摘要:

The reproductive biology of the arctiid mothsCreatonotos transiensandC. gangisexhibits a novel ontogenetic phenomenon, the morphogenesis of male coremata size being directly controlled by the quantity of hostplant‐derived pyrrolizidine alkaloids ingested by the larvae. In addition, the same alkaloids directly control the quantity of male pheromones synthesized and available for deployment by these scent organs. Reproduction in these insects thus shows striking linkages between ecological, behavioural, chemical and morphological features. This paper presents an account of the general biology of the moths, and reviews the literature onCreatonotosas a basis for reports on experimental wor

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1989.tb02518.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Adults of a freshwater‐feeding population ofLampetra fluviatilis(L.) in Loch Lomond, Scotland, were trapped on their upstream (spawning) migration in the main inflow to the loch, the Endrick Water. These animals could be distinguished from the more typical anadromous upstream migrantL. fluviatilis, from the Endrick Water and the nearby catchment of the River Forth, principally by their smaller total length, greater disc, snout and eye size and much darker pigmentation. These, and other morphometric and meristic characteristics have been compared for populations ofL. fluviatilisandLampetra planeri(Bloch) from the Lomond and Forth catchments using univariate and multivariate statistics. The Endrick Water ‘dwarf’L. fluviatiliswas found to differ significantly from the otherLampetrastudied, in a number of body proportions in addition to those traits mentioned above, and also in mean numbers of trunk myomeres and teeth. These differences are likely to be due to a combination of the effects of genetic isolation, and the short (freshwater) feeding phase of the ‘dwarf’L. fluviatilis, which may, therefore, represent the intermediate stage between parasitic and non‐parasitic forms in theL. fluviatilis/L. planeris

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1989.tb02519.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Eighteen graded non‐metric characters and 30 measurements of the mandible and lower dentition were used to investigate the grouping of African species of the generaCrocidura, SuncusandSylvisorex.Seventy‐seven taxa (species, subspecies and synonyms), including four European species, were represented by one to nine mandibles (147 mandibles in all), and the means of four Pleistocene African species were also included. The metric data were subjected to principal component and canonical variate analyses, and the non‐metric data to principal component analysis. Grouping was detected by comparing the results of the three analyses. Six groups are recognized within the genusCrocidura, typified byC. fumosa, C. turba, C. russula, C. fuscomurina, C. hirtaandC. flavescens. Sylvisorexis divisible into two groups, typified byS. lunarisandS. granti.The African species ofSuncus(but not the introduced species,S. murinus) form a single group, which is linked to theSylvisorex grantigroup.Suncusis closely related to, or convergent with, theCrocidura fuscomurinagroup. The first non‐metric principal component, the second metric principal component and the second canonical variate are significantly correlated. It is considered that these together represent a general trend of evolutionary advance. Phylogenetic relations are discussed in the light of this;Crociduramay be dip

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1989.tb02520.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Two Triassic sphenodontid reptiles,Brachyrhinodon tayloriandPolysphenodon mulleri, are redescribed. Both genera are blunt‐snouted forms but, as a result of distortion in the original fossils, the degree to which the snouts are shortened has previously been over‐elaborated. An elongate temporal region and an interorbital width exceeding that of the parietal table are both derived characters in sphenodontids.Polysphenodonis plesiomorphic for both conditions, whereasBrachyrhinodondisplays the derived states. Therefore, it is assumed that the reduced snout has been independently derived in each genus. The limb elements ofPolysphenodonare long relative to the size of the skull and are similar in proportions to some species ofHomoeosaurus.This resemblance is considered to be indicative of similar locomotory requirements rather than close evolutionary relationships. Cladograms showing possible interrelationships within the Sphenodontida are based on twenty‐nine character s

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1989.tb02521.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY