Category Archives: Annelida

The venom system of bloodworms

Recently, we published a paper with the title “Comparative analyses of glycerotoxin expression unveil a novel organization of the bloodworm venom system” and with this “behind-the-paper-style” blog I want to give some insights how we came to our conclusions. The paper was published by Richter et al. (2017) in BMC Evolutionary Biology and is open access.

Venoms and venom systems evolved many times independently across the animal tree of life. That spiders or snakes can be venomous is well-known. Also, the venom of the iconic cone-snails has been investigated in detail. However, venomous annelids have been (mostly) neglected so far. There are around 20,000 annelid species, but only few of them have been convincingly shown to be venomous. E.g., fireworms (Amphinomidae) can burn like hell if you touch them, which is due to an inflammation-inducing substance called complanine. However, this is passively delivered when their chaetae break and therefore these animals should be regarded as poisonous (which still make them an interesting target for studying the content and evolution of their toxins). In contrast, venomous are those animals which actively deliver their toxin cocktail,. e.g., for predation, defense or competition. Only glycerids and leeches are convincingly demonstrated to represent venomous annelids (von Reumont et al. 2014). For several other annelids (e.g., chrysopetalids, polynoids or sigalionids) it has been speculated that they might be venomous, however, our own dissections could not reveal convincing evidence of venom glands or an apparatus to deliver the venom in several investigated taxa. Nevertheless, different groups of scale-worms (e.g., Pisione spp., Pholoe spp.) remain good candidates to include venomous species, but desperately need to be studied in detail. And I also would not be surprised if more examples from other annelid taxa will be discovered in the future. Continue reading The venom system of bloodworms

A worm called Anton

In 2010 when I still had my lab in Leipzig (Germany) we started noticing that a species of syllid annelids can be frequently found in our warm water aquariums. As we were working on annelid phylogenomics, we were quite happy having easy access to these animals in Leipzig, a place that is at least several hundreds kilometers away from any access to the sea. We sequenced the transcriptome, but couldn’t identify the animal (neither by morphology nor barcoding) to the species level. The following years, the population remained stable. Ovbviously they were reproducing quite well and we usually had a peak of individuals in late spring. We realized that this so far undescribed species has the potential to be our lab rat for different research questions, e.g., on syllid reproduction and regeneration. Consequently, we decided to formally describe this animal (Aguado et al. 2014). Even though we could not indicate its native geographical range of occurrence, we described it in such detail that it should be recognized when found outside our aquariums. In honor of the newborn son (Anton Helm) of one member of our research team we named the species Typosyllis antoni (Fig. 1). Continue reading A worm called Anton

A list of tweeting polychaetologists

Inspired by a blog post of Christopher Mah I started to compile a list of polychaetologists who are active on twitter. Polychaetologists are researchers interested in polychaete biology, taxonomy and evolution. Polychaetes are those (mostly marine) Annelida which are not clitellates. Phylogenetic analyses convincingly support that also echiurans, sipunculans, siboglinids and myzostomids are part of Annelida. We (Anne Weigert and myself) reviewed the current state of annelid phylogeny here. I did not include clitellatetologists (is this an even existing term?), as I do not have a good overview whats going on in research in this field and who is on twitter. I broadly considered everybody who could show up at the International Polychaete Conference (IPC) as potential polychaetologist. This meeting takes place every three years. The last one ended just in August in Cardiff (check for talks and twitter storify here), the next one will be in Long Beach, Los Angeles in 2019. Moreover, I included some tweeting scientists who from time to time end up working with polychaetes. I also tried to sort the twitter accounts into different research fields. But this is mostly to put some order and I am aware that many of them could easily fit in two or more of the categories. It is also likely that I overlooked several tweeting polychaetologists. Just leave a comment in case I forgot you (or somebody you know) – or if you are super unhappy ending in the wrong category or on the list at all. Continue reading A list of tweeting polychaetologists