I recently performed a necropsy on a waterbird from coastal California and after removing the eyeballs, found hundreds of adult mites within the orbital fascia. The location was no where near the lacrima structures (if that is what they are called in birds). I would greatly appreciate any references where this has been previously reported. Thanks!
Hello Kate. i had read in a book that worms. i say that they can be Cyathostoma spp.
These are most definitely not worms and are arachnid adults - mites with 8 legs. Keep the answers coming!
Dear Kate,
I've never heard of mites behind the eyeballs of birds, although I suppose there are so many astonishing, and revolting, places that mites live that an acarologist shouldn't be too surprised (but delighted too!). Birds seem to suffer these indignities more than most creatures: mites from various lineages have invaded their respiratory tracts, skin and feathers (external and internal); some are even cloacal. And while I know of no mites on or beneath the eyeballs of birds, the eyeballs of bats are home to the genus Opsonyssus, proving that eyes are fair game. These mites are also nasal, so a similar pathway is possible for birds (i.e. something like a rhinonyssid mite, like Ptilonyssus, also using the eye).
I'd be inclined to ask your compatriot Barry OConnor at the University of Michigan. He and his colleagues have published numerous works on mites from birds. You'll get the all important identification and information on how novel these mites and their habitat are!
Kind regards, Owen.
I agree with Dr.Owen. However another mite Dermanyssus gallinae commonly enter en masse into the nasopharyngeal system in dead birds. These mites might have accidentally entered behind the eyeballs.
Never seen or heard of these mites in the eyeballs of birds before, but I've seen some Myxosporea parasites living behind the eyes and operculum of Nile perch fish in Lake Victoria Kenya.
They may be nasal mites that migrated due to host death or crowding. I think a good jumping off point may be:
KNEE, W., H. PROCTOR and T.D. GALLOWAY. 2008. Survey of nasal mites (Rhinonyssidae, Ereynetidae, and Turbinoptidae) associated with birds in Alberta and Manitoba, Canada. The Canadian Entomologist 140: 364-379.
Throwing some of them on a slide with Hoyer's solution may allow you to clear the specimen for identification using a key.
Thanks for these suggestions! They are definitely mites -as opposed to worms and myxozoans- and based on the other rhinonyssids we're pulled from dozens of other bird species, they are pretty different from typical nasal mites. I will definitely hunt down Opsonyssus sp. literature as this might be kin. The bird was not dead when it was collected, so it is unlikely that the infection occurred post-mortem. The particular host species was a cormorant, which interestingly have extremely small nasal passages - to the point typical nasal mites would be unable to pass through them. We are currently working with mite specialists to identify them and will update as information becomes available. Thanks again, and any additional suggestions are most welcome!
Barry O'Connor was able to confirm that this is a deutonymph of Neottialges (Pelecanectes) evansi. The eye is a strange place for it, but they are common enough in the bird species we were looking at. We'll post the note when it is published. Thanks to everyone.
Hi Kate -
Thanks for posting the answer - and thanks to Barry too! It was an intriguing find.
All the best, Owen.
Dr. Kate
Thank you for giving new information on ocular mites. Can I have the reprint of the published report?
Regards
Thilakan
I'll definintely update the publication once it is out. It is in preparation at the moment and we expect submission & acceptance in the next 2-3 months.
FYI, I've found a pub that found these same mites under the eyelids of kingfishers! email me with your email and I'll pass along if you don't have access to:
Boyd, E.M., Fry, A.E. (1971) Metazoan parasites of the Eastern Belted Kingfisher, Megaceryle alcyon alcyon. The Journal of Parasitology 57(1) 150-156.
Thanks Dr.Kate. Please send the reprint to my email id [email protected]
The publication was accepted earlier this month, stay tuned to Journal of Parasitology for the full report. Thanks to Barry for the ids!
The real take-home message for the paper is we don't really know if this a rare occurrence or an under-reported phenomenon. It is possible that we just aren't looking behind the eyes during enough neecropsies and are missing these guys when they do occur. The paper I shared earlier from Boyd & Fry (1971) weren't initially looking under the eyelids (they never removed the eyeballs to look inside the orbit), but once they did, they found high prevalence of the mites.
If you are performing necropsies, please take a look under the yelids & behind the eyes, you might just find a handful of these mites!
Hi all! We were able to identify these as deuteronymphs with the help of some great experts. We published on this finding in 2017. Check out the publication with some great pics !
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