Mitopus morio

Abstract: Before a reliable picture can be formed of energy transformations within a community, more information must be available on the efficiency with which animals in nature utilize their food materials. The present paper extends the study of Phillipson (1960) on the utilization of food by adults of Mito-pus monio (F.) to a study of food utilization throughout the whole of this organism's life history. It presents results on the percentage assimilation of food in the laboratory, and the amount of energy obtained by M. monio from its food at various stages of its life history under natural conditions.

Abstract: Chromosomes ofCaddo agilis (Caddidae) and fifteen species of Phalangiidae were investigated . In three species, Nelima satoi, N . similis, and Eumesosoma roeweri, presence of XY-XX (male heterogametic) sex chromosome system was newly ascertained . On the other hand, ZW-ZZ (female heterogametic) sex chromosome system was suggested to be present in Mitopus morio .Effeminate (2n = 20) and normal (2n = 18) males of Protolophus tuberculatus were found to differ in chromosome number. A survey of known records of chromosome numbers in Caddidae and Phalangiidae revealed a general trend that the number is greater in both Caddidae (2n = 30) and Phalangiinae (2n = 20-36), fewer in Gagrellinae (2n = 10-22), and intermediate in Leiobuninae (2n = 16-26) . Evolutionary trends are briefly discussed and compared with those in other arachnids

Abstract: Invertebrate primary succession is investigated across a chronosequence in the subalpine (birch woodland) zone at Fabergstolsbreen using pitfall traps. Presence and abundance of taxa, functional groups and communities are examined using a geo-ecological approach including mapping, graphical analysis, two-way indicator species analysis (TWINSPAN) and non-metric multidimensional scaling (NMS). Twenty-nine of the 67 recorded taxa, and 14 of the 37 epigeal (surface active) taxa colonize terrain deglacierized for <20 years and catches of most of these pioneer taxa attain an early peak on terrain deglacierized for <40 years. Catches of most later colonizers peak in the mature (‘climax’) stage where 86% of the pioneer taxa and 79% of the epigeal pioneers are also recorded. The number of taxa increases across the chronosequence as new taxa, predominantly predators, appear but relatively few taxa drop out of the succession, and as the dominant species in the traps changes from the harvestman, Mitopus morio, to the...

Abstract: Bryophytes from seven different genera colonized 3- to 6-year-old ground near a receding glacier in central South Norway. Microscopic studies of the gut content in pioneer invertebrates revealed that mosses were grazed upon by four species: an abundant and large Collembola (Bourletiella hortensis), a moss-eating Byrrhidae beetle (Simplocaria metallica), and two omnivorous Carabidae beetles (Amara alpina and A. quenseli). The three most abundant moss species were preferred by the moss-eaters: Pohlia filum, Ceratodon purpureus, and Bryum arcticum. Special parts of the moss plant could be selected. Three other Collembola species present were classified as herbivores because they had diatom algae in their gut, indicating that they grazed on terrestrial biofilm. Chironomidae midges hatching from young ponds represented an important element in the gut content of three common predators: the Opiliones Mitopus morio, and two Carabidae beetles Nebria nivalis and Bembidion hastii. The present data show that...