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The authors describe and illustrate Helicoductus thulakoceras n. g., n. sp., a parasite of Charadrius marginatus (Aves: Charadrii) from South Africa. This hymenolepidid cestode is 1.5-3 mm long, with a rostellum armed with 10 diorchoid hooks 75-80 m long (mean 77 m) and anomalous terminal genital ducts. One spine (10-15 m long) is inserted at the ventral extremity of the male genital pouch. An invaginated cirrus is absent. A non-retractable and non-invaginable external tube, 25-30 × 4-2.5 m, appears as a spiral, sclerotinised, spinous canal, which is non-retractable, non-invaginable and directed dorso-ventrally from the genital pouch to a second ventral canal parallel with the male genital pouch; the second canal is thin and spine-like (15-20 × 1.5 m) with a thick hyaline muff. These peculiar anatomical structures are discussed. They are considered to justify the erection of a new genus.  相似文献   

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Mariauxiella pimelodi n. g., n. sp. (Cestoda, Monticelliidae, Othinoscolecinae) is described from the South American siluriform fishes Pimelodus ornatus and Pimelodus sp. caught in Brazil and Paraguay. When compared with other genera of South American monticelliids, the new genus exhibits the following morpho-anatomical characters: the particular development of the distal circular musculature of the suckers acting as a sphincter; the medullar ovary projecting numerous lobules into the dorsal cortex; and the uterus situated in the ventral cortex but with numerous outgrowths penetrating the medulla and reaching the dorsal cortex in pregravid proglottids. The new species is the fourth monticelliid cestode recorded from Pimelodus.  相似文献   

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Summary Sobolevicanthus transvaalensis n.sp. is described from the Cape Teal, Anas capensis Gmelin, 1789, collected in the Republic of South Africa. The new species possesses 8 skrjabinoid hooks 78–88 m long (mean 85 m) and a short claviform cirrus-sac 79–143 m long and resembles S. javanensis (Davis, 1945) and S. terraereginae (Johnston, 1913). It can be distinguished from S. javanensis by its shorter cirrus-sac and smaller cirrus diameter, and by differences in the morphology of the accessory sac and vagina and in their position relative to the cirrus-sac. It can be separated from S. terraereginae on the basis of cirrus length and diameter. The basal diameter of the cirrus in S. terraereginae is three times that in S. transvaalensis. ac]19830414  相似文献   

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Haemoproteus gabaldoni n. sp. is described from the Muscovy duck Cairina moschata from Caracas, Venezuela and is compared to H. greineri and H. nettionis which have been described previously from the Anatidae. The highly amoeboid outline, volutin granules and small number of pigment granules of H. gabaldoni serve to readily separate this species from the other two.  相似文献   

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Incubation temperature is an important maternal effect in birds that can influence numerous offspring traits. For example, ducklings from eggs incubated at lower temperatures have lower growth rates, protein content, and are in poorer body condition than ducklings from eggs incubated at higher temperatures. Based on these observations, we predicted that incubation temperature would indirectly influence performance through its direct effects on body size. Wood duck (Aix sponsa) eggs were incubated at three ecologically relevant temperatures (35, 35.9, 37°C). After hatching, all ducklings were housed under identical conditions and were subjected to aquatic and terrestrial racing trials at 15 and 20 days posthatch (dph). Contrary to our prediction, incubation temperature did not influence most duckling body size parameters at 15 or 20?dph. However, incubation temperature did have a strong influence on locomotor performance independent of body size and body condition. Ducklings hatched from eggs incubated at the lowest temperature had significantly reduced maximum aquatic swim velocity than ducklings from higher temperatures. Maximum terrestrial sprint velocity followed a similar pattern, but did not differ statistically among incubation treatments. To our knowledge, this is the first study to demonstrate that slight changes in incubation temperature can directly affect locomotor performance in avian offspring and thus provide a significant source of phenotypic variation in natural wood duck populations.  相似文献   

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The authors describe and illustrate Wardium canarisi n. sp. (Cestoda: Hymenolepididae), an intestinal parasite of Arenaria melanocephala (Aves: Charadrii) from Alaska, characterised by a strobila 20–40 mm long, 10 aploparaksoid hooks 19–21 m long, a short cylindrical cirrus (40 m) covered with very minute spines (0.2 m), and a short (8–18 m) and extremely narrow (1 m) copulatory vagina. These characters have no equivalent, even approximate, among the 27 species of Wardium parasitic in the Charadrii which are reviewed. The genus Debrosia Spassky, 1987 appears to be justified.  相似文献   

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Nadejdolepis bealli n. sp. a parasite from Calidris alpina in Alaska (USA), is described and illustrated. It is 3-4 cm long and has: rostral nitiduloid hooks 95-96 m long, with the blade a little longer than the handle; three testes in a symmetrical triangle; a cirrus-sac 175 m long, not crossing the median line; a cirrus borne on an unarmed basal bulb, 25 m long when evaginated, and armed with numerous, compact and very thin spines 1 m long; a short (25 m) membranous and tubular vagina with neither a sclerotinoid section nor a sphincter; and a pyriform seminal receptacle. The species is differentiated from the other species of the genus with rostral hooks of comparable length by the configuration of the male and female genital ducts; they have no equivalent particularly in the shortness of the evaginated cirrus and the type of spines with which it is armed. Mention is also made of the presence of Nadejdolepis paranitidulans (Golikova, 1959) and Wardium amphitricha (Rudolphi, 1819) from the same host in Alaska.  相似文献   

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Summary Lobatodiscus australiensis n.g., n.sp. (family and subfamily uncertain) and Elseyatrema microacetabularis n.g., n.sp. (family Paramphistomidae, subfamily Dadaytrematinae?), from the intestine of the freshwater turtle Elseya dentata (Gray) in Queensland, Australia, are described. Lobatodiscus has a large lobed acetabulum, small oral diverticula which do not protrude out of the oral sucker, two pairs of lymph vessels and no oesophageal bulb. Elseyatrema has a small acetabulum, large protruding oral diverticula, an oesophageal bulb, juxtaposed testes, one pair of rudimentary lymph vessels and no cirrus-sac. ac]19830626  相似文献   

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Monodelphoxyuris dollmeiri n. g., n. sp. is described from the caecum of Monodelphis emiliae (Thomas) (Marsupiala: Monodelphidae) collected in the eastern region of the Andes of Peru. M. dollmeiri n. sp. differs from the closest pinworm described from marsupials in the Neotropics (Didelphoxyuris thylamisis Gardner & Hugot, 1995) in having operculate eggs and males that possess a tip prolonged of tail and a different kind of area rugosa. Several other species of pinworms have been described from marsupials in Australia, but all are characterised by possessing of a buccal capsule that is strongly cuticularised with interradial lamellae. These structures are lacking both in M. dollmeiriandD. thylamisis. Monodelphoxyuris n. g. is characterised by a mouth opening into a depression and lateral alae composed of two longitudinal crests. Males possess an area rugosa composed of six ventral sagittal mamelons, a caudal extremity prolonged by a robust tip of the tail which is directed backwards, four pairs of genital papillae (two pairs lateral adanal and sessile, one pair just posterior to the spicule aperture, and the last pair at posterior extremity and pedunculate). Females possess an opisthodelphic uterus, a reflected ovary and operculate, unembryonated, oval eggs.  相似文献   

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