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Parthenogenesis did not consistently evolve in insular populations of Ischnura hastata (Odonata,Coenagrionidae) 下载免费PDF全文
M. OLALLA LORENZO‐CARBALLA CHRISTOPHER HASSALL ANDREA C. ENCALADA IAGO SANMARTÍN‐VILLAR YUSDIEL TORRES‐CAMBAS ADOLFO CORDERO‐RIVERA 《Ecological Entomology》2017,42(1):67-76
1. The evolutionary advantages that have driven the evolution of sex are still very much debated, and a number of benefits of parthenogenesis over sexual reproduction have been proposed. In particular, parthenogenetic individuals are thought to exhibit higher probabilities of establishment following arrival in new, isolated habitats such as islands. 2. One notable example of parthenogenesis occurring in islands is the damselfly Ischnura hastata, an American species that has colonised the Azores archipelago, where the populations consist only of females. This is the only known example of parthenogenesis within the insect order Odonata. 3. Here, two island populations of I. hastata were studied, one in the Galapagos and one in Cuba, to test whether island colonisation is consistently associated with parthenogenesis in this species. Field capture–mark–recapture studies and laboratory rearing of field‐collected eggs were undertaken in both areas. 4. Sex ratios in the field were found to be heavily female‐biased among mature individuals; however, fertility rates of field‐collected eggs were high, and the sex ratios in the laboratory did not differ from 1 : 1. Data from laboratory rearing showed that shorter larval development times and shorter adult life spans in males result in protandry, which might explain the skewed sex ratios in the field. 5. These findings are consistent with sex differences in key demographic parameters which could predispose I. hastata to parthenogenesis. However, the Azores population of I. hastata remains the only documented case of asexual reproduction in this insect group. 相似文献
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LORENZO PERUZZI NICODEMO GIUSEPPE PASSALACQUA 《Botanical journal of the Linnean Society. Linnean Society of London》2008,157(4):763-774
A morphometric study on five populations of the Onosma echioides complex was carried out through univariate analysis, principal coordinate analysis and cluster analysis (the unweighted pair‐group method with arithmetic mean; UPGMA). In consideration of the quantitative morphological variability, of the known karyological homogeneity and of the allopatric distribution of the taxa, we propose here to treat this complex as a single species subdivided in four subspecies. The names O. angustifolia Lehm., O. canescens J. et C. Presl, O. dalmatica Scheele, O. echioides var. columnae Lacaita, O. echioides var. veronensis Lacaita and O. javorkae Simonkai are typified. The new combinations O. echioides subsp. angustifolia (Lehm.) Peruzzi & N. G. Passal., O. echioides subsp. canescens (J. et C. Presl) Peruzzi & N. G. Passal. and O. echioides subsp. dalmatica (Scheele) Peruzzi & N. G. Passal. are proposed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 763–774. 相似文献
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GIACOMO SANTINI LORENZO TUCCI LORENZO OTTONETTI FILIPPO FRIZZI 《Ecological Entomology》2007,32(3):319-326
Abstract. 1. The organisation of an ant assemblage inhabiting an olive orchard in central Italy was analysed and patterns of dominance among ant species were described in order to assess (i) the relationship between thermal dependency and degree of behavioural dominance, and (ii) the relationship between dominance and discovery ability.
2. Activity patterns of the most abundant species on trees were examined in a sample of 120 trees during spring and summer. The degree of behavioural dominance and the ability of different species to discover new food sources were assessed using tuna baiting on a subset of 80 trees.
3. Different ant species showed contrasting patterns of activity. Some species (such as Lasius lasioides , Camponotus lateralis , and Camponotus piceus ) were most active during the warmer part of the day, while others restricted their activity to the cooler hours ( Camponotus aethiops and Plagiolepis pygmaea ). Some species (such as Crematogaster scutellaris ) were active irrespective of the time of day.
4. No clear relationship was observed between temperature of maximal activity and degree of behavioural dominance. There was, however, a positive relationship between behavioural dominance and thermal range of activity. A positive relationship between dominance and ability to find resources, with the most behaviourally dominant and aggressive species being most efficient in finding food items, was also observed.
5. The results support the idea that the temperature–dominance relationship is much more complex in Mediterranean-type habitats than in other ecosystems. Of particular interest is the positive dominance–discovery relationship. This finding contrasts with previous investigations, which reported a negative relationship between dominance and discovery ability and suggested that this pattern plays a role in promoting the coexistence of species in ant communities. 相似文献
2. Activity patterns of the most abundant species on trees were examined in a sample of 120 trees during spring and summer. The degree of behavioural dominance and the ability of different species to discover new food sources were assessed using tuna baiting on a subset of 80 trees.
3. Different ant species showed contrasting patterns of activity. Some species (such as Lasius lasioides , Camponotus lateralis , and Camponotus piceus ) were most active during the warmer part of the day, while others restricted their activity to the cooler hours ( Camponotus aethiops and Plagiolepis pygmaea ). Some species (such as Crematogaster scutellaris ) were active irrespective of the time of day.
4. No clear relationship was observed between temperature of maximal activity and degree of behavioural dominance. There was, however, a positive relationship between behavioural dominance and thermal range of activity. A positive relationship between dominance and ability to find resources, with the most behaviourally dominant and aggressive species being most efficient in finding food items, was also observed.
5. The results support the idea that the temperature–dominance relationship is much more complex in Mediterranean-type habitats than in other ecosystems. Of particular interest is the positive dominance–discovery relationship. This finding contrasts with previous investigations, which reported a negative relationship between dominance and discovery ability and suggested that this pattern plays a role in promoting the coexistence of species in ant communities. 相似文献
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Abstract. The response of Triatoma infestans (Klug) to odours left behind by walking insects was analysed. The insects aggregated on papers marked with putative chemical footprints in the absence of other assembling chemical signals. Contact of the receptor insect with the treated surface was necessary to elicit the response because the signal was not able to attract insects, only to arrest them on marked surfaces. These requirements contrast with other chemical aggregation signals of triatomines that attract the insect and involve olfactory responses. By washing the cuticle of the insects with hexane and impregnating papers with the extract, a response was evoked in test insects similar to that elicited by papers on which insects had walked. The biological role of this novel aggregation factor is discussed in relation to other assembling signals of different origin. 相似文献
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MUKERREM FENERCI-MASSE JEAN-PIERRE MASSE CONSUELO ARIAS† LORENZO VILAS† 《Palaeontology》2006,49(4):769-794
Abstract: Archaeoradiolites gen. nov. (Radiolitidae), mainly characterized by radially arranged branching walls structuring the outer shell layer, includes two species, Archaeoradiolites primitivus gen. et sp. nov. and Archaeoradiolites hispanicus gen. et sp. nov. (type species), the distinction of which is based on size, shell habit and development of the radially branching microstructure. Their geographical distribution is restricted to south-east Spain and south-west France, i.e. the Western European Tethyan margin, whereas data from the Black Sea coast of Turkey suggest a possible extension to the Eastern European Tethyan margin. Each species has a distinct biostratigraphic distribution within the Upper Aptian (mainly the Gargasian). Agriopleura is suggested to be the direct ancestor of Archaeoradiolites, which in turn is considered as the progenitor of Eoradiolites. The onset of the Radiolitidae is associated with global oceanic changes that favoured calcite as opposed to aragonite biomineralization. The acquisition of a porous shell microstructure appears, in many respects, biologically advantageous and may account for gaining a rapid (< 1 myr) ecological ability for efficient colonization and occupation of space of the family in the earlier phase of its radiation. 相似文献
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SARA FRATINI LAPO RAGIONIERI CHIARA PAPETTI GAETANO PITRUZZELLA ROCCO RORANDELLI SILVIA BARBARESI LORENZO ZANE 《Molecular ecology resources》2006,6(1):179-181
Seven polymorphic microsatellite loci were isolated and characterized from the grapsid crab Pachygrapsus marmoratus using FIASCO (fast isolation by AFLP of sequences containing repeats) protocol. Twenty‐seven primer pairs were designed, 14 of which worked well in polymerase chain reaction (PCR), amplifying a fragment of the expected size. Variability was tested in 18 specimens collected along the coast of Tuscany (Italy). Five loci were discarded due to stutter products during their amplification, and two resulted to be monomorphic. The remaining seven loci, showed a number of alleles ranging from two to 14 and an observed heterozygosity ranging from 0.12 to 0.67. 相似文献
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EMANUELE SUSANA CHIARA PAPETTI FEDERICA BARBISAN ERICA BORTOLOTTO SIMONA BUCCOLI TOMASO PATARNELLO LORENZO ZANE 《Molecular ecology resources》2007,7(5):791-793
We characterized eight polymorphic microsatellites in the Scotia icefish Chaenocephalus aceratus (Perciformes, Notothenioidei, Channichthyidae) that is endemic of Southern Ocean waters surrounding the tip of the Antarctic Peninsula. Microsatellites were isolated from a partial genomic library enriched for an AC motif. The number of alleles ranged from two to 19 with a mean observed hererozygosity of 0.71. Loci were in Hardy–Weinberg equilibrium and no evidence for linkage disequilibrium was found. These molecular markers will be useful to investigate Scotia icefish genetic structure, possibly providing insights on its effective population size and demographic history. 相似文献