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1.
The spider genus Metabus (Tetragnathidae) previously included nine species: the type M. gravidus O. P.-Cambridge, 1899 – junior synonym of Leucauge ocellata (Keyserling) – from Central America and eight species from Chile. In this paper, the classification of the Metabus species-complex is revised, and two new genera, with three new species and five new combinations, are described. Allende gen. nov. is created for four Chilean species not congeneric with the type of Metabus : the type A. puyehuensis sp. nov. , A. patagiatus (Simon) comb. nov. , A. nigrohumeralis (F. O. P.-Cambridge) comb. nov. and A. longipes (Nicolet) comb. nov. Further additions to the Chilean fauna are under the new genus Mollemeta gen. nov. – created for M. edwardsi (Simon) comb. nov. – and three new species of Chrysometa : C. acinosa sp. nov. , C. levii sp. nov. and C. maitae sp. nov. Metabus now includes four species: M. ocellatus (Keyserling) comb. nov. , M. debilis (O. P.-Cambridge) comb. nov. , M. ebanoverde sp. nov. and M. conacyt sp. nov. All of these species were included in a phylogenetic analysis of 38 tetragnathid and 12 orbicularian outgroup terminals scored for 105 morphological and behavioural characters. The results suggest that Metabus as previously circumscribed is polyphyletic. The phylogenetic relationships within tetragnathids are briefly discussed. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 285–335.  相似文献   

2.
Agnarsson, I., Kuntner, M., Coddington, J. A. & Blackledge, T. A. (2009). Shifting continents, not behaviours: independent colonization of solitary and subsocial Anelosimus spider lineages on Madagascar (Araneae, Theridiidae). —Zoologica Scripta, 39, 75–87. Madagascar is a biodiversity hotspot, thought to be colonized mostly via Cenozoic dispersal from Africa, followed by endemic radiation of multiple lineages. Anelosimus spiders are diverse in Madagascar, and, like their congeners in the Americas, are most diverse in wet montane forests. Most Anelosimus species are social in that they cooperate in web building and prey capture either during a part of their life cycles (subsocial), including hitherto studied Malagasy species, or permanently (quasisocial). One Central American coastal species, Anelosimus pacificus, has secondarily switched to solitary living, and available evidence suggests that its closest relatives from S. America and Europe are likely also solitary. Here, we show that the only known coastal Anelosimus species in Madagascar and Comoros –Anelosimus decaryi and Anelosimus amelie sp. n. – are also solitary. Using a phylogenetic approach, we test two competing hypotheses: (i) that Malagasy Anelosimus are monophyletic and thus represent a second example of reversal to solitary living in a littoral habitat or (ii) that solitary and subsocial lineages independently colonized Madagascar. We find that solitary Malagasy Anelosimus are closely related to their solitary counterparts from Europe and the Americas, while subsocial Malagasy species nest sister to Anelosimus nelsoni from S. Africa. This finding suggests that (i) the two Anelosimus lineages colonized Madagascar independently and (ii) a reversal to solitary behaviour has occurred only once in Anelosimus. Thus, solitary littoral Malagasy species did not descend from Malagasy mountains, but arrived from much further afar. African and possibly American origin of the two lineages is implied by our findings. To restore natural classification of Anelosimus, Seycellocesa Koçak & Kemal is synonymized with it.  相似文献   

3.
Social spiders are unusual among social organisms in being highly inbred-males and females mature within their natal nest and mate with each other to produce successive generations. Several lines of evidence suggest that in spiders inbred social species originated from outbred subsocial ancestors, a transition expected to have been hindered by inbreeding depression. As a window into this transition, we examined the fitness consequences of artificially imposed inbreeding in the naturally outbred subsocial spider Anelosimus cf. jucundus. Subsocial spiders alternate periods of solitary and social living and are thought to resemble the ancestral system from which the inbred social species originated. We found that inbreeding depression in this subsocial spider only becomes evident in spiders raised individually following the end of their social phase and that ecological and demographic factors such as eclosion date, number of siblings in the group and mother's persistence are more powerful determinants of fitness during the social phase. A potential explanation for this pattern is that maternal care and group living provide a buffer against inbreeding depression, a possibility that may help explain the repeated origin of inbred social systems in spiders and shed light on the origin of other systems involving regular inbreeding.  相似文献   

4.
Abstract The evolution of group living is regarded as a major evolutionary transition and is commonly met with correlated shifts in ancillary characters. We tested for associations between social tendency and a myriad of abiotic variables (e.g., temperature and precipitation) and behavioral traits (e.g., boldness, activity level, and aggression) in a clade of spiders that exhibit highly variable social structures (genus Anelosimus). We found that, relative to their subsocial relatives, social species tended to exhibit reduced aggressiveness toward prey, increased fearfulness toward predators, and reduced activity levels, and they tended to occur in warm, wet habitats with low average wind velocities. Within-species variation in aggressiveness and boldness was also positively associated with sociality. We then assessed the functional consequences of within-species trait variation on reconstituted colonies of four test species (Anelosimus eximius, Anelosimus rupununi, Anelosimus guacamayos, and Anelosimus oritoyacu). We used colonies consisting of known ratios of docile versus aggressive individuals and group foraging success as a measure of colony performance. In all four test species, we found that groups composed of a mixture of docile and aggressive individuals outperformed monotypic groups. Mixed groups were more effective at subduing medium and large prey, and mixed groups collectively gained more mass during shared feeding events. Our results suggest that the iterative evolution of depressed aggressiveness and increased within-species behavioral variation in social spiders is advantageous and could be an adaptation to group living that is analogous to the formation of morphological castes within the social insects.  相似文献   

5.
The Neotropical genera of the linyphiid spider subfamily Erigoninae are revised at the genus level. Emphasis was placed on genera endemic to the Neotropics and species with dubious relationships to their nominal genera, especially species from the older literature. This work recognizes 50 genera in the Neotropics, of which 39 genera are strictly endemic to the Neotropics, three are represented outside the Neotropics by one species, and eight genera have significant representation both in and beyond the Neotropics. Three additional genera, Ceraticelus Simon, 1884, Idionella Banks, 1893, and Eulaira Chamberlin & Ivie, 1933, are represented in northern Mexico and/or the West Indies, but are best classified as having a Nearctic or Holarctic distribution. Species previously placed in the typically northern hemisphere genera Gongylidiellum Simon, 1884, Leptorhoptrum Kulczynski, 1894, Macrargus Dahl, 1886, Minyriolus Simon, 1884, Oedothorax Bertkau, 1883, Phanetta Keyserling, 1886, and Tmeticus Menge, 1868 are found to be misplaced or nomina dubia; two genera endemic to the Neotropics, Clitistes Simon, 1902 and Zilephus Simon, 1902 are nomina dubia. The genus Beauchenia Usher, 1983 is an erigonine, not a mynoglenine; there are no known representatives of the Mynogleninae in the Neotropics. One hundred and forty new combinations are established; 19 genera are synonymized including Micromaso Tambs‐Lyche, 1954, revalidation rejected; 34 species are synonymized. The following new genera are established: Gigapassus gen. nov. , Intecymbium gen. nov. , Moyosi gen. nov. , Orfeo gen. nov. and Toltecaria gen. nov. Malkinella Millidge, 1991 and Valdiviella Millidge, 1985 are preoccupied; Malkinola nom. nov. and Valdiviola nom. nov. are established as replacement names. The following new species are described: Asemostera daedalus sp. nov. , Asemostera enkidu sp. nov. , Asemostera janetae sp. nov. , Fissiscapus attercop sp. nov. , Gonatoraphis lysistrata sp. nov. , Gravipalpus standifer sp. nov. , Microplanus odin sp. nov. , Moyosi chumota sp. nov. , Myrmecomelix leucippus sp. nov. , Neomaso damocles sp. nov. , Notiomaso exonychus sp. nov. , Paraletes pogo sp. nov. , Psilocymbium acanthodes sp. nov. , Smermisia holdridgi sp. nov. and Smermisia parvoris sp. nov. The following species remain misplaced in inappropriate genera: Erigone fellita Keyserling, 1886, Erigone zabluta Keyserling, 1886, and Oedothorax fuegianus (Simon, 1902). For 23 species, type specimens could not be located and the species could not be unambiguously identified; the type of Macrargus pacificus Berland, 1924 could not be located, but it is transferred to Laminacauda Millidge, 1985. The female of Onychembolus subalpinus Millidge, 1985 described by Millidge in 1991 is mismatched; this female is Notiomaso exonychus sp. nov. ; the true female of Onychembolus subalpinus was described as both Neomaso bidentatus Millidge, 1991 syn. nov. and Neomaso tridentatus Millidge, 1991 syn. nov. The male and female of Asemonetes[now Asemostera]arcana (Millidge, 1991) are not conspecific; a male thought to be conspecific with the female of A. arcana is newly described; the true female of A. arcana is unknown. The transfer of Emenista dentichelis Berland, 1913 to Laminacauda comb. nov. renders Laminacauda dentichelis Millidge, 1991 a junior homonym; the replacement name Laminacauda baerti nom. nov. is provided for Laminacauda dentichelis Millidge. The following species were erroneously placed in erigonine genera: Oedothorax bisignatus Mello‐Leitão, 1945 is synonymized with Theridion calcynatum Holmberg, 1876 syn. nov. (Theridiidae); Liger incomta O. Pickard‐Cambridge, 1896 is transferred to Theridion Walckenaer, 1805 (Theridiidae) [Theridion incomtum comb. nov. ]; Erigone ectrapela Keyserling, 1886 is transferred to Dictyna Sundevall, 1833 (Dictynidae) [Dictyna ectrapela comb. nov. ]; Erigone peruana Keyserling, 1886 is transferred to Thymoites Keyserling, 1884 (Theridiidae) [Thymoites peruanus comb. nov. ]; Adelonetria dubiosa Millidge, 1991 is not a linyphiid and will be dealt with elsewhere. Lomaita darlingtoni Bryant, 1948 is confirmed as a linyphiid, not a mysmenid. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 149 (Suppl. 1), 1–263.  相似文献   

6.
The species of Scleropactidae from America are revised and redescribed. A phylogeny hypothesis based on an analysis of morphological characters is presented. The genera are redefined and the generic placement of several species is corrected. The Neotropical Scleropactidae include Colomboscia , Scleropactes , Circoniscus , Neosanfilippia , Sphaeroniscus , Richardsoniscus , Spherarmadillo , Colomboniscus , Amazoniscus and Protosphaeroniscus . The genus Chileoniscus is excluded from the Scleropactidae. Sphaerobathytropa is excluded from the Scleropactidae and its previous record from Argentina is revealed to be erroneous. Synuropus is revalidated and excluded from the Scleropactidae. The following new genera are introduced: Scleropactoides gen. nov. , Globopactes gen. nov. , Caecopactes gen. nov. , and Troglopactes gen. nov. Thirteen species are described as new: Caecopactes minimus sp. nov. , Colomboscia parva sp. nov. , Globopactes falconensis sp. nov. , Globopactes hispidus sp. nov. , Globopactes meridae sp. nov. , Scleropactes cotopaxii sp. nov. , Scleropactes ecuadoriensis sp. nov. , Scleropactes pululahua sp. nov. , Scleropactoides curvatus sp. nov. , Circoniscus hirsutus sp. nov. , Sphaeroniscus quintus sp. nov. , Spherarmadillo nebulosus sp. nov. , and Chileoniscus armadillidioides sp. nov. Identification keys to all species are provided.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 (Suppl. 1), 1–339.  相似文献   

7.
Solorinella nigrescens Thor sp. nov., is described from Peru. Only one species of Solorinella, S. asteriscus Anzi from Europe and Pakistan, has been known previously. The morphology of the two populations of 5. asteriscus in central Europe and southern Norway is discussed. They differ chiefly in spore width. Toninia tristis is reported for the first time from Peru and South America.  相似文献   

8.
This paper contributes to a revision of the genus Halectinosoma . Four new species are described, based on examination of ectinosomatid material from localities in western Europe, eastern Canada and the Arctic. Halectinosoma mandibularis sp. nov. is distinguishable from other species by the reduced setation of the mouthparts and enlarged mandibular gnathobase. Halectinosoma latisetifera sp. nov. bears an affinity with H. cooperatum but is easily distinguished by the shape of the setae on the female fifth leg. A species previously erroneously ascribed to H. finmarchicum (Scott) by several authors is described here as Halectinosoma kliei sp. nov. Halectinosoma gothiceps (Giesbrecht) is redescribed and the closely related Halectinosoma paragothiceps sp. nov. is described and distinguished from H. gothiceps . It is considered likely that some previous records of H. gothiceps are in error.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 453–475.  相似文献   

9.
10.
Calyptraeid gastropods are well know for the taxonomic difficulties caused by their simple, phenotypically variable shells. In this paper I demonstrate that what was previously considered to be a single species, Crepidula aculeata , is an ancient (3–15 Myr) cryptic species complex made up of at least eight species, and that this group should be placed in the genus Bostrycapulus . Despite the difficulty in finding diagnostic adult shell and anatomical features upon which species can be unambiguously identified, DNA sequences, protoconch morphology, embryonic morphology and developmental characters clearly differentiate these eight species. A single species with direct development and nurse eggs is present in the South Atlantic, and a species with planktotrophic development occurs in the equatorial Pacific. The species from Japan, Australia, Florida, the Pacific coasts of Mexico and Central America, and the Cape Verde Islands all have direct development. Most of these species are separated by > 15% divergence in COI sequence data. The fossil record of Bostrycapulus goes back to the Miocene, which agrees with genetic estimates of divergences within the genus ranging from 3 to 15 Mya. Surprisingly, these ancient species differ only slightly in morphology from each other and genetic differentiation does not correlate with geographical distance. I revise the genus Bostrycapulus on the basis of differences in adult morphology, embryonic morphology, mode of development, protoconch morphology, and DNA sequence data. I also describe four new species ( B. pritzkeri sp. nov., B. odites sp. nov., B. latebrus sp. nov. and B. urraca sp. nov. ) and remove three others ( B. gravispinosus , B. calyptraeformis , and B.  cf. tegulicius ) from synonymy with B. aculeatus .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 75−101.  相似文献   

11.
12.
Species range boundaries often form along environmental gradients that dictate the success of the phenotypes present in each habitat. Sociality may allow colonization of environments where related species with a solitary lifestyle cannot persist. Social spiders in the genus Anelosimus appear restricted to low- and mid-elevation moist environments in the tropics, while subsocial spiders, common at higher elevations and latitudes, appear to be absent from the lowland tropical rainforest. Here, we seek factors that may simultaneously prevent subsocial Anelosimus species from colonizing the lowland rainforest while favouring species with large social groups in this habitat. To this end, we transplanted small groups of a subsocial species, which contain the offspring of a single female, from cloud forest habitat in the centre of its natural range to lower montane rainforest on the range margin and to lowland rainforest outside of the species range. Groups transplanted at the range margin and below their range limit were less likely to disperse and experienced increased mortality. This was correlated with greater rainfall intensity and ant abundance. We show that protection from rainfall enhances the performance of small groups of spiders in the lowland rainforest, and suggest that predation or disturbance by ants may influence the geographical range limits of this species.  相似文献   

13.
In this study we revise the cheilostome bryozoan genus Buffonellaria Canu & Bassler, 1927 and its Mediterranean and north-east Atlantic species, thereby addressing several existing problems. First, a lectotype for the type species, Buffonellaria divergens (Smitt, 1873) from Florida, is chosen, which proves to be distinct from the European species. Second, the two hitherto established north-east Atlantic species [ Buffonellaria nebulosa ( Jullien & Calvet, 1903 ) and Buffonellaria porcellanum Arístegui Ruiz, 1987], are redescribed, which were poorly documented until now. Third, close inspection of material, collected from Spitsbergen to tropical West Africa, using scanning electron microscopy reveals that the actual number of species, all previously referred to either B. divergens or Stephanosella biaperta (Michelin, 1848), is distinctly greater in the north-east Atlantic than has been previously acknowledged. As a result, seven new species are introduced ( Buffonellaria acorensis sp. nov. , Buffonellaria antoniettae sp. nov. , Buffonellaria arctica sp. nov. , Buffonellaria harmelini sp. nov. , Buffonellaria jensi sp. nov. , Buffonellaria muriella sp. nov. , and Buffonellaria ritae sp. nov. ), whereas two are left in open nomenclature. With the increase in number of species, the extremely broad geographical range of distribution assumed for B. divergens breaks down to numerous restricted areas. However, although most species have only been reported from a single location, B. arctica sp. nov. seems to have a fairly wide distribution in the Arctic region.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 537–566.  相似文献   

14.
Macropora is a distinctive genus of anascan cheilostomes. All species have large zooids with an extensive cryptocystal frontal shield perforated by numerous pores through which parietal muscle strands pass. Also characteristic of Macropora are the calcified opercula closing the d -shaped orifice, avicularia resembling autozooids but having slightly enlarged, typically crenulated opercula/mandibles, and large ovicells that are often costate. This mostly Australasian genus has a documented fossil record stretching back to the Eocene. Here we revise the generic diagnosis of Macropora and describe eight new species from New Zealand (three Recent: M. nodulosa sp. nov. , M. filifera sp. nov. and M. carlosi sp. nov. ; five fossil: M. septispinosa sp. nov. , M. similis sp. nov. , M. pittensis sp. nov. , M. leeae sp. nov. and M. bullata sp. nov. ) and one new species from Japan ( M. mawatariorum sp. nov. ), the only species known with certainty to occur in the northern hemisphere. New observations are given for some previously described species, several of which are illustrated using SEM for the first time. The northern hemisphere Upper Cretaceous species Monoporella exsculpta (Marsson), showing features allowing it to be placed tentatively in the stem-group of Macropora , is redescribed. Attempts to resolve the phylogenetic relationships of species within Macropora were hampered by the relatively few morphological characters compared with the number of species, and it proved impossible to obtain a phylogeny robust to slight changes in taxon and/or character inclusion. The favoured cladogram has poor bootstrap and Bremer support, and its stratigraphical and biogeographical congruences are low.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 115–146.  相似文献   

15.
16.
记述采自中国河南和四川的叶蜂科叶蜂属2新种:黄胸短角叶蜂Tenthredo yingkehei sp.nov.,丹巴短角叶蜂Tantrhedo danbanica sp.nov..根据模式标本补充描述了分布于甘肃的近缘种黑柄短角叶蜂Tenthredo ruzickai Haris et Roller,2007.新种模式标本保存于湖南长沙中南林业科技大学昆虫模式标本室.  相似文献   

17.
记述中国瘦足蝇科裸瘦足蝇属Cliobata Enderlein 2新种:浅褐裸瘦足蝇Cliobata ecruis sp. nov.和周氏裸瘦足蝇Cliobata choui sp. nov.。浅褐裸瘦足蝇的鉴别特征为体浅褐色,胸部褐色具黄色斑;翅近端部具宽的透明带;生殖叉褐色,其臂部几乎与基部等长,臂基部中央具新月形凹陷。周氏裸瘦足蝇的鉴别特征为体黑色;翅近端部透明带窄;生殖叉黑褐色,其臂部长于基部,臂基部中央具半圆形凹陷。新种模式标本保存在中国农业大学昆虫博物馆。  相似文献   

18.
Abstract  The genus Menippus is revised for Australia, with six species, three of which are new: M. cynicus Clark, M. darcyi sp. nov. , M. ewani sp. nov. , M. fugitivus (Lea), M. sufi sp. nov. and M. yulensis (Jacoby) comb. nov. (from Diorhabda Weise). Menippus yulensis was described from New Guinea. This species and M. darcyi were formerly confused in Australia with M. fugitivus , which is now considered endemic to Lord Howe Island. The species formerly considered M. fugitivus and protected under the Threatened Species Conservation Act, New South Wales, is now named M. darcyi . A key is provided for the Australian species of Menippus and a lectotype designated for M. yulensis . The composition of Menippus is discussed and three non-Australian species are transferred to this genus: M. inconspicua (Jacoby) comb. nov. (from Diorhabda Weise); M. laterimaculata (Jacoby) comb. nov. ; and M. marginipennis (Jacoby) comb. nov. (from Galerucella Crotch). A revised checklist of Menippus species is given. The recorded foodplants of Menippus are species of Celtis (Ulmaceae).  相似文献   

19.
The phylogenetic relationships amongst the Arminidae were analysed based upon morphological characters of 58 presently described species or nudibranchs, including 35 previously described Arminidae and 20 new species of Dermatobranchus. From the literature review and anatomical examinations, 43 characters were considered for 78 taxa. These characters were polarized using Berthella canariensis as the outgroup taxon and the type species of several other genera identified from recent publications. The resulting phylogeny supports the monophyly of Arminidae, Dermatobranchus, Doridina, and Proctonotidae. The paraphyly of the Arminina is further demonstrated in this study. Two previously described, but poorly known, species of Indo-Pacific Armina are redescribed, Armina magnaBaba, 1955 and Armina paucifoliataBaba, 1955. The anatomy and taxonomic status of nine previously described species of Dermatobranchus were examined in this study. The anatomy of Dermatobranchus pustulosus (van Hasselt, 1824) has been overlooked since Bergh (1888) illustrated the radula of van Hasselt's specimen. It is redescribed and its range is extended to several new localities in the western Pacific. Dermatobranchus pulcherrimus Miller & Willan, 1986 is considered here as a new synonym of Dermatobranchus rubidus (Gould, 1852). The following 20 species of Dermatobranchus are new and are described in the present paper: Dermatobranchus albineus sp. nov., Dermatobranchus arminus sp. nov., Dermatobranchus caesitius sp. nov., Dermatobranchus caeruleomaculatus sp. nov., Dermatobranchus cymatilis sp. nov., Dermatobranchus dendonephthyphagus sp. nov., Dermatobranchus diagonalis sp. nov., Dermatobranchus earlei sp. nov., Dermatobranchus fasciatus sp. nov., Dermatobranchus funiculus sp. nov., Dermatobranchus kalyptos sp. nov., Dermatobranchus kokonas sp. nov., Dermatobranchus leoni sp. nov., Dermatobranchus microphallus sp. nov., Dermatobranchus oculus sp. nov., Dermatobranchus phyllodes sp. nov., Dermatobranchus piperoides sp. nov., Dermatobranchus rodmani sp. nov., Dermatobranchus semilunus sp. nov., and Dermatobranchus tuberculatus sp. nov. Eighteen of these new taxa are found in the Indo-Pacific tropics and two are found in temperate South Africa, D. albineus and D. arminus. Unique combinations of morphological characters distinguish these as new species of Dermatobranchus. Several species that are externally similar have radically divergent internal morphology, are members of different clades of Dermatobranchus, and represent cryptic species. Especially important is the radular morphology, which shows remarkable diversity of form, probably related directly to the diversification of feeding of members of this clade on various octocorals.  相似文献   

20.
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