摘要:

AbstractThe recent members of the phylum Cnidaria were analyzed with phylogenetic methodology and the help of the PAUP Computer program. The Cnidaria are established as a monophylum by their cnidocysts, planula larva, and a polyp stage. The Ctenophora were seen as the most probable sister group of the Cnidaria. Arguments for the monophyly of the cnidarian classes Anthozoa, Scyphozoa, Cubozoa, and Hydrozoa were providea. For the ground plan of the Cnidaria the following characters were postulated: triphasic life cycle consisting of a planula larva, a benthic polyp stage, and a sexually propagating medusa like stage. For the polyp a radial symmetry, lack of septae, and hollow tentacles were assumed. The original medusa probably was tetraradial and developed from the polyp stage by a total metamorphosis. Twelve polarized characters were used to generate cladograms. The most parsimonious one showed the Anthozoa as the first offshoot of the tree with the united Scyphozoa, Cubozoa and Hydrozoa forming its sister group. Within this sister group the Scyphozoa and Cubozoa were seen as sistergroups to each other. Both groups united are then the sistergroup of the Hydrozoa. A bootstrap analysis yielded the same tree with high probabilities for the internal nodes. Despite assuming a planktonic origin of the Cnidaria in this investigation, the resulting cladogram is also compatible with an evolution of the medusa stage within the Cnidaria after the splitting‐off of the Anthozoa. The possible loss of the medusa stage in the Anthozoa is discusse

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe phylogeny of the Phyllodocidae (Polychaeta Annelida) is examined in an analysis which includes previously unnoticed characters of the nervous system. Concentrating on four problems of importance in understanding the phylogeny of the family, a study of the nervous system demonstrated that: 1. A median antenna, such as that present in species ofEulalia, is not homologous to the nuchal papilla of, for example,EteoneandPhyllodoce; 2. Nuchal organs, presumably found in all phyllodocids, are basically homologous, but four separate types may be recognized; 3. The anterior concentration of the first segments (particularly their tentacular cirri), which is evident in most phyllodocids, is accompanied by different alterations of the ventral nervous system. The polarities of these changes are not self‐evident; 4. A study of the ventral nervous system ofEteonereveals that the first apparent segment, bearing two pairs of tentacular cirri, must be regarded as homologous to the second segment of all other phyllodocids. Furthermore, this genus descended from forms in which a segment was present anterior to the first apparent segment, the first two segments possibly bearing tightly packed tentacular cirri.In connection with other characters, this information was used to produce a cladogram, which has some surprising features. The most unexpected result is the prediction thatEteoneis the sister group of a taxon containing the generaParanaitis, Chaetoparia, andPhyllodoce.The results are discussed and compared to those of other investigator

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe monophyly of Staphylinidae, Paederinae and Cryptobiina is discussed. Using a cladistic analysis based on 40 exoskeletal characters, a hypothesis on the phylogeny of genera of Afro‐tropical Cryptobiina is proposed. The cladogram clearly shows that these beetles have evolved alone three main pathways. Pathway 1 relates to a single genus,Matropium, the representatives of which exhibit many characters in plesiomorphic state and inhabit soil organic horizons of the Afroalpine zone in Zaïre. With regard to pathways 2 and 3, the observation of certain morphological traits (e. g. the shape of metanotum, the design of mesocoxal cavities) leads to the assumption that genera have developed distinct predation strategies and/or locomotion modalities: on the one hand, three strictly forest dwelling genera (Cryptofagiella, PachyryptumandNitidicryptum) have specialized towards a modality of running down or stalking prey in the rain forest; on the other hand, the eight remaining genera would have gained the ability either to hunt by flight or to move quickly in connection with an increase of flight performances, head mobility and visual acuity. This latter evolutionary pattern appears to be particularly evident in highly evolved genera likeMonocrypta, AfrophitodumandOpbitod

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractWe have carried out bimonthly collections ofDrosophilaspecies during a 16 month period in three localities of California (Eureka, Davis, and Gilroy).D. subobscura, which has colonized North America only a few years ago, is well established and has an annual abundance cycle similar to that observed in the Old World. The differences between the three localities account for 26.4% of the species diversity. Davis and Gilroy exhibit similarities attributable to their similar environmental conditions. Seasonality accounts for 46% and 50.4 % of the species diversity in Davis and Gilroy respectively, but only for 39.4% in Eureka. Differences between years explain only a small percentage of the total species diversity. A correspondence analysis of the association between species and months of collection shows ecological similarities betweenD. subobscuraand the Nearctic members of theobscuraspecies group.

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractTwo morphological different species of hairtails,Trichiurus lepturusandT. japonicuswere compared by starch gel electrophoresis. Isozyme patterns of eight metabolic enzymes and general muscle proteins using extracts of eye, muscle, liver and heart revealed 16 loci. The polymorphic loci weresAAT‐1, GPI‐A, GPI‐B, IDHP‐1 andPGM‐2 for at least one of the two species. There were no fixed allelic isozyme patterns to differentiate among them. NEI's genetic identity (I) between the two species was calculated. An I index of 0.986 suggests that the two morphologically different hairtails belong to the same species,Trichiurus

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00191.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractProgressive and regressive changes of brain size within EquidaeFromHyracotheriumtoEquusbrain size increased eightfold independently from body size. In domestication brain size is reduced; within mammals the amount of reduction depends on cephalization. Species with high cephalization show much more reductions than those with low cephalization. Among the ancestors of domesticated mammals wild horses have the highest cephalization level; reduction of brain size of more than 30% in domesticated horses could be expected. The size of the brain case of domesticated horses is only 14 % smaller than in wild Przewalski horses. We think that populations of the wild Przewalski horses have been crossbreeds between wild and domesticated animals.There is no difference in size of the brain case capacity and the brain weight between the Przewalski horses from zoological gardens and domesticated horses. This may be due to further crossbreeding between Zoo‐Przewalski horses and domesticated horses and to artificial selectio

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00192.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Wünnenberg, W.: Physjologie des Winterschlafes. Mammalia depicta, Heft 14. Beihefte Zeitschrift für Säugetierkunde. Hamburg und Berlin:Petersen, M. E.; Kirkegaard, B. (Eds.): Systematics, Biology and Morphology of World Polychaeta. Proceedings of the 2nd International Polychaete Conference Copenhagen 1986.Böhme, W.; Horn, H.‐G. (Eds.): Advances in monitor res

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00193.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY