Hi everyone,
I have an amphipod that is evading identification. I think it belongs to the family Oedicerotidae, particularly in the genera Synchelidium or Pontocrates.
I have come to this conclusion as it has a subchelate gnathopod (G)1, a chelate G2 and a distinct rostrum. Photographs of the specimen are attached.
However, the crux is that neither genus is recorded in Australian waters. I have Lincoln's British Marine Amphipoda: Gammaridea and it does appear to match the description of these genera but it exhibits a mix of the feature that separates between them, i.e. the palm of G1 is half toothed and half smooth.
I have attached scans of the genera descriptions for your interest(extracted from Lincoln's book).
Anyone have any ideas? Could we have a new amphipod in Australia?
Samples collected from the Peel Harvey Estuary, Western Australia (temperate waters).
All the best,
Sorcha
I'm not familiar with Australian fauna but it is definitely Oedicerotidae and to me it doesn't look like any of the species in Europa. The rostrum is a bit like P. arcticus, but a colorpattern is present only in Synchelidium or Pontocrates altamarinus, but quite different then in yours. So no non-indigenous species from Europe if you ask my opinion.
Hi Ton*. Thanks for commenting. Good to know I am on the right track. It does have very distinctive characteristics so hopefully we can identify it. There has been new species described from that family recently (Hughes and Lowry 2009) so it is possible there is another one to be added. I will try contact more people familiar with the family.
Hi Sorcha, also not familiar with Australian taxa but I agree with you, the gnathopods and the rostrum firmly place it in Oeditoceridae. In NE Atlantic specimens the differentiation between Synchelidium and Pontocrates is based on the palm of gnathopod 1 having teeth ( Synchelidium) or being smooth (Pontocrates). Also the dactylus of the pereiopods (5 and 6) in Pontocratus is tiny compared to Synchelidium. I can't see either from your photos so hard to tell. Besides, this might very well be another totally different genus from Australia. Good luck in your investigations!
P. S. I have a Pdf of Lincolns' book. Interested? If so, send me a pm on [email protected] or leave your emailadress here.
Hi Jose. Thanks very much for commenting. I did look to see if it belonged to either genera you have mentioned but it has a half-toothed, half-smooth palm placing it somewhere in between the two. This may be a characteristic of an Australian genus but I have not had much luck locating it. The hunt continues!
Also thank you Ton. I have purchased a hard copy of the book - couldn't resist, so I am all set for now. I appreciate the thought though!
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