Diario del proyecto Australasian fishes

According to the Australian Faunal Directory, the Onion Trevally occurs in tropical waters from off Exmouth Gulf, Western Australia (22º05´S) to off Newcastle, New South Wales (32º52´S).

For this reason, we were surprised to see John Sear's observation of an individual at Clifton Gardens. This is the first known observation of the species from Sydney Harbour. It's also the 7th time a species has been observed in the harbour for the first time since the 2022 publication of the Sydney Harbour fishes paper by DiBattista and colleagues.

When asked about his observation, John stated, "It was right at the end of my dive. I was heading towards the shore in about 2m of water when I came across three of them. I realised immediately that it was a trevally I wasn't familiar with due to body shape and fin size. With very little air left I only had a few minutes to get a shot and they weren't keen to have their photographs taken. To overcome backscatter in silty water I try to get as close as possible to the subject, but it's easy to overexpose the shot with trevally as strobe light reflects back from the silver body. To fix that I either reduce the strobe output, or point the strobes outwards."

We are delighted that John managed to take such excellent photos despite starting to run out of air and the inherent challenges of photographing trevallies. Thanks John for adding yet another species to the steadily growing Sydney Harbour fish list.

Reference

Joseph D. DiBattista, Tanika C. Shalders, Sally Reader, Amanda Hay, Kerryn Parkinson, Robert J. Williams, Jemina Stuart-Smith and Mark McGrouther, 2022. A comprehensive analysis of all known fishes from Sydney Harbour. Marine Pollution Bulletin 185. pp 1-13. View paper

PS. In different publications the species is sometimes referred to as Carangoides caeruleopinnatus or Turrum coeruleopinnatum.

ChatGPT is all the rage at the moment. On a whim, I asked it to "tell me about the iNaturalist Australasian Fishes Project". Below was the response.

I couldn't have said it better myself. :)

In case you were wondering, the image was created by typing 'fish with diver using computer' into DALL.E

The recent observation of a Y-bar Shrimpgoby, Cryptocentrus fasciatus, in Sydney Harbour, marks a significant range extension for this small fish species. The goby was photographed by John Sear, (@johnsear), in Manly, making it the first documented sighting of the species in Sydney Harbour.

The Y-bar Shrimpgoby is a small fish species that occurs in tropical Indo-west Pacific waters. It is characterized by having five brown y-shaped bars on the body and blue spots or dashes on the head and body.

John's observation of a Y-bar Shrimpgoby in Sydney Harbour represents a massive range extension for the species. Until now the accepted southern limit to distribution of the species was believed to be One Tree Island, Queensland (23°30'S). View the Australian Faunal Directory.

Goby expert, Dr Doug Hoese, examined the observation and confirmed it to show the xanthic phase of Cryptocentrus fasciatus. He acknowledged the possibility of confusion with another species, the Bluelined Shrimpgoby, Cryptocentrus bulbiceps.

This discovery marks John Sear's third observation of a species previously undocumented in Sydney Harbour. His keen eye and dedication to documenting marine life have proven instrumental in expanding our knowledge of the local biodiversity.

This observation highlights yet again the importance of citizen science in contributing to our knowledge of marine biodiversity. The collaboration between underwater photographers and scientists who provide expert identifications showcases the power of community involvement in advancing scientific knowledge.

An oldie but a goodie!

An interesting observation was made by Andrew Green (@dentrock) in Jervis Bay, New South Wales, back in April 2016. This observation occurred five months before the Australasian Fishes Project went online. Andrew spotted a Whitebarred Goby, Amblygobius phalaena, which expanded the known distribution of the species approximately 150 kilometers south of its previously recognized southern limit of Sydney. You can find more information about the distribution of this species at the Australian Faunal Directory.

Andrew expressed his surprise at encountering the fish, considering his familiarity with it from tropical and Lord Howe Island surveys. He mentioned that identifying the species is relatively easy, thanks to its distinctive shape and demeanor or "vibe," making it unlikely to be confused with other species. He also mentioned that photographing it posed no challenges, as the Whitebarred Goby is not a shy species and can be easily approached. Andrew further noted that he hasn't seen a Whitebarred Goby in Jervis Bay since 2016. That particular year might have been favorable for tropical vagrants.

At a recent evening lecture at the Australian Museum celebrating the 50th anniversary of the creation of their Lizard Island Research Station, an Australasian Fishes member and supporter participated in a panel discussion following an address by Dr Anne Hoggett AM, the island’s co-Director who has lived and worked on the island for many years along with her co-director husband, Dr Lyle Vail, AM. Of course, the address was excellent, and it reinforced the needs for remote research stations across the Great Barrier Reef.

It was always a pleasure to see an Australasian Fishes Project participant contributing to public discussion, and an even further delight to see someone promoting not only traditional marine research, but also, delivering a powerful message in support of citizen science. The professional researcher on the stage was Dr Joseph Dibattista, who joined the AFP project in 2017 after joining the staff of the Australian Museum. On his iNaturalist page he tells us, “I am interested in coastal ecosystems, understanding the effects of tropicalisation on Australian fish species and identifying those that may act as indicators of change, and exploring new ways to track and monitor environmental shifts in our oceans with environmental DNA (eDNA).”

Here are a few questions, answered by Joey about his research, his work at the Australian Museum and Australasian Fishes. He tells us, “I grew up on the “island” of Montreal in Canada, but really only experienced the ocean after the age of 9 or 10 on overseas trips. My interest in science began with now very out of date chemistry kits, microscopes, and observing the behaviour of animals in our neighbourhood.”

Why the interest in the Australasian Fishes and how did you get involved with our project?

“My now retired colleague, Mark McGrouther, introduced me to the project while he was still Collection Manager of the Ichthyology Section at the Australian Museum. I saw value in this project as a citizen to identify fishes and provide permanent verifiable records of biodiversity in my own backyard, and I saw value as a scientist for sourcing biodiversity data around Australia and New Zealand to validate our species detections using DNA-based approaches. In the past few years, I’ve also learned how big a role these verifiable records can play in advancing protection or conservation of sites of importance."

Could you tell us a little about your typical, fish identification process?

“I usually start with body shape or form, colouration, fin placement, and then any other distinguishing morphological features or behaviours (i.e., solitary versus schooling, etc.). The holy grail for fish taxonomists would be an in-focus (up close) photo of the side profile of the fish with all fins displayed.”

Do you go into the water much these days. Scuba, snorkel, etc.?

“As part of my community-focused project funded by Blue World on “Marine Biodiversity in Southern Sydney Harbour”, I get to snorkel regularly at Parsley Bay in Vaucluse, a wonderful hidden gem both on land and in the sea. My best advice is to be one with the fishes and do not chase them around. The moment they sense your intention to approach them, they are likely to be gone for quite some time. Also, be sure to take your time and look for fish big and small. If focused entirely on larger predatory fishes you tend not to have your eye in for the smaller cryptic fishes, which get missed.”

What was the most difficult fish you had to identify? Why was it difficult?

“I suspect many taxonomists would agree, mullet are very difficult to identify from photographs based on many species sharing characters.”

It appears a lot of taxonomy has gone down the genetic route, rather than the traditional physical inspection process.

“I would consider genetics simply another “character” that can and should be used for taxonomic descriptions of fishes. Additionally, no species can and should be described solely based on genetics. I think the biggest advantage to genetics is the ability to quickly match unknown tissues, specimens, or even weird and wacky fish larvae to adult species based on their DNA sequences, or at least guide someone in that process.”

What are your personal, current areas of research? How long have you been engaged in these areas? International collaborations?

“My current areas of research have shifted to coastal ecosystems, understanding the effects of tropicalisation on Australian fish species and identifying those that may act as indicators of change, and exploring new ways to track and monitor environmental shifts in our oceans with environmental DNA (eDNA). In our field, you must be collaborative and inventive, and so I work with dozens of researchers (domestic and international) and stakeholders at any given time on a number of different projects. Diversity in your collaborators and research topics allow you to extend your “shelf life” in science. Engaging with the general community is just as important for me.

What do you think about the project? Are we making a contribution, and if so, in what areas do you believe the data we are collecting will ultimately be useful, in a scientific context? What advice would you give our participants or words of encouragement would you offer?

I was fortunate enough to put together two scientific publications in the past two years with colleagues (including Mark McGrouther) that used Australasian Fishes records to 1) generate an up-to-date annotated checklist of fishes recorded from Sydney Harbour (we observed a 15% increase in species since 2013), and 2) demonstrate that quality-filtered citizen science data can in fact be used to improve taxonomic representation and the geographic breadth of species monitoring in Australia.”

One of the most important roles of citizen scientists is not only to collect data for future scientific research and discovery, but is to work with the professional scientific community in ways which benefit both. Scientists like Dr Dibattista are among a growing legion of science professionals who recognise the importance of community engagement and how to utilise the vast store of volunteer labour which is the citizen science community. We are grateful for his work on the Australasian Fishes Project and hope his research continues to prove productive in the advancement of our knowledge of the Australian marine environment.

This journal post was written by Australasian Fishes member, Harry Rosenthal.