Crab.e.cam recently posted on Facebook, “How many species can you see? What are they doing? You’ll see Magpie Perch, Sweep, Zebrafish, Moonlighter, and Old Wives. There were also drummer cropped out! 6 species swimming together. The old wives and moonlighters are cleaning the other fish! Watch the zebras pause in a vertical pose as they pick!”
It was David Muirhead who brought Crab.e.cam’s post to my attention – “Hi Steve, have you seen Crab.e.cam‘s Facebook clip from Second Valley showing adult old wives cleaning zebrafish? Moonlighters also hosting, but the old wife segment is pretty convincing, and several zebrafish are in typical client pose.
“I’m annoyed at myself, because when I’ve dived Second Valley a few times recently, I’ve wondered what caused the tight gathering of zebrafish, old wife, sea sweep and Moonlighters high up the water column. Strange to see. But I didn’t notice the cleaning, which in hindsight is the obvious reason.
“Drat…! I’ve certainly been impressed with the scarcity of Western Cleaner Clingfish during the HAB. They seem slow to return, in functional numbers anyway. Or maybe they are there but so well fed, having too many clients to service, that they hide themselves from divers? I’m again clueless here. WCCs must have short lives, so recruitment shouldn’t take long. Unless the eggs are very sensitive to residual low concentrations of brevitoxins, etc..??”
When I viewed the post in question, I found that David had made these comments: –
“Remarkable. I’ve never seen adult old wives cleaning i.e. as hosts for clients that want external parasites, etc.. removed. Moonlighter yes, old wife no. I wonder if this previously anecdotally uncommon interaction is happening because something has to fill the niche left undermanned by death of traditional temperate reef fish cleaners during the HAB? I’ve seen very few Western Cleaner Clingfish since the onset of the HAB, and far fewer pencil weed whiting, and even young Blackspotted Wrasse are quite uncommon currently at Second Valley, cw pre HAB numbers. Seems logical that a severe prolonged HAB would alter behaviour of many, perhaps all fish species in some ways. Cleaning is an essential service for all reef fish, be they temperate or tropical, so something has to fill the temporary breach when the usual cleaners aren’t available. FWIW I’ve been wondering if the recent observation, by many divers, of magpie perch aggregating in groups of up to 10 or so individuals, often on sandy bottom in bigger caves at places like Second Valley, might be because some shrimps (in addition to the well-known temperate cleaner shrimps, i.e. Rockpool Shrimp, Palaemon serenus, and Ancylomenes aesopius) that prefer sandy habitat are doing the cleaning. Magpie Perch used to strongly favour Western Cleaner Clingfish for the host role, but the HAB could have changed that. All just speculation on my part. But great footage, Crab.e.cam!”
So, moonlighters and old wives (the hosts) were seen cleaning external parasites, etc.. from magpie perch, sweep, drummer & zebrafish (the clients).
To see past articles about fish cleaners posted to our web site, visit MLSSA fish cleaners articles , for example, briefly discusses “a juvenile Moonlighter cleaning sub-adult zebrafish”.
This photo of myself was taken by David in 2017. It appears to show a moonlighter following a scaly fin, as if the moonlighter is cleaning the scaly fin: –
This photograph of mine was taken at Port Lincoln in 2010: –
It shows a mix of moonlighters, zebra fish, drummer and an old wife all swimming close together.