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New insights into phylogenetic relationships of Rhabdocoela (Platyhelminthes) including members of Mariplanellida
No full textAbstract
Background
Previous flatworm phylogenetic research has been carried out analysing 18S and 28S DNA markers. Through this methodology, Mariplanellinae subfamily has been recently re-classified as Mariplanellida status novus. This new classification implied that 3 genera belonged to Mariplanellida: Mariplanella, Lonchoplanella and Poseidoplanella. In this study, we aim to clarify some of the relationships within Rhabdocoela analysing 18S and 28S DNA markers of a total of 91 species through Maximum Likelihood and Bayesian Inference methodologies. A total of 11 species and genera, including Lonchoplanella, from the island of Sylt are included and had not previously been involved in any molecular phylogenetic analyses.
Results
Our phylogenetic results support Mariplanellida as an independent group within Rhabdocoela and its status as an infraorder. Our study suggests that Lonchoplanella axi belongs to Mariplanellida. Within Rhabdocoela, Haloplanella longatuba is nested within Thalassotyphloplanida, instead of Limnotyphloplanida. Within Kalyptorhynchia, the taxon Eukalyptorhynchia turned out to be paraphyletic including members of Schizorhynchia. These results also support the position of the genus Toia separate from Cicerinidae.
Conclusions
Lonchoplanella axi belongs to Mariplanellida, whose status as infraorder is herein confirmed. The genus Toia belongs separate from Cicerinidae. Further research is needed to clarify the phylogenetic relationships of Hoploplanella. Most of the species, genera and families included in this study with more than one terminal are monophyletic and well supported. Adding gene markers and complementary morphological studies will help to clarify those relationships that remain uncertain.Open-Access-Publikationsfonds 202
Species composition and abundance of macrozoobenthos in surface sediments off Sylt collected during HEINCKE cruise HE311
No full textZoobenthos and sediments time series in southern Königshafen, Sylt, Germany, 2003 to 2012
No full textIn supplement to an ongoing zoobenthos and sediments time series in the subtidal of List Reede, the adjoining intertidal area was sampled 46 times between September 2003 and June 2012. During that period, the same 12 sites were analysed for macrozoobenthos and granulometric sediment composition, always contemporaneous as possible to subtidal sampling dates. The resulting data set was deemed to enable comparisons of subtidal and intertidal variability of sediment and community composition
Statistics for grain size analysis of surface sediments off Sylt collected during HEINCKE cruise HE218
No full textZoobenthos and sediments time series at List Reede, Sylt, Germany, 2003 to 2019
No full textA shallow subtidal area in the northern Wadden Sea was monitored over 17 years for sediment parameters and macrobenthic fauna using stratified random sampling of a grid of 50 sampling positions. Samples were collected with a Reineck-type box-corer of 0.02 m² surface area, always during preceeded high tide. Granulometric sediment composition was analysed from a sub-sample of each box-core using a diffraction laser particle-size analyser. Macrobenthos (sieved through 1 mm square meshes and fixed in buffered formalin solution) was counted, identified to species level, and the size of hard-shelled individuals measured. The amount of shell detritus was quantified as wet-weight in the benthos samples. From 2003 to 2007 sampling was approximatively monthly and from 2008 to 2013 seasonally. When a new ship with larger drought was put into operation, the number of sampling sites needed to be reduced to 33 from 2014 onwards and sampling frequency was only once per year in autumn
Macrozoobenthos and sediment composition in the North Sea and the Wadden Sea near the Island of Sylt between 1992 and 2002
No full textIn order to log the temporal development of macrozoobenthos populations, three coastal areas of the North Sea and the Wadden Sea near Sylt were sampled at least once a year in autumn. Each area was subdivided into four subunits about 1-2 km apart from each other, and each subunit was sampled by six box cores. These cores were analysed for both macrozoobenthos and the granulometric sediment composition.
After six years we started to compare the benthos data with data from larger-scale spatial sampling. It turned out that local sampling sites of a few km² failed to adequately describe population development on a regional scale (tens of km) in most of the species, i.e. spatial extrapolation is not possible in the highly dynamic shallows of the North Sea. As a consequence, this sampling program ceased in 2002 and was replaced by a 9,000 km² sampling grid from 2003 onwards - see doi:10.1594/PANGAEA.87046
Macrozoobenthos abundance in the prospective wind farm "Butendiek" and surroundings (2003-03)
No full textGranulometric composition of surface sdiments in the prospective wind farm "Butendiek" and surrounding (2003-03)
No full textHydroacoustic and Sediment data collected during AL-519/1 in January 2019 in the German Bight
No full textDuring the research cruise AL-519-1 with RV Alkor the effects of dredging measures in an extraction site west off Sylt (German Bight) were investigated. Here, sandy material was extracted since 1984 for beach nourishment on the Island of Sylt. The extraction site lies approx. 7 km west of Sylt and has an extend of 5.5 km*3 km with water depths between 13 and 32 m. The investigations took place in January 2019 and lasted about five days.
In order to assess the morphology of the study site, a gapless bathymetry was measured using a multibeam echosounder (ELAC Seabeam 1000, 180 kHz). For the determination of further seafloor characteristics and backscatter responses of the seafloor, a sidescan sonar were used (Imagenex YellowFin 872, 330 kHz). In addition, 55 sediment samples were taken in different domains of the study site (e.g. old dredging pits, new dredging pits, unaffected seafloor). The sediment samples were examined with regard to their grain sizes as well as their macrozoobenthos community composition
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