Helminth fauna of Norops fuscoauratus (D’Orbigny, 1837) (Squamata: Dactyloidae) in the Atlantic Forest, northeastern Brazil

The composition of macro endoparasites associated with the lizard Norops fuscoauratus (Squamata) was analysed in two localities in the Atlantic Forest on the northeast of Brazil between December 2012 and July 2015. 74 specimens of N. fuscoauratus were examined and five species of helminths were reported, being: (a) for the population of Pernambuco: Cystacanth (Prevalence=37.5%), Physaloptera retusa Rudolphi, 1819 (Prevalence=4.16%), larva of flatworm (Prevalence=2.08%), Rhabdias sp. (Prevalence=2.08%) and Strongyluris oscari Travassos, 1923 (Prevalence=2.08%), and (b) of Alagoas: S. oscari (Prevalence=17.85%) and Rhabdias sp. (Prevalence=3.57%). The differences in the composition of endoparasites in the two populations are attributed to individualities of environments occupied by the lizards. The collection period does not influence the abundance of parasites, but when associated with sex, there was a positive correlation with the abundance of helminths, with more females than males being infected with parasites in the rainy season.

Loimologically significant pinniped helminths in Chukotka

The purpose of the research is study of pinniped helminth fauna in Chukotka, and the analysis of the fish of the main commercial families infected with pathogens of helminthozoonoses based on modern literature.Materials and methods. The helminths were collected in autumn of 2019 from pinnipeds caught in the Mechigmenskaya Guba of the Bering Sea in the Chukotka Autonomous Okrug by the method of partial helminthological dissection per Skryabin (gastrointestinal tract). Samples were examined from 6 walruses and 26 seals (13 spotted seals and 13 ringed seals). The helminths found were fixed in 70% alcohol. The helminth species were identified at the Department of Parasitology and Veterinary and Sanitary Examination of the MVA named after K. I. Skryabin using reference literature.Results and discussion. All pinnipeds were infected with nematodes of the family Anisakidae. Mature Pseudoterranova desipiens were found in the walrus (Infection Prevalence = 16.7% with Infection Intensity = 3 specimens/animal), mature Ps. desipiens, as well as Contracoecum osculatum and Anisakis simplex larvae (IP = 30.8% with II from 5 to 57 specimens) were found in the spotted seal, and Ps. desipiens larvae and mature Ps. desipiens were found in the ringed seal (IP = 15.4% with II from 1 to 4 specimens). Thus, only Ps. desipiens were represented by mature stages (females and males), and two other species of anisakids, C. osculatum and A. simplex, were found in the seals in the larval stage.

Helminth fauna of Scomberomorus sierra (Actinopterygii: Scombridae) in southeastern Gulf of California, Mexico

Summary From January to May 2015, a sample of 50 individuals of the Pacific sierra Scomberomorus sierra Jordan and Starks, 1895 captured off Mazatlán (southeastern Gulf of California, Mexico) were reviewed for helminths. A total of 6, 255 parasitic worms belonging to 11 species (9 in adult stage and 2 larvae) were obtained. Trematoda was the best represented group with 6 species of Didymozoidae Monticelli, 1888 and 1 of Bucephalidae Poche, 1907. In addition, 2 monogenean species and 2 of Nematoda were collected. In this study, the first molecular sequences for didymozoid species in Mexico were generated, and for Glomeritrema sp. at worldwide level. The most prevalent species were Didymocylindrus sp. (92 %) and Didymocystis scomberomori (MacCallum & MacCallum, 1916) (88 %), whereas the monogenean Thoracocotyle crocea MacCallum, 1913 reached the highest value of mean intensity (75.2). The coincidence between the helminthological composition established in our study and that reported for the same scombrid in 4 localities from the Mexican South Pacific (sharing 10 species) suggests that this group of species persistently parasitize S. sierra throughout its distribution along the Mexican Pacific coast; furthermore, due to the richness of didymozoids and the affinity of Thoracocotylidae species for S. sierra, both groups can be considered typical parasites of this fi sh.

New findings of trematodes of the superfamily Echinostomatoidea Looss, 1899 in birds from the Czech Republic

Summary In the Czech Republic, 12 freshly dead birds belonging to four species were examined helminthologically during a period of 2015 – 2019. They were six Caspian gulls Larus cachinnans (Lariformes), three goosanders Mergus merganser (Anseriformes), two common snipes Gallinago gallinago, and one common curlew Numenius arquata (Charadriiformes). Concerning trematodes, five echinostomatoids species were found, namely Aporchis massiliensis (obtained from one positive Caspian gull), Echinoparyphium macrovitellatum (one positive from six Caspian gulls), Echinostoma academica (one positive common curlew), Echinostoma stantschinskii (one positive from two common snipes), and Echinochasmus mergi (one positive from three goosanders). All the five echinostomatoids species represent the first records for the helminth fauna of the Czech Republic; the fl ukes A. massiliensis and E. macrovitellatum are recorded for the first time in the Central Europe or the Europe at all, respectively.

An overview of helminths of the European fire-bellied toad Bombina bombina (Amphi-bia, Anura) in the Volga River Basin

The helminthofauna of Bombina bombina (Linnaeus, 1761) has been studied to an unequal degree in different parts of the habitat. Thus, it has been studied in more detail in the west of its range (in the countries of central and eastern Europe) and in less detail in the center (in Belarus and Ukraine). There were few data on helminths of this host in the east of its range (in Russia). For the first time, an inventory of the helminthofauna in B. bombina was carried out for populations in the Volga River Basin. The results of our own research are presented and supplemented with information from other authors. We summarized scattered data on helminths from 390 specimens of amphibians collected over more than 40 years in the territory of five regions: Kaluga and Samara regions, the Republics of Mordovia, Tatarstan and Bashkortostan. The helminthofauna includes 21 species from three classes: Trematoda (15), Chromadorea (5) and Clitellata (1). For each species, we give the systematic position, localization, places of detection, geographical distribution and characteristics of the life cycle. The leech Helobdella stagnalis (Linnaeus, 1758) was first recorded in the European fire-bellied toad in Europe. Four species of trematodes are new to this amphibian species in Russia: Haematoloechus abbreviatus (Bychowsky, 1932), Paralepoderma cloacicola (Luhe, 1909), larvae, Tylodelphys excavata (Rudolphi, 1803), larvae and Astiotrema monticelli (Stossich, 1904), larvae. Another species of trematode – Strigea strigis (Schrank, 1788), larvae – was first recorded in this host within the boundaries of the Volga Basin. A specific parasite is the trematode Haematoloechus abbreviatus (Bychowsky, 1932). The number and composition of the species of helminths of the European fire-bellied toad vary in different regions; the structure of the helminth fauna is generally stable and includes three groups of species: adult and larval stages of trematodes, adult nematodes-geohelminths. The results of the study create a database for further population studies and contribute to the development of ideas about the distribution and formation of the amphibian helminth fauna in Europe, Russia and the Volga Basin.

Helminths in Myomorph Rodents (Rodentia, Myomorpha) from the National Park “Smolny” and Its Surroundings (European Russia)

The National Park “Smolny” is a large forest area, located in the center of European Russia. The helminth fauna of myomorph rodents was studied for the first time within the National Park in 2018–2020. Rodents were examined by the method of complete helminthological dissection. A total of 30 species of parasites were recorded in 11 rodent species: 6 trematodes, 11 cestodes and 13 nematodes. The trematode Plagiorchis maculosus (Rudolphi, 1802) was found in Clethrionomys glareolus (Schreber, 1780) from the Russian fauna for the first time. Clethrionomys glareolus and Microtus arvalis (Pallas, 1779) are new hosts for P. maculosus and metacestode Versteria mustelae (Gmelin, 1790), respectively. The most widespread and eurybiont rodent species have the most diverse and rich helminth fauna, such as C/glareolus (14 species), Apodemus agrarius (Pallas, 1771) (12) and Sylvaemus uralensis (Pallas, 1811) (10). The helminth fauna is less diverse in Sylvaemus flavicollis (Melchior, 1834), M. arvalis (7 species each), Microtus agrestis (Linnaeus, 1761) (5), Microtus subterraneus (de Selys-Longchamps, 1836) (3), Sicista betulina (Pallas, 1779) (2) and Arvicola amphibius (Linnaeus, 1758) (1). Сomparative analysis the helminth fauna of small rodents from the National Park “Smolny” with micromammals from other regions of European Russia revealed that the high similarity with other areas reaches the helminth fauna of M. subterraneus, S. flavicollis, S. uralensis, S. betulina, A. amphibius and M. agrestis.

Helminth fauna of spawning pacific herring Clupea pallasii from the Taui population (Tauiskaya Guba Bay, Okhotsk Sea)

Parasites of spawning pacific herring (Clupea pallasii Valenciennes in Cuvier et Valenciennes, 1947) from the Taui population are explored on the samples caught on two spawning grounds located in the Ola lagoon and Amakhton Bay (Tauiskaya Guba Bay, Okhotsk Sea), and 17 species of helminthes are found, including 6 trematodes, 5 cestodes, 4 nematodes, and 2 acanthocephalans. Some differences in species composition of helminthes and their infestation were found between these estuarine and marine spawning grounds. In the Ola lagoon, 16 species of helminthes were identified, including 5 species of cestodes, whereas only 13 species of helminthes, including 3 species of cestodes, were found in the Amakhton Bay. The Taui population of herring is distinguished from the Okhotsk and Gizhiga-Kamchatka populations by presence of nematodes Hysterothylacium aduncum, l, and Ascorophis pacificus with rather high rates of invasion (occurence = 52.9 %; mean abundance = 4.16) and trematode Bucephaloides spp. On the other hand, the herring from the Taui population has common dangerous parasites with other populations in the Okhotsk Sea, as trematode Brachyphallus crenatus and nematode Anisakis spp. (larvae), with high degree of infestation.

Morphological and molecular identification of nematodes in the tayra Eira barbara from Campeche, Mexico

Summary The tayra Eira barbara is a Neotropical mustelid considered as an endangered species by Mexican environmental authorities. Despite the considerable information available on the biology and ecology of E. barbara, little is known about its helminth fauna. Here, we provided new records of nematodes from a road-killed tayra in Calakmul, Campeche, Mexico. The species identification of nematodes was based on morphological studies and molecular analysis of fragments of the 28S gene. The tayra specimen was infected by three nematodes: Molineus sp., Physalopterinae gen. sp. and Angiostrongylus vasosum. To our knowledge, this study is the first to report the natural infection of E. barbara with Molineus sp. and Physalopterinae gen. sp. Our study provides the first nucleotide sequences of nematodes parasitizing E. barbara providing a starting point against which future studies may be compared.