Hello. I work in a research group specializing on cymothoid isopods. Can you please tell me what host you found this isopod on, and specifically where on the host? Any other details would be great. Have you preserved the specimens in anything? Are they common? I think I have an idea of the genera, but would like some more information first before giving you my best idea. Photos are indeed a bit tricky to judge from...
Hello. I work in a research group specializing on cymothoid isopods. Can you please tell me what host you found this isopod on, and specifically where on the host? Any other details would be great. Have you preserved the specimens in anything? Are they common? I think I have an idea of the genera, but would like some more information first before giving you my best idea. Photos are indeed a bit tricky to judge from...
Sorry, Hamed, I thought they came from fish. Cymothoid isopods are permanent fish parasites. It would be very interesting if these are cymothoids and were alive and not attached to a host.
Hamed, was the parasite alive? If this is a cymothoid adult parasite, then it would be extremely rare for it to be isolated from the host, and landing on coral would be a matter of chance. Parasites of fish need the fish in order to survive, and adult cymothoids are not mobile (without their host). There may be several anecdotes to explain why the isopod was found in the coral, but I don't know if they are biologically meaningful. It could just have been by chance. How often have you observed this?