Tag Archives: SEM

Door #16: First molecular-based phylogeny of onuphid bristle worms

Onuphidae are marine bristle worms with very rich external morphology and outstanding diversity of life styles within a single polychaete family. Onuphids can be very abundant in some marine biotopes, modifying the environment by their complex ornamented tubes and influencing the structure of benthic communities. They are very widely spread in the ocean inhabiting various biotopes from the intertidal zone down to hadal depths. Onuphids are widely harvested as bait sustaining local fisheries in southeastern Australia, Mediterranean and Portuguese coasts and are even commercially farmed with the full reproductive cycle from fertilization till fully-grown worms (up to 30 cm in length) in aquaculture facility.

Nothria otsuchiensis - a bristle worm from NSW, Australia (author N. Budaeva)

Nothria otsuchiensis – a bristle worm from NSW, Australia (author N. Budaeva)

The system of Onuphidae with 23 genera grouped into two subfamilies has been suggested by Hannelore Paxton (1986) and has been widely accepted since then. The first phylogeny based on the analysis of the combination of 16S rDNA and 18S rDNA genes has been recently published in Molecular Phylogenetics and Evolution. None of the subfamilies or tested genera appeared to be para- or polyphyletic showing a strong congruence between the traditional morphology-based systematics of the family and the newly obtained molecular-based phylogenetic reconstruction. However the previously suggested hypotheses on intrageneraic relationships within onuphidae were largely rejected.

Phylogenetic tree of a bristle worm family Onuphidae (Budaeva et al., 2016)

Phylogenetic tree of a bristle worm family Onuphidae (Budaeva et al., 2016)

Suggested reading:

Budaeva N., Schepetov D., Zanol J., Neretina T., Willassen E. 2016. When molecules support morphology: Phylogenetic reconstruction of the family Onuphidae (Eunicida, Annelida) based on 16S rDNA and 18S rDNA. Molecular Phylogenetics and Evolution 94(B): 791–801. http://dx.doi.org/10.1016/j.ympev.2015.10.011

Paxton, H., 1986. Generic revision and relationships of the family Onuphidae (Annelida: Polychaeta). Records of the Australian Museum 38, 1–74. http://australianmuseum.net.au/uploads/journals/17658/175_complete.pdf

Aquabait Marine Worm Aquaculture: http://www.aquabait.com.au/about_aquabait_marine_worm_aquaculture.phtml

Nataliya Budaeva’s web page: http://nataliyabudaeva.wix.com/nataliyabudaeva


Door #5: A (so far) undescribed species of bristle worm

Diopatra sp

Diopatra sp. Photo: M. Hektoen

Pictured above is a cute polychaete (bristle worm) from the genus Diopatra. It was collected in Mauritania, and has been photographed using Scanning Electon Microscopy (SEM). Although I ended up describing 9 new species of Diopatra worms in my master’s thesis, many worms were still left undescribed, this is one of those.