| 1. |
- Erséus, Christer, 1951, et al.
(författare)
-
The popular model annelid Enchytraeus albidus is only one species in a complex of seashore White Worms (Clitellata, Enchytraeidae)
- 2019
-
Ingår i: Organisms Diversity & Evolution. - : Springer Science and Business Media LLC. - 1439-6092 .- 1618-1077. ; 19:2, s. 105-133
-
Tidskriftsartikel (refereegranskat)abstract
- The white worm Enchytraeus albidus Henle, 1837 (Clitellata, Enchytraeidae) is easy to keep in laboratory cultures, and has therefore been employed as a model organism in basic and applied biological research. Its natural habitat includes terrestrial composts and wrack beds on seashores. However, the name E. albidus is currently used for a complex of morphologically similar and closely related species. We here revise the components of the E. albidus species complex based on a sample of 100 Enchytraeus specimens from 56 sites, most of which are across Europe. These samples were DNA-barcoded for the mitochon- drial COI gene. A subset of them was sequenced for the nuclear ITS2 and H3 markers. Six species were delimited with strong support by the COI and ITS2 gene trees, as well as by a multi-locus species delimitation analysis. These species are identified morphologically and described as E. albidus s. str. (with designation of a neotype); Enchytraeus moebii (Michaelsen, 1885); Enchytraeus albellus Klinth, Erséus and Rota, sp. nov., E. cf. krumbachi (Čejka, 1913), E. sp. 1 (unnamed), and Enchytraeus polatdemiri Arslan and Timm, 2018. The last-mentioned species is a soda lake specialist, whereas E. albidus s. str. is both terrestrial and marine littoral; all other species occur only in seashores. The phylogeny of this group was estimated using the multi-species coalescent model. Monophyly of the E. albidus complex was recovered. Within this complex, three groups were recovered as monophyletic, but the relationship between them is unclear. One group comprises E. albidus s. str., E. albellus, and E. moebii; the second group E. cf. krumbachi and the unnamed E. sp. 1, and the third consists of only E. polatdemiri. This study serves as a framework for genetic identification of white worms used for experimental purposes.
|
|
| 2. |
- Klinth, Mårten, 1990, et al.
(författare)
-
Investigating the Clitellata (Annelida) of Icelandic springs with alternative barcodes
- 2019
-
Ingår i: Fauna Norvegica. - 1502-4873 .- 1891-5396. ; 39, s. 119-132
-
Tidskriftsartikel (refereegranskat)abstract
- DNA barcoding is an invaluable tool to identify clitellates, regardless of life stage or cryptic morphology. However, as COI (the standard barcode for animals) is relatively long (658 bp), sequencing it requires DNA of high quality. When DNA is fragmented due to degradation, alternative barcodes of shorter length present an option to obtain genetic material. We attempted to sequence 187 clitellates sampled from springs in Iceland. However, the material had been stored at room temperature for two years, and DNA of the worms had degraded, and only three COI sequences were produced (i.e., <2% success rate). Using two alternative barcodes of 16S (one ca. 320 bp, the other ca. 70 bp long) we increased the number of sequenced specimens to 51. Comparisons of the 16S sequences showed that even the short 70 bp fragment contained enough genetic variation to separate all clitellate species in the material. Combined with morphological examinations we recognized a total of 23 species, where at least 8 are new records for Iceland, some belonging to genera new for Iceland: Cernosvitoviella and Pristina. All the new taxa are included in an updated species list of Icelandic Clitellata. The material revealed some stygophilic species previously known to inhabit springs, but true stygobionts, which are restricted to groundwater habitats, were not found. Our study shows that short 16S fragments can be obtained from DNA too degraded to be used in traditional COI barcoding, and contain enough genetic variation to separate closely related clitellate species.
|
|
| 3. |
- Lee, J., et al.
(författare)
-
Two species of Lumbricillus (Enchytraeidae, Annelida) new to Antarctica
- 2019
-
Ingår i: Polar Research. - : Norwegian Polar Institute. - 0800-0395 .- 1751-8369. ; 38
-
Tidskriftsartikel (refereegranskat)abstract
- The intertidal fauna of the Antarctic Peninsula has a relatively high species diversity, due to its warmer environment compared to other parts of Antarctica. Marine oligochaetes are, in general, one of the most diverse and ecologically important benthic organism groups, at least in the littoral zone. Antarctica has been one of the least studied areas with regard to oligochaete diversity. Here we report two Lumbricillus species (Lumbricillus antarcticus Stephenson, 1932 and Lumbricillus sejongensis sp. nov.) new to Antarctica, found in a tidal pool on the Barton Peninsula, King George Island. The diversity of this genus remains poorly known for Antarctica and the Subantarctic islands, and what we know is based on a few patchy studies.
|
|
