18S rDNA phylogeny of the Tubificidae (Clitellata) and its constituent taxa: dismissal of the Naididae

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.     

Phylogenetic analysis of Tubificidae (Annelida, Clitellata) based on 18S rDNA sequences

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.     

Cladistic analysis of the subfamilies within the Tubificidae (Oligochaeta)

A hypothesis of phylogenetic relationships within the family Tubificidae is presented, based on a Wagner analysis of morphological characters in the different subfamilies. Two major lincages are recognized. One, including the subfamilies Tubificinae, Telmatodrilinae and Limnodriloidinae, is supported by a synapomorphic ability to form slender spermatozeugmata in the spermathecae; the other, including Rhyacodrilinae (paraphyletic), Phallodrilinae, and the (present family) Naididae, is supported by two synapomorphics, the possession of modified penial setae and numerous coelomocytes (the latter secondarily lost in the Phallodrilinae). Some implications for the classification of the Tubificidae are discussed.     

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

A 573-bp region of the mitochondrial gene cytochrome c oxidase subunit I (COI) of two species of Inanidrilus Erséus and four species of Olavius Erséus (Phallodrilinae, Tubificidae) is used in a parsimony analysis together with a selection of 35 other annelids (including members of Polychaeta, Pogonophora, Aphanoneura, and the clitellate taxa Tubificidae, Enchytraeidae, Naididae, Lumbriculidae, Haplotaxidae, Lumbricidae, Criodrilidae, Branchiobdellida and Hirudinea), and with two molluscs as outgroups. The data support the monophyly of the Olavius and Inanidrilus group, with a monophyletic Inanidrilus . However, parsimony jackknife analyses show that most of the other groups are unsupported by the data set, thus revealing a large amount of homoplasy in the selected gene region. Practically no information is given of within/between family relationships except for a few, closely related species. This suggests that the analysed COI region is not useful, when used alone, for inferring higher level relationships among the annelids.     

Some aquatic oligochaetes of the Nilgiris,South India

Eight species of aquatic oligochaetes, belonging to the families Naididae and Tubificidae, are reported, of which six species are new to the Nigiris. Tubifex tubifex known from Coonoor is reported again from this area.     

Aspects of the phylogeny of the marine Tubificidae

A tentative phylogeny of the oligochaete family Tubificidae, with emphasis on the marine representatives, is presented. The scheme is based on the morphology and arrangements of prostate glands and the setal patterns. The rhyacodriline, more or less diffuse prostates are regarded as a primitive stage in prostate evolution, preceded only by the aprostate condition assumed for the ancestor of the family. An early split of the subfamily Rhyacodrilinae supposedly led to (1) a marine branch, from which evolved the highly diverse, exclusively marine subfamilies Phallodrilinae and Limnodriloidinae, and (2) a freshwater branch, which later divided into the Telmatodrilinae, Tubificinae and Aulodrilinae. The marine subfamilies invariably lack hair setae, whereas about half of the species within the other, freshwater subfamilies possess such setae in their dorsal bundles. Some marine genera, such as Monopylephorus (Rhyacodrilinae), Tubificoides and Clitellio (both Tubificinae) are regarded as recent off-shoots from the main freshwater stock.The families Naididae and Opistocystidae are considered likely to have evolved from rhyacodriline Tubificidae, whereas Phreodrilidae, the fourth family within the suborder Tubificina, is regarded as a sister group to the Tubificidae.     

Aquatic Oligochaeta in Italy, with special reference to Naididae

We present a list of Italian freshwater and marine Oligochaeta in the families Lumbriculidae, Haplotaxidae, Tubificidae, Naididae, Propappidae, Criodrilidae, and Lumbricidae, representing 57 genera and 130 species. Published data reflect the incomplete knowledge of the Italian oligochaete fauna, restricted to certain geographical areas. Subterranean aquatic and marine fauna are of particular interest as these have been studied the least. We provide a comprehensive review of the Naididae including, for the first time, southern Italy and the islands of Sicily and Sardinia. The distribution of species is discussed and taxonomic problems arising from the morphological variability of Italian material are examined.     

中国水栖寡毛类的研究 Ⅳ.仙女虫科和颤蚓科的新记录和稀有种

本文共记载仙女虫科和颤蚓科的9个种,其中6个种是国内新记录,即森珀头鳃虫（Branchiodrilussemperi）、三齿尾盘虫（Derotrifida）、平叉吻盲虫（Pristinasynclites）、坦氏泥蚓（Ilyodrilustempletoni）、美洲管水蚓（Aulodrilusamericanus）、维氏沼丝蚓（Telmetodrilusvejdovskyi）;同时将一亚种［昌都两栖吻盲虫（Pristinaamphibiorticachangtuensis）］提升为种［昌都小吻盲虫（Pristinellachangtuenssisstat．etcomb．nov．）］。     

Oligochaetes (Naididae, Tubificidae, Opistocystidae, Enchytraeidae, Sparganophilidae and Alluroididae) of Guyana

About 50 species in more than 20 genera of the microdrile oligochaete families Tubificidae, Naididae, Opistocystidae, and Enchytraeidae and the freshwater megadrile families Sparganophilidae and Alluroididae were identified in recent collections made in Guyana. Only seven species in these families were previously recorded from Guyana. The aquatic oligochaete fauna has similar components to those of the southeastern United States, other locations in South America, and across lower latitudes in the northern hemisphere. A high diversity of species is found in the naidids especially in the genera Pristina and Pristinella, especially considering the small number of locations that have been sampled. The collections include approximately 12 new species of rhyacodrilines (Tubificidae), Dero, Pristina, Pristinella (Naididae), Brinkhurstia (Alluroididae), Hemienchytraeus and Aspidodrilus (Enchytraeidae). This is the first record of Aspidodrilus from outside of Africa and the first new record since 1952.     

Marine Oligochaeta from the Koster Area, West Coast of Sweden, with Descriptions of Two New Enchytraeid Species

A total of 28 species of marine Oligochaeta (belonging to the families Naididae, Tubificidae and Enchytraeidae) are reported from eulittoral and sublittoral sediment samples taken in the Koster area on the Swedish West Coast. Lumbricillus algensis sp.n. and Grania ovitheca sp.n. are described and their morphological and taxonomical relations to other enchytraeids are discussed. L. algensis is characterized mainly by its spermathecae, which project into segment VI, and by its very large penial bulbs. G. ovitheca possesses no dorsal setae, the ventral setae being present posterior to the clitellum only, and its spermathecae consist of a narrow duct and a large egg-shaped to oval ampulla, filling most of the coelom of segment V. Four sublittoral species, Limnodriloides barnardi (Tubificidae), Lumbricillus semifuscus, Marionina sublitoralis and Grania roscoffensis (all Enchytraeidae) are reported as new to the Swedish fauna.     

Oligochaetes (Naididae,Tubificidae, Enchytraeidae and Alluroididae) of Guyana,Peru and Ecuador

More than 41 species in 23 genera of the microdrile oligochaete families Tubificidae, Naididae, Opistocystidae, and Enchytraeidae and the freshwater megadrile family Alluroididae have been identified in recent collections made in Peru, Guyana and Ecuador. Just less than 70% of our species records are new for one or more of these countries and one is a new, albeit tentative, generic record for the South American continent. About 16 species new to science remain to be described. One of these is only the second reported species of Brinkhurstia (Alluroididae) and possesses unusual, single, very elongate penial setae. All of our species records are pertinent to tests of different hypotheses about historical and phylogenetic relationships among organisms of northern and southern South America and North America. The species, including new ones, with limited distributions are of particular significance to such hypotheses.     

Morphogenesis of the Genital Ducts and Spermathecae in Clitellio arenarius, Heterochaeta costata, Tubificoides benedii (Tubificidae) and Stylaria lacustris (Naididae) (Annelida, Oligochaeta)

The development of the male genital ducts in Clitellio arenarius, Tubificoides benedii, Heterochaeta costata (Tubificidae) and Stylaria lacustris (Naididae) is studied with the purpose of investigating the homologies between different parts of the ducts. In both Tubificidae and Naididae, the male duct comprises a funnel, a vas deferens and an atrium. There may also be a prostate gland (diffuse or compact) in association with the duct. The funnel and vas deferens, in all four species, originate from the peritoneal (mesodermal) cells in the posterior septa in the testes segment, whereas the atrium develops from an epidermal (ectodermal) invagination. The prostate glands have different origins in different taxa; in S. lacustris it differentiates from the peritoneal (mesodermal) cells surrounding the atrium, but in H. costata and T. benedii it develops by a multiplication of the atrial (ectodermal) cells; C. arenarius lacks a prostate gland. The development of the spermathecae and the female duct is also studied. The spermatheca is an epidermal invagination. The female duct is of mesodermal origin. However, the position of the duct differs; in S. lacustris the female duct is lateral and the pore is in the ovarian segment, while in the tubificids studied the duct is ventral with the pore in the segment behind the one containing the ovary.     

New records of aquatic Oligochaeta from Texas,with observations on their ecological characteristics

Twenty-six species of aquatic oligochaetes are reported from Texas, including 18 Naididae, seven Tubificidae, and one Glossoscolecidae. Illustrations are provided for ten species recorded for the first time from the state: Chaetogaster cristallinus, Nais elinguis, Nais pardalis, Pristina acuminata, Pristina sima, Stylaria lacustris, Aulodrilus limnobius, Ilyodrilus templetoni, Limnodrilus claparedianus, and Sparganophilus tamesis. Species accounts include presently known distributions in Texas and ecological and morphological characteristics.     

Distribution and habitat characteristics of Naididae and Tubificidae in the inland waters of Israel and the Sinai Peninsula

Nineteen species of Naididae and fourteen species of Tubificidae were found in collections from inland waters in Israel and Sinai. The local distribution patterns of the majority of these species were determined. The ranges of several physical and chemical variables characterizing the habitats of each species were defined. A correlation was found between the distribution patterns of some species and the following variables: salinity, temperature, dissolved oxygen, current velocities and stability of the habitats.     

Aquatic oligochaeta from among the roots of eichhornia crassipes solms

The paper records the presence of sixteen species of aquatic oligochaetes, belonging to the Aeolosomatidae (1 species). Naididae (13 species) and Tubificidae (2 species), living in association with the floating roots of the water hyacinth, Eichhornia crassipes Solms., from a tank in Vizianagaram town in Andhra Pradesh, India. Of these, Aeolosoma hyalinum Bunke, 1967 and Dero obtusa D'Udekem, 1855 are new records for the Indian sub-continent.     

Nuevos aportes al conocimiento de los Oligoquetos del Rio Paraná Medio y algunos tributarios

This paper treats the Oligochaeta species found in the benthos of lotic, environments of the Middle Parana River, secondary channels and tributaries (29° 10’ S ‐ 59° 15’ W and 32°00’ 60°40’ W). Nineteen species of Naididae, Tubificidae, Opistocystidae, Haplotaxidae and Lumbricidae are reported. A comparative analysis of setal morphology and number for the Naididae is provided. Slavina appendiculata is redescribed, and new records from Argentina noted. Dero (Aulophorus) aff. gravelyi, Dero (Dero) palmata and Nais, bretscheri are newly recorded for South America.     

Study on zooperiphyton and zoobenthos of a small river

The special traits of zooperiphyton and zoobenthos structures in a small river were studied. Under conditions of maximal proximity of niches, these groups of invertebrates retain taxonomic and ecological heterogeneity. Differences in zooperiphyton and zoobenthos taxonomic structures are most pronounced in terms of presence of dipterans, oligochetes, and mollusks. In the periphyton, the dominant groups are chironomid (orthocladines, chironomines, and tanitarsines) larvae, oligochetes of fam. Naididae and mollusks of fam. Limnaeidae. In the benthos chironomid (chironomines and tanirodines), oligochetes of fam. Tubificidae, and mollusks of fam. Pisidiidae are dominant. On average, the bottom invertebrates are considerably larger than fouling organisms. At similar abundance values, the biomass of benthos is by an order of magnitude higher compared to zooperiphyton. Ranging of average biomasses of zooperiphyton and zoobenthos revealed that the leader common for both communities is the large and mobile predatory leech, Erpobdella octoculata (Linnaeus). The anthropogenic impact and zoogenic (beavers) impact upon the river biota are comparable to each other.     

Comparative study of the cuticle in some aquatic oligochaetes (Annelida: Clitellata)

An examination of the cuticle of six aquatic oligochaete species using transmission electron microscopy revealed a larger morphological variation than previously known. Three freshwater species, Aulodrilus pluriseta, Spirosperma ferox (both Tubificidae), and Pristina breviseta (Naididae), and three marine species, Clitellio arenarius, Heterochaeta costata (both Tubificidae), and Paranais litoralis (Naididae), were investigated. The arrangement of the collagen fibers in the cuticle differs among the studied species. Only S. ferox shows an "orthogonal grid," i.e., layers of parallel fibers perpendicular to each other, as earlier described for lumbricids and enchytraeids. Clitellio arenarius and H. costata have fibers arranged in layers, while A. pluriseta and P. litoralis have irregularly distributed fibers. Pristina breviseta lacks cuticular fibers. The matrix surrounding the collagen fibers (when present) continues outside the fiber layer, making up a thin epicuticle, which has a unique banding in each of the studied species. The external surface of the epicuticle is covered with epicuticular projections. Their number, shape, and attachment to the epicuticle vary among the studied species. Furthermore, a distinctive internal substructure of the projections was observed in H. costata, A. pluriseta, S. ferox, and P. breviseta. Microvilli, extensions from the epidermal cells, penetrate the cuticle and terminate at its outer surface. In three species microvilli were observed to pinch off the epicuticular projections. The size, number, and shape of the latter vary; no typical microvilli were observed in S. ferox.     

Oligochaeta of the middle Po River (Italy): principal component analysis of the benthic data

The application of principal component analysis to two types of habitat (the benthos of macrophytes and of central river bed) enabled us to single out some of the factors that affect the dynamics and the structure of the oligochaete population and its various reactions to environmental conditions. As regards macrophytes, the distribution of the variables on the basis of the first component is correlated, to a certain extent, with a seasonal factor without any significant differences among sites. The largest population is most closely correlated with the summer months. In fact, we found that the Naididae and Tubificidae species generally develop in larger numbers at higher temperatures. For the Tubificidae, we could detect a precise seasonal cycle. In the central river bed habitat, the first component was correlated with the river discharge, which determines the granulometric characteristics of the sediment; we noticed a correlation among the sites that have the same characteristics, regardless of sampling site or date. The species which correlate most closely among themselves are the Tubificidae Limnodrilus hoffmeisteri, Tubifex tubifex, L. udekemianus and L. profundicola, which are very characteristic of environments that contain abundant organic matter. The second component is correlated with temperature, and hence with the availability of oxygen, which determines the presence and the abundance of more sensitive species.     

Oligochaeta of the Danube River — a faunistical review

The aim of this work is to discuss the distribution of Oligochaeta (Annelida) in the Danube River using the collections made by the Joint Danube Survey 2007 (JDS2) on more than 2800 km of the river. The basic faunistical features of the oligochaete assemblages were analysed with regard to three main sectors of the Danube (upper, middle and lower reaches, the last with the Danube Delta). A total of 52 oligochaete taxa have been recorded. Most of the observed species are typical of the potamon-type rivers in the region, and are well adapted to moderate-to-high organic load. The highest taxa richness and frequency of occurrence were observed among the Tubificidae family. Naididae, Propappidae, Enchytraeidae and Haplotaxidae had also low frequency. The upper reach of the Danube showed the lowest species richness, while the middle reach is characterised by its highest species richness. Construction of dams and regulation of the riverbed have resulted in an increase of limno(rheo)philic taxa which prefer slow-flowing and lentic zones.