More Senator Fish Behaviour

by Steve Reynolds

In my report Recent Return to Rapid I wrote about how I came across a male senator wrasse just laying ahead of me.

I didn’t know what the senator wrasse was doing so intently. At the time, I thought that perhaps it was a fish cleaning situation, with the senator wrasse being cleaned by another fish. The senator wrasse then turned side on and allowed me to take a good side shot of it before starting to swim away from me.

I now recall writing about this behaviour 5 years ago in my report Unusual Behaviour by Senator Fish …. . In that report I stated, “I witnessed some unusual behaviour by the species during a dive at Rapid Bay jetty in March 2015. There seemed to be more male Senator Fish than usual swimming around. They weren’t swimming in schools or large groups, but there did seem to be more than what I would normally expect to see around during a dive anywhere.

“The unusual behaviour that I witnessed by them was that many of them were often rubbing their bodies in the substrate, as can be seen in these photographs:

“This really caught my eye. I had no idea why they were doing that. I don’t recall whether each of the photographs show a different fish. In each case, the fish is seen rubbing its body in the substrate, but adjacent to algal growth which appears to be at the base of a jetty pile.

“Has anyone else ever witnessed this kind of behaviour by Senator Fish? Does anyone know what the reason is?”

We have still not yet received a response to this question. We have, however, now received a response to the discussion in Recent Return to Rapid.

Margot Morelli commented on the report, “I have a video of a senator wrasse wriggling (as if to itch) from Rapid Bay, Sept 2019. Happy to pass it on if you’re interested.” The short video footage demonstrates the strange body rubbing by senator fish.

(Video taken by Margot Morelli)

We lifted these stills from the video (one is a crop of the other): –

(Photos taken by Margot Morelli)

I also recall seeing a single male Senator Fish during my dive at Rapid Bay jetty on 23rd January 2016 , as reported in More Photos of a Male Senator Fish….

My previous sightings of the behaviour have been in January, March and June, whereas Margot’s sighting was in September, so there’s no obvious pattern there. It seems that the behaviour occurs all year round. In relation to any suggestion of fish cleaning beahviour, Margot added, “I didn’t see any other creatures hanging around the fish.” We will be keeping an eye on this strange behaviour by the fish.

By Steve Reynolds

Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve is a keen diver, underwater explorer, photographer and is chief author of the Society's extensive back catalogue of newsletters and journals.

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