Occurrence, Distribution and Morphological Description of 11 Species of Endemic Giant Pill-Millipedes of the Genus Arthrosphaera (Diplopoda: Sphaerotheriida: Arthrosphaeridae) in Southern India
The endemic giant pill-millipedes belonging to the genus Arthrosphaera has a long history of occurrence and distribution in the Indian Subcontinent. According to the earlier and recent records, up to 40 species of Arthrosphaera are confined to southern India and Sri Lanka. Being detritus feeders, they are sensitive to narrow range of abiotic factors and their population is dwindling due to severe human interference especially landscape modification or modern forestry/agricultural practices. There is an urgent need to update the status, occurrence and distribution in distinct ecological conditions of pill-millipedes in southern India as they are important component in organic matter decomposition as well as nutrient turn over in the forests or plantations. Based on recent surveys, the present study attempts to update occurrence, distribution and morphological description (light and scanning electron microscopy) with a diagnostic key for identification of 11 species of pill-millipedes occurring in the Western Ghats of India with commentary on their distribution pattern in different ecological conditions and impact of edaphic factors.
Cytological Investigations on some Indian Diplopoda (Myriapoda)
THE class Myriapoda has received scant attention from cytologists, the order Diplopoda even less. Among the earlier contributions to this field of study, mention may be made of Oettinger1, Sokoloff2 and Bessiere3. Barring a recent contribution to the cytology of three South Indian species of Diplopoda by Natarajan4, no attention has been devoted to chromosome studies in this group.
Germination ecology of Central Asian Stipa spp: differences among species, seed provenances, and the importance of field studies
Stipa-species are wide-spread in Central Asia, but sexual reproduction in the dry steppes is rare. To facilitate conservation and restoration of these important rangelands, we studied germination characteristics of three common Mongolian Stipa-species under field- and lab conditions. Seeds of Stipa krylovii, Stipa gobica and Stipa glareosa were sown at the study site in Southern Mongolia over two consecutive years during which period tests were carried out to ascertain whether competition or herbivory are the main constraints of seedling establishment. In addition, we tested germination and seed viability in the laboratory under two different temperature regimes (20/10°C and 8/4°C), as well as the effect of cold-stratification. The lab experiments also included S. krylovii seeds originating from three climatically different provenances. None of the three Stipa-species seedlings emerged during the first 2 years of the field study. However, after an unusually intense rain event in the third year, 3% of S. krylovii, 0.6% of S. glareosa and 0.1% of S. gobica seeds germinated in the study plots. The factors ‘sowing-year’ and ‘vegetation’ significantly affected seedling emergence, whereas grazing had no effect at all. Under laboratory conditions a high percentage of viable seeds of S. gobica and S. glareosa germinated at both incubation temperatures, and cold-stratification had no effect on germination or viability. Germination of S. krylovii seeds required warmer temperatures and cold-stratification had a positive effect. Such evidence for dormancy was more pronounced in seeds from the moister, northern provenances. Germination of Stipa-species in the field is rare and only possible under exceptionally moist conditions. Conservation should thus concentrate on steppe conservation rather than on restoration. Where artificial reseeding is necessary, differences among species and also among different seed provenances should be taken into account.