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Genital Characters (genital + character)
Selected AbstractsExtreme body size variability in the golden silk spider (Nephila edulis) does not extend to genitaliaJOURNAL OF ZOOLOGY, Issue 1 2000Gabriele Uhl Abstract Nephila edulis is a spider with large body size variability in males and females. Genital characters show negative allometric values compared to somatic characters. In males, the embolus (the most important structure for sperm transfer) had a significantly lower coefficient of variation than body size. This suggests that male genitalia are under stabilizing selection favouring intermediate size. Female N. edulis showed a trend similar to males regarding allometric values in genitalia. In females, however, the variation coefficient in a specific genital character crucial for successful copulation did not differ from that of indicators for overall body size. This suggests that in Nephila the genitalia of the females experience less stabilizing selection than those of the males. In male and female genitalia, the mode of selection seems to cause developmental instability not in degrees of fluctuating asymmetry but in the degree of data scatter which indicates a lower coefficient of determination. [source] Notes on two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and IshidaENTOMOLOGICAL SCIENCE, Issue 2 2009Kôji SASAKAWA Abstract Two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and Ishida, were revised based on the male endophallus (inner sac everted from aedeagus). P. amagisanus was newly recorded based on a single male from Kyushu, southwest Japan, far from its known distribution (Honshu; the Fuji-Hakone-Izu volcano area), although additional materials are necessary to confirm this record. Despite a highly disjunct distribution, no conspicuous difference was recognized in either external or genital characters between the materials from Honshu and Kyushu. The nominal species P. fujitai was separated into two species, P. fujitai (Honshu) and Pterostichus eoyoritomus sp. nov. (Shikoku; type locality: Mount Jingayama); these two species have some significant differences in the endophallic structures. Character states in male genitalia suggest a sister relationship between P. eoyoritomus sp. nov. and Pterostichus yoritomus Bates. [source] Taxonomy and biogeography of Central European Kybos (Insecta, Hemiptera, Cicadellidae)MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2009Roland Mühlethaler Abstract The Central European species of the taxonomically difficult Holarctic typhlocybine genus Kybos are revised. Currently it is impossible to identify females and nymphs. In addition the otherwise diagnostic shape of the male genitalia is linked by intermediates in some morphologically similar nominal species. The second important diagnostic structure, the male sound apodemes, is not yet fully developed in teneral males, a fact which was not sufficiently taken into consideration by some authors. The present study evaluates the morphological variation of the male genitalia and sound apodemes. Females and nymphs are investigated for taxonomically relevant characters. The study did not yield previously unknown characters particularly for the females and nymphs but suggested that the variation of the male genitalia has previously been underestimated. For this reason K. perplexus Ribaut, 1952 and K. paraltaicus Orosz, 1996 are synonymised with K. strigilifer (Ossiannilsson, 1941) (new synonymies). The base of the female ovipositor is variable within Kybos and separates species groups but does not diagnose species. Nymphs vary in leg dimensions and colour forming the same species groups as the female genitalia but, again, do not diagnose species. In the cladistic analysis the female genital characters make the most important contribution to tree structure whereas the male genitalia are of less importance, contrary to species diagnoses. It is interesting to note that the cladogram comprises a monophyletic group of Betulaceae feeders. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Speciation on the Azores islands: congruent patterns in shell morphology, genital anatomy, and molecular markers in endemic land snails (Gastropoda, Leptaxinae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009KURT JORDAENS Morphological data, in combination with molecular data, may provide invaluable insights into speciation processes on archipelagos. Land snails offer ample opportunities to evalutate adaptive and non-adaptive speciation scenarios. However, studies investigating processes of differentiation and speciation on the Azores are scarce. The present study comprises a morphometrical analysis of shell and genital characters in a group of Azorean land snails (Pulmonata, Leptaxinae). Geographical isolation appears to be an important mechanism underlying morphological and molecular differentiation in the Azorean Leptaxini, instead of adaptive radiation through ecological differentiation. Nevertheless, we could not exclude the occurrence of ecological speciation on the oldest island (Santa Maria) where two species that markedly differ in shell-shape co-occur. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 166,176. [source] | ||||||||||