Unknown creatures with unusual parasites

Have you ever ever heard about chaetognaths, aka arrow worms? They’re a phylum of worm-like animals largely discovered as a part of planktonic communities worldwide. Their title originates from chaeto (spines) and gnatha (jaws). As you may see within the image beneath, their title refers to their hooked, greedy spines situated on both sides of their head. Chaetognaths use their spines to understand their prey (generally different arrow worms!). Fortunately for us, they’re just some cm lengthy, as much as 10-12 cm in some circumstances, so nothing to fret a lot about. They’ll even have a humorous, Edvard Munch’s The Scream’s-like look, such because the benthic chaetognath beneath. With over 130 species described worldwide, our data on their true range and distribution remains to be very scarce. What we do know is that they’re some of the vital planktonic predators and the second-most considerable planktonic group. Most species are clear, and infrequently categorized as a part of the so-called gelatinous zooplankton. Nonetheless, ca. 20% of the species are benthic chaetognaths that may be discovered near the seabed (just like the shocked man beneath).

Via Artsdatabanken venture ParaZoo (Metazoan Parasites of non-crustacean Zooplankton) we’re finding out the variety of parasites related to jellyfish, comb jellies and chaetognaths. As we discovered very attention-grabbing specimens from our sampling journeys to Svalbard, we joined a latest journey to Torsvåg in Northern Norway, hoping to get extra materials from this understudied space. You may learn extra about this joint fieldwork right here and right here. Our MSc scholar Lea will inform you a bit extra about her MSc venture, and her expertise in Torsvåg.

From Lea:
Hei! I’m Lea, a Grasp scholar engaged on my Grasp thesis concerning the final C within the C + C + C analysis group: Cnidaria, Ctenophora, and now Chaetognaths! I’m working with parasites of chaetognaths in Norwegian waters, a nonetheless a lot understudied subject. On the sampling journey to Torsvåg in Northern Norway, I acquired first hand experiences with a wide range of sampling strategies, cool jellies, and attending to know everybody higher from the marine workforce on the College Museum.

Among the many sampling strategies, my favorite was undoubtedly catching the jellies with a small web on the pier (see Determine 2). There, we – fearless of the everchanging climate circumstances – caught the most important jellies of our journey. Afterwards, I used to be primarily in control of checking jellies for parasites for the ParaZoo, the place we discovered trematoda in 2 totally different jelly species!

Sadly, pelagic chaetognaths have been very sparse in Torsvåg. We even deployed manually (!) a plankton web all the best way to 200 m deep in seek for chaetognaths, however we solely discovered about 30 in complete, that have been additionally unparasitized. Fortunately, the polychaete group subsequent door may supply some consolation.

Let me introduce you to my absolute favorite species from the journey: The benthic chaetognath Spadella cephaloptera! Have a nasty day? – Simply check out the consistently shocked, involved, and barely uncanny face of this small fella! You may rely on me overusing this species in my upcoming shows!

All in all, I developed a whole lot of helpful expertise, starting from figuring out widespread (and unusual) gelatinous zooplankton species to untangling a fishing rope! It was such a tremendous expertise to be a part of this sampling journey!

Determine 2. Internet sampling from totally different places in stunning Torsvåg. Spadella cephaloptera trying consistently shocked as a result of corona ciliata beneath the 2 eye pigments (Photographs: Joan J. Soto-Angel and Lea Dober)

From Joan and Lea