I am sorry that I introduced a topic into the forum which has caused such controversy and strong feelings. I read an article in the Guardian and thought that it may be of interest to forum members and that (as in the past) people would point me to some of the scientific evidence, have an informed discussion and that I could piggy back on the knowledge of others. Rather naively, I didn’t think of the emotional power of this question and the deeply held views that people on the forum hold. To those posters to or readers of the thread that have been upset by the topic: please accept my apologies.
I think, however, that this is an important topic. First of all, I must add a caveat, this isn’t an issue that I have thought about much, I am an occasional fly fisherman, when I was younger enjoyed course fishing (both of these are/were more for the environment than for catching fish which is/was a rare occurrence). I also eat fish.
The debate on the thread took me back to the research literature. I must add in another caveat here, this is not my area of specialism and I am acutely aware of the difficulties associated with literature reviews undertaken by non-specialists! I am not an Ichthyologist and understand that some people on the forum are.
The conclusions that I drew:
1. There is a relative paucity of literature or research evidence. Using Scopus I found 9 articles from 2008-19 on “Fish Intelligence” and 35 on “Fish Cognition”. It was also notable that there was a relative lack of citation and co-citation (many articles had been cited only a handful of times and a key review had only been cited 57 times). This suggests (to a non-specialist) a limited cumulative development of knowledge in this area. Much of the literature that I found related to fish intelligence in the context of catching fish (c.f., Xue, Liu, Zhang and Minami 2008). I can only speculate on the reason for this, however, this may be because this in part because funding for this type of research may be difficult to acquire or that much of the funding may come from interests related to the fishing industry.
2. Some evidence suggests fish have individual differences or “personality”: “Fish also showed evidence of personality, with significant and repeatable individual differences in foraging, chasing, and habitat use.” (Church and Grant 2019)
3. A recent review of literature in this area indicated that fish have the level of perception and cognitive abilities on the match of other vertebrates (Brown 2015). “Recent reviews of fish cognition suggest fish show a rich array of sophisticated behaviours. For example, they have excellent long-term memories, develop complex traditions, show signs of Machiavellian intelligence, cooperate with and recognise one another and are even capable of tool use)” (Brown 2105). I looked at some of the more recent work and picked up an which looked a spatial capability and learning using experimental work using guppies,
Poecilia reticulata which indicated that they could solve complex mazes on the same level as primates and rodents (Lucon-Xiccato, Bisazza 2017). Although female guppies performed better at this than males. The authors of this piece noted “…growing evidence that bony fish possess cognitive abilities previously thought exclusive to mammals” (Lucon-Xiccato, Bisazza 2017).
4. Fish feel pain “A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates”. (Brown 2015)
5. “Cognitive flexibility is one emergent area of research. While only a few species have been studied, it seems fish are capable of inhibiting previously learned behaviours, of reversal learning and display innovative behaviours and problem solving in new situations”. (Vila Pouca and Brown 2017)
6. Play: “Since the observation of fishes’ natural behaviour is rare compared to other vertebrates… Because of the diversity and sophistication of behaviours and cognitive abilities of fishes, it seems only reasonable to assume play behaviour also occurs in fish and thus should be further investigated. (Vila Pouca and Brown 2017) They noted a paper which pointed to play behaviour in cichlids.
7. “Complex social behaviours in fish have been widely acknowledged and reviewed and include social learning and traditions, individual recognition, cooperation and shared intentionality, dominance hierarchies, social status and transitive inference” (Vila Pouca and Brown 2017).
My conclusion is that the scientific knowledge in this area seems limited and emergent, however, strongly points for fish intelligence on the same basis and vertebrates and therefore similar moral and ethical issues related to how we treat them.
I agree with Tim:
This is an interesting overview on f
ish intelligence, for those who haven't already seen it.
I think different species of fish undoubtedly exhibit behaviours that could be interpreted as intelligence. But sometimes it is difficult to determine the difference between behaviour which is innate, genetically hardwired through natural selection, and that which is learned or developed through experience.
I also think that we all have an innate psychological tendency toward
anthropomorphism, and attribute human traits, emotions or intentions to none human entities. It's something that has been prevalent throughout human history, and is deeply ingrained in human culture throughout the world.
However, both points could work in relation to any non-human animal.
I think there is an opportunity and perhaps a moral and ethical need for further research.
One impediment to further research seems to be the difficulty in observing fish behaviour. Brown (2015) noted that most people’s contact with fish is when it’s served them on a plate and that “fish seldom have the opportunity to express their natural behavioural patterns in captivity.” I think, however, that this community strive to create natural environments in which fish can express their natural behavioural patterns in captivity, perhaps most clearly exemplified in the creation of biotopes. In short we spend months creating naturalistic environments and then months watching fish interact with each other and the environment. Equally, many of the fish that have been studied are fish that we keep (e.g guppies and cichlids) and many of the other fish that we keep haven't been studied. We, therefore, have our own slices of nature or ‘laboratories’ (depending on your view) in which we can observe, test hypothesis, reflect upon and report findings. While Ichthyologists like Tai Strietman undertake pioneering work in the field, can we make a minor contribution from our armchairs? Could places like the UKAPS site become laboratories in our living rooms to conduct some citizen science? This may be already occurring in which case please forgive me for my ignorance, however, we “feel more comfortable imagining science as the exclusive preserve of lab-coated professors in well lit, publicly funded laboratories, surrounded by gleaming, expensive apparatus. In truth, though, the history of science is rooted in research carried out by independent devotees, driven by resourcefulness, passion and curiosity.”
https://www.theguardian.com/science...cience-how-internet-changing-amateur-research
References
Brown, C., 2015. Fish intelligence, sentience and ethics.
Animal cognition,
18(1), pp.1-17.
Church, K.D. and Grant, J.W., 2019. Ideal despotic distributions in convict cichlids (Amatitlania nigrofasciata)? Effects of predation risk and personality on habitat preference.
Behavioural processes,
158, pp.163-171.
Lucon-Xiccato, T. and Bisazza, A., 2017. Complex maze learning by fish.
Animal Behaviour,
125, pp.69-75.
Vila Pouca, C. and Brown, C., 2017. Contemporary topics in fish cognition and behaviour 16 pp 46-52
Xue, Y., Liu, H., Zhang, X. and Minami, M., 2008, September. Research on Fish Intelligence for Fish Trajectory Prediction Based on Neural Network. In
International Symposium on Neural Networks (pp. 364-373). Springer, Berlin, Heidelberg.
