Parasite on Seadragon
Karolyn Landat, @diverk (left image below), took this wonderful photo (above, left) of a Leafy Seadragon under a jetty in South Australia. Attached to the 'neck' of the fish is a parasitic isopod, Creniola laticauda.
Karolyn stated, "With regards to seeing the Leafy (or any critter underwater) with an isopod on it, you wonder how they feel with it stuck to them, especially when it's as big as that one! It must bother them surely. There is the urge to pick them off and relieve the fish of the burden, but of course we don't touch anything and it's obviously a natural occurrence (well, not man-made or induced at least), so you let it take its course and don't interfere. I've read somewhere that they do drop off eventually, which is reassuring. With regards to the dive in general, it's always a delight to see Leafies, we never got tired of seeing/watching and shooting them (with the camera). We hadn't seen a lot of them at that particular site/jetty, so it was a pleasure to find him.
Janine Baker, @marinejanine (right image above), is the founder and manager of the marine citizen science group South Australian Conservation Research Divers (SACReD), which has been active in South Australia for 15 years
Janine stated that "One of the seadragons I have identified in our Dragon Search SA project has been carrying the same female Creniola parasite for at least 1 year, in the same position. For some other identified animals in our set, the parasite is present at one time and then gone a few months later. One diver has observed several large female Creniola clustered at the head end on one seadragon, and that is uncommon. When there are multiple Creniola on a single animal, usually one large female is attached, plus some small males (which reportedly move from host to host)."
Janine sent the list, below, of links to seadragon records from South Australia that contain images of Creniola laticauda.
https://www.inaturalist.org/observations/153880408
https://www.inaturalist.org/observations/153880526
https://www.inaturalist.org/observations/153880104
https://www.inaturalist.org/observations/147821507 - This observation shows a seadragon which has had a Creniola in same position for 12 months.
https://www.inaturalist.org/observations/147819898
https://www.inaturalist.org/observations/147819154
https://www.inaturalist.org/observations/147446562
https://www.inaturalist.org/observations/124706496
https://www.inaturalist.org/observations/124706404
https://www.inaturalist.org/observations/110105094
https://www.inaturalist.org/observations/109222356
https://www.inaturalist.org/observations/107676505
https://www.inaturalist.org/observations/106432163
https://www.inaturalist.org/observations/105754381
https://www.inaturalist.org/observations/104172307
https://www.inaturalist.org/observations/107676512
https://www.inaturalist.org/observations/106590632
https://www.inaturalist.org/observations/106824842
https://www.inaturalist.org/observations/106576894
https://www.inaturalist.org/observations/106432163
https://www.inaturalist.org/observations/104172307
https://www.inaturalist.org/observations/104072936
https://www.inaturalist.org/observations/103522398
https://www.inaturalist.org/observations/101819358
https://www.inaturalist.org/observations/86369066
https://www.inaturalist.org/observations/73918007
https://www.inaturalist.org/observations/73280019
https://www.inaturalist.org/observations/72408116
https://www.inaturalist.org/observations/71930743
https://www.inaturalist.org/observations/68136207
https://www.inaturalist.org/observations/68136219
https://www.inaturalist.org/observations/37703544
https://www.inaturalist.org/observations/37703541
https://www.inaturalist.org/observations/32136701
https://www.inaturalist.org/observations/153880526
https://www.inaturalist.org/observations/153880104
https://www.inaturalist.org/observations/147821507 - This observation shows a seadragon which has had a Creniola in same position for 12 months.
https://www.inaturalist.org/observations/147819898
https://www.inaturalist.org/observations/147819154
https://www.inaturalist.org/observations/147446562
https://www.inaturalist.org/observations/124706496
https://www.inaturalist.org/observations/124706404
https://www.inaturalist.org/observations/110105094
https://www.inaturalist.org/observations/109222356
https://www.inaturalist.org/observations/107676505
https://www.inaturalist.org/observations/106432163
https://www.inaturalist.org/observations/105754381
https://www.inaturalist.org/observations/104172307
https://www.inaturalist.org/observations/107676512
https://www.inaturalist.org/observations/106590632
https://www.inaturalist.org/observations/106824842
https://www.inaturalist.org/observations/106576894
https://www.inaturalist.org/observations/106432163
https://www.inaturalist.org/observations/104172307
https://www.inaturalist.org/observations/104072936
https://www.inaturalist.org/observations/103522398
https://www.inaturalist.org/observations/101819358
https://www.inaturalist.org/observations/86369066
https://www.inaturalist.org/observations/73918007
https://www.inaturalist.org/observations/73280019
https://www.inaturalist.org/observations/72408116
https://www.inaturalist.org/observations/71930743
https://www.inaturalist.org/observations/68136207
https://www.inaturalist.org/observations/68136219
https://www.inaturalist.org/observations/37703544
https://www.inaturalist.org/observations/37703541
https://www.inaturalist.org/observations/32136701
Thank you Karolyn and Janine for your observations and comments.