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Christer Erseus - One of the best experts on this subject based on the ideXlab platform.
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Groundwater and marine intertidal Tubificidae (Oligochaeta) from the Canary and Cabo Verde Islands, with descriptions of two new species
2016Co-Authors: Christer Erseus, Subfamily RhyacodrilinaeAbstract:groundwater fauna Seven species of Tubificidae are recorded from the Canary Is-lands, viz. Heterodrilus amplus n. sp., Coralliodrilus levia-triatus Erséus, 1979, Limnodriloides agnes Hrabĕ, 1967, L. jan
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iczn rules a farewell to Tubificidae annelida clitellata
Zootaxa, 2008Co-Authors: Christer Erseus, Mark J Wetzel, Lena M. GustavssonAbstract:Morphological and molecular characters support that the former clitellate family Naididae Ehrenberg, 1828 is nested within another family, Tubificidae Vejdovský, 1876. To avoid paraphyly of the latter, it has been suggested that the two should be regarded as a single taxon. A recent decision by the International Commission of Zoological Nomenclature [2007; opinion 2167 (Case 3305)] ruled against a proposed reversal of the nomenclatural priority of Naididae over Tubificidae, with the consequence that all former tubificids should now be regarded as members of the Naididae whenever these two names are regarded as synonyms. The paper is a plea to clitellate researchers to conform to this ruling.
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ICZN rules—a farewell to Tubificidae (Annelida, Clitellata)
Zootaxa, 2008Co-Authors: Christer Erseus, Mark J Wetzel, Lena M. GustavssonAbstract:Morphological and molecular characters support that the former clitellate family Naididae Ehrenberg, 1828 is nested within another family, Tubificidae Vejdovský, 1876. To avoid paraphyly of the latter, it has been suggested that the two should be regarded as a single taxon. A recent decision by the International Commission of Zoological Nomenclature [2007; opinion 2167 (Case 3305)] ruled against a proposed reversal of the nomenclatural priority of Naididae over Tubificidae, with the consequence that all former tubificids should now be regarded as members of the Naididae whenever these two names are regarded as synonyms. The paper is a plea to clitellate researchers to conform to this ruling.
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Cuticular ultrastructure in some marine oligochaetes (Tubificidae)
Invertebrate Biology, 2005Co-Authors: Lena M. Gustavsson, Christer ErseusAbstract:. The ultrastructure of the thin, non-cellular cuticle is described for 6 marine oligochaetes, representing 3 of the subfamilies (Phallodrilinae, Limnodriloidinae, and Rhyacodrilinae) of the Tubificidae. The main components of the cuticle in these 6 species, as in most other oligochaetes examined, are: (1) a fiber zone closest to the epidermis, consisting of collagen fibers embedded in a matrix, (2) an epicuticle, which is a continuation of the matrix outside the fiber zone, and (3) epicuticular projections, which are membrane-bound bodies covering the outer surface of the epicuticle. The projections are probably formed by the microvilli that penetrate the cuticle from the epidermal cells below, but this was confirmed only in the studied limnodriloidines. Three of the species examined, Duridrilus turdus, Olavius vacuus, and Heterodrilus paucifascis, lack microvilli. The morphology of the components in the cuticle differs between the studied species. The collagen fibers may form an “orthogonal grid” (i.e., layers of parallel fibers perpendicular to the layers immediately above and below), or they may form parallel layers, or be irregularly scattered. The number of dense layers in the epicuticle, as well as the shape and internal structure of the epicuticular projections, also vary. All these characters might be useful in future phylogenetic analyses to achieve better hypotheses of relationships within oligochaetes as well as to other groups.
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phylogeny of Tubificidae annelida clitellata based on mitochondrial and nuclear sequence data
Molecular Phylogenetics and Evolution, 2005Co-Authors: Erica Sjolin, Christer Erseus, Mari KallersjoAbstract:The tubificid clitellates are a common component in the freshwater bottom fauna and are also the most abundant oligochaete group in marine habitats. There are over 800 described species classified in six subfamilies; Tubificinae, Limnodriloidinae, Rhyacodrilinae, Telmatodrilinae, Phallodrilinae, and Naidinae. In this study we examine the phylogenetic relationships in Tubificidae using a combination of mitochondrial 16S rDNA and nuclear 18S rDNA sequence data. Sequences were obtained from five outgroup and 56 ingroup taxa, including five of the six subfamilies of Tubificidae. The data were analysed by maximum parsimony and Bayesian inference. The resulting tree topologies are virtually without conflict. Several associations traditionally recognized within the family Tubificidae are supported, in the Bayesian analysis including a sister group relationship between Tubificinae and Limnodriloidinae. The results also indicate that Rhyacodrilinae is polyphyletic-some of its members (Heterodrilus spp.) fall into a clade with Phallodrilinae, all other groups with Naidinae. Naidinae is also polyphyletic with two rhyacodriline genera, Monopylephorus and Ainudrilus, nested within. Most of the tubificid genera included in the study are supported as monophyletic; however, Tubifex and Limnodriloides are refuted. and Tubificoides is unresolved from other tubificine taxa. (c) 2005 Elsevier Inc. All rights reserved.
Mari Kallersjo - One of the best experts on this subject based on the ideXlab platform.
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phylogeny of Tubificidae annelida clitellata based on mitochondrial and nuclear sequence data
Molecular Phylogenetics and Evolution, 2005Co-Authors: Erica Sjolin, Christer Erseus, Mari KallersjoAbstract:The tubificid clitellates are a common component in the freshwater bottom fauna and are also the most abundant oligochaete group in marine habitats. There are over 800 described species classified in six subfamilies; Tubificinae, Limnodriloidinae, Rhyacodrilinae, Telmatodrilinae, Phallodrilinae, and Naidinae. In this study we examine the phylogenetic relationships in Tubificidae using a combination of mitochondrial 16S rDNA and nuclear 18S rDNA sequence data. Sequences were obtained from five outgroup and 56 ingroup taxa, including five of the six subfamilies of Tubificidae. The data were analysed by maximum parsimony and Bayesian inference. The resulting tree topologies are virtually without conflict. Several associations traditionally recognized within the family Tubificidae are supported, in the Bayesian analysis including a sister group relationship between Tubificinae and Limnodriloidinae. The results also indicate that Rhyacodrilinae is polyphyletic-some of its members (Heterodrilus spp.) fall into a clade with Phallodrilinae, all other groups with Naidinae. Naidinae is also polyphyletic with two rhyacodriline genera, Monopylephorus and Ainudrilus, nested within. Most of the tubificid genera included in the study are supported as monophyletic; however, Tubifex and Limnodriloides are refuted. and Tubificoides is unresolved from other tubificine taxa. (c) 2005 Elsevier Inc. All rights reserved.
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18S rDNA Phylogeny of the Tubificidae (Clitellata) and Its Constituent Taxa: Dismissal of the Naididae
Molecular phylogenetics and evolution, 2002Co-Authors: Christer Erseus, Mari Kallersjo, Maria Ekman, Rasmus HovmöllerAbstract:Abstract The phylogeny of the Tubificidae, and of most of its subfamilies and some of its genera, is revisited, on the basis of sequences of 18S ribosomal DNA in a selection of species. Forty-six new 18S sequences of Naididae (6), Tubificidae (37), Phreodrilidae (1), Lumbriculidae (1), and Enchytraeidae (1) are reported and aligned together with corresponding sequences of 21 previously studied taxa. The 18S gene of Insulodrilus bifidus provides the first molecular evidence that phreodrilids are closely related to tubificids, corroborating previous conclusions based on morphology. The data further support the monophyletic status of Tubificidae, provided that the “Naididae” is regarded a part of this family; “naidids” may not even constitute a monophyletic group. It is thus suggested that the family name Naididae is formally suppressed as a junior synonym of the Tubificidae. The 18S gene also resolves a number of relationships within the tubificids. Among the subfamilies, Tubificinae is supported, Rhyacodrilinae and Phallodrilinae are revealed as nonmonophyletic, and Limnodriloidinae remains unresolved. Most tubificid genera tested for monophyly are corroborated by the data, only one ( Tubifex ) is refuted, and two ( Tubificoides and Limnodriloides ) are unresolved from other taxa. It is concluded that it will be valuable to expand the taxonomic sampling for 18S rDNA in clitellates, and in annelids in general, as this is likely to improve the resolution at many levels. However, it will be equally important to combine the annelid 18S data with other gene sequences and nonmolecular characters, to estimate the phylogeny of these common and diverse worms with greater precision.
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Phylogenetic analysis of Tubificidae (Annelida, Clitellata) based on 18S rDNA sequences.
Molecular phylogenetics and evolution, 2000Co-Authors: Christer Erseus, Tore Prestegaard, Mari KallersjoAbstract:Tubificids are aquatic clitellate worms, but recent analyses of morphological characters suggested that this family, as currently recognized, is paraphyletic. Sequences of the 18S rDNA gene of 40 protostome worm species (including 13 representatives of the Tubificidae) and 2 mollusc species were cladistically analyzed to test the monophyly of the Tubificidae and that of some of its constituent subfamilies. Under all alignments tested, the same general phylogenetic pattern emerged. The data support the idea that the Naididae, another clitellate taxon, is associated with some “rhyacodriline” groups within the Tubificidae. The data also corroborate the idea that the Tubificinae and the Limnodriloidinae are monophyletic but indicate that the Rhyacodrilinae and the Phallodrilinae are not. Bathydrilus does not appear to be closely related to other “phallodriline” genera.
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A test of monophyly of the gutless Phallodrilinae (Oligochaeta, Tubificidae) and the use of a 573-bp region of the mitochondrial cytochrome oxidase I gene in analysis of annelid phylogeny
Zoologica Scripta, 1999Co-Authors: Johan A. A. Nylander, Christer Erseus, Mari KallersjoAbstract:A test of monophyly of the gutless Phallodrilinae (Oligochaeta, Tubificidae) and the use of a 573 bp region of the mitochondrial cytochrome oxidase I gene in analysis of annelid phylogeny.
Lena M. Gustavsson - One of the best experts on this subject based on the ideXlab platform.
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iczn rules a farewell to Tubificidae annelida clitellata
Zootaxa, 2008Co-Authors: Christer Erseus, Mark J Wetzel, Lena M. GustavssonAbstract:Morphological and molecular characters support that the former clitellate family Naididae Ehrenberg, 1828 is nested within another family, Tubificidae Vejdovský, 1876. To avoid paraphyly of the latter, it has been suggested that the two should be regarded as a single taxon. A recent decision by the International Commission of Zoological Nomenclature [2007; opinion 2167 (Case 3305)] ruled against a proposed reversal of the nomenclatural priority of Naididae over Tubificidae, with the consequence that all former tubificids should now be regarded as members of the Naididae whenever these two names are regarded as synonyms. The paper is a plea to clitellate researchers to conform to this ruling.
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ICZN rules—a farewell to Tubificidae (Annelida, Clitellata)
Zootaxa, 2008Co-Authors: Christer Erseus, Mark J Wetzel, Lena M. GustavssonAbstract:Morphological and molecular characters support that the former clitellate family Naididae Ehrenberg, 1828 is nested within another family, Tubificidae Vejdovský, 1876. To avoid paraphyly of the latter, it has been suggested that the two should be regarded as a single taxon. A recent decision by the International Commission of Zoological Nomenclature [2007; opinion 2167 (Case 3305)] ruled against a proposed reversal of the nomenclatural priority of Naididae over Tubificidae, with the consequence that all former tubificids should now be regarded as members of the Naididae whenever these two names are regarded as synonyms. The paper is a plea to clitellate researchers to conform to this ruling.
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Cuticular ultrastructure in some marine oligochaetes (Tubificidae)
Invertebrate Biology, 2005Co-Authors: Lena M. Gustavsson, Christer ErseusAbstract:. The ultrastructure of the thin, non-cellular cuticle is described for 6 marine oligochaetes, representing 3 of the subfamilies (Phallodrilinae, Limnodriloidinae, and Rhyacodrilinae) of the Tubificidae. The main components of the cuticle in these 6 species, as in most other oligochaetes examined, are: (1) a fiber zone closest to the epidermis, consisting of collagen fibers embedded in a matrix, (2) an epicuticle, which is a continuation of the matrix outside the fiber zone, and (3) epicuticular projections, which are membrane-bound bodies covering the outer surface of the epicuticle. The projections are probably formed by the microvilli that penetrate the cuticle from the epidermal cells below, but this was confirmed only in the studied limnodriloidines. Three of the species examined, Duridrilus turdus, Olavius vacuus, and Heterodrilus paucifascis, lack microvilli. The morphology of the components in the cuticle differs between the studied species. The collagen fibers may form an “orthogonal grid” (i.e., layers of parallel fibers perpendicular to the layers immediately above and below), or they may form parallel layers, or be irregularly scattered. The number of dense layers in the epicuticle, as well as the shape and internal structure of the epicuticular projections, also vary. All these characters might be useful in future phylogenetic analyses to achieve better hypotheses of relationships within oligochaetes as well as to other groups.
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Case 3305. Tubificidae Vejdovský, 1876 (Annelida, Clitellata): proposed precedence over NAIDIDAE Ehrenberg, 1828
The Bulletin of zoological nomenclature, 2005Co-Authors: Christer Erseus, Lena M. Gustavsson, Ralph O. BrinkhurstAbstract:The purpose of this application, under Article 23.9.3 of the Code, is to conserve the usage of the family-group name Tubificidae Vejdovský, 1876 for a well known group of aquatic oligochaetous clitellates. Following recent molecular studies it has been concluded that NAIDIDAE Ehrenberg, 1828 is a phylogenetic member of the taxon previously referred to as Tubificidae, implying that these two names are synonyms. Both names have long been used by aquatic biologists as associated with two functionally separated groups of worms. The junior name Tubificidae, with the famous Tubifex worm as its type, has been used for about 800 benthic species, which are burrowing or living interstitially in various limnic and marine sediments. The senior name NAIDIDAE, on the other hand, has been referred to about 175 species, most of which are epibenthic or epiphytic in freshwater habitats. It is proposed that the family-group name Tubificidae be given precedence over NAIDIDAE.
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Development of the genital ducts in Telmatodrilinae (Tubificidae, Clitellata).
Journal of morphology, 2004Co-Authors: Lena M. GustavssonAbstract:In Tubificidae, the male genital duct comprises a funnel in the testes segment, followed by a vas deferens, an atrium, and, frequently, a copulatory structure in the adjacent ovarian segment. There may also be a diffuse or compact prostate gland in association with the duct. The morphology and position of the genital ducts are important for the classification of the oligochaetous Clitellata. Different parts of the male duct, however, have been named without regard to whether they are homologous or not. One way to establish better hypotheses of homology is to study the detailed morphology and/or the development of the genital ducts. The morphogenesis of the genital ducts in Alexandrovia onegensis (Telmatodrilinae) is described. The male funnel originates by multiplication of peritoneal (mesodermal) cells in the posterior septum in the testes segment. A cord of these cells breaks through the septum and grows backwards into the next segment, where it connects to the epidermis. This cord gives rise to the vas deferens, and is therefore mesodermal in origin. The atrium in A. onegensis develops from a primary epidermal (ectodermal) invagination. The vas deferens and atrium connect and a continuous duct from the testes segment to the exterior is formed. Several compact prostate glands develop along the atrium, each being formed from cells in the atrial epithelium. The spermatheca develops from an invagination of the epidermis in the testes segment. The female duct is formed from peritoneal (mesodermal) cells in the posterior septum in the ovarian segment. These developmental findings strengthen the hypothesis about a closer relationship between the Telmatodrilinae and Tubificinae (both Tubificidae). J. Morphol. 262:791–799, 2004. © 2004 Wiley-Liss, Inc.
Rut Collado - One of the best experts on this subject based on the ideXlab platform.
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Two new species of freshwater Oligochaeta from the North‐west Iberian Peninsula: Krenedrilus realis sp. nov. (Tubificidae) and Cernosvitoviella bulboducta sp. nov. (Enchytraeidae)
Journal of Zoology, 1996Co-Authors: E. Martínez‐ansemil, Rut ColladoAbstract:Two new species of aquatic Oligochaeta are described from the North-west Iberian Peninsula: Krenedrilus realissp. nov. (Tubificidae) and Cernosvitoviella bulboductasp. nov. (Enchytraeidae). Krenedrilus realis is the fourth species in a genus of small and presumably plesiomorphic Tubificinae. It is closely related to K. sergei Giani, Erseus & Martinez-Ansemil, 1990. Cernosvitoviella bulboducta belongs to a genus of small amphibiotic enchytraeids. It is close to C. ampullax Klungland & Abrahamsen, 1981 and C. tatrensis (Kowalewski, 1916). Supplementary data to the diagnosis of C. tatrensis are given. The presence of two small glands attached to the gut immediately behind the pharyngeal bulb is noticed in C. bulboducta and C. tatrensis. This previously unknown character is probably more common in the genus than has been supposed.
Lin Lin - One of the best experts on this subject based on the ideXlab platform.
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Sludge reduction with Tubificidae and the impact on the performance of the wastewater treatment process.
Journal of environmental sciences (China), 2007Co-Authors: Xuesong Guo, Junxin Liu, Yuansong Wei, Lin LinAbstract:To reduce excess sludge, a Tubificidae reactor was combined with an integrated oxidation ditch with vertical circle (IODVC), and a new integrated system was developed for wastewater treatment. A pilot-scale of this integrated system was tested to investigate the sludge reduction with Tubificidae and the impact on effluent quality and sludge production. The dominant worm was Branchnria Sowerbyi in the Tubificidae reactor after inoculation of Branchnria Sowerbyi and Limnodrilns sp., and the maximal volume density of wet Tubificidae in vessels of the Tubificidae reactor was 17600 g/m3. Two operational modes, treating the excess sludge (first mode) and the returned sludge (second mode) of IODVC by the Tubificidae reactor, were used in this experiment. The results showed that the excess sludge reduction rate was 46.4% in the first mode, and the average sludge yield of the integrated system was 6.19 x 10(-5) kg SS/kg COD in the second mode. Though the sludge returned to IODVC via the Tubificidae reactor, it had little impact on the effluent quality and the sludge characteristics of the IODVC. No new type of recalcitrant substance in the supernatant was discharged into the environment when the sludge was treated by Tubificidae. The experimental results also indicated that no significant changes occurred on the viscosity, specific resistance, and the floc size distribution of the sludge.
