Molecular phylogeny provides new insights on the taxonomy and composition of Lyperosomum Looss, 1899 (Digenea, Dicrocoeliidae) and related genera

Lyperosomum Looss, 1899 is one of the largest genera of the Dicrocoeliidae and is one of the best examples of the systematic complexity and taxonomic instability within this family. We present the molecular analyses based on novel sequences of nuclear and mitochondrial genes obtained from 56 isolates of adult flukes and larval stages of dicrocoeliids belonging to Lyperosomum, Skrjabinus, Zonorchis as well as previously available sequence data. According to obtained results we propose to return Zonorchis clathratus and Z. petiolatus into Lyperosomum, and to recognize L. alagesi as a synonym of L. petiolatum. Our study shows that L. petiolatum commonly occurs in Europe in corvids as well as in several species of migratory songbirds, e.g. Sylvia atricapilla. At the same time, the Turdidae appear to host a distinct species of Lyperosomum. The phylogenetic analysis has clearly demonstrated the paraphylepic nature of Lyperosomum and indicated the need of its thorough revision preferably using specimens from type hosts and type territories of nominal species. In addition, inclusion of numerous not yet sequenced dicrocoeliid genera into future phylogenetic studies is necessary to clarify the interrelationships of taxa within the family and stabilize its system

Distribution of large lungworms (Nematoda: Dictyocaulidae) in free-roaming populations of red deer Cervus elaphus (L.) with the description of Dictyocaulus skrjabini n. sp.

Lungworms of the genus Dictyocaulus are causative agents of parasitic bronchitis in domestic and wild ungulates. This study investigates the distribution, morphology and genetic diversity of D. cervi and a new lungworm species, Dictyocaulus skrjabini n. sp. infecting red deer Cervus elaphus, fallow deer Dama dama and moose Alces alces in Poland and Sweden. The study was conducted on 167 red deer from Poland and on the DNA of lungworms derived from 7 fallow deer, 4 red deer and 2 moose collected in Sweden. The prevalence of D. cervi and D. skrjabini n. sp. in dissected red deer in Poland was 31.1% and 7.2%, respectively. Moreover, D. skrjabini n. sp. was confirmed molecularly in 7 isolates of fallow deer lungworms and 1 isolate of red deer lungworms from Sweden. Dictyocaulus skrjabini n. sp. was established based on combination of their distinct molecular and morphological features; these included the length of cephalic vesicle, buccal capsule (BC), buccal capsule wall (BCW), distance from anterior extremity to the nerve ring, the width of head, oesophagus, cephalic vesicle, BC and BCW, as well as the dimensions of reproductive organs of male and female. Additionally, molecular analyses revealed 0.9% nucleotide sequence divergence for 1,605 bp SSU rDNA, and 16.5–17.3% nucleotide sequence divergence for 642 bp mitochondrial cytB between D. skrjabini n. sp. and D. cervi, respectively, and 18.7–19% between D. skrjabini n. sp. and D. eckerti, which translates into 18.2–18.7% amino acid sequence divergence between D. skrjabini n. sp. and both lungworms

Changes in acanthocephalan infection of the Antarctic fish Notothenia coriiceps in Admiralty Bay, King George Island, over 29 years

A comparison between the levels of infection with Acanthocephala of the fish Notothenia coriiceps in Admiralty Bay (South Shetland Islands, Antarctic) in 1978/79 and 2007/08 is presented. The same eight acanthocephalan species, three echinorhynchids ma− turing in fish, Aspersentis megarhynchus (dominant species), Metacanthocephalus john− stoni (subdominant species) and M. dalmori (common species), and five polymorphids ma− turing in mammals and birds, Corynosoma hamanni, C. pseudohamanni (both co−dominant species), C. arctocephali and C. bullosum (both common species), and C. shackletoni (rare species), were found. Echinorhynchids were more numerous in 2007/08 (mean abundance 46.54 versus 35.35 in 1978/79), whereas polymorphids more numerous in 1978/79 (mean abundance 74.35 versus 36.40 in 2007/08). The overall results therefore demonstrated that echinorhynchids were more numerous than polymorphids in 2007/08 and the reverse was true in 1978/79. This situation is dependent mainly upon the decreased infections with C. hamanni, C. pseudohamanni and C. bullosum, and to a lesser degree upon the increasing of infections with M. johnstoni. The decrease of the three Corynosoma spp. is possibly associ− ated with the decreasing of populations of final hosts, seals, on the shore of Admiralty Bay in the vicinity of Arctowski Station

Helminths - less known inhabitants of Antarctica

Polscy badacze prowadzą systematyczne badania parazytologiczne w Antarktyce od 1977 r., tj. od czasu, gdy powstała Stacja Naukowa PAN im. H. Arctowskiego na wyspie King George w archipelagu Szetlandów Południowych. Badaniami objęto przywry mono- i digeniczne, tasiemce, nicienie i kolcogłowy zebrane z antarktycznych ryb, ptaków i ssaków. W tym czasie opisano 55 nowych dla nauki gatunków pasożytniczych robaków: 27 gatunków przywr digenicznych z ryb kostnoszkieletowych; 16 gatunków tasiemców (w tym 12 gatunków z ryb, 3 gatunki z ptaków i jeden ze ssaków); 3 gatunki nicieni (2 z ryb kostnoszkieletowych i jeden z ptaków) oraz 9 gatunków kolcogłowów (2 z ryb kostnoszkieletowych, 3 z ptaków i 4 gatunki ze ssaków). Opisano także dwa gatunki przywr monogenicznych. U ryb kostnoszkieletowych, oprócz form dorosłych stwierdzono postacie larwalne robaków pasożytujących w stadium dorosłym u innych antarktycznych kręgowców.Polish parasitological studies in Antarctica have been conducted from 1977 when H. Arctowski Station of Polish Academy of Sciences was founded. All groups of helminths - Digenea, Cestoda, Nematoda and Acanthocephala were examined. In total, 55 new species of helminths were described. Among them there were: 27 species of Digenea in bony fishes, 16 species of Cestoda (12 in fishes, 3 in birds, one in mammals), 3 species of Nematoda (2 in bony fishes, one in birds) and 9 species of Acanthocephala (2 in bony fishes, 3 in birds and 4 in mammals). Two new species of Monogenea (external parasites) were found as well. Antarctic bony fishes are known as final, intermediate and paratenic hosts of parasites. They play an important role in life cycles of helminths parasitizing other Antarctic vertebrates

Host-dependent morphology of Isthmiophora melis (Schrank, 1788) Luhe, 1909 (Digenea, Echinostomatinae) – morphological variation vs. molecular stability

Abstract Background Echinostomes are cosmopolitan digenean parasites which infect many different warm-blooded hosts. Their classification is extremely confused; the host spectrum is wide, and morphological similarities often result in misidentification. During our long-term studies on the helminth fauna of rodents and carnivores we have collected 27 collar-spined echinostomes which differ in morphology to an extent that suggests the presence of more than one species. Here, we describe this material, and the extent of host-related variation in this parasite. Methods Specimens of Isthmiophora isolated from four host species (badger, American mink, hedgehog, striped field mouse) were subject to morphological and molecular examination; the data were statistically analysed. Results Our results show that genetically all the Isthmiophora specimens obtained from all the examined hosts are conspecific and represent I. melis. On the other hand, the individuals isolated from Apodemus agrarius are morphologically distinct and, based on this criterion alone, should be described as a new species. Conclusions The morphological traits of Isthmiophora melis are much variable and host-dependent; without molecular analysis they would suggest a necessity to describe a new species or even genus. Such a high level of intraspecific variability may be affected by the host’s longevity