Goby and the remarkable 9-3

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Off the Queensland shores there are a number of subtly differing types of goby. One of them, Paragobiodon xanthosomus, is typically a yellowy-emerald colour (xanthos is Greek for yellow), but is not celebrated for its beauty or grace. It is in truth a rather unlovely fish.

‘I don’t mean to be harsh,’ I say, ‘but they’re not nature’s finest.’

‘Oh, noooo,’ says Marian Wong, laughing. ‘I just love them.’ She spends a significant proportion of her professional life studying goby and other small fish. ‘But I know what you mean, a lot of people say that. They say, “Marian, couldn’t you find a prettier fish to follow?” People say, “Marian, why are you studying the ugliest fish on the reef? Why can’t you study a cute one like Nemo?” But I love goby. I’m happy to stare at them the entire time. I’m beyond redemption.’

We break off temporarily as the Skype connection falters. Wong is at the opposite end of the earth to me. She has followed the fish. Wong, now in her thirties, has straight, immaculate shoulder-length dark hair and an accent that is hard to pin down. ‘It’s a bastardisation of everywhere I’ve been,’ she says. Hailing from a family of Malaysian origins, she was born in the UK and did her undergraduate degree in zoology at Girton College, Cambridge. Then she followed the fish. First to Queensland, then to Canada, and now back to Australia, at Wollongong University, where she is a Senior Lecturer at the School of Biological Sciences. She laughs a lot. At fish, at us, our pretensions.

‘But why, Marian?’ I ask.

‘Why what?’

I had to ask. ‘Why you and fish?’

‘I blame my father. He was a dedicated aquarist who annoyed my mum by keeping fish tanks in their tiny one-bed flat in London back in the day. Didn’t see many fish in the River Cam, of course, so after Cambridge I was very pleased to go to Australia.’

And why not fish? Fish have found ways to survive for 450 million years – they have earned the right to be studied. Wong did her doctorate work at James Cook University in Queensland, a college instituted on 20 April 1970, the inauguration chosen to be exactly 200 years to the day that the restless Yorkshire lad from Marton, Captain James Cook, first sighted Australia. Wong’s research site was Lizard Island, another speck in the surrounding sea, but 750 miles to the north of Heron Island, basking in the northern reach of the Barrier Reef. (Cook actually ran HMS Endeavour aground on the reef.) Around Lizard Island the ugly little goby swims along the best it can and tries to find a life in the wild and dangerous sea within a complex social group of similarly vulnerable and unlovely fish. It pretty much keeps to the coral. It’s safe if it keeps to its little patch of coral. But while there it does something unusual, even remarkable.

‘You see them,’ Wong says, ‘all lining up. They are careful not to touch each other, but they are there lined up and it couldn’t be by chance. It was performative – a real event, a performance. And then we knew: this is important. It’s not random, it’s not by chance they’re doing this. We had to investigate it academically. It means something.’

But what? The point of scholarship, of the Academy, begun in 387 BCE when Plato opened his school on that patch of land that Cimon had beautified, is to understand. (Plato’s most famous pupil, Aristotle, in large part was a biologist.) So what was this goby behaviour about?

‘We watched and watched. We began to realise what they were doing,’ Wong says. ‘It’s all to do with the 9-3. We knew something was going on around the 9-3.’

Each group consists of a principal pair of dominant fish, male and female, the breeding pair, and then a number of non-breeding females, up to around 15 such subordinates.

‘They were displaying. We began to get what was going on down there. Think of it this way: the coral is safety. The group is. But there’s no such thing for fish as a free lunch. They have to pay to stay.’

‘Pay? And the cost?’ I ask.

She laughs. ‘Okay, this is the thing,’ Wong says. ‘Fasting. The fish fast.’

Female goby exhibit a careful gradation in size, diminishing in stature progressively. In fish such as goby, social rank – where in the queue one is – is determined primarily by size. Relative body size matters greatly and group members are acutely attuned to minute variations.

‘So when they’re lining up,’ Wong says, ‘they’re actually evaluating one another. Literally, they’re sizing each other up.’

These assessments constitute critical clues about where you are in the hierarchy, and consequently what you are entitled to – and what is expected of you. But the dilemma of social groups is that without some kind of restraint, subordinates would have a strong motivation to usurp their immediate ‘superiors’ and claw their way up the ladder. Such ambition, if replicated by all or even significant numbers of subordinates, who themselves would have sub-subordinates immediately below them, would be a nightmare. It would degenerate into the fearful dreamscape that haunted Oxford philosopher Thomas Hobbes: incessant mass conflict – bellum omnium contra omnes. Ethnological evidence, however, indicates that it doesn’t happen like that. There are certainly contests for supremacy. But social animals tend to form themselves into relatively stable societies of functioning communal groups over time. How does that happen?

One contributory mechanism is the threat of eviction – of ostracism. As Wong puts it, ‘Once they’re outside the coral, they’re basically eaten. Stay in the coral, you’re safe. Out? Eaten. So it’s pretty serious. It’s a credible threat.’

Thus the threat of ostracism acts as an effective mechanism to control the behaviour of subordinates and promote the relative peace and durable stability of the group. For animals like goby where size matters greatly, the unrestrained growth of subordinates would threaten dominant fish. This problem is accentuated by the fact that fish grow asymptotically (smaller fish grow more rapidly than larger ones). Therefore the closer that subordinates grow to superior fish, the more of a threat they become: the more likely it is that in a contest they would be able to successfully evict their immediate dominant. Thus mechanisms have evolved whereby – to an extraordinarily precise degree – the growth of subordinates is regulated.

In coral-dwelling goby the figure is 0.93.

 

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About ostracism: here.

Where to get the book: here.