33 research outputs found
Weitere Angaben zur Regenwurmfauna Frankreichs mit Beschreibung f\ufcnf neuer Arten (Oligochaeta: Lumbricidae)
Volume: 106Start Page: 983End Page: 100
New and little known giant earthworms from Madagascar (Oligochaeta: Kynotidae)
During a survey of the soil macrofauna of Madagascar three giant earthworm species were collected in the eastern part of the island. One of them, Kynotus friderici Michaelsen, 1931, is a known species described as K. longus var. friderici Michaelsen, 1931 and elevated to species rank herein. The other two species, K. giganteus sp. n. and K. proboscideus sp. n., proved to be new to science. K. giganteus measures alive 1350-1400 mm in length, 20-25 mm in diameter; K. proboscideus alive is ca 500-600 mm long and 15-20 mm in diameter. All worms belong to the Malagasy endemic family Kynotidae
Effects of cropping and tree density on earthworm community composition and densities in central Cameroon
Earthworms can have positive effects upon crop growth in the tropics. If soils are to be managed sustainably, then more attention should be paid to the effects of cultivation and cropping practices upon earthworms. When forest vegetation is cleared, slashed, burned and land is tilled and cultivated, earthworm abundance, diversity and activity are reduced. Conversely, retaining trees in agroecosystems may maintain earthworm populations during the cropping phase. Here, we assessed the impact on earthworm species diversity and densities of crop cultivation in the understorey of timber plantations thinned to two tree densities and compared these with uncropped, undisturbed timber plantation controls. The plots were reassessed after two and a half years of fallow to see whether populations had recovered. The experiment was in central Cameroon. Seventeen earthworm species were recorded from Eudrilidae subfamilies Eudrilinae and Pareudrilinae, Ocnerodrilidae and Acanthodrilidae, most of which were endemics. This included two new species from two new genera from the sub-family Pareudrilinae, one new species from one new genus of Ocnerodrilidae, two new species of Dichogaster and one new species of Legonodrilus. Ten species were epigeic, six were endogeic and one was anecic. Generally, earthworm densities were lower in cropped plots than in the undisturbed plantation control. The most abundant species was a Legonodrilus sp. nov. with average densities of 49 individuals mâ2 in the crop phase and 80 ind. mâ2 in the fallow phase. By the fallow phase, densities in the low tree density (120 ind. mâ2) were higher than in the high density (40 ind. mâ2). The densities of the epigeic Acanthodrilidae were significantly reduced to 7 ind. mâ2 in the cropped plots compared with 42 ind. mâ2 in the control plots. The effects of cropping were thus species-specific and more work is required to identify which of these endemics are the ecosystem engineers in the system
Influence of driver ant swarm raids on earthworm prey densities in the Mount Kenya forest: implications for prey population dynamics and colony migrations
J. O. Ogutu is ILRI authorAfrican driver ants are nomadic social mesopredators feeding on a highly diverse array of prey species at different trophic levels. Colonies of certain driver ant species have a biomass which can equal that of medium-sized mammalian carnivores and the ultimate cause of their nomadic life-style is thought to be local prey depletion. The impact of driver ant swarm raids is therefore expected to be strong but the degree to which they reduce prey populations has not been quantified and it is unknown whether these spectacular predators exert significant top-down effects. We examined the combined effect of driver ant (Dorylus molestus) and swarm-attending bird (Alethe poliocephala) predation on the population dynamics of earthworms, which constitute the antsâ main prey type in the montane forest of Mount Kenya. Pre-raid earthworm biomass densities in the soil layer down to a depth of 8 cm varied by a factor of 31. The immediate effect of swarm raids was a reduction in earthworm numbers in this layer, but 8 days later earthworm numbers had recovered to pre-raid levels. When earthworm biomass densities were compared, no significant effect of swarm raids was detected. The estimated proportion of earthworm prey biomass extracted from 0 to 8 cm layer by driver ants and birds together was about 2.2%. Although colony distribution was overdispersed as expected based on knowledge of D. molestus migratory behaviour, predation events were highly localized. Predation frequency was low (once every 62 days on average) and highly variable. These results indicate that earthworm prey is highly abundant but at the same time so difficult to harvest that swarm raids exert only a marginal influence on earthworm populations. Longer-term studies would be required to determine whether earthworm populations are limited by swarm raids. The small impacts of individual raids and rapid recovery of earthworm prey populations likely underlie the low frequency of migrations and short distances travelled by migrating colonies of D. molestus
New earthworms from Madagascar with key to the Kynotus species (Oligochaeta: Kynotidae)
Investigation of earthworms collected in Madagascar resulted in the discovery of two new species belonging to the endemic family Kynotidae: Kynotus sihanakus and Kynotus sakafotsy spp. nov. In addition to the description of both new species, Kynotus voeltzkowi Michaelsen, 1897 and Kynotus schistocephalus Michaelsen, 1897 were recorded for the first time after the original description. DNA barcoding, provided here for the first time for species of Kynotidae, proved to be highly efficient in recognizing Kynotus species showing 100% bootstrap support for all the putative species analyzed. An identification key to the Kynotus species is provided to facilitate further researches on earthworms of this biodiversity hotspo
Contribution to the knowledge of the earthworm fauna of Turkey with description of three new species (Clitellata: Megadrili)
PubMedID: 30313691During a recent survey, 29 earthworm species were collected from different parts of Turkey, 27 of which belong to the family Lumbricidae, one to Acanthodrilidae and one to Megascolecidae. Dendrobaena proved to be the most speciose genus with 12 recorded species including two species new to science, Dendrobaena pavliceki and Dendrobaena taurica spp. nov. In addition a third new species was also found belonging to the East Mediterranean genus Healyella: Healyella zicsii sp. nov. From the species recorded earlier for Turkey, D. fridericae uludagi Omodeo & Rota, 1991 and He. boluana Omodeo & Rota, 1989 were found for the first time since the original description. With these new records the number of earthworm species recorded for Turkey is raised to 84. Copyright © 2018 Magnolia Press.K100369 Hungarian Scientific Research FundThis research was supported by the Hungarian Scientific Research Fund (OTKA K100369)
New acanthodrilid species from Madagascar (Clitellata, Acanthodrilidae)
During collecting trips to Madagascar in the last decade several Acanthodrilidae sensu lato species were collected. The newly acquired material expresses high variability of the excretory system containing meroic, holoic vesiculate and holoic avesiculate species. The possible relationships of the Malagasy acanthodrilids is discussed and five species; Acanthodrilus hesperus, Eodriloides metandricus, Howascolex proprioporus, Howascolex vohimanus and Vazimbascolex alaotranus spp. n. are described. Vazimbascolex gen. n. represents also a new genus to science. The holoic avesiculate Acanthodrilus majungianus Michaelsen, 1897 and A. voeltzkowi Michaelsen, 1897 are conditionally transferred to the South African genus Eodriloides Zicsi, 1998; Eodrilus dauphinianus Michaelsen, 1910 and Microscolex (Notiodrilus) hyalochaeta Michaelsen, 1907 to Howascolex Michaelsen, 1901
An annotated checklist of earthworms of Greece (Clitellata: Megadrili)
Szederjesi, TĂmea, Vavoulidou, Evangelia, Chalkia, Christina, DĂĄnyi, LĂĄszlĂł, Csuzdi, Csaba (2017): An annotated checklist of earthworms of Greece (Clitellata: Megadrili). Zootaxa 4272 (1): 57-82, DOI: https://doi.org/10.11646/zootaxa.4272.1.
Species Richness and Density of Earthworms in Relation to Soil Factors in Olive Orchard Production Systems in Central Greece
Earthworms can be used as bioindicators of soil management as they are easy to classify and very sensitive to changes of both physical and chemical soil parameters. The aim of this work was to study relations between earthworm species (richness and density) and the physicochemical soil properties such as pH, organic matter, soil moisture, and texture (percentages of sand, silt, and clay) under different farming practices (organic and conventional) in olive groves in central Greece. The data revealed significantly greater values of earthworm species richness, density, soil organic matter, and moisture in the organic olive groves than in the conventional ones. Furthermore, total earthworm density was positively correlated to earthworm Shannon diversity index, soil moisture, organic matter, nitrogen, phosphorus, and potassium in organic olive groves. However, total earthworm density was negatively correlated to soil pH and silt in conventional olive groves. It can be concluded that species richness and density of earthworms in olive groves can be considered as sensitive indicators of management practices