The regeneration capacity of an earthworm, Eisenia fetida, in relation to the site of amputation along the body

It is well known that parts of earthworms can survive if they are cut off. Our aim was to link the regeneration capacity of an earthworm, Eisenia fetida (Oligochaeta, Annelida) with the site of the amputation, so we amputated earthworms at different body segment locations along the length of the body to examine the different survival rates and regeneration lengths of the anterior, posterior, and medial sections.
The greatest survival rates occurred for earthworms with the most body segments remaining after amputation. The anterior regeneration lengths were of two types. The lengths of regeneration of amputated from body segment 6/7 to further down the body posteriorly increased gradually (Type L_I). However, the regeneration lengths of earthworm which were amputated behind the 23rd segment, with less than a quarter of the total segments remaining, did not increase until the blastema and tail bud formation (Type L_II). These treatments were not completely regeneration. There were significant differences in both survival rates and lengths of regeneration lengths between immature earthworms and clitellate adult earthworms during the early stages of regeneration, but not at later stages of regeneration. The immature earthworms had a greater regeneration potential than clitellate adults amputated at the same segment. The survival rates of earthworms were correlated significantly with the number of body segments remaining after amputation, but not with the position of the amputation. The relationships between the survival rates and the numbers of remaining segments could be described by linear regressions. The anterior regeneration lengths were correlated with the position of the amputation, but not with the number of remaining segments; the posterior regeneration lengths, were not correlated with the number of segments remaining nor the amputation position. The anterior regeneration length was not related to the survival rates for all earthworm amputations after 30 days but was related in this way after 60 days.     

The regeneration capacity of an earthworm, Eisenia fetida, in relation to the site of amputation along the body

It is well known that parts of earthworms can survive if they are cut off. Our aim was to link the regeneration capacity of an earthworm, Eisenia fetida (Oligochaeta, Annelida) with the site of the amputation, so we amputated earthworms at different body segment locations along the length of the body to examine the different survival rates and regeneration lengths of the anterior, posterior, and medial sections.
The greatest survival rates occurred for earthworms with the most body segments remaining after amputation. The anterior regeneration lengths were of two types. The lengths of regeneration of amputated from body segment 6/7 to further down the body posteriorly increased gradually (Type L_I). However, the regeneration lengths of earthworm which were amputated behind the 23rd segment, with less than a quarter of the total segments remaining, did not increase until the blastema and tail bud formation (Type L_II). These treatments were not completely regeneration. There were significant differences in both survival rates and lengths of regeneration lengths between immature earthworms and clitellate adult earthworms during the early stages of regeneration, but not at later stages of regeneration. The immature earthworms had a greater regeneration potential than clitellate adults amputated at the same segment. The survival rates of earthworms were correlated significantly with the number of body segments remaining after amputation, but not with the position of the amputation. The relationships between the survival rates and the numbers of remaining segments could be described by linear regressions. The anterior regeneration lengths were correlated with the position of the amputation, but not with the number of remaining segments; the posterior regeneration lengths, were not correlated with the number of segments remaining nor the amputation position. The anterior regeneration length was not related to the survival rates for all earthworm amputations after 30 days but was related in this way after 60 days.     

Printed in Great Britain Mandobius regalis gen. et sp.n. (Copepoda: Poecilostomatoida: Lichomolgidae) associated with the coral Pectinia lactuca in New Caledonia

A new genus, Mandobius gen.n, containing a new species, M. regalis sp.n., is associated with the coral Pectinia lactuca in New Caledonia. The new copepod differs conspicuously from the allied genus Paramolgus in having only one seta on the first segment of the first antenna, in the formula 1,11,3 for the third segment of the endopodite of leg 1, and in the formula 11,1,5 for the third segment of the exopodite of leg 4.     

Dynamics of the Biological Activity of Litter as It Is Transformed by Earthworms

The dynamics of the biological activity of litter during its transformation were studied under laboratory conditions. The model group of soil saprophages was represented by earthworms (Eisenia genus). The system litter–droppings—litter + droppings–soil was investigated. The feeding activity of earthworms intensified biological processes in the decomposing plant residues. A fraction of readily hydrolyzable nitrogen was accumulated in the worm droppings. Dressing the litter with droppings shifted transformation of the plant materials towards mineralization.     

A new species of the shrew‐mouse,Archboldomys (Rodentia: Muridae: Murinae), from the Philippines

A new species of murid rodent belonging to the ‘shrew‐mouse’ genus Archboldomys is described from Kalinga Province in northern Luzon Island, Philippines. This is the third known species of this endemic Philippine genus. The new species is distinguished from its congeners by consistent differences in adult body size, limb and tail proportions, coloration and texture of the pelage, and cranial and dental dimensions. Members of this genus are small, diurnal rodents that feed mainly on earthworms and other soil invertebrates, and occur in high elevation montane and mossy forests habitats. The new species may be restricted to the northern portion of the Cordillera Central, whereas its congeners occur in widely separated highland areas in other portions of Luzon. The fact that similar distribution patterns are seen for members of other endemic genera suggests that habitat vicariance may have shaped much of the diversification of murid rodents on Luzon.     

Eudrilinae from southern Nigeria and a taximetric appraisal of the family Eudrilidae (Oligochaeta)

A small collection of Eudrilid earthworms from Nigeria is reported. Two species proved to be of special interest, the first, lagosensis Beddard, is usually placed in the genus Hyperio-drilus and the second is new to science. Their affinities and the uncertainties about the classification of the Eudrilidae are discussed. These problems led into a taximetric study of the family. It is concluded that on the basis of the accepted generic criteria, the subfamilies (Eudrilinae and Pareudrilinae) are phenetically valid and the Eudrilinae may be subdivided according to whether species have paired or single male and spermathecal pores. Further, the two species whose doubtful status prompted the investigation, may each be placed in a separate genus. The new species is accommodated in a new genus, described herein, while Heliodrilus Beddard is resurrected for lagosensis which is the type-species. Additionally, a new interpretation is provided of the structure and function of the posterior male organs of Hippopera nigeriae Taylor.     

Acidovorax-like symbionts in the nephridia of earthworms

Dense accumulations of bacteria in the excretory organs, nephridia, were first described more than 75 years ago in members of the annelid family Lumbricidae (earthworms). These nephridial symbionts were assumed to play a role in the degradation of proteins in the excretory fluid for nitrogen recycling. In the present study, the phylogenetic affiliation of the nephridial bacteria of the earthworms Lumbricus terrestris, Aporrectodea tuberculata, Octolasion lacteum and Eisenia foetida was resolved. The 16S rRNA gene sequences of the symbionts formed a monophyletic cluster within the genus Acidovorax. Similarity between symbiont sequences from different host species was 95.5-97.6%, whereas similarity was> 99% between symbiont sequences from individuals of the same species. Densely packed bacteria were detected in the ampulla of the nephridia by fluorescence in situ hybridization (FISH) using Acidovorax-specific oligonucleotide probes. No other bacterial cells could be found by FISH, although a few sequences other than Acidovorax had been found by PCR and cloning. These results suggest that the Acidovorax-earthworm symbiosis is a stable, host-specific association that has evolved from a common bacterial ancestor. Given the close phylogenetic relationship of the symbionts to proteolytic, free-living Acidovorax species, they may indeed play a role in protein degradation during nitrogen excretion by earthworms.     

A new species of the genus Lightiella: the first record of Cephalocarida (Crustacea) in Europe

A new species of Cephalocarida belonging to the genus Lightiella is described. Like all known species of Lightiella , the new species is characterized by reduction of trunk segment 8, which also lacks both pleura and thoracopods. The diagnostic characters of the species are: (1) one seta on the inner distal corner of the penultimate endopodal segment of second maxilla and thoracopods 1–5; (2) only one claw on the distal segment of the endopod of thoracopod 6. A cladistic analysis of 27 morphological characters was used to estimate the phylogeny of all species of Lightiella , with all other cephalocarid species used as outgroups. The discovery of this species in the Mediterranean fills a gap in the distribution of the genus and of the entire class.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 209–220.     

Meristoderes gen. nov., a new kinorhynch genus, with the description of two new species and their implications for echinoderid phylogeny (Kinorhyncha: Cyclorhagida, Echinoderidae)

A new kinorhynch genus, Meristoderes gen. nov., and two new species from Spain and the Solomon Islands, respectively, are described. The new genus is distinguished from all other genera by the first segment consisting of a closed cuticular ring, and the second segment having partial tergosternal junctions, and a superficial midventral fold. This is a new cuticular configuration that may shed light into the phylogenetic relationships of echinoderid kinorhynchs. Meristoderes macracanthus gen. et sp. nov. from the Mediterranean coast of Spain is recognised by the presence of middorsal spines on segments 4, 6 and 8, ventrolateral tubules on segment 2, lateroventral tubules on segment 5, lateroventral spines on segments 6-9, lateral accessory tubules on segment 8, one pair of laterodorsal tubules on segment 10. Meristoderes galatheae sp. nov. from the Solomon Islands is recognized by having a middorsal spine on segment 4 only, ventrolateral tubules on segment 2, lateroventral tubules on segment 5, lateroventral spines on segments 6-9, lateral accessory tubules on segment 8 and subdorsal tubules on segment 10. Both species have a pattern of paraventral perforation site clusters on segments 3-9, with conspicuously long bracteate hairs from the posteriormost perforations sites on the segments 3-7 and 3-6, respectively.The new genus Meristoderes gen. nov. is included into the family Echinoderidae Bütschli, 1876 and appears closely related with the genera Cephalorhyncha Adrianov, 1999 and Echinoderes Claparède, 1863. The new information it provides is discussed to clarify the internal phylogeny of Echinoderidae. The terminology for cuticular characters in the overlapping area between consecutive segments is also standardized.     

New earthworm species of the genus Amynthas Kinberg, 1867 from Thailand (Clitellata, Oligochaeta, Megascolecidae)

Four new species of terrestrial earthworms from the zebrus-group in the genus Amynthas Kinberg, 1867, are described from Nan province, north Thailand: Amynthas phatubensissp. n., from Tham Pha Tub Arboretum, Amynthas tontongsp. n., from Tontong Waterfall, Amynthas borealissp. n., from Chaloemprakiat district, and Amynthas srinansp. n., from Srinan National Park.After comparing with the two closely related Laos species Amynthas chandyi Hong, 2008 and Amynthas namphouinensis Hong, 2008, the four new species show clear morphological differences, and also it is confirmed that there are no previous records of the species described here. Amynthas phatubensissp. n. is the largest (longest) sized of these earthworms and is the only species that lives in limestone habitats. The genital characters are different among them and also from the two Laotian species. Molecular systematics would be a good method for further analysis of the diversity and species boundaries in SE Asian Amynthas.     

A new species of Acontiophorus Brady, 1880 (Copepoda: Siphonostomatoida) from Ushuaia,Argentina

A new species of Acontiophorus belonging to the family Asterocheridae was found in Ushuaia, Patagonia, southern Argentina. The new species is distinctive in having 9-segmented antennule, five setae on terminal endopodal segment of leg 1, seven elements on terminal segment of leg 1 and leg 4 exopods, and characteristic setation on maxillule lobes. This combination of characteristic features does not occur in any other species of the genus. The genus Acontiophorus is recorded for the first time from the South Atlantic.     

New ommatids from the Late Jurassic of western Liaoning, China （Coleoptera： Archostemata）

A new genus Amblomma gen. nov. of fossil beetles is erected and can be assignedto the family Ommatidae because its two procoxal cavities are contiguous and the articulations of the abdominal ventrites are abutting. The new genus is similar to Zygadenia Handlirsch, 1906 (=Notocupes Ponomarenko, 1964), Tetraphalerus Waterhouse, 1901,Rhobdocupes Ponomarenko, 1966 and Sinocupes Lin, 1976, but can be distinguished from other genera according to the following characters: the second segment of antennae is shorterthan the third one in length; the posterior tarsi with the basal segment is obviously shorter than the three following taken together in length; the antennae reach the posterior ridge of prothroax in length, and the sides of the prothroax with serrulate margin. Four new species of the new genus are described and figured: Amblomma psilata gen. et sp. nov., Amblomma rudis gen. et sp. nov., Amblomma epicharis gen. et sp. nov., and Amblomma stabilis gen. etsp. nov. A key to species within this new genus is provided. All the specimens are collected from the Late Jurassic Yixian Formation of western Liaoning and are now housed in the College of Life Science, Capital Normal University, Beijing, China.     

Interactions Between the Nematode Parasite of Pigs,Ascaris suum,and the Earthworm Aporrectodea longa

Pig faeces in which Ascaris suum eggs had been embryonating for 57 days were placed in buckets of soil containing either 30 or no earthworms (Aporrectodea longa). When present, earthworms consumed the faeces and transported the eggs down into the soil, without inflicting any visible damage on the eggs. In later experiments 10 earthworms from the above experiment were fed to each of ten pigs, and another 40 earthworms were dissected. None of the 10 pigs became infected with A. suum through consumption of earthworms, and none of the dissected earthworms were found to contain A. suum larvae. This experiment indicates that A. longa did not act as a paratenic host for A. suum but shows that earthworms are very efficient in transporting A. suum eggs from faeces deposited on the soil surface into the soil.     

Taxonomy of the Neotropical Genus Americabaetis,New Status (Insecta: Ephemeroptera: Baetidae)

Americabaetis (Insecta: Ephemeroptera: Baetidae), previously considered synonymous with Acerpenna, is reinstated and given generic rank. The genus differs from Acerpenna in lacking hindwings, gills on abdominal segment 1, and a conical process between the male genital forceps, and in possessing apically rounded gills on abdominal segment 7. The genus has a general Neotropical distribution with a northern limit in east-central Mexico. Five new species of Americabaetis are described from South America: A. alphus, new species, from Argentina, Bolivia, Brazil, Chile, and Paraguay; A. labiosus, new species, from Brazil, Paraguay, and Uruguay; A. longetron, new species, from Brazil, Paraguay, and Uruguay; A. maxifolium, new species, from Paraguay; and A. titthion, new species, from Brazil. Americabaetis boriquensis, new combination; A. intermedius, new combination; A. naranjoi, new combination; A. pleturus, new combination; and A. robacki, new combination, are reviewed.     

Phylogeographic analysis of invasive Asian earthworms (Amynthas) in the northeast United States

Phylogeographic studies are useful in reconstructing the history of species invasions, and in some instances can elucidate cryptic diversity of invading taxa. This can help in predicting or managing the spread of invasive species. Among terrestrial invasive species in North America, earthworms can have profound ecological effects. We are familiar with the centuries‐old invasions of European earthworms (Lumbricidae) and their impacts on nutrient cycling in soils. More recent invasions by Asian earthworms of the family Megascolecidae are less fully understood. We used data for two mitochondrial gene fragments, cytochrome oxidase I (COI) and 16S rRNA, to examine the relationships among populations of Asian earthworms in the megascolecid genus Amynthas in the northeast United States. Recent reports have indicated that one species in particular, Amynthas agrestis, is having detrimental effects in mixed forest ecosystems, and we were interested in understanding the invasion history for this species. We were surprised to discover three divergent mitochondrial lineages of Amynthas occurring sympatrically in upstate New York. Given the gap between intra‐ and inter‐lineage sequence divergences, we propose that these three lineages represent cryptic species of Amynthas, one of which is A. agrestis. For each of the three lineages of Amynthas, we observed shared haplotypes across broad geographic distances. This may reflect common origins for populations in each lineage, either by direct routes from native ranges or through post‐introduction spread by natural dispersal or human‐mediated transport within North America. Management efforts focused on horticultural imports from Asia, commercial nurseries within the USA, and on prohibition of bait disposal may help to reduce the further invasion success of Amynthas.     

指蕈甲属分类研究(鞘翅目,大蕈甲科)

对指蕈甲属Dactylotritoma昆虫进行了分类研究,描述1新种,即卧龙大蕈甲D.wolongensis sp.nov.,新种与分布在山西的D.chinensis Araki,1942近似,二者的主要区别是:前者下颚须末节非常宽,有中足基节线,鞘翅整个红棕色;后者下颚须末节宽,无中足基节线,鞘翅后部黑色.提供了已知种目录及其检索表.模式标本保存于河北大学博物馆.     

Tracking and predation on earthworms by the invasive terrestrial planarian Bipalium adventitium (Tricladida, Platyhelminthes)

The potential ecological impact of exotic terrestrial planarians will be determined in part by their sensory abilities and predatory behavior. It has been suggested that these flatworms may only encounter their earthworm prey by chance, hence restricting the breadth of species they will feed upon and the number of microhabitats in which predator-prey interactions occur. We hypothesized that those flatworms that have already successfully invaded North America (genus Bipalium) actually detect and follow chemical trails of earthworms and possess the behavioral repertoire needed to feed on the prey in a range of microhabitats. We examined: (1) the tendency of Bipalium adventitium to follow chemical trails left by injured and un-injured earthworms; (2) the behavioral repertoire and predatory success of B. adventitium feeding on three earthworm species in subterranean tunnels; and (3) the response of flatworms to the reportedly defensive secretions of the earthworm Eisenia fetida in tunnels. B. adventitium detected and followed trails of earthworm mucus and secretions left by injured and un-injured earthworms. Flatworms followed trails on a range of substrates and pursued and captured three species of earthworms in subterranean tunnels, including individuals many times their mass. Although most behavior exhibited during underground attacks was similar to that reported for surface encounters, the flatworms also behaved in ways that blocked earthworm escape from tunnels. The flatworms were less successful at preying on E. fetida than on Lumbricus rubellus and Lumbricus terrestris in underground tunnels and showed some aversion to the secretions from E. fetida.