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The Scarce Chaser (Libellula fulva) is widespread in Europe and in many regions is relatively common. It is also abundant in the lake districts of western and northern Poland. Although the species frequently occurs in large numbers its biology is poorly known. Emergence of L. fulva was investigated in this study as a contribution to the life history of the species. Studies were carried out in the vicinity of Chojno (52°41′ N, 16°12′ E) on the edge of the Notecka Forest in 2003 and 2004. The stem habitat of the population is a stream with the adjacent swamps. Libellula fulva belongs to the spring species sensu Corbet (1999). The emergence of the studied population lasted 19 days (between 18 May and 5 June) and 31 days (between 13 May and 12 June) in 2003 and 2004, respectively. It was characterised by synchronous and, especially in the first phase, mass emergence. The high synchronisation is reflected in the fact that 50% of the population had emerged by the seventh (in 2003) and the fifth (in 2004) days of the process. This is vital to the imagines, which mature and return to the water body as soon as possible to reproduce. Timing of the end of emergence depends on atmospheric conditions during its duration and the conditions preceding the start of emergence on a given day. In the daily course there is a tendency for emergence to finish as soon as possible. Extension of the emergence is synonymous with increased mortality in the dragonfly population caused by predators.  相似文献   

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The present study re-examines the detailed morphology of the type-species, Diclidophora merlangi (Kuhn, in Nordmann, 1832) Krøyer, 1838, and other Diclidophora species parasitic on gadid fishes: D. denticulata (Olsson, 1876) Price, 1943, D. esmarkii (Th. Scott, 1901) Sproston, 1946, D. luscae (van Beneden & Hesse, 1863) Price, 1943, D. minor (Olsson, 1868) Sproston, 1946, D. palmata (Leuckart, 1830) Diesing, 1850, D. phycidis (Parona & Perugia, 1889) Sproston, 1946, D. pollachii (van Beneden & Hesse, 1863) Price, 1943 and the recently described D. micromesisti Suriano & Martorelli, 1984. An amended generic diagnosis of Diclidophora Krøyer, 1838 (synonym Diclidophora Diesing, 1850) is provided, which includes the presence of a prostatic vesicle in the terminal male genitalia and the distal fusion of the median and peripheral sclerites, a1 and c1 in the clamp anterior jaw. Macrouridophora n. g. is herein proposed for species previously considered in Diclidophora, which are parasitic on macrourid and morid fishes. The clamp morphology in Macrouridophora n. g. has distinct lamellate extension attachments to peripheral sclerites c1 and the distal portion of d1, with no distal fusion between a1 and c1 in the anterior jaw. Macrouridophora macruri (Brinkmann, 1942) n. comb. is chosen as the type-species. Nine other species are herein transferred to Macrouridophora n. g.: M. coelorhynchi (Robinson, 1961) n. comb., M. lotella (Machida, 1972) n. comb., M. nezumiae (Munroe, Campbell & Zwerner, 1981) n. comb. and M. tubiformis (Rohde & Williams, 1987) n. comb. are redescribed, based on the re-examination of type or voucher specimens. Macrouridophora attenuata (Mamaev & Zubtschenko, 1979) n. comb., M. caudata (Mamaev & Zubtschenko, 1984) n. comb., M. papilio (Mamaev & Avdeev, 1981) n. comb., M. paracoelorhynchi (Mamaev & Paruchin, 1979) n. comb. and M. physiculi (Mamaev & Avdeev, 1981) n. comb. have adequately described haptoral clamps in the literature. The clamp morphology in Macrouridophora sp. from Lepidorhynchus denticulatus in Australia is also considered. Diclidophora whitsonii Suriano & Martorelli, 1984 is herein transferred to the genus Macruricotyle Mamaev & Ljadov, 1975, as M. whitsonii (Suriano & Martorelli, 1984) n. comb. D. embiotocae Hanson, 1979 is herein considered a species incertae sedis. D. caudospina Khan & Karyakarte, 1983 and D. paddiforma Deo & Karyakarte, 1979 are herein considered species inquirendae. D. aglandulosa Deo, 1977, D. glandulosa Das, 1972, D. minuta Das, 1972 and D. spindale Deo, 1977 are formally dismissed as nomina nuda. The systematic position of Diclidophora Krøyer, 1838 and Macrouridophora n. g. in the subfamily Diclidophorinae Cerfontaine, 1895 (sensu Mamaev, 1976) is discussed.  相似文献   

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The genus Lasinus Sharp, 1874 of the Pselaphodes complex of genera (Pselaphitae: Tyrini: Tyrina) is revised. The three so far known species, Lasinus mandarinus Raffray, 1890, Lasinus monticola Sawada, 1961 and Lasinus spinosus Sharp, 1874 are redescribed. Eight new species, Lasinus sinicus sp. n. from China, Lasinus mikado sp. n., Lasinus yamamotoi sp. n., Lasinus inexpectatus sp. n., Lasinus yakushimanus sp. n., Lasinus amamianus sp. n., Lasinus saoriae sp. n., and Lasinus okinawanus sp. n. from Japan, are described. And all species are illustrated. Lectotypes are designated for Lasinus mandarinus and Lasinus spinosus. An identification key to species of the genus Lasinus is provided.  相似文献   

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Sciadicleithrum juruparii n. sp. is described from the gills of the Neotropical cichlid fish Satanoperca jurupari (Heckel) caught in the Guamá River, in the delta of the Amazon River, at Belém, Pará State, Brazil. Diagnostic characters of the new species are a basally articulated male copulatory organ with clockwise coils and an accessory piece; a ventral bar with a median process; similar hooklets; vagina in the form of a sclerotised tube; and a sinistral vaginal aperture with a sclerotised papilla lying in a small surface depression. It is the only species of Sciadicleithrum Kritsky, Thatcher & Boeger, 1989 with a medial projection on the ventral bar.  相似文献   

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Patrick Scaps 《Hydrobiologia》2002,470(1-3):203-218
The common ragworm Hediste diversicolor inhabits the shallow marine and brackish waters in the North Temperate Zone of the Atlantic. This infaunal species builds U or Y-shaped burrows in the soft sediments. H. diversicolor is gonochoristic and remains atokous throughout its life. Due to the facility of harvesting of individuals by hand and their maintenance, this species represents a good biological material for experimental studies. In consequence, the common ragworm served as a model for endocrine control of reproduction in Polychaeta and played a fundamental role in the study of immune defence in Polychaeta.Life history characteristics (longevity, spawning season, feeding tactics and growth) and population dynamics (sex ratio, density and biomass) vary greatly according to geographical location of the populations. In addition, inter-population morphological, biochemical and physiological differences have been noticed in individuals from different areas and different environmental conditions in the same areas and could be related to the limited dispersal capacity of the species. H. diversicolor interacts with its environment. The construction of burrows by individuals increases the sediment–water interface. When they ventilate their burrows, individuals verticalize oxic zones into the sediment and promote microbial and meiofaunal growth alongside their burrows. Moreover, the common ragworm is a species of commercial interest because of its use as bait in recreational fishing and as food in aquaculture. In order to alleviate environmental pressure caused by excessive demand over optimal sustainable yield of bait fisheries, intensive aquaculture has been proposed. The common ragworm could be also used as biomonitor of pollution in estuarine ecosystems.  相似文献   

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Up till now, plant macroremains of hunter-gatherer groups at the end of the last Ice Age and the very early Holocene have very rarely been investigated on the Iberian Peninsula and elsewhere. The use of systematic recovery techniques at the archaeological cave site of Santa Maira has allowed the recovery of a large amount of plant remains (fruits, seeds and wood) from Upper Palaeolithic and Epipalaeolithic levels (12000–9000 b.p.) Charcoal analysis has allowed us to reconstruct the surrounding vegetation of the site. In the valley bottoms mesophilous woodland with Quercus was present even in the lowest layers (Upper Magdalenian) During the Late-glacial Juniperus was very important, in the early Holocene Quercus (both evergreen and deciduous) took over. Large numbers of macroremains of fruits (Quercus sp., Sorbus sp., Olea sp. and Vitis sp.) were found, but a significant quantity of legumes together with a few grass seeds have also been identified. This assemblage most probably represents the gathering of wild plant resources by the inhabitants of the cave, and allows us to reconstruct some of the food gathered from plant resources.  相似文献   

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Oöcysts of Eimeria whitakeri n. sp. are described from the faeces of the least shrew, Cryptotis parva (Insectivora: Soricidae), from Texas, USA. The oöcysts are spherical to subspherical, 17.4 × 16.4 (15–19 × 13–18.5) μm, with a bi-layered wall; their shape-index (length/width) is 1.1 (1.0–1.2). A micropyle and oöcyst residuum are absent, but a large polar granule is present. The sporocysts are ovoidal, 11.2 × 7.5 (9.5–12 × 6.5–8) μm, with Stieda and substieda bodies; their shape-index is 1.5 (1.4–1.6). The sporozoites each possess both anterior and posterior refractile bodies.  相似文献   

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