DNA barcoding of Naididae (Annelida, Oligochaeta) based on COI and ITS2 genes in China

Exploring the effectiveness of DNA barcoding in species identification is prerequisite for biodiversity conservation and environmental monitoring. Aquatic oligochaete could serve as an excellent indicator in aquatic monitoring programs. However, few studies have examined the effectiveness of DNA barcoding in these specific organisms. The mitochondrial COI gene and nuclear ITS2 gene of 83 specimens belonging to 36 species of 18 genera were sequenced in this study. The results showed that there was a barcode gap between species of Naididae, and the intraspecific genetic distances of each species were smaller than interspecific genetic distances. The classification results of ABGD (Automatic Barcode Gap Discovery) were consistent with those of morphological identification except for Tubifex tubifex and Lumbriculus variegatus. All species were successfully distinguished in the phylogenetic tree based on ITS2 gene, which was coincident with morphological result. Our results provided evidence that DNA barcoding can be used as an effective and convenient tool for species identification of the family Naididae and even aquatic oligochaete.

A literature revision of Pararhyacodrilus Snimščikova, 1986, with the erection of a new genus, Semernodrilus gen. nov. (Oligochaeta, Tubificidae, Rhyacodrilinae)

The aquatic oligochaete genus Pararhyacodrilus Snimščikova, 1986 included four species, P. aspersus Snimščikova, 1986, the type species, P. palustris (Ditlevsen, 1904), P. ekmani (Piguet, 1928), and P. confusus Semernoy, 2004. Rhyacodrilus palustris (Ditlevsen, 1904) and R. ekmani var. profundalis Lastočkin, 1937, have been associated with Pararhyacodrilus, as a result of different nomenclature-related confusions. A new taxon, Semernodrilus gen. nov., is erected for the Baikalian Pararhyacodrilus confusus Semernoy, 2004. As a result, Pararhyacodrilus includes two species, P. aspersus and P. ekmani.

New species of aquatic oligochaetes (Annelida: Clitellata) from tufa barriers in Croatia

Two new aquatic oligochaete species are described from tufa barriers in Croatia. The reproductive system in the phallodriline Aberrantidrius mihaljevici Vučković et al. n. sp. conforms to the general pattern in the genus but it is distinguished by a combination of characters, including the shape and length of penial chaetae (3 times the mean length of somatic chaetae), atrium shape and spermathecal pore position (anterior in the postatrial segment). The lumbriculid Stylodrilus tofaceus Rodriguez et al. n. sp. is mainly distinguished from congeners by the spindle-shaped spermathecal ducts with high lining epithelium, and position of the spermathecal pores. These two new taxa reveal that aquatic oligochaete communities in tufa barriers of karstic regions may be of particular interest with respect to diversity of endemic taxa, and also for study of colonization routes of this interesting habitat, with possible relations with groundwaters. The finding of one specimen attributable to the genus Eclipidrilus may open ainteresting research on the biogeography of this Nearctic genus.

The aquatic oligochaete fauna of Lake Çıldır, Ardahan-Kars, Turkey, including an updated checklist of freshwater annelids known to occur in the country

In this paper, we present the results of the first survey for aquatic oligochaetes in Lake Çıldır, northeastern Turkey, during which 22 oligochaete species were recorded from the lake. The results of this survey were integrated into an updated and annotated list of oligochaetes and other aquatic annelids occurring in the country, summarized from historical and recent publications. Currently, the freshwater annelid fauna of Turkey includes 150 species of oligochaetes (1 Crassiclitellata, 21 Enchytraeidae, 1 Propappidae, 1 Haplotaxidae, 4 Lumbriculidae, 56 Naidinae, 64 Tubificinae, 2 Lumbricidae), 1 species of Branchiobdellida, and 6 species of Aphanoneura (1 Potamodrilidae and 5 Aeolosomatidae). Although studies focusing on the aquatic oligochaete fauna of Turkey have increased over the past 15–20 years, species diversity still remains unclear.

Citations for the published proceedings of our 14 International Symposia on Aquatic Oligochaetes (1979–2018)

These special publications, below, present overviews of and papers presented during our triennial international symposia on aquatic oligochaete biology. Three similar names for our symposia have been used since we began as a group in 1979: International Symposium on Aquatic Oligochaete Biology (ISAOB), International Symposium on Aquatic Oligochaetes (ISAO), and International Symposium on Aquatic Oligochaeta (ISAO).

Aquatic Oligochaete Communities in Amazonian Streams, Saracá-Taquera National Forest, Pará, Brazil

The aim of this study was to analyze aquatic oligochaete distribution in relation to water column physicochemical variables, structural environmental variation, and predominant substrates in the preserved Amazonian streams of the Saracá-Taquera National Forest (FLONA Saracá-Taquera), northwest Pará, Brazil. Oligochaetes are widely used as bioindicators for monitoring aquatic environments as they are very sensitive to pollution and environmental changes. Physicochemical and structural variables were measured from 100 stream segments in order to understand the distribution of oligochaetes in Amazonian streams. Biotic samples were collected using Surber samplers in three of the most predominant substrate types in each segment. PERMANOVA testing showed that there was a significant difference in the oligochaete community among some substrates, potentially caused by a difference in the abundance of the most common taxa. Canonical Correspondence Analysis showed that physical variables drive the distribution of oligochaetes in preserved Amazonian streams, as they determine the formation of different substrates along the stream, from the source to the mouth; favoring the presence of oligochaetes with more specific ecological needs in low-order streams, and the presence of oligochaetes capable of colonizing various types of substrates and deeper zones in high-order streams. These results suggest that water depth and channel width are the main drivers of aquatic oligochaete distribution along Amazonian streams, determining the formation of unstable and low-quality substrates and, consequently, the low colonization by oligochaetes in high-order streams; and more diverse and stable substrate formation in low-order streams, favoring the colonization by diverse taxa of aquatic oligochaetes in low-order Amazonian streams.

First record of the alien aquatic oligochaete species Monopylephorus limosus (Hatai, 1898) (Annelida) in Central Europe

The paper reports on the first record of the Asian aquatic oligochaete species Monopylephorus limosus (Hatai, 1898) in Central Europe. The species was found in the lower course of the Bolina River (S Poland), which is contaminated with saline mine waters. One immature individual was collected in the late summer of 2017. M. limosus co-occurred with Paranais litoralis, Nais elinguis and juvenile Enchytraeidae. To date, M. limosus is one of the 29 non-native annelids that are known to occur in Poland.