) (n = 107) and Scorpaena spp. (n = 107) were examined and their microcotylid specimens morphologically and molecularly characterized. Microcotyle merche n. sp. ex H. dactylopterus and specimens of Microcotyle algeriensis Ayadi, Gey, Justine & Tazerouti, 2016 from a new host and locality (Scorpaena scrofa from the north-east Atlantic) are herein described. Both species are phylogenetically close, but their morphology is markedly different mostly because the anterior lobe of the haptor present in other Microcotyle species is almost absent in M. algeriensis. Findings of M. merche n. sp. in the Mediterranean also excludes the presence of Microcotyle sebastis in this sea, encouraging the review of the exceptionally large host range and geographical distribution of this species.

Amphibians are a widespread Chordata taxon and are important for maintaining the balance of both terrestrial and aquatic ecosystems. Brazil has a rich amphibian fauna; however, little is known about the role of their ecology and phylogenetic relationships during the assembly processes of associated endoparasite communities. Herein, we describe an endoparasite community in an anuran assemblage in the Caatinga, a unique biome of dry forests in north-eastern Brazil. We studied endoparasite diversity, as well as the effects of body length, body mass, body volume and sex on parasite abundance. We also investigated the influence of ecological and historical factors and anuran microhabitat use on endoparasite composition. We analysed individuals from 13 anuran species distributed across five families: Odontophrynidae (Proceratophrys cristiceps); Leptodactylidae (Leptodactylus fuscus, Leptodactylus vastus, Leptodactylus macrosternum, Leptodactylus troglodytes and Physalaemus cuvieri); Hylidae (Pithecopus gonzagai, Scinax x-signatus, Boana raniceps and Dendropsophus nanus); Bufonidae (Rhinella diptycha and Rhinella granulosa); and Microhylidae (Dermatonotus muelleri). We found nine species of endoparasites, including seven nematodes (Aplectana membranosa, Cosmocerca sp., Oswaldocruzia mazzai, Raillietnema spectans, Rhabdias fuelleborni, Schrankiana sp. and Physaloptera sp.), one species of Trematoda (Glypthelmins pseudium) and one non-identified cestode. There was no significant relationship between endoparasite abundance and host body length, body mass, body volume and sex. A phylogenetic principal component analysis showed that ecological factors had a greater influence on endoparasite assemblage than historical factors. Similarly, our results showed that ecological factors had a greater influence on anuran microhabitat use compared to historical factors, which contributed to the generalist characteristics presented by most of the sampled endoparasite species.

The growth of Philophthalmus gralli from jordan was studied experimentally by inoculating 10 excysted metacercariae around the right eye of 47 day-old chicks. The growth rate was slow in the first three days during which flukes did not exceed 0·30 mm long. Then growth become rapid reaching 2·70 mm long on day 24. This was followed by a low growth rate during which the flukes grew from 2·70 mm to 2·90 mm on day 40. The flukes started to appear in the left eye on the day 12 post-inoculation of metacercariae in the development of P.gralli from Jordan was the same as of other species of Philophthalmus. However, a sixth stage, post-maturation stage, is suggested in addition to the 5 developmental stages of Philophthalmus. The ratio of the transverse diameter of the ovary to that of testes in the post-maturation stage was 1:1·1–1:1·2.

1. Brevicaecum niloticum McClelland, 1957 is redescribed and differences from the original description are pointed out.

2. The characters of the genus Brevicaecum are amended.

3. A new subfamily Brevicaecinae is erected for the genus Brevicaecum.

Spirocamallanus papillicaudatus n. sp. from Pomadactylus oligodon, S. partitus n.sp. from Pomacentrus partitus, S. spinicaudatus n. sp. from Holocentrus marinus and S. garnotus n.sp. from Halichoeres garnoti are described from marine fishes of Puerto Rico which is recorded as a new geographical locality for the genus Spirocamallanus. S. plumierus n.sp. is described from a marine fish, Diapterus plumieri, of the Golfo de Cariaco, Cumana, Venezuela. These new species are distinguished from the known species mainly on the basis of number and arrangement of caudal papillae and different body measurements.

The effect of flubendazole orally administered at 10 mg/kg/day for 5 consecutive days (the 11th, 20th or 40th post-infection) on the number of first-stage larvae (L1) of Angiostrongylus cantonensis released in the faeces of rats each infected with 40 third-stage larvae was determined. Faecal examination for 5 months, the period from medication to dissection of rats, showed that L1 release ceased in all the rats of medicated groups by about 1 week after the termination of dosing and resumed 1–2 months later in 86% of the rats which were dissected at the end of experiments with the recovery of adult worms of both sexes. Throughout the period of 5 months, about 2–4×104 L1/gram of fresh faeces was recorded in non-medicated control groups. There was a 38–79% reduction in adult worms at the dissection. Microscopic examination of the uteri of the remaining adult worms and lung tissues of rats confirmed no normal egg production in the adult worms from rats of medicated groups, except the rats with the resumption of faecal L1 release.

Experiments involving cattle, horses, pigs and fowls are presented which are considered to give evidence that thiabendazole is highly active against the Strongyle parasites but not so active against the ascarid parasites of the digestive tract of these animals. The strongyles of cattle can be controlled with a dose of 75–100 mg./kg. and those of horses with as little as 25 mg./kg. In pigs 100 mg./kg. was very active against Oesophagostomum dentatum but this dose level was of poor efficiency against Ascaris lumbricoides. A high dose of 500 mg./kg. appeared to be necessary to control Ascaridia galli in the fowl.

Different types of proteoglycans (PGs) from adult worms of Schistosoma haematobium, were sequentially extracted using chaotropic agents under associative conditions (0.5 M GnCl), dissociative conditions (4 M GnCl) and detergents (Triton X-100 and SDS). The extracts were designated Fl, F2, F3 and F4, respectively. The highest amount of uronic acid and carbohydrate was detected in the associative extract (Fl) while the highest amount of protein was detected in the SDS extract (F4). Agarose polyacrylamide gel electrophoresis (A-PAGE) indicated the presence of a different PG in each extract with different electrophoretic mobilities. Agarose gel electrophoresis of glycosaminoglycan (GAG) separated from GnCl, associative and dissociative extracts, and the residue suggested the presence of dermatan sulphate in the two extracts and the residue, in addition to a GAG-like material found in the associative extract only. This glycosaminoglycan showed resistance to digestion with all mucopolysaccharidases and nitrous acid treatment. Gel filtration chromatography of associative extract on Sepharose CL-6B indicated the presence of three main uronic acid peaks (P1, P2 and P3). Chondroitin sulphate was the main GAG that could be detected in peak one (P1). Peak two (P2) contains carbohydrate and uronic acid but has no protein or absorbance at 280 nm. P2 has two types of GAGs: dermatan sulphate and a GAG-like material. The role of this PG in helping the adult schistosomes in evading immobilization by the host blood clotting cascade is discussed. Antibodies to peak one and peak two were detected in hamster sera infected with S. haematobium and S. mansoni using the ELISA test. The specificity of peak two was found to be evident in its low cross-reactivity (18.9%) when confronted with S. mansoni infected sera.

In lambs under six months of age infected with 10,000 H. contortus third stage larvae two effects were observed as a result of the treatment regimes administered: 1. Reduced adult worm burdens, indicating protection, occurred in the animals treated with combined transfer factor, adult parasitic antigen and precipitated immunoglobulin whereas other treatment combinations produced no significant effects. 2. Defined patterns of histological changes in the abomasa were associated with each treatment and cumulative effects were recognized when combined treatments were given. The responses induced by transfer factor treatment suggest the development of a hypersensitivity reaction outwith the changes seen in primary H. contortus challenge.

The development of the larvae of Breinlia booliati a new filarial parasite of the forest rat Rattus sabanus in Aedes togoi is described. Complete larval development to the infective stage occurred in the fat body of the head, the thorax, and especially the abdomen of the mosquito. The first moult occurs at 7 days and the second at 11 days. As the larvae grow very rapidly in length, the parts of the parasitized fat body cells which harbour the developing larvae take on a syncytial appearance. By the 11th day, the larvae move out from the fat body into the haemocoele. The infective forms are found in the proboscis at the 12th day after the infecting blood meal.

The gross morphology and histological and cytological architecture of the lymph system of Orthocoelium scoliocoelium were studied. Each main vessel, near the intestinal bifurcation forms a spindle-shaped sinus. Lymphocytes, similar to the primitive blood cells, have been seen to form aggregates in certain regions of the lymph system. In addition, detailed histochemical observations were made on the localization and distribution pattern of various phosphatases, esterases and dehydrogenases. It is suggested that the lymph system, in addition to the functions already known, may also selectively reabsorb certain important outgoing higher fatty acids from the excretory system. Furthermore, the lymphocytes may also be involved in the defence mechanism of the worm. The nature and function of fine granules in the lymph remain speculative.

The in vitro cultivation technique of Echinococcus granulosus protoscoleces usually states the necessity of a biphasic medium with a solid protein substrate for strobilar development to take place; otherwise, in a monophasic medium, protoscoleces follow a vesicular development. However, in some monocphasic cultures, the development of several strobilate individuals (in different quantities and stages of development, depending on the culture) were observed. The only known diference form cultures made previously and snice, where the development was vesicular, was the batch of foetal calf serum used in the constitution of the liquid medium, and this is presumed to be the cause of this unexpected strobilar development.

Ostertagia trifurcata was first described by Ransom (1907) from sheep and goats in United States. It has since been reported from various other countries and appears to have a world wide distribution. This species is recorded from India for the first time, in the present paper.

In Great Britain, O. trifurcata was first recorded by Boulenger (1914) but his record seems to have been overlooked by Travassos (1987). It has also been reported from sheep and goats in different parts of Great Britain by Morgan (1925), Jones (1926) and Oldham and Morgan (1984). All these workers report the occurrence of this species in association with Ostertagia circumcincta. Elsewhere, the association of O. circumcincta and O. trifurcata has been reported by Tetley (1984) from New Zealand, Ransom (1911) from United States, Gebauer (1982) from Germany and Saquenet (1946) from Algeria. In my collection from India (Kangra District), O. trifurcata,is present in small numbers together with O. circumcincta which is always the predominant species. In a collection of helminths from Cyprus in the London School of Hygiene and Tropical Medicine a few O. trifurcata were found in association with a large number of O. circumcincta.

When carrying out hatching experiments it would frequently be an advantage to have a quantitative measure of the activity of the root excretion used and search was accordingly made for a stable substance which could be made to a solution of constant known strength and which could be used as the basis for the comparison of the activity of different samples of root excretion. Hurst (Hurst 1937) records that tyrosine in dilute solution, lysine in the form of its picrate as well as picric acid at ·01% concentration caused active hatching to occur and experiments using the above single cyst technique were conducted to investigate these claims. The results with the former two substances were disappointing but dilute picric acid solutions were found to be very active. Since it is hoped to publish a further paper in which the effects of picric acid will be considered quantitatively and in detail it is not proposed to publish data in this article but concentration experiments showed that picric acid is most active at ·02—·01% concentrations, the solutions being made up in distilled water. Several experiments were conducted in which picric acid in these concentrations was compared with water and with root excretion; in all cases picric acid hatches were significantly greater than water hatches although picric acid was not generally as active as root excretion taken from vigorously growing plants.

Eleven cestode specimens were collected from the intestine of Prinops plumata which was brought into the Department for examination. They appear to be a new species for which the name Anomotaenia prinopsia is given.

Gemmaecaputia australis sp. nov. and Vallisiopsis australis sp. nov. are described from the gills of the striped barracuda, Sphyraena obtusata Cuvier & Valenciennes. G. australis differs from all other species in the genus by the presence of a bifurcated copulation canal and small spines on the penis. V. australis differs from the other species in the genus because of the presence of an unsclerotised penis and seven opisthaptoral clamps. The method of adhesion of V. australis is described and an account given of its adhesion on the host gills.

(1) Rats and mice are specific hosts to N. brasiliensis.

(2) The life span of the parasite may reach up to 100 days in the rat but is much shorter in other experimental animals.

(3) Chickens do not become infected with this parasite.

(4) It was found that the route of migration of this parasite inside the body to the lungs was via the lymph system and not via the blood in all experimental animals.

(5) The larvae, after application to the skin, reach the lymph glands draining the site of infection, not before 12 hours ; and they reach the lungs at 18 hours after exposure to infection.

Early third-stage larvae of Gnathostoma spinigerum were cultured in RPMI-1640 supplemented with 25mM NaHCO3,100 units/ml penicillin G, 100 μg/ml of streptomycin, 5 μg/ml of amphotericin B and 10% foetal calf serum at 37°C under 5% CO2 in air for 60 days. After 3 days of cultivation, the larvae moulted. Body sizes increased from 0.49 ± 0.09 × 0.07 ± 0.01 mm in length and width to 4.08 ± 0.48 × 0.32 ± 0.04 mm after 60 days of cultivation. The maximum body length and width of these larvae were 4.94 mm and 0.35 mm, respectively. The survival rate (67.5 %) of the worms was observed at the end of cultivation. The addition of foetal calf serum was found to be essential for growth and development.