Cestode of the family Hymenolepididae from ducks of Chukotka: Microsomacanthus parasobolevi sp. n.--a widely distributed parasite of eider ducks

A new species of the genus Microsomacanthus Lopez-Neyra, 1942 is described. The material was collected from eider ducks (Somateria mollissima, S. fischeri, and S. spectabilis) in the Chaunskaya lowland (North-Western Chukotka). Microsomacanthus parasobolevi sp. n. differs from the closest species of this genus (M. polystictae Regel, 1988, M. sobolevi Spassky et Jurpalova, 1964; M. strictophalius Tolkatchieva, 1966) by the structure and size of the copulatory organ. Wide distribution of the new species was detected based on the cestodes collections from eider ducks of the Eastern Chukotka, Lena River mouth (in the museum of the Institute of the Parasitology RAS) and Iceland (Karl Skirnisson's cestode collection of the common eider). Furthermore, this species was reported once of the common eider in Newfoundland and Labrador, but erroneously identified as Hymenglejns (Microsomacanthnis) formosoides Spasskaja et Spassky, 1961 by Bishop and Threlfall (1974).     

Life-cycles of cestodes of the genus Branchiopodataenia Bondarenko & Kontrimavichus, 2004 (Cestoda: Hymenolepididae) from gulls in Chukotka

Data are presented on the life-cycles and the postembryonal development of four species of Branchiopodataenia Bondarenko & Kontrimavichus, 2004, B. anaticapicirra Bondarenko & Kontrimavichus, 2004, B. arctowskii (Jarecka & Ostas, 1984), B. haldemani (Schiller, 1951) and B. pacifica (Spassky & Jurpalova, 1968), which are specific parasites of gulls. The investigation was carried out in Chukotka (Chaun Bay) between 1971 and 1981 under natural and experimental conditions. Branchiopod crustaceans were exclusive natural and experimental intermediate hosts of all of the species studied; this fact provided additional evidence for the erection of Branchiopodataenia. The metacestodes exhibit a pattern of postembryonal development and a typical larval form, termed a 'cercocyst', which is a modification of a cysticercoid. This modification of the metacestode does not occur in species of Wardium Mayhew, 1925, the genus with which species of Branchiopodataenia had previously been affiliated.     

Microsomacanthus polystictae sp. n. and other cestodes of the family Hymenolepididae (Cyclophyllidea) from Steller's eider Polysticta stelleri from the Chaun lowlands (northwestern Chukotka)

8 species of cestodes belonging to the family Hymenolepididae were recorded from Polysticta stelleri (Pall.) in the Chaun lowland. A new species of hymenolepidids, Microsomacanthus polystictae sp. n., differing from close (by the length of proboscis hooks) species of the genus in the structure and size of the copulatory organ is described. Brief diagnosis of the new species: cestodes small, specimens ending with hermaphrodite proglottids 2.44 to 2.91 mm long. Proboscis hooks 0.038 to 0.042 mm long, blade 0.011 to 0.012 mm long. Strobila of maximum length with 84 proglottids. In young male proglottids the aporal testis half as large as poral and median ones, in well-developed proglottids testes 0.020 to 0.026 X 0.023 to 0.032 mm. Bursa of cirrus 0.150 to 0.190 X 0.020 to 0.028 mm. Cirrus 0.107 mm long, basis 0.008 to 0.011 mm wide, median part 0.012 to 0.014 mm wide, apical part 0.004 mm wide. Cirrus armed with spines 0.003 to 0.004 mm long. Ovary bilobate, yolk gland compact. Spermatheca small, situated medially, in front of poral ovary lobe. Copulative part of vagina sacciform, 0.086 to 0.118 mm long, 0.023 to 0.037 mm maximum width. Distally and proximally vagina with muscular sphincters. Uterus sacciform, with 35 to 40 embryos. There were no mature "eggs" in the material.     

Diversity and biogeographical relationships of the Australian cestode fauna

The Australian cestode fauna remains poorly documented with a total of 342 species recorded to date. The best-studied host groups are the elasmobranchs and the marsupials, but even in these groups, only 32 and 25% of known host species, respectively, have been examined for parasites. Overall, cestodes have been reported from only 5% of the known vertebrate species. Representatives of virtually all cestode orders and most of the cyclophyllidean families have been recorded from Australia. In spite of these deficiencies, some biogeographical patterns are discernible. In the elasmobranchs, a significant proportion of the known cestodes is endemic while other associations exist with eastern Pacific and Indo-west Pacific faunas. Also identifiable is a group of cosmopolitan species. The nematotaeniids of amphibians suggest Gondwanan affiliations, while the known proteocephalideans, parasitic in reptiles and amphibians, may represent an Asian invasion. Associations of the avian cestodes represent an unexplored but potentially rewarding avenue of biogeographical study. The cestodes of mammals include families with a Gondwanan distribution (Linstowiidae, Hymenolepididae) as well as those (Anoplocephalidae) with an apparent origin in southeast Asia. In addition, a number of genera of cyclophyllidean cestodes (Anoplotaenia, Dasyurotaenia) occurring in marsupials represent biogeographical challenges, not being accommodated within any of the known cestode families. The Australian cestode fauna therefore provides potentially outstanding opportunities for studies of the biogeographical relationships of a number of cestode groups.     

Relictolepis gen. n.--a new cestode genus (Cyclophyllidea: Hymenolepididae) from rodents of the Russian Far East and the description of R. feodorovi sp. n

A new cestode genus and species Relictolepis feodorovi gen. et sp. n. having armed scolex is described ex Clethrionomis rufocanus Sundevall, 1846 (Rodentia, Microtinae) from the Russian Far East.     

Springtails (Collembola) of eastern Chukotka: Characteristics of the fauna and species assemblages

A total of 139 collembolan species from 55 genera were found in coastal tundra near the settlement of Lavrentiya in the eastern part of the Chukchi Peninsula. The local fauna of the region is quite “Beringian” in species composition but its structure appears to be in full agreement with the known characteristics of southern tundra faunas of other sectors in the Arctic. The specificity of collembolan complexes of the main plant associations in the studied area is not very high because the predominant collembolan species usually inhabit a wide range of communities. The performed study on Collembola fails to confirm the conventional view of a significantly higher diversity of northeastern Palaearctic faunas. Despite the rather southern position of the studied coastal tundra, the species richness of its collembolan fauna seems to be the same as or only slightly higher than that of analogous landscapes in the other Arctic sectors. The apparent discrepancy between relatively low diversity of Collembola at the local level as shown herein and its rich regional fauna may be the result of increased differentiation of the collembolan fauna of the region characterized by very complex orography and extremely contrasting climatic conditions.     

Two new cestode species of the family Hymenolepididae Perrier, 1897 (Cyclophyllidea) from passerine birds in Ethiopia,with the erection of Citrilolepis n. g.

Systematic Parasitology - Two new cestode species of the family Hymenolepididae Perrier, 1897 are described from birds of the order Passeriformes at Wondo Genet, Ethiopia. Passerilepis zimbebel n....     

Mathevolepis junlanae sp. n. (Cyclophyllidea: Hymenolepididae: Ditestolepidini), a new cestode species from shrews of Far East

Mathevolepis junlanae sp. n. from shrews (Sorex spp.) of Far East is described given. The new species occupies an intermediate position between the Palaearctic species M. petrotschenkoi Spassky, 1948 (total number of proglottids--4) and M. skrjabini (Sadovskaya, 1965) (10-12 segments in a series) by the number of synchronously developing proglottids (2-4). The new species differs from M. larbi Karpenko, 1982 by the structure and measurements of copulative apparatus in proglottids. In M. larbi, vagina S-shaped, vagina length 0.147-0.154 mm, cirrus length 0.146-0.149 mm, and cirrus bursa reaching aporal excretory vessels. M. junlanae sp. n. has cirrus bursa slightly crossing center line of sexually mature proglottids, cirrus about half as long (0.084-0.092 mm), and smaller sac-shaped vagina (0.075-0.10 mm). The new species differs from the Nearctic representative M. macyi (Locker and Rausch, 1952) by lesser measurements of cirrus bursa (0.12-0.14 mm versus 0.4 mm) and a fewer number of proglottids in series (2-4 versus 5-7).     

A new species of cestode, Vampirolepis muraiae n. sp. (Cyclophyllidea: Hymenolepididae), from a Chinese bat

Vampirolepis muraiae n. sp. (Cestoda: Cyclophyllidea: Hymenolepididae) is described on the basis of a single specimen from a mouse-eared bat, Myotis sp., from Yunnan Province, China. It is distinguished from its congeners on the basis of the size and shape of the rostellar hooks, which have a blade shorter than the guard, the tubular structure of the initial stage of the developing uterus and eggs with a thick outer coat.     

Two new species and a new phyllobothriid cestode genus from sharks of the genus Negaprion Whitley (Carcharhiniformes)

Alexandercestus n. g. (Cestoda: Tetraphyllidea) is erected for two cestode species found parasitising the two known species of lemon sharks (Carcharhiniformes: Negaprion spp.). This new genus differs from all other phyllobothriid genera except for Hemipristicola Cutmore, Theiss, Bennett & Cribb, 2011, Marsupiobothrium Yamaguti, 1952, Nandocestus Reyda, 2008, Orectolobicestus Ruhnke, Caira & Carpenter 2006, Orygmatobothrium Diesing, 1863, Paraorygmatobothrium Ruhnke, 1994 and Phyllobothrium van Beneden, 1849 in possessing uniloculate bothridia with an apical sucker and neck scutes. Alexandercestus differs from Orectolobicestus and Nandocestus in lacking marginal loculi on the bothridia, from Paraorygmatobothrium in possessing uninterrupted vitelline follicles at the level of the ovary and from Phyllobothrium in being euapolytic as opposed to anapolytic and in lacking posteriorly bifid bothridia. The new genus lacks the central accessory bothridial organ seen in specimens of Orygmatobothrium, and lacks the central bothridial accessory sucker of specimens of Marsupiobothrium. Alexandercestus spp. compare most favourably with specimens of Hemipristicola, especially with respect to aspects of proglottid morphology, but differ in possessing aristate gladiate spinitriches rather than serrate gladiate spinitriches on the proximal bothridial surface. In addition, the bothridia of Alexandercestus spp. are comparatively more fleshy and foliose than those in specimens of Hemipristicola. Two new species of Alexandercestus n. g. are described, Alexandercestus gibsoni n. sp. from Negaprion acutidens, collected from off northern Australia and the Marshall Islands, and Alexandercestus manteri n. sp. from N. brevirostris, collected off the islands of Bimini and the Florida Keys. The two new species differ in total length and vitelline follicle distribution. Bayesian inference and parsimony analysis of the D1–D3 region of the large nuclear ribosomal DNA of 17 published and seven novel sequences placed A. gibsoni as the sister taxon to a clade containing Hemipristicola gunterae Cutmore, Theiss, Bennett & Cribb, 2011 and species of Paraorygmatobothrium. This result supports the erection of Alexandercestus as a genus separate from Hemipristicola and Paraorygmatobothrium. At the present time, species of Alexandercestus are known only from hosts of the carcharhinid genus Negaprion Whitley; examination of extensive survey data suggests this may be the extent of the host distribution of this genus.     

The Karyotype of Chukotka Chars from the Estikhed Lake (Eastern Chukotka)

The karyotype of chars from the Estikhed Lake (Eastern Chukotka) was examined. This karyotype comprises 78 chromosomes, NF = 98. Marker chromosomes include one pair of submetacentrics, one pair of large acrocentrics, and one pair of large subtelocentrics with very short second arms. Nucleolus organizer regions are located in telomeric regions of short arms of marker submetacentric chromosomes. Small heterochromatin blocks are observed in centromeric regions of most chromosomes. The Chukotka char karyotype is very similar to that of Taranetz charSalvelinus taranetzi from the Achchen Lake: these karyotypes differ only in stability of the chromosome number.     

Dynamics of physiological parameters in the nestling of black-backed gull Larus marinus experimentally infested by the cestode Microsomacanthus ductilus (Cestoda: Hymenolepididae)

The effect of the invasion with the cestode Microsomacanthus ductilus on physiological and biochemical processes in black-backed gull Larus marinus was examined. Experimental invasion of the gull nestling by the cestodes has been performed. Dynamics of the protein, lipid, and carbohydrate metabolism in the time history of the invasion was observed, in comparison with noninfested nestling. Increasing of the content of alpha-globulins and decreasing of the content of protein and albumin in the blood plasma of experimentally infested birds were registered to 4th day after invasion. To 7th day after invasion the level of general lipids and phospholipids decreases, while the content of gamma-globulins and modified form of albumin increases. To 10th day after invasion symptoms of intoxication were observed, but some parameters proved to be reverted to normal condition. So, it can be assumed, that the most intensive reorganization of the metabolism in infested birds takes place in the period between 4th and 7th days after infestation. Possible causes of the observed phenomena are discussed.