Christer Erséus - Academia.edu (original) (raw)

Papers by Christer Erséus

ZooKeys, 2015

Citation: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Mich... more Citation: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Michaelsen, 1888) (Clitellata, Enchytraeidae), with the description of a new species. ZooKeys 501: 1-14.

ZooKeys, 2015

Corrigenda: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Mi... more Corrigenda: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Michaelsen, 1888) (Clitellata, Enchytraeidae), with the description of a new species. ZooKeys 501: 1-14.

Following recent phylogenetic assessments using DNA data, the aquatic oligochaete family Naididae... more Following recent phylogenetic assessments using DNA data, the aquatic oligochaete family Naididae (=Naidina Ehrenberg, 1828) is proposed to be treated as a subfamily, Naidinae, within Tubificidae Vejdovský, 1876. [A complication of this proposal is that the family-group name Naididae is older than Tubificidae, and thus, according to the International Code of Zoological Nomenclature, should have precedence over the latter; this will be dealt with in a separate application to the International Commission of Zoological Nomenclature.] Naidinae appears to be closely related to taxa currently placed in another tubificid subfamily, Rhyacodrilinae, but it is argued that, while Naidinae is likely to be a natural group, Rhyacodrilinae is most probably not, neither with nor without the inclusion of the naidines. It is thus predicted that future revisions will involve splitting of Rhyacodrilinae rather than a drastic change in the circumscription of Naidinae.

The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivri... more The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivrihisar (Eskişehir, Central Anatolia), is one of the most important bird conservation areas in Turkey. This area also encompasses the mouth of the torrential Göksu Stream, which is partly hyporheic. During this study (2001)(2002)(2003), 1,471 specimens representing 34 taxa of aquatic Oligochaeta were collected from the Balıkdamı Wetland. All the species identified are new records for Balıkdamı. Two species, Coralliodrilus amissus sp. n. and Gianius anatolicus sp. n., are new to science, and five species, Stylodrilus parvus (Hrabě et Černosvitov, 1927), Chaetogaster diastrophus (Gruithuisen, 1828), Peipsidrilus libanus , Tubifex acuticularis Martinez-Ansemil et , and Epirodrilus moubayedi Giani et , are new records for Turkey. Two other species, Peipsidrilus libanus and Tubifex acuticularis, are re-described. The oligochaete fauna of the wetland was dominated by widely distributed tubificid taxa. The lumbriculid Stylodrilus parvus was the most abundant species in the Göksu stream. The two new phallodriline species are remarkable since most representatives of this subfamily live in the marine environment. Due to the species richness and diversity of Oligochaeta, as well as of several other animal groups, the Balıkdamı wetland area deserves conservation.

A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed ... more A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed by Bayesian inference to estimate the phylogeny of a sample of the clitellate family Enchytraeidae (86 species representing 14 nominal genera). Monophyly, as well as a basal dichotomy, of the family Enchytraeidae obtained maximum support, with one clade containing Hemienchytraeus and Achaeta, the other the remaining 12 genera analysed. The latter group is basally resolved in several well-supported clades. Lumbricillus and Grania are closely related. Bryodrilus, Oconnorella, Henlea and two species of Marionina (M. cf. riparia, and M. communis) form a well-supported clade. Cognettia is sister to Stercutus, and Cernosvitoviella sister to Mesenchytraeus, and the four together appear to be a monophyletic group. A large part of the taxonomically problematic Marionina appears to be a group not closely related to the type species (M. georgiana), and this group also includes Enchytronia. Further, this Marionina/Enchytronia group appears to be sister to a clade comprising the more or less littoral marine genera Stephensoniella and Enchytraeus. Hemifridericia, Buchholzia and Fridericia, the three genera characterized by two types of coelomocytes, also form a well-supported clade. The study corroborates most of the multi-species genera analysed (Cognettia, Cernosvitoviella, Mesenchytraeus, Oconnorella, Henlea, Enchytraeus, Grania, Buchholzia and Fridericia); only Lumbricillus and Marionina are non-monophyletic as currently defined.

Zoologica Scripta, 1981

Introduction The existence of a vast marine oligochaete fauna in Australia has become apparent in... more Introduction The existence of a vast marine oligochaete fauna in Australia has become apparent in recent studies in the coral sands of Heron and Wistari Reefs at the southern end of the Great Barrier Reef (Jamieson 1977; ErsCus 1980, 1981 a, b). The present account describes ...

Applied and Environmental Microbiology, 2005

Olavius crassitunicatus is a small symbiont-bearing worm that occurs at high abundance in oxygen-... more Olavius crassitunicatus is a small symbiont-bearing worm that occurs at high abundance in oxygen-deficient sediments in the East Pacific Ocean. Using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization, we examined the diversity and phylogeny of bacterial symbionts in two geographically distant O. crassitunicatus populations (separated by 385 km) on the Peru margin (water depth, 300 m). Five

Nature, 2001

Stable associations of more than one species of symbiont within a single host cell or tissue are ... more Stable associations of more than one species of symbiont within a single host cell or tissue are assumed to be rare in metazoans because competition for space and resources between symbionts can be detrimental to the host. In animals with multiple endosymbionts, such as mussels from deep-sea hydrothermal vents and reef-building corals, the costs of competition between the symbionts are outweighed by the ecological and physiological flexibility gained by the hosts. A further option for the coexistence of multiple symbionts within a host is if these benefit directly from one another, but such symbioses have not been previously described. Here we show that in the gutless marine oligochaete Olavius algarvensis, endosymbiotic sulphate-reducing bacteria produce sulphide that can serve as an energy source for sulphide-oxidizing symbionts of the host. Thus, these symbionts do not compete for resources but rather share a mutalistic relationship with each other in an endosymbiotic sulphur cycle, in addition to their symbiotic relationship with the oligochaete host.

This study describes the fauna of the marine enchytraeid genus Grania at two locations on the Aus... more This study describes the fauna of the marine enchytraeid genus Grania at two locations on the Australian Great Barrier Reef: Lizard and Heron Islands. Collections were made from 1979 to 2006, yielding four new species: Grania breviductus sp. n., Grania regina sp. n., Grania homochaeta sp. n. and Grania colorata sp. n.. A re-description of Grania trichaeta Jamieson, 1977 based

Zootaxa, 2013

Lake Hazar is an alkaline oligotrophic lake of tectonic origin, located in the Eastern Anatolia r... more Lake Hazar is an alkaline oligotrophic lake of tectonic origin, located in the Eastern Anatolia region in Turkey, 1248 m a.s.l. Its surface area is 80 km 2 , the average depth 93 m and maximum depth 205 m. The lake and its surroundings are under protection as a region of historical value. During the present study (2007)(2008)(2009)(2010)(2011)(2012), samples were taken from 15 stations located at a depth of 2-200 m. Oligochaeta comprised 69% of the total invertebrate abundance. The profundal oligochaete fauna was found to consist of only three tubificid taxa, all of the subfamily Tubificinae. Potamothrix alatus hazaricus Timm & Arslan, n. ssp. was dominating anywhere down to maximum depths while Psammoryctides barbatus (Grube) and Ilyodrilus(?) sp. occurred seldom. All three are new records for Lake Hazar. Potamothrix alatus hazaricus shares the "winged" body shape in its genital region with the nominal, brackish-water subspecies P. a. alatus Finogenova, 1972, and the lateral position of the spermathecal pores and the shape of the ventral chaetae with the freshwater subspecies P. a. paravanicus Poddubnaja & Pataridze, 1989 known from Transcaucasian lakes. The mitochondrial COI barcoding gene suggests long separation between the two taxa, but the nuclear ITS region shows no variation. The generic position of Ilyodrilus (?) sp. remains obscure since its internal genitalia could not be studied.

Zoologica Scripta, 2010

The Nearctic species of Rhynchelmis (Clitellata, Lumbriculidae) are known primarily from cool-wat... more The Nearctic species of Rhynchelmis (Clitellata, Lumbriculidae) are known primarily from cool-water habitats in western North America. Their taxonomy has so far been based on limited collections from isolated localities, using intuitive assessment of morphological characters. This approach has proved unsatisfactory when additional populations of closely related species were sampled and scrutinized for incorporation in the present classification. Therefore, in this study, mitochondrial (cytochrome c oxidase subunit I and 16S rDNA) and nuclear internal transcriber spacer (ITS rDNA) genes were analysed as phylogenetic markers of Nearctic Rhynchelmis species. A combined approach with all the three gene regions provided a better resolution than any of the individual genes by itself. The genes demonstrated monophyly of all major groupings proposed on the morphological basis. Within the Rhynchelmis yakimorum complex, however, the genetic data and distribution suggested that two clades initially referred to as a 'R. yakimorum variant 1', one from the lower Snake River drainage in Idaho and one from southern coastal Oregon, might represent two separate species. On the other hand, the sympatric distribution and low genetic distance between Rhynchelmis gustafsoni and a form tentatively identified as 'R. cf. yakimorum' (both collected in eastern Idaho) indicated conspecific status. This study also showed that the cytochrome c oxidase subunit I (COI) gene, which may be informative of recent and on-going speciation and useful for species discrimination (as a DNA barcode), is less suitable as a single molecular marker for phylogenetic inference. Regardless of whether one deals with very closely related species (such as those of the yakimorum complex), with taxa with a wide and disjunct distribution (such as Rhynchelmis rostrata), or with more distantly related species, COI data should be supplemented by other genetic markers as well as morphological and biogeographical information.

Organisms Diversity & Evolution, 2008

On the basis of new material from various Pacific regions we critically evaluate the characters f... more On the basis of new material from various Pacific regions we critically evaluate the characters for the taxonomy of the genus Questa and the former Questidae, a taxon now concluded to be a lineage within the family Orbiniidae. Two new species, Questa retrospermatica sp. n. from Hawaii (with similar forms also from New Caledonia and China), and Questa fijiensis sp.

Molecular Phylogenetics and Evolution, 2010

A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed ... more A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed by Bayesian inference to estimate the phylogeny of a sample of the clitellate family Enchytraeidae (86 species representing 14 nominal genera). Monophyly, as well as a basal dichotomy, of the family Enchytraeidae obtained maximum support, with one clade containing Hemienchytraeus and Achaeta, the other the remaining 12 genera analysed. The latter group is basally resolved in several well-supported clades. Lumbricillus and Grania are closely related. Bryodrilus, Oconnorella, Henlea and two species of Marionina (M. cf. riparia, and M. communis) form a well-supported clade. Cognettia is sister to Stercutus, and Cernosvitoviella sister to Mesenchytraeus, and the four together appear to be a monophyletic group. A large part of the taxonomically problematic Marionina appears to be a group not closely related to the type species (M. georgiana), and this group also includes Enchytronia. Further, this Marionina/Enchytronia group appears to be sister to a clade comprising the more or less littoral marine genera Stephensoniella and Enchytraeus. Hemifridericia, Buchholzia and Fridericia, the three genera characterized by two types of coelomocytes, also form a well-supported clade. The study corroborates most of the multi-species genera analysed (Cognettia, Cernosvitoviella, Mesenchytraeus, Oconnorella, Henlea, Enchytraeus, Grania, Buchholzia and Fridericia); only Lumbricillus and Marionina are non-monophyletic as currently defined.

Molecular Phylogenetics and Evolution, 2010

Opistocystidae Č ernosvitov, 1936 is a largely Neotropical oligochaete taxon containing seven spe... more Opistocystidae Č ernosvitov, 1936 is a largely Neotropical oligochaete taxon containing seven species. Its familial status has never been formally challenged, although possible close relationships with Naididae and Phreodrilidae have been noted. Mitochondrial 12S and 16S rDNA, and nuclear 18S rDNA, of a range of aquatic oligochaete taxa, including Trieminentia corderoi (Opistocystidae), were analysed by Bayesian inference. This showed that T. corderoi is a derived lineage within Naididae, closely related to Pristina and its monotypic subfamily Pristininae. Opistocystidae as a whole (with its three genera, Opistocysta, Trieminentia, and Crustipellis) is thus likely to be a group within Naididae.

Molecular Phylogenetics and Evolution, 2006

Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In ... more Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In this study, we evaluated the phylogenetic status of Naidinae, and examined the phylogenetic relationships within the group. Sequence data from two mitochondrial genes (12S rDNA and 16S rDNA), and one nuclear gene (18S rDNA), were used. Sequences were obtained from 27 naidine species, 24 species from the other tubificid subfamilies, and five outgroup taxa. New sequences (in all 108) as well as GenBank data were used. The data were analysed by parsimony and Bayesian inference. The tree topologies emanating from the different analyses are congruent to a great extent. Naidinae is not found to be monophyletic. The naidine genus Pristina appears to be a derived group within a clade consisting of several genera (Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus) from another tubificid subfamily, Rhyacodrilinae. These results demonstrate the need for a taxonomic revision: either Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus should be included within Naidinae, or Pristina should be excluded from this subfamily. Monophyly of four out of six naidine genera represented by more than one species is supported: Chaetogaster, Dero, Paranais, and Pristina, respectively.

Journal of Zoological Systematics and Evolutionary Research, 2010

Individuals of five nominal species of Grania (Annelida: Clitellata: Enchytraeidae) were collecte... more Individuals of five nominal species of Grania (Annelida: Clitellata: Enchytraeidae) were collected from locations in Sweden, Norway and France, for studies on the intraspecific variation at the Cytochrome Oxidase I (COI) locus of mitochondrial DNA and internal transcribed spacer (ITS) region of nuclear DNA. It was found that the previously described morphospecies in general contain low variation compared to the betweenspecies variation in both loci. In one instance, however, an individual morphologically indistinguishable from G. ovitheca was found to be deviant and instead cluster with G. postclitellochaeta both by COI and ITS. We describe this individual as a new species: G. occulta sp.n. Furthermore, phylogenetic analyses were conducted, showing a close relationship between G. variochaeta, G. occulta, G. ovitheca and G. postclitellochaeta, as well as between G. pusilla and G. maricola. Using the results from the phylogenetic analyses, we discuss the evolution of morphological characters in Scandinavian species of Grania.

Sarsia: North Atlantic Marine Science, 2003

... Emilia Rota, Dipartimento di Scienze Ambientali, Sezione di Sistematica ed Ecologia Animale e... more ... Emilia Rota, Dipartimento di Scienze Ambientali, Sezione di Sistematica ed Ecologia Animale e Vegetale, Universita` di Siena, Via PA Mattioli 4, IT-53100 Siena, Italy. ... Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway Page 2. ...

Journal of Morphology, 2008

Various types of free-floating cells are found in the coelomic fluid of representatives of severa... more Various types of free-floating cells are found in the coelomic fluid of representatives of several annelid groups. The ultrastructure of these "coelomocytes," however, has been studied to a limited degree. In this study, we used a transmission electron microscope to investigate the coelomocytes in specimens of five species of Naidinae and three species of Rhyacodrilinae (all oligochaetous clitellates within the family Tubificidae). These were compared with each other and with previously described coelomocytes of representatives of other oligochaete taxa. Only one distinguishable coelomocyte type was found in the studied specimens: a round to oblong cell without pseudopodia or other appendages, primarily containing membrane-bound granules of varying electron density, a prominent network of rough endoplasmic reticulum, and free ribosomes. This type differs to a great extent from most of the previously described coelomocytes, but shows similarities to certain types found in members of Enchytraeidae and Megascolecidae. Although we noticed some variation, we did not find any ultrastructural characters in these cells obviously useful for phylogenetic studies within Tubificidae.

Hydrobiologia, 1994

The marine tubificid oligochaete fauna of Belize is the most diverse that has been described for ... more The marine tubificid oligochaete fauna of Belize is the most diverse that has been described for the Caribbean Sea, with records for over 50% of all known Caribbean species. Tubificids were sampled at 77 stations around the outer barrier of the coral reefs off the Belize mainland. A total of 1,529 individuals representing 52 species were collected. Species distribution patterns were controlled mainly by sediment type and the presence or absence of mangroves. Six species (Phallodrilus molestus, Tubt$coides bermudae, Inanidrilus leukodermatus, Heterodrilusjlexuosus, Bathydrilus formosus, Smithsonidrilus hummelincki) with diverse life history characteristics were common and had broad habitat preferences being found in various types of heterogeneous sandy sediments. Heterodrilus jlexuosus was the only common species in these samples known only in Belize. The other five common species range from Belize to Florida or Bermuda. Most other species have narrower habitat preferences and are limited to specific habitats. For example, one group of gutless species was restricted to organically enriched fine to medium sands, a group of Limnodriloidinae occurred only in mud around mangrove cays, and a group of meiofaunal species were restricted to saline groundwater.

ZooKeys, 2015

Citation: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Mich... more Citation: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Michaelsen, 1888) (Clitellata, Enchytraeidae), with the description of a new species. ZooKeys 501: 1-14.

ZooKeys, 2015

Corrigenda: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Mi... more Corrigenda: Martinsson S, Rota E, Erséus C (2015) On the identity of Chamaedrilus glandulosus (Michaelsen, 1888) (Clitellata, Enchytraeidae), with the description of a new species. ZooKeys 501: 1-14.

Following recent phylogenetic assessments using DNA data, the aquatic oligochaete family Naididae... more Following recent phylogenetic assessments using DNA data, the aquatic oligochaete family Naididae (=Naidina Ehrenberg, 1828) is proposed to be treated as a subfamily, Naidinae, within Tubificidae Vejdovský, 1876. [A complication of this proposal is that the family-group name Naididae is older than Tubificidae, and thus, according to the International Code of Zoological Nomenclature, should have precedence over the latter; this will be dealt with in a separate application to the International Commission of Zoological Nomenclature.] Naidinae appears to be closely related to taxa currently placed in another tubificid subfamily, Rhyacodrilinae, but it is argued that, while Naidinae is likely to be a natural group, Rhyacodrilinae is most probably not, neither with nor without the inclusion of the naidines. It is thus predicted that future revisions will involve splitting of Rhyacodrilinae rather than a drastic change in the circumscription of Naidinae.

The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivri... more The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivrihisar (Eskişehir, Central Anatolia), is one of the most important bird conservation areas in Turkey. This area also encompasses the mouth of the torrential Göksu Stream, which is partly hyporheic. During this study (2001)(2002)(2003), 1,471 specimens representing 34 taxa of aquatic Oligochaeta were collected from the Balıkdamı Wetland. All the species identified are new records for Balıkdamı. Two species, Coralliodrilus amissus sp. n. and Gianius anatolicus sp. n., are new to science, and five species, Stylodrilus parvus (Hrabě et Černosvitov, 1927), Chaetogaster diastrophus (Gruithuisen, 1828), Peipsidrilus libanus , Tubifex acuticularis Martinez-Ansemil et , and Epirodrilus moubayedi Giani et , are new records for Turkey. Two other species, Peipsidrilus libanus and Tubifex acuticularis, are re-described. The oligochaete fauna of the wetland was dominated by widely distributed tubificid taxa. The lumbriculid Stylodrilus parvus was the most abundant species in the Göksu stream. The two new phallodriline species are remarkable since most representatives of this subfamily live in the marine environment. Due to the species richness and diversity of Oligochaeta, as well as of several other animal groups, the Balıkdamı wetland area deserves conservation.

A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed ... more A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed by Bayesian inference to estimate the phylogeny of a sample of the clitellate family Enchytraeidae (86 species representing 14 nominal genera). Monophyly, as well as a basal dichotomy, of the family Enchytraeidae obtained maximum support, with one clade containing Hemienchytraeus and Achaeta, the other the remaining 12 genera analysed. The latter group is basally resolved in several well-supported clades. Lumbricillus and Grania are closely related. Bryodrilus, Oconnorella, Henlea and two species of Marionina (M. cf. riparia, and M. communis) form a well-supported clade. Cognettia is sister to Stercutus, and Cernosvitoviella sister to Mesenchytraeus, and the four together appear to be a monophyletic group. A large part of the taxonomically problematic Marionina appears to be a group not closely related to the type species (M. georgiana), and this group also includes Enchytronia. Further, this Marionina/Enchytronia group appears to be sister to a clade comprising the more or less littoral marine genera Stephensoniella and Enchytraeus. Hemifridericia, Buchholzia and Fridericia, the three genera characterized by two types of coelomocytes, also form a well-supported clade. The study corroborates most of the multi-species genera analysed (Cognettia, Cernosvitoviella, Mesenchytraeus, Oconnorella, Henlea, Enchytraeus, Grania, Buchholzia and Fridericia); only Lumbricillus and Marionina are non-monophyletic as currently defined.

Zoologica Scripta, 1981

Introduction The existence of a vast marine oligochaete fauna in Australia has become apparent in... more Introduction The existence of a vast marine oligochaete fauna in Australia has become apparent in recent studies in the coral sands of Heron and Wistari Reefs at the southern end of the Great Barrier Reef (Jamieson 1977; ErsCus 1980, 1981 a, b). The present account describes ...

Applied and Environmental Microbiology, 2005

Olavius crassitunicatus is a small symbiont-bearing worm that occurs at high abundance in oxygen-... more Olavius crassitunicatus is a small symbiont-bearing worm that occurs at high abundance in oxygen-deficient sediments in the East Pacific Ocean. Using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization, we examined the diversity and phylogeny of bacterial symbionts in two geographically distant O. crassitunicatus populations (separated by 385 km) on the Peru margin (water depth, 300 m). Five

Nature, 2001

Stable associations of more than one species of symbiont within a single host cell or tissue are ... more Stable associations of more than one species of symbiont within a single host cell or tissue are assumed to be rare in metazoans because competition for space and resources between symbionts can be detrimental to the host. In animals with multiple endosymbionts, such as mussels from deep-sea hydrothermal vents and reef-building corals, the costs of competition between the symbionts are outweighed by the ecological and physiological flexibility gained by the hosts. A further option for the coexistence of multiple symbionts within a host is if these benefit directly from one another, but such symbioses have not been previously described. Here we show that in the gutless marine oligochaete Olavius algarvensis, endosymbiotic sulphate-reducing bacteria produce sulphide that can serve as an energy source for sulphide-oxidizing symbionts of the host. Thus, these symbionts do not compete for resources but rather share a mutalistic relationship with each other in an endosymbiotic sulphur cycle, in addition to their symbiotic relationship with the oligochaete host.

This study describes the fauna of the marine enchytraeid genus Grania at two locations on the Aus... more This study describes the fauna of the marine enchytraeid genus Grania at two locations on the Australian Great Barrier Reef: Lizard and Heron Islands. Collections were made from 1979 to 2006, yielding four new species: Grania breviductus sp. n., Grania regina sp. n., Grania homochaeta sp. n. and Grania colorata sp. n.. A re-description of Grania trichaeta Jamieson, 1977 based

Zootaxa, 2013

Lake Hazar is an alkaline oligotrophic lake of tectonic origin, located in the Eastern Anatolia r... more Lake Hazar is an alkaline oligotrophic lake of tectonic origin, located in the Eastern Anatolia region in Turkey, 1248 m a.s.l. Its surface area is 80 km 2 , the average depth 93 m and maximum depth 205 m. The lake and its surroundings are under protection as a region of historical value. During the present study (2007)(2008)(2009)(2010)(2011)(2012), samples were taken from 15 stations located at a depth of 2-200 m. Oligochaeta comprised 69% of the total invertebrate abundance. The profundal oligochaete fauna was found to consist of only three tubificid taxa, all of the subfamily Tubificinae. Potamothrix alatus hazaricus Timm & Arslan, n. ssp. was dominating anywhere down to maximum depths while Psammoryctides barbatus (Grube) and Ilyodrilus(?) sp. occurred seldom. All three are new records for Lake Hazar. Potamothrix alatus hazaricus shares the "winged" body shape in its genital region with the nominal, brackish-water subspecies P. a. alatus Finogenova, 1972, and the lateral position of the spermathecal pores and the shape of the ventral chaetae with the freshwater subspecies P. a. paravanicus Poddubnaja & Pataridze, 1989 known from Transcaucasian lakes. The mitochondrial COI barcoding gene suggests long separation between the two taxa, but the nuclear ITS region shows no variation. The generic position of Ilyodrilus (?) sp. remains obscure since its internal genitalia could not be studied.

Zoologica Scripta, 2010

The Nearctic species of Rhynchelmis (Clitellata, Lumbriculidae) are known primarily from cool-wat... more The Nearctic species of Rhynchelmis (Clitellata, Lumbriculidae) are known primarily from cool-water habitats in western North America. Their taxonomy has so far been based on limited collections from isolated localities, using intuitive assessment of morphological characters. This approach has proved unsatisfactory when additional populations of closely related species were sampled and scrutinized for incorporation in the present classification. Therefore, in this study, mitochondrial (cytochrome c oxidase subunit I and 16S rDNA) and nuclear internal transcriber spacer (ITS rDNA) genes were analysed as phylogenetic markers of Nearctic Rhynchelmis species. A combined approach with all the three gene regions provided a better resolution than any of the individual genes by itself. The genes demonstrated monophyly of all major groupings proposed on the morphological basis. Within the Rhynchelmis yakimorum complex, however, the genetic data and distribution suggested that two clades initially referred to as a 'R. yakimorum variant 1', one from the lower Snake River drainage in Idaho and one from southern coastal Oregon, might represent two separate species. On the other hand, the sympatric distribution and low genetic distance between Rhynchelmis gustafsoni and a form tentatively identified as 'R. cf. yakimorum' (both collected in eastern Idaho) indicated conspecific status. This study also showed that the cytochrome c oxidase subunit I (COI) gene, which may be informative of recent and on-going speciation and useful for species discrimination (as a DNA barcode), is less suitable as a single molecular marker for phylogenetic inference. Regardless of whether one deals with very closely related species (such as those of the yakimorum complex), with taxa with a wide and disjunct distribution (such as Rhynchelmis rostrata), or with more distantly related species, COI data should be supplemented by other genetic markers as well as morphological and biogeographical information.

Organisms Diversity & Evolution, 2008

On the basis of new material from various Pacific regions we critically evaluate the characters f... more On the basis of new material from various Pacific regions we critically evaluate the characters for the taxonomy of the genus Questa and the former Questidae, a taxon now concluded to be a lineage within the family Orbiniidae. Two new species, Questa retrospermatica sp. n. from Hawaii (with similar forms also from New Caledonia and China), and Questa fijiensis sp.

Molecular Phylogenetics and Evolution, 2010

A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed ... more A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed by Bayesian inference to estimate the phylogeny of a sample of the clitellate family Enchytraeidae (86 species representing 14 nominal genera). Monophyly, as well as a basal dichotomy, of the family Enchytraeidae obtained maximum support, with one clade containing Hemienchytraeus and Achaeta, the other the remaining 12 genera analysed. The latter group is basally resolved in several well-supported clades. Lumbricillus and Grania are closely related. Bryodrilus, Oconnorella, Henlea and two species of Marionina (M. cf. riparia, and M. communis) form a well-supported clade. Cognettia is sister to Stercutus, and Cernosvitoviella sister to Mesenchytraeus, and the four together appear to be a monophyletic group. A large part of the taxonomically problematic Marionina appears to be a group not closely related to the type species (M. georgiana), and this group also includes Enchytronia. Further, this Marionina/Enchytronia group appears to be sister to a clade comprising the more or less littoral marine genera Stephensoniella and Enchytraeus. Hemifridericia, Buchholzia and Fridericia, the three genera characterized by two types of coelomocytes, also form a well-supported clade. The study corroborates most of the multi-species genera analysed (Cognettia, Cernosvitoviella, Mesenchytraeus, Oconnorella, Henlea, Enchytraeus, Grania, Buchholzia and Fridericia); only Lumbricillus and Marionina are non-monophyletic as currently defined.

Molecular Phylogenetics and Evolution, 2010

Opistocystidae Č ernosvitov, 1936 is a largely Neotropical oligochaete taxon containing seven spe... more Opistocystidae Č ernosvitov, 1936 is a largely Neotropical oligochaete taxon containing seven species. Its familial status has never been formally challenged, although possible close relationships with Naididae and Phreodrilidae have been noted. Mitochondrial 12S and 16S rDNA, and nuclear 18S rDNA, of a range of aquatic oligochaete taxa, including Trieminentia corderoi (Opistocystidae), were analysed by Bayesian inference. This showed that T. corderoi is a derived lineage within Naididae, closely related to Pristina and its monotypic subfamily Pristininae. Opistocystidae as a whole (with its three genera, Opistocysta, Trieminentia, and Crustipellis) is thus likely to be a group within Naididae.

Molecular Phylogenetics and Evolution, 2006

Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In ... more Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In this study, we evaluated the phylogenetic status of Naidinae, and examined the phylogenetic relationships within the group. Sequence data from two mitochondrial genes (12S rDNA and 16S rDNA), and one nuclear gene (18S rDNA), were used. Sequences were obtained from 27 naidine species, 24 species from the other tubificid subfamilies, and five outgroup taxa. New sequences (in all 108) as well as GenBank data were used. The data were analysed by parsimony and Bayesian inference. The tree topologies emanating from the different analyses are congruent to a great extent. Naidinae is not found to be monophyletic. The naidine genus Pristina appears to be a derived group within a clade consisting of several genera (Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus) from another tubificid subfamily, Rhyacodrilinae. These results demonstrate the need for a taxonomic revision: either Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus should be included within Naidinae, or Pristina should be excluded from this subfamily. Monophyly of four out of six naidine genera represented by more than one species is supported: Chaetogaster, Dero, Paranais, and Pristina, respectively.

Journal of Zoological Systematics and Evolutionary Research, 2010

Individuals of five nominal species of Grania (Annelida: Clitellata: Enchytraeidae) were collecte... more Individuals of five nominal species of Grania (Annelida: Clitellata: Enchytraeidae) were collected from locations in Sweden, Norway and France, for studies on the intraspecific variation at the Cytochrome Oxidase I (COI) locus of mitochondrial DNA and internal transcribed spacer (ITS) region of nuclear DNA. It was found that the previously described morphospecies in general contain low variation compared to the betweenspecies variation in both loci. In one instance, however, an individual morphologically indistinguishable from G. ovitheca was found to be deviant and instead cluster with G. postclitellochaeta both by COI and ITS. We describe this individual as a new species: G. occulta sp.n. Furthermore, phylogenetic analyses were conducted, showing a close relationship between G. variochaeta, G. occulta, G. ovitheca and G. postclitellochaeta, as well as between G. pusilla and G. maricola. Using the results from the phylogenetic analyses, we discuss the evolution of morphological characters in Scandinavian species of Grania.

Sarsia: North Atlantic Marine Science, 2003

... Emilia Rota, Dipartimento di Scienze Ambientali, Sezione di Sistematica ed Ecologia Animale e... more ... Emilia Rota, Dipartimento di Scienze Ambientali, Sezione di Sistematica ed Ecologia Animale e Vegetale, Universita` di Siena, Via PA Mattioli 4, IT-53100 Siena, Italy. ... Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway Page 2. ...

Journal of Morphology, 2008

Various types of free-floating cells are found in the coelomic fluid of representatives of severa... more Various types of free-floating cells are found in the coelomic fluid of representatives of several annelid groups. The ultrastructure of these "coelomocytes," however, has been studied to a limited degree. In this study, we used a transmission electron microscope to investigate the coelomocytes in specimens of five species of Naidinae and three species of Rhyacodrilinae (all oligochaetous clitellates within the family Tubificidae). These were compared with each other and with previously described coelomocytes of representatives of other oligochaete taxa. Only one distinguishable coelomocyte type was found in the studied specimens: a round to oblong cell without pseudopodia or other appendages, primarily containing membrane-bound granules of varying electron density, a prominent network of rough endoplasmic reticulum, and free ribosomes. This type differs to a great extent from most of the previously described coelomocytes, but shows similarities to certain types found in members of Enchytraeidae and Megascolecidae. Although we noticed some variation, we did not find any ultrastructural characters in these cells obviously useful for phylogenetic studies within Tubificidae.

Hydrobiologia, 1994

The marine tubificid oligochaete fauna of Belize is the most diverse that has been described for ... more The marine tubificid oligochaete fauna of Belize is the most diverse that has been described for the Caribbean Sea, with records for over 50% of all known Caribbean species. Tubificids were sampled at 77 stations around the outer barrier of the coral reefs off the Belize mainland. A total of 1,529 individuals representing 52 species were collected. Species distribution patterns were controlled mainly by sediment type and the presence or absence of mangroves. Six species (Phallodrilus molestus, Tubt$coides bermudae, Inanidrilus leukodermatus, Heterodrilusjlexuosus, Bathydrilus formosus, Smithsonidrilus hummelincki) with diverse life history characteristics were common and had broad habitat preferences being found in various types of heterogeneous sandy sediments. Heterodrilus jlexuosus was the only common species in these samples known only in Belize. The other five common species range from Belize to Florida or Bermuda. Most other species have narrower habitat preferences and are limited to specific habitats. For example, one group of gutless species was restricted to organically enriched fine to medium sands, a group of Limnodriloidinae occurred only in mud around mangrove cays, and a group of meiofaunal species were restricted to saline groundwater.