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1.
A total of 1136 Ephemeroptera, Plecoptera and Trichoptera were caught from March 1993 to March 1994 at the Weidlingbach, a first to fourth order forest brook near Vienna. Austria, using pyramid-type emergence traps at tree sampling stations (390, 360 and 260 m above sea level). Five species comprised 67.1 % of the catch: the ephemeropterans Paraleptophlebia submarginata (Stephens), Habroleptoides confusa Sartori and Jacob and Habrophlebia lauta Eaton, and the plecopterans Nemoura flexuosa Aubert and Leuctra hippopus Kempny. Most taxa emerged from April to August, but the plecopterans Leuctra prima Kempny and Capnia bifrons (Newman) were caught early in the year (January to April), and Leuctra digitata Kempny (Plecoptera), Chaetopteryx fusca Brauer and Chaetopteryx major McLachlan (Trichoptera) emerged in September and October. In Ephemeroptera and Trichoptera, similarities between species groups were highest at the two upstream sampling stations; in Plecoptera and in pooled taxa, however, similarities were highest at the middle and downstream sites. Except in Trichoptera, diversity was highest at the middle station situated at 360 m above sea level.  相似文献   

2.
Summary A new species of spiruroid nematode,Gongylonema aegypti, is described from two rodents,Mus musculus andGerbillus gerbillus, from Egypt.G. aegypti is distinguished from closely related species by the size of the spicules and gubernaculum, the absence of cuticular bosses in males, and the size of the egg. SEM studies suggest that the generic diagnosis ofGongylonema should be amended to include the presence of a dorsal pore on the cephalic plate and the presence around the buccal cavity of three triangular teeth (not lips) and two sclerotized plates or interlabia. ac]19850414  相似文献   

3.
Leuctra istenicae (Plecoptera: Leuctridae), an apterous species from Pohorje mountains (Slovenia, Yugoslavia), is described. Notes on ecology and relationships to other apterous species of Leuctra are added.  相似文献   

4.
Leuctridae is the richest stonefly family on the European continent, with many species of Leuctra often coexisting in sympatry in the same lotic environment. In this work we studied the life cycle and feeding habits of two species, Leuctra fusca and L. hippopus, coexisting in a small Italian Apennine stream. The life cycles of the two species are non‐overlapping, i.e., periods of nymphal growth and adult emergence are separated. Nymphs of both species feed mainly on detritus, but quantities of coarse particulate organic matter (CPOM) and diatoms are also ingested. Larger nymphs of both species ingest more CPOM and fewer diatoms. This suggests a similar trophic behaviour through their development. For example, they act as collector‐gatherers in their earlier instars and as collector‐gatherers or as shredders in their later instars (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

5.
Resource dynamics and detritivore production in an acid stream   总被引:2,自引:0,他引:2  
1. Life history patterns and production of eight shredder‐detritivore species were studied in relation to the detritus dynamics of a small acidic stream in England. Mean annual detritus inputs (direct and lateral sources combined) were approximately 400 g m?2 year?1 and showed significant seasonal and annual variation. 2. Detritus standing stock did not increase significantly during times of high input, reflecting low retention efficiency. However, the mean detritus standing stock was relatively large (108 g m?2) reflecting a slow decomposition rate typical of acid streams. 3. Four species were univoltine with highly synchronous patterns of emergence and recruitment (Leuctra inermis, Leuctra hippopus, Capnia vidua and Amphinemura sulcicollis). Two species were univoltine with extended patterns of emergence and recruitment (Nemoura cinerea, Potamophylax cingulatus). Leuctra nigra was apparently semivoltine, while Protonemura meyeri showed two successive cohorts in the second year of the study, suggesting either bivoltinism or cohort splitting. 3. Secondary production of the dominant shredders was 1.67 g m?2 year?1 in 1997 and 1.99 g m?2 year?1 in 1998, which is low compared with other small European streams. This was probably because of an impoverished invertebrate community and poor food quality associated with acid conditions. Food availability probably did not account for the low production as the detritus standing stock far exceeded the estimated shredder ingestion of 42–50 g m?2 year?1. 4. Despite low overall shredder production, species‐specific production was high, possibly because of competitive release in this species‐poor acid stream. Periods of high production and growth showed no relationship with detritus availability but were closely related to life history.  相似文献   

6.
In the Volga and Don river basins, 17 stonefly species are known: 16 from the Volga, and 6 from the Don basin. The fauna is dominated by the species with wide, European (Isogenus nubecula, Nemoura flexuosa, N. dubitans, Amphinemura sulcicollis, Brachyptera braueri, Isoperla difformis, I. grammatica, Leuctra hippopus, Xanthoperla apicalis, Siphonoperla burmeisteri) and Transpalaearctic ranges (Taeniorterykh nebulosa, Nemurella pictetii, Amphinemura borealis, Nemoura cinerea, Capnia atra, Leuctra fusca, Isoperla obscura).  相似文献   

7.
The third instar larvae of Agabus clypealis (Thomson, 1867) and A. pseudoclypealis Scholz, 1933 are described. Important morphological structures (head, legs, and abdominal segment 8 with urogomphi) are illustrated. Both species share a completely sclerotized abdominal segment 6 with A. setulosus (J. Sahlberg, 1895). Morphological characters and species phenology are discussed in relation to the A. confinis-species group. All available literature records and some new and additional data on distribution of the two species are provided. Agabus clypealis is recorded for the first time from Estonia, and there is no reason to doubt the records of A. pseudoclypealis from Kazakhstan.  相似文献   

8.
1. Emergence and inland dispersal of adult stoneflies (Plecoptera) and caddisflies (Trichoptera) from Broadstone Stream, an acidic and iron-rich stream in southern England, were studied over 10 months in 1996–1997. Fifteen pyramidal emergence traps were placed randomly in a 200-m stretch. Three Malaise traps were placed above the stream and six more on each side (one wooded, one open) along a transect at distances of 1, 15, 30, 45, 60 and 75 m from the channel. 2. More than 16 000 stoneflies, belonging to 11 species, and just under 400 caddisflies (22 species) were caught. Four dominant stoneflies (Leuctra fusca, Leuctra nigra, Leuctra hippopus and Nemurella pictetii) accounted for 96% and 95% of the catches in the emergence and Malaise traps, respectively. Two caddisflies (Plectrocnemia conspersa and Potamophylax cingulatus) accounted for 63% of the catch in the Malaise traps. Few caddisflies were taken in emergence traps. 3. The emergence periods of L. fusca, L. nigra and L. hippopus were well-defined and unimodal, whereas that of N. pictetii was prolonged and erratic. Overall, more females (1285) emerged than males (740). 4. Female stoneflies and caddisflies were in the majority in the Malaise traps above the stream. On land, significantly more females than males of L. fusca, L. nigra and P. cingulatus were caught. The sex ratio of the remaining species did not deviate significantly from 1:1. 5. The three Malaise traps placed above the stream caught most of the stoneflies though there was also dispersal away from the channel, the numbers caught declining with distance. Exponential models explained between 67% and 99% of the variation in numbers of individuals with distance from the channel in the four common stoneflies. Half the individuals went less than 11–16 m from the stream, while 90% travelled less than 51 m. Significantly more L. nigra and N. pictetii were caught in the woodland than on the open side, whereas L. hippopus showed no overall preference for either side.  相似文献   

9.
The effect of brown trout (Salmo trutta L.) on invertebrate drift density was examined in three previously fish-free springbrooks. Drift density was studied during the day following the sequential introduction of: 1) empty cages, 2) cages containing trout, and 3) empty cages. Each period lasted three whole days, and drift density was measured at daytime and night-time every day. Control drift density was determined using empty cages in two similar springbrooks.Night-time drift density of large Gammarus pulex L. (>3.9 mg DW ind–1) decreased compared to that of smaller size-groups following trout introduction, and was significantly lower (p<0.05) than the pre-introductory level after the trout had been removed again.The daytime drift density of large G. pulex remained unchanged, as did both daytime and night-time drift density of smaller size-groups of G. pulex, and the other taxa investigated (Leuctra hippopus (Kempny), Leuctra nigra (Olivier), Amphimura sp., Nemoura flexuosa Aubert, and Baetis rhodani (Pict.)). No significant changes in drift density were observed in two control springbrooks.  相似文献   

10.
A new species of a cucullanid nematode is described, illustrated and compared with Cucullanus brevispiculus Moravec, Kohn & Fernandes, 1993 and C. rhamphichthydis Moravec, Kohn & Fernandes, 1997, two species previously reported as parasitizing freshwater fish in South America. The new species is characterized mainly by markedly short spicules, deirids and excretory pore situated posterior to the oesophago-intestinal junction, presence of strongly sclerotized plates in the oesophastome and oesophagus divided into two distinct portions.  相似文献   

11.
ABSTRACT

A new species of ghost shrimp, Neocallichirus pinheiroi, is described based on specimens collected in subtidal habitats of Saquaira beach, northeastern coast of Brazil. This new species resembles N. lemaitrei Manning, 1993, but differs from it primarily in having a third maxilliped propodus expanded ventrally, and in the case of males, a large subtriangular tooth on the cutting edge of the major cheliped dactylus. Diagnostic features of the new species include: (i) frontal margin of carapace with rounded lateral projections not exceeding rostrum distal margin, (ii) third maxilliped carpus with row of sclerotized setae on median internal surface, (iii) minor cheliped with cutting edge of dactylus microscopically pectinate, (iv) endopod of male second pleopod with appendices interna and masculina. This is the seventh described species of the genus Neocallichirus from the western Atlantic and the fourth report of this genus in Brazil. A key for identification of western Atlantic species belonging to the genus is provided.  相似文献   

12.
The growth of aquatic insects in a small mountain stream was studied with emphasis on water temperature. Growth of the five dominant species was examined in relation to degree-days. This measure accounts for time and the minimum temperature necessary for insect growth. All species showed reduced specific growth rates with lower temperatures, but some (Ephemerella dorothea, Leuctra tenella, Neumoura wui) did not stop growing at even the lowest water temperatures. Both Diplectrona modesta and Paraleptophlebia assimilis had minimum growth temperatures. Studies demonstrated that the growth of stream insects is directly proportional to the number of degree-days experienced by a population.  相似文献   

13.
A new miniature species of the endemic Neotropical genus Hyphydrophilus (Chilopoda: Geophilomorpha, Geophilidae) is described and illustrated, after the holotype female and paratype female, from the Yungas rainforest of Salta province, northwestern Argentina. H. minellii sp. nov. is compared in detail with the other two species currently assigned to the taxon, i.e. H. adisi Pereira, Minelli & Barbieri, 1994 and H. projectus Pereira, Foddai & Minelli, 2000, both from Brazil, from which it differs by the presence of a small slightly sclerotized and inwards directed process of internal limbs of tentorium. Other unique traits of the new taxon are the relatively high number of leg-bearing segments (59), antennal articles I–IV with numerous large setae on the latero-external side, apical medial edge of forcipular trochanteroprefemur with a well-developed slightly pigmented tooth, dorsal and ventral medial edges of the forcipular tarsungulum slightly serrate, sternal pore-fields present on anterior region of the trunk only. This is the first report of the genus Hyphydrophilus from Argentina and the Yungas forests; previously it was only known to occur in Central Brazilian Amazonia, thus the present record represents a remarkable extension of the known range of this taxon.  相似文献   

14.
A new species of Puccinia with diorchidioid teliospores is described from Urochloa decumbens (Poaceae) in Panama. It differs from the other known species of Puccinia with diorchidioid teliospores by uredinia with paraphyses and urediniospores with 3–4 scattered germ pores. Twenty-one known species of rust fungi are cited for Panama for the first time. Alveolaria cordiae is a poorly known species which is reported, described and illustrated in detail for the first time on Cordia spinescens in Panama.  相似文献   

15.
Five male entocytherid ostracods of four different species recovered from signal crayfish Pacifastacus leniusculus were observed exhibiting false mating behaviors with either another adult male, an A1 sub‐adult male, or an A3 juvenile of indeterminate species and sex. In all five instances, the ostracod being mated was not sclerotized, indicating recent molt. In one case, a male of Uncinocythere thektura was observed in false copulation with an A1 male of a different species, U. occidentalis, suggesting that taxonomic designations of females in mixed populations of Uncinocythere can be problematic. Possible reasons for false mating behavior include stress of being confined post‐collection, lack of available females, or possibly males mistaking non‐sclerotized partners for A1 females.  相似文献   

16.
C. Lemburg 《Zoomorphology》1998,118(3):137-158
 The ultrastructure of the cuticle of adult and larval Priapulus caudatus and Halicryptus spinulosus is investigated and new features of cuticle formation during moulting are described. For the localization of chitin by TEM wheat germ agglutinin coupled to colloidal gold was used as a marker. Proteinaceous layers of the cuticle are revealed by digestion with pronase. The cuticle of larval and adult specimens of both species consists of three main layers: the outer, very thin, electron-dense epicuticle, the electron-dense exocuticle and the fibrillar, electron-lucent endocuticle. Depending on the body region, the exocuticle comprises two or three sublayers. The endocuticle can be subdivided into two sublayers as well. In strengthened parts such as the teeth, the endocuticle becomes sclerotized and appears electron-dense. Only all endocuticular layers show an intense labelling with wheat germ agglutinin-gold conjugates in all investigated specimens. Additional weak labelling is observed in the exocuticle III layer of the larval lorica of P. caudatus. All other cuticular layers remain unlabelled. Chitinase dissolves the unsclerotized endocuticular layers almost completely, but also exocuticle II and partly the loricate exocuticle III. The epicuticle, the homogeneous exocuticle I and the sclerotized endocuticle are not affected by chitinase. The labelling is completely prevented in all layers after incubation with chitinase. Pronase dissolves all exocuticular layers, but not evenly. The presumably sclerotized regions of exocuticle I are not affected as well as the complete epicuticle and the endocuticle. All cuticular features of the Priapulida are compared with the cuticle of each high-ranked taxon within the Nemathelminthes with special regard to the occurrence of chitin. Based on this out-group comparison it can be concluded that: (1) a two-layered cuticle with a trilaminate epicuticle and a proteinaceous basal layer represents an autapomorphic feature of the Nemathelminthes, (2) the stem species of the Cycloneuralia have already evolved an additional basal chitinous layer, (3) such a three-layered cuticle is maintained as a plesiomophy in the ground pattern of the Scalidophora and (4) in the Nematoida, the chitinous basal layer is replaced by a collagenous one at least in the adults; the synthesis of chitin is restricted to early developmental phases or the pharyngeal cuticle. Accepted: 12 March 1998  相似文献   

17.
Peter Zwick 《Hydrobiologia》1990,194(3):207-223
Upstream oviposition flights of several Plecoptera species of the genera Leuctra, Nemoura, Isoperla and Siphonoperla along the Breitenbach, Hesse, Germany are inferred from 1. oviposition occuring upstream from emergence areas; 2. size differences and size-shifts between emerging and egg-laying females; 3. concentration of oviposition in upstream sections of the emergence area. The last point relies on direct catches of egg-laying females with sticky traps, and on over-representation of old, mature females in upstream emergence traps towards the end of, or even after actual emergence periods. Criteria for age class discrimination of the respective taxa are described. The validity of the present and of other indirect evidence for directed adult flights and the significance of adult upstream displacement are discussed. Optical orientation cues are suggested. Females of Leuctra prima and Siphonoperla torrentium are shown to gain 25–50% dry weight by feeding in the terrestrial environment; general information indicates many other Plecoptera may be similar in this respect. Terrestrial adult life is shown to last for 3–8 weeks. This long time, evidence of important flight activity and feeding together suggest that the terrestrial phase is spent as an active adult, the inevitable risks of which may form an important control of population dynamics.  相似文献   

18.
Lees, D. C., Rougerie, R., Zeller‐Lukashort, C. & Kristensen, N. P. (2010). DNA mini‐barcodes in taxonomic assignment: a morphologically unique new homoneurous moth clade from the Indian Himalayas described in Micropterix (Lepidoptera, Micropterigidae). —Zoologica Scripta, 39, 642–661. The first micropterigid moths recorded from the Himalayas, Micropterix cornuella sp. n. and Micropterix longicornuella sp. n. (collected, respectively, in 1935 in the Arunachel Pradesh Province and in 1874 in Darjeeling, both Northeastern India) constitute a new clade, which is unique within the family because of striking specializations of the female postabdomen: tergum VIII ventral plate forming a continuous sclerotized ring, segment IX bearing a pair of strongly sclerotized lateroventral plates, each with a prominent horn‐like posterior process. Fore wing vein R unforked, all Rs veins preapical; hind wing devoid of a discrete vein R. The combination of the two first‐mentioned vein characters suggests close affinity to the large Palearctic genus Micropterix (to some species of which the members of the new clade bear strong superficial resemblance). Whilst absence of the hind wing R is unknown in that genus, this specialization is not incompatible with the new clade being subordinate within it. A 136‐bp fragment of Cytochrome oxidase I successfully amplified from both of the 75‐year‐old specimens strongly supports this generic assignment. Translated to amino acids, this DNA fragment is highly diagnostic of this genus, being identical to that of most (16 of the 26) Micropterix species studied comparatively here, 1–4 codons different from nine other species (including Micropterix wockei that in phylogenetic analyses we infer to be sister to other examined species), whilst 7–15 codons different to other amphiesmenopteran genera examined here. A dating analysis also suggests that the large clade excluding M. wockei to which M. cornuella belongs appeared <31 million years ago. These findings encourage discovery of a significant radiation of Micropterix in the Himalayan region. Our analysis has more general implications for testing the assignment of DNA mini‐barcodes to a taxon, in cases such as museum specimens where the full DNA barcode cannot be recovered.  相似文献   

19.
The last instar larva and the pupa of Ptilocolepus extensus McLachlan, 1884, an endemic of the Iberian Peninsula, are described for the first time. The final instar larva of Pt. extensus bears close resemblance to those of Ptilocolepus granulatus (Pictet, 1834), but the abdomen has a well-developed dorsal sclerotized plate on segment VIII; this is a morphological feature which has not been observed in any other Ptilocolepinae. Final instar larvae make dorsoventrally flattened, elongate-oval cases of leaf pieces from several moss and liverwort species; such cases are characteristic of the Ptilocolepinae. Some additional data on biology and geographical distribution are given.  相似文献   

20.
The first rigorous analysis of the phylogeny of the North American vaejovid scorpion subfamily Syntropinae is presented. The analysis is based on 250 morphological characters and 4221 aligned DNA nucleotides from three mitochondrial and two nuclear gene markers, for 145 terminal taxa, representing 47 species in 11 ingroup genera, and 15 species in eight outgroup genera. The monophyly and composition of Syntropinae and its component genera, as proposed by Soleglad and Fet, are tested. The following taxa are demonstrated to be para‐ or polyphyletic: Smeringurinae; Syntropinae; Vaejovinae; Stahnkeini; Syntropini; Syntropina; Thorelliina; Hoffmannius; Kochius; and Thorellius. The spinose (hooked or toothed) margin of the distal barb of the sclerotized hemi‐mating plug is demonstrated to be a unique, unambiguous synapomorphy for Syntropinae, uniting taxa previously assigned to different subfamilies. Results of the analysis demonstrate a novel phylogenetic relationship for the subfamily, comprising six major clades and 11 genera, justify the establishment of six new genera, and they offer new insights about the systematics and historical biogeography of the subfamily, and the information content of morphological character systems.  相似文献   

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