A rather strange animal (or part of an animal) was caught on the hook near the Montenegrin coast (Mediterranean Sea - Adriatic Sea) at a depth of approx. 20 m. It was returned back to the sea, we only have photos of it. It was approx. 15 cm long. We are having a hard time identifying it, help is appreciated.
except for the three extensions it reminds me a bit of a the pharynx of a Glycera spec. which has broken off. I can see something that look like jaws.
My guess would be the pharynx of a polychaete of the family Eunicidae. Some of them (e.g. Eunice aphroditois) can get fairly large (2 meters and beyond!). The jaws look similar to jaws of these giant eunicids.
Yes, that family Eunicidae also crossed my mind, but for some reason (4 hooked jaws instead of 2 toothed and robust jaws in Eunicidae) I have chosen for Glyceridae, but these 2 lateral extensions doesn't fit. However, I only have seen 1 species of Eunicidae here in The Netherlands, which is clearly different than this one, so variability in this family is unknown to me.
In my opinion it could be the pharynx of a polychaete belonging to the family Acoetidae (which encomprises several large predators).
It is certainly the pharynx of a species of Acoetidae (Annelida: Polychaeta). Species of this family are large and, although they live in tubes on the seabed, are known to leave these in search of food. There are accounts of them being caught on baited hooks.
Thank you for your answers! Although there is certain similaritiy with more or less all mentioned taxa, we still can't pinpoint exact species... Sadly, we don't have preserved specimen, it would make identification much easier...
My gues id that this might be a pharynx of an eunicid or onuphid. The largest eunicid I have seen in the Mediterranean was more than 1 m long and about 2 cm wide, so the pharynx of one of these enormous worms can perfectly fit with the measures of that in the photos.
On the other hand, glycerid jaws have inner sides not serrated and, also, do not have the numerous plates that can be seen here. The four jaws may be maxillae I and II, which are often hooked (see, for instance the image here attached).
As the pharynx is not fully evaginated, my guess is that the two lateral expansions may either be the placement of the labrum or, more likely, some glandular expansions connected with the function of the maxilla. but I am not sure about this.
In any case, it seem clear that this is the pharynx of a polychaete. Either a eunicid or a onuphid, these worms are very aggressive and it is not the first time I have seen (or heard about) an angling fishermen fishing one of them.
I doubt whether the acoetid species can be identified from the pharynx alone. Characters associated with this have not featured in identification keys. Their pharynges are all fairly similar with the two upper and 2 lower jaws (each pair close together) and, in some (Polyodontes, Panthalis and Eupolydontes), single long mid-dorsal and mid-ventral papillae. Members of these three genera all occur in the Mediterranean; Polyodontes maxillosus was originally described from the Adriatic by Ranzani (1817).
In Pettibone's (1989) revision of the Acoetidae, she cites (p. 11) Eisig (1887) as reporting fishermen in the Bay of Naples (30 m depth) catching Polyodontes maxillosus on hooks baited with worm or small fish. Another account (Saint-Loup 1889) recorded a 2m long specimen caught on a hook baited with the abdomen of a large hermit crab in the Gulf of Marseilles (50m depth).
I forgot about acoetids ! I agree with Andy that this pharynx can belong to a member of this family. They are even more aggressive that eunicids and onuphyds.
No doubt that the pharynx belongs to an Acoetid species. In Turkey, some species attach the fishermen's hooks and broke off the pharynx.
Andrew Mackie is right. There is no doubt that this fragment is a pharynx of an acoetid scaleworm. I have images of preserved specimens of Polyodontes maxillosus with extended pharynx. They look exactely the same as the picture provided here. As Andy mentioned, without at least a good part of the anterior body it is not possible to identify specimens with some certainty to species level, however, P. maxillosus might be a good guess
Thank you again for suggestions... I've been going through the images of mentioned taxa and certain characteristics are similar... However, I can't find any images of P. maxillosus, I'd be very grateful if someone could provide some images for comparison...
See page 97, fig 37a-n in Fauvel (1923)
http://www.faunedefrance.org/bibliotheque/docs/P.FAUVEL(FdeFr05)Polychetes-errantes.pdf
Indeed, it looks very similar! Thank you very much, you've all been very helpful!!
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