The morphology of the population of Vipera berus occurring in North Korea is given, and the taxonomic position of this isolated southeastern population is discussed. By comparing it with material from all parts of the range for Vipera berus including all currently recognized subspecies (berus, sachalinensis, bosniensis) it is obvious that the North Korean population should be included in the easternmost subspecies sachalinensis.
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386In a population of adders (Vipers berus) in Southwest Sweden, melanistic males were heavier than normal coloured males of the same length. Victory in male-male sexual combats was positively related to size. Higher risk ofpredation in the black morph was inferred from experiments showinga high predator attack rate on models of the black morph. Even the bright colour in newly moulted basking males of the normal morph gives cryptic protection. In females, melanism probably also attects body size and risk of predation by visually searching predators. The thennoregulatory influence of black colour, the reproductive success and the maintenance of two colour morphs in the population are discussed.
Vipera berus is widely distributed throughout the northern part of Europe and Asia. Characterization of several toxic effects of its venom in the mouse, as well as of in vitro enzymatic activities was performed. Vipera berus venom displayed in vitro proteolytic, fibrinolytic, anticoagulant, and phospholipase A2 activities. The i.p. LD50 of the venom for Swiss mice was 0.86 micrograms/g (95% confidence limits 0.71-1.01 microgram/g). Significant local tissue-damaging effects, including edema, hemorrhage and myonecrosis, were observed. The local edema was characterized by rapid onset, reaching a maximum after 0.5-1 hr, and with dose-dependent persistence. The hemorrhagic potency was measured by a skin test, giving a minimum hemorrhagic dose value of 3.2 micrograms. The venom also induced a moderate local myonecrosis, evidenced by histological evaluation of injected tissue (gastrocnemius), and by biochemical parameters (increase of plasma creatine kinase activity, and decrease of muscle residual MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide)-reducing activity). Characterization of the venom by SDS-polyacrylamide gel electrophoresis revealed 10 (reduced) or 11 (unreduced) main protein bands, which were further analyzed in relation to mol. wt and relative concentration by densitometry. A rabbit antiserum to V. berus venom recognized all main venom bands by immunoblotting. This antiserum cross-reacted to a variable extent with several crotaline venoms, as assessed by enzyme immunoassay.
Andrew Bakiev, Wolfgang Böhme, Ulrich Joger // Handbuch der Reptilien und Amphibien Europas; Band 3/IIB, Schlangen (Serpentes) III Viperidae. Aula-Verlag, Wiebelsheim 2005; Seiten 63–76.
To prove that predators are morphologically adapted to the size of their prey one has to demonstrate that the morphological variation in the trophic apparatus is related to the prey size distribution and that the variation in the trait has some effect on individual fitness. I have studied geographic variation in relative head length (RHL) of adders, Vipera berus, on the Swedish mainland and on groups of islands in the Baltic Sea, and the relationship between RHL and physical condition, a character related to fitness. I also examined the relationship between RHL and sex and colour morph. Relative head length of adders was smallest on the mainland and increased on the islands with increasing body size of the main prey, Microtus agrestis, suggesting stabilizing selection for head size within each population. There was no difference in RHL between sexes or colour morphs. However, physical condition was positively correlated with RHL, indicating directional selection for larger heads. The observed pattern is interpreted as an evolutionary response to the geographic variation in body size of the main prey species and the smaller number of alternative prey species available on islands.
