I have a confession to make. At the start of every dive, I make a wish for the critter I would most like to encounter and frequently those wishes come true. But recently I dared to make the ultimate wish: ‘Something I had never seen before’. As it turns out, this is a potent wish and to my absolute amazement and delight, the wish came true three times over two consecutive dives. The underwater universe in all its wonder and benevolence delivered to me a rarely seen Melibe nudibranch, a gorgeous velvet fish walking along the bottom of the ocean floor and an extraordinary sighting of a mysterious deep pelagic fish – only the third reported sighting of this species in Port Phillip Bay in 109 years – in less than two metres of water.
As I entered the water from the shore alone on 16 October 2017 and descended into the shallow water, I could barely believe my eyes. To my right just outside the pylons was an enormous silvery fish marked with four odd black spots on each side – as long as my car is wide and as thin as a piece of cardboard – floating in cobra fashion with its tail dragging across the sand. For several moments, I struggled to make sense of what I was seeing – could this truly be a fish? In all the marine identification books I’d studied, I had never seen any remotely similar, nor in more than 500 dives beneath the local piers along the long stretch of bay. Was this some strange toy like an underwater kite, attached by a thread to some invisible child on the pier above?
Gradually I convinced myself that the fish was indeed real, and soon it was clear that someone with a fishing rod had spied it in the shallows too and was dangling a bit of bait to try to catch it. Knowing instinctively that this animal was rare for this area and that the physical capture of such a fiendishly flat fish would not satisfy any hungry humans above, I readied my camera to capture some photos and video of this puzzling yet compelling beast. Slowly the strange animal and I floated together along the shallows for twenty minutes, far away from the pier with its bits of bait dangling dangerously from hooks on invisible threads.
Later that evening and still unable to locate the fish in my ID books (because it simply wasn’t there), I posted a call for help on a local Facebook page. While most group members quickly guessed it might be an oarfish due to the sheer size of the animal, I wasn’t convinced based on how incredibly thin the animal was, compared to oarfish that have bodies shaped more like fatter eels that can grow up to 17 metres in length.
My friend Alan Beckhurst who works at the Marine and Freshwater Discovery Centre in Queenscliff (and who in my opinion knows more about marine life than many scientists, marine biologists and Google put together) was the first to arrive at an accurate identification: Trachipterus trachypterus Ribbonfish (also known as a Peregrin Dealfish), a sub-tropical species that he assumed was ‘a little lost’. A Wikipedia entry suggested that the 2 metre fish I had photographed and videoed was possibly not far off maturity:
While Alan tried to track down as much information as possible, initially he advised that he was unable to find records of any sightings in Victoria and advised me to report the sighting to Redmap (redmap.org.au), a site that records ‘What’s on the move in Australian Seas’. Upon further research, Alan then found two listed sightings for Port Phillip Bay on Discoverlife.org, one in 1908 and another in 1938 as recorded by the Melbourne Museum, making mine the third reported sighting in 109 years, made all the more rare by being a live sighting.
Dianne Bray, Senior Collections Manager at Museum Victoria, said ‘Fantastic … The species usually occurs in oceanic waters and as such is poorly known. Many museum specimens were fish that washed ashore – they’re definitely not adapted to life in the shallows. We have a few from PPB in our collection, all from the outer parts of the Bay (plus others from elsewhere in Victoria). I hope this one makes it back outside the Bay, but if you hear of it washing up somewhere please let me know so that we can retrieve it for the collections’.
Mark McGrouther, Curator of the Australasian Fishes project on iNaturalist and Fish Collection Manager of the Australian Museum initially commented: ‘Wonderful. I think this is a juvenile Southern Ribbonfish, Trachipterus jacksoniensis. There is currently only one observation of the species on Australasian Fishes at the moment. Yours would be a fantastic addition’. Later he published the following journal entry, confirming Alan’s original identification:
Morgan Grant, author of ‘Grant’s Guide to Fishes’ said, ‘I’ve never seen that species before – the more common one is Trachipterus arawatae. Looks like we can learn something from each other!’ He then posted this:
It has been a thrill to see the expert ichthyologists getting excited about this unexpected encounter. Ultimately, the fact that these fish are considered ‘rare’ may be more because humans are not in the water frequently enough to see them when they appear. I feel very privileged to have arrived under the pier just in time to ‘capture’ this animal with film and photos before an unsuspecting fisher managed to ‘catch’ this spectacular animal on the end of a hook. I can only hope this special fish finds some way to live a long and happy life, floating like a shimmering cobra through the waters of Port Phillip!
Love and bubbles,