Our dive plans at Port Noarlunga reef on 24th March didn’t quite go to plan, but then we had a chance to make a few observations during our swim back to the jetty in low visibility conditions.

One such observation concerned this Zebra Fish that had quite a ‘hump-head’: –

(Taken by Steve Reynolds)

This how the head of a Zebra Fish normally looks: –

(Taken by David Muirhead)

Our attention was also brought to the fact that Old Wives have this red band at the top of their eyes: –

(Taken by Wayne Leifert)

I received a double tap on my forearm whilst I was lining up a photograph of a fish. I thought that someone was trying to get my attention, but I got a big surprise when I found that a starfish was sitting on my forearm.

Had it fallen there, or had someone just placed it there as some kind of prank? I just knocked it off and continued to look for a fish to photograph.

I was even more surprised when I sighted an ‘out of place fish’ next to the reef at the end of the jetty. It looked like a tropical species that didn’t belong there. It took off under the jetty before I could raise my camera. I later looked for it again, without success.

I was very fortunate that Belinda Batterby later told me that she had seen the same fish species and that she may have got it in some of her video footage.I felt very lucky when she provided me with this still from her video: –

(From a still from video footage taken by Belinda Battersby)

The photo confirmed my belief that the fish was a Western Crested Morwong (aka WA Magpie Morwong), Goniistius gibbosus. Western Crested Morwong were previously not recorded in SA waters. As the name suggests, they were only seen in southern WA. Their sudden occurrence in SA is a huge range extension for the species.

I received confirmation of further sightings by other divers when I shared Belinda’s still online. I have now reported the sighting to iNaturalist and Redmap. Holly Barnett later sent me this photo of the same species seen at Port Noarlunga (jetty or reef) during January: –

(Taken by Holly Barnett)

Holly’s sighting had been two months earlier than my own. She had also posted her sighting and photo on iNaturalist. My thanks go to Belinda & Holly for their help.

I also found this large long-spined seaurchin deep in the reef: –

(Taken by Steve Reynolds)

(Taken by Steve Reynolds)

Here are some more photos of the hump-headed zebra fish: –

(Taken by Steve Reynolds)

(Taken by Steve Reynolds)

(Taken by Steve Reynolds)

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.

2 thought on “Observations made during our recent dive at Port Noarlunga Reef”
  1. Fantastic info about that Morwong’s range extension. (Well done those involved).
    I guess we’ll be seeing more of them, if they’re here as a result of global warming, although obviously it is too early to determine whether that’s relevant:)

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