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1.
The anatomical and morphological variability of sporocysts and metacercariae of Leucochloridium sp. recovered from natural infected Succinea pfeifferi Rossm?ssler collected in the Agdenes area. Norway (63 degrees 35'N, 9 degrees 45'E), was studied by light microscopy. The results are compared with five species from the Nearctic and Palearctic with known adult stage (L. variae McIntosh, 1932; L. fuscostriatum Robinson, 1947; L. perturbatum Pojmanska, 1969; L. subtilis Pojmanska, 1969; L. fuscum Rietschel, 1970) and nine species with unknown adult stage. In the larval stages no morphological taxonomical characters were found to separate Leucochloridium sp. as a species distinct from the five (and nine) species. The variability and validity of the characters used is discussed.  相似文献   

2.
Transmission of Leucochloridium species to their definitive avian hosts may be facilitated by the rhythmic movement of coloured sporocyst broodsacs in the ocular tentacles of infected snails. These broodsacs resemble caterpillars and by enticement increase the probability of predation by birds. Broodsac banding pattern and colour (green, yellow to red/brown) have traditionally formed part of the taxonomic criteria for the genus. In this study, sequence divergence of the 5.8S rDNA gene and associated internal transcribed spacers (ITS1 and ITS2) in two of the most frequently observed Leucochloridium taxa from Europe is related to broodsac type based on colour and banding pattern. The present green-banded broodsac (L. paradoxum Carus, 1835) and brown-banded broodsac forms (L. variae McIntosh, 1932) differ in ITS sequence by 6.8%, confirming their distinctness. No intraspecific differences were noted within each colour morph in specimens collected from Poland, Denmark or Norway, indicating that a single taxon of each type occurs in Europe. The significance of these findings to our understanding of metapopulation dynamics and evolutionary ecology of Leucochloridium is discussed.  相似文献   

3.
Summary The sporocyst and metacercaria of Leucochloridium paradoxum Carus, recovered from Succinea putris L. in Norway, are described and figured. Adults recovered from experimental infection of Taeniopygia guttata (Vieillot) with L. paradoxum metacercariae are described, using results from scanning electron microscopy, and compared with earlier information. The family Leucochloridiidae Poche is revised. Four genera are recognized within the family (i.e. Leucochloridium Carus, 1835; Urogonimus Monticelli, 1888; Urotocus Looss, 1899; Michajlovia Pojmanska, 1973). The larval ecological and morphological characteristics are tabulated for the three genera with known larval stages. The status of the genus Neoleucochloridium Kagan, 1951, is changed, on the grounds of larval similarities with Leucochloridium Carus. This means that within the genus Leucochloridium Carus three subgenera are erected, based primarily on sporocyst characteristics. These are Leucochloridium, Neoleucochloridium and Papilloleucochloridium. The diagnostic larval and adult characters are tabulated. The known larval records of species in the genus Leucochloridium are discussed and revised within the framework of this new classification. ac]19790812  相似文献   

4.
The damselfly genus Enallagma originated in the Nearctic, and two Nearctic lineages recently underwent radiations partly associated with multiple independent habitat shifts from lakes dominated by fish predators into lakes dominated by dragonfly predators. A previous molecular study of four Palearctic morphospecies and all representative Nearctic species identified the presence of two cryptic species sets, with each set having Palearctic and Nearctic representatives. However, the cryptic species within each set are not sibling species. Here, we present quantitative data on ecologically important larval morphologies and behaviors involved in predator avoidance and on adult male morphological structures involved in mate recognition to quantify the phenotypic relationships among these cryptic species sets. For the adult stage, our data indicate strong parallel evolution of the structures involved in specific mate recognition-the male cerci. For the larval stage, morphometric analyses show that the Palearctic species evolved a nearly identical morphology to the sibling-clade members in the Nearctic that live in waters where dragonflies are the top predators. This implicates the importance of dragonfly predation in the history of the Palearctic clade. Behavioral analyses suggest population differentiation in response to the actual predator environment in the Palearctic clade, consistent with the species differentiation seen in the Nearctic. Our results suggest parallel evolution of adult traits that influence specific mate choice and larval traits that influence ecological performance underlie the striking similarity of Enallagma species across continents. This concurrent parallel evolution in both stages of a complex life cycle, especially when both stages do not share the same selective environment, may be a very unusual mechanism generating cryptic species.  相似文献   

5.
Abstract. The mountain midges (Diptera: Deuterophlebiidae) of the Palaearctic Region are revised to include eight species. Four new species are described: D. brachyrhina sp. nov., D.oporina sp. nov. and D. blepharis sp.nov. from the Himalayas (Assam and Sikkim), and D.bicarinata sp. nov. from southern Korea. A lectotype is designated for D.mirabilis Edwards, and a key to adult males of all Palaearctic species is provided.
Larval, pupal and adult characters were used to reconstruct the phylogenetic and biogeographic relationships of world species of Deuterophlebiidae. Based on features of the adult male, the Himalayan species D. brachyrhina and D. oporina are considered the most primitive deuterophlebiids. The Nearctic species D. inyoensis is proposed as the sister group of the remaining species. Relationships among the latter are based primarily on larval and pupal characters; however, lack of information about the immature stages of several Palaearctic species contributes to a poorly resolved phylogeny. Several alternative hypotheses are presented and discussed. All phylogenetic alternatives suggest that the Nearctic fauna originated from at least two invasions of North America.  相似文献   

6.
7.
Abstract. The subgenus Sabethinus of Sabethes is redescribed and defined on the basis of shared morphological features observed in the adult, larval and pupal stages of four known species, two of which are described as new. Each species is described and illustrated in detail, and keys are provided for the identification of the adult and larval stages. The treatment of each species also includes an annotated summary of previous literature, a brief systematic discussion and information on bionomics and distribution. The species comprising the subgenus are Saintermedins, Samelcinonymphe, Saxhyphydes sp.n. and Sakliogenes sp.n.  相似文献   

8.
The establishment of in vitro cultivation techniques to maintain larval and adult stages of the trematode Schistosoma mansoni has facilitated research on diverse aspects of the biology of this parasite. Because of the difficulty in obtaining defined intramolluscan stages of this parasite, one aim of this study was to develop an in vitro technique for the generation of defined clonal daughter sporocyst (DSp) generations that originate from a single mother sporocyst. Sporocysts died when cultured singly; however, when single sporocysts were cultured in inserts within wells with about 1,000 others, the single individuals produced daughters asexually. In recent years, evidence has been accumulating for variability among, and within, schistosome populations. Such variability has been seen in both larval and adult stages. Even within clonal cercariae, genomic and biochemical heterogeneity has been observed, indicating the existence of a yet unknown mechanism that generates variability during larval development. Therefore, another aim of this study was to examine clonal DSps generated in vitro for diversity regarding the presence or absence of a specific repetitive DNA element (W1). Such sporocysts were found by molecular analysis to be heterogeneous with respect to the occurrence of W1. This phenomenon had previously been observed in clonal schistosome populations and described as genomic instability. In this study, we provide the first molecular evidence that variability can be generated within sporocyst generations, supporting the hypothesis of mitotic recombination events during the asexual life stage of schistosomes.  相似文献   

9.
Abstract The campoplegine genus Benjuminia is herein revised, with ten species being described as new, in addition to the five previously known species. Phylogenetic relationships of Benjuminia to other genera are discussed, and a cladogram presented for the species. Two monophyletic species groups are recognized, one being confined to the Palearctic and the other to the Nearctic. Examination of larval morphology not only fails to reveal larval characters for distinguishing Benjuminia but leads to the conclusion that use of larval morphology to identify campoplegine species is a dubious practice.  相似文献   

10.
The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensis sp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensis sp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given.  相似文献   

11.
Loricifera is a phylum of minute animals that live exclusively in marine sediments. A total of 33 species have been described so far in this phylum; however, several more are already known from preliminary observations. Loriciferans are characterised by a complex life cycle, which involves a succession of several adult and larval stages. Here, we describe a new type of loriciferan larval stage: the Shira larva. The gross morphology of this larva is generally similar to that of the most prominent larval type of Loricifera, the so-called Higgins larva. However, the Shira larva possesses a number of unique features, namely (1) a single pair of anteroventral setae is present in the most anterior region of the abdomen, (2) the bases of the anteroventral setae are very large and swollen, (3) the thorax and abdomen are thinner than the introvert and (4) the abdominal region is divided into five sub-regions. Accordingly, we described the new species, Tenuiloricus shirayamai gen. nov. et sp. nov. (incertae sedis). The new findings are discussed from a comparative perspective with the Higgins larva as well as with the fossil of a putative loriciferan larval stage from the Middle Cambrian.  相似文献   

12.
13.
Pulsating broodsacs of Leucochloridium sp. (Trematoda: Leucochloridiidae) were found from amber snails (Succinea lauta) in Iwate, the northern part of Honshu, Japan. A pattern with red-brown vertical stripes was characteristic of the broodsac. Very similar broodsacs were already detected from Okinawa Islands, the southern archipelago of Japan, and tentatively identified as Leucochloridium cf. passeri. A phylogenetic analysis based on DNA sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) showed that Leucochloridium sp. is different at species level from L. cf. passeri and that both species are related to Leucochloridium vogtianum from Europe. In this study the definitive identification of larval Leucochloridium sp. was impossible, but the resulting phylogeny confirmed that at least 4 species of Leucochloridium are distributed in Japan, depending on locality and climate. The DNA barcode generated in this study will be useful in detecting the adult stage of Leucochloridium sp. from birds.  相似文献   

14.
Trachymolgus purpureus Fisher & Dowling sp. n. is described from the Ozark highlands of North America. A diversity of imaging techniques are used to illustrate the species including low-temperature scanning electron microscopy (LT-SEM), stereomicrography, compound light micrography, and digitally created line drawings. Developmental stages (larva, nymphs, and adult) and morphology are illustrated and discussed, and terminological corrections are suggested. Trachymolgus recki Gomelauri, 1961 is regarded as being described from tritonymphs. A key to Trachymolgus is presented.  相似文献   

15.
This study describes the fauna of predator insects, parasitoids and ants associated with aphids on kale (Brassica oleracea L. var. acephala D.C.) in organic system. The aphid was identified as Lipaphis pseudobrassicae Davis, and this is the first record of the species attacking kale in Brazil. Primary parasitism by Diaeretiella sp. and Aphidius sp. and hyperparasitism by Aphydencyrtus sp., Alloxysta sp., Pachyneuron sp. and Syrphophagus sp. were observed. Twenty species of Coccinellidae were collected, and eight of them were observed in adult and larval stages attacking the aphid: Hyperaspis (Hyperaspis) festiva Mulsant, which was the most abundant (72.5% of all predator insects obtained), Cycloneda sanguinea (L.), Eriopis connexa Germar, Coleomegilla maculata DeGeer, Hippodamia convergens Guérin, Heterodiomus sp., Scymnus (Pullus) sp.1 and Scymnus (Pullus) sp.2. Aphidophagous Syrphidae larvae collected on leaves ofkale infested by L. pseudobrassicae belong to the species Allograpta exotica (Wiedemann) and Ocyptamus gastrostactus (Wiedemann). Larvae and pupae of Syrphidae were parasitized by Pachyneuron sp., Syrphophagus sp. and Diplazon laetatorius Fabricius. Larvae of Chrysopodes sp. were observed feeding on L. pseudobrassicae. Species of ants associated with the colony of this aphid were Ectatomma quadridens Fabricius and Pheidole sp.  相似文献   

16.
Fishes exhibit a remarkable diversity of body shape as adults; however, it is unknown whether this diversity is reflected in larval stage morphology. Here we investigate the relationship between larval and adult body shape as expressed by body elongation. We surveyed a broad range of ray-finned fish species and compared body shape at larval and adult stages. Analysis shows that the vast majority of fish are more elongate at the larval stage than at the adult stage, and that adults display greater interspecies variation than larvae. We found that the superorder Elompomorpha is unique because many species within the group do not follow the observed elongation trends. These results indicate that much of the diversity observed in adults is achieved in post-larval stages. We suggest that larval morphology is subject to common constraints across the phylogeny.  相似文献   

17.
Abstract : Specimens originally identified as Arostrilepis horrida from the Nearctic are revised, contributing to the recognition of a complex of cryptic species distributed across the Holarctic region. Previously unrecognized species are described based on specimens in cricetid (Neotominae) and geomyid rodents. Arostrilepis mariettavogeae n. sp. in Peromyscus californicus from Monterey County, California and Arostrilepis schilleri n. sp. in Thomomys bulbivorus from Corvallis, Oregon are characterized. Consistent with recent studies defining diversity in the genus, form, size, and spination (pattern, shape, and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac and arrangement of the testes. Species of Arostrilepis have not previously been described in rodents outside of the Arvicolinae or from localities in the Nearctic. These studies emphasize the need for routine deposition of archival specimens and information, from survey, ecological, and biogeographic studies, in museum collections to serve as self-correcting records for biodiversity at local, regional, and continental scales.  相似文献   

18.
The sparetus-group of Entedon is revised. Six species are recognized for the group, including one new species, E. lucasi Gumovsky sp. n., which is described from Algeria. All species are either diagnosed or described, and illustrated, and new distribution records are provided. An illustrated dichotomous key to all species of the group is given. Biology of two species, E. thomsonianus Erd?s and E. sparetus Walker, is studied in detail: both species proved to be egg-larval parasitoids of stem-boring weevils, Lixus cardui Olivier on the scotch thistle Onopordum acanthium and Gymnetron asellus (Gravenhorst) on mullein Verbascum sp., respectively. The morphology of larval stages and peculiarities of parasitoid-host relationships are described. Possible benefits of egg-larval parasitism for Entedon species are discussed.  相似文献   

19.
We describe the morphology of the foregut of the spider crab Maja brachydactyla Balss, 1922, from first larval stage to adult, with detailed stage‐specific documentation using light and scanning electron microscopy. A total of 40 ossicles have been identified in the foregut of adults of M. brachydactyla using Alizarin‐Red staining. The morphological pattern of the ossicles and gastric mill is very similar to other Majoidea species with only a few variations. The foregut of the zoeae stages appeared as a small and simple cavity, with a cardio‐pyloric valve that separates the stomach into cardiac and pyloric regions. The pyloric filter is present from the first zoea, in contrast to the brachyuran species which have an extended larval development. Calcified structures have been identified in the cardio‐pyloric valve and pyloric region of the zoeal stages. The most significant changes in foregut morphology take place after the metamorphosis from ZII to megalopa, including the occurrence of the gastric mill. In the megalopa stage, the foregut ossicles are recognizable by their organization and general morphology, but are different from the adult phase in shape and number. Moreover, the gastric teeth show important differences: the cusps of the lateral teeth are sharp (no molariform); the dorsal tooth have a small, dentate cusp (not a well‐developed quadrangular cusp); and the accessory teeth are composed of one sharp peak (instead of four sharp peaks). The gastric mill ontogeny from megalopa to adult reveals intermediate morphologies during the earlier juvenile stages. The relationship between gastric mill structures with food preferences and their contribution to the brachyuran phylogeny are briefly discussed. J. Morphol. 276:1109–1122, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

20.
Abstract
The gall-forming scale insect Callococcus leptospermi was studied in the field to determine its life history and method of distribution on the host plant, Leptospermum sp., previously L. juniperinum (Sm.) Domin (prickly tea tree, Myrtaceae). This paper complements earlier taxonomic studies on C. leptospermi. Until now the adult female has provided most of the available data on the species. Newly described stages include the second instar male, the third instar assumed female and the adult male. The sexually dimorphic first instar and adult female are redescribed. Callococcus leptospermi is ovoviviparous. It is dispersed by migration of second instar larvae from the parent gall to new feeding sites.  相似文献   

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