Natures wonders: archerfish (Introduction)

by David Turell , Wednesday, June 22, 2022, 17:52 (883 days ago) @ David Turell

Squirts water like an archer to get prey:

https://www.the-scientist.com/notebook/archerfish-defy-notion-that-complex-vision-requi...

"Fortunately for researchers, archerfish (family Toxotidae) readily spit at targets in a lab in exchange for snacks, says University of Oxford visual ecologist Cait Newport, who adds that the fish are “very hard workers . . . and generally not too shy.” These features make them a powerful model for studying visual cognition in fish, a group that diverged from its most recent common ancestor with humans roughly 420 million years ago. Even though they lack a cortex, the part of the mammalian brain that processes visual stimuli, archerfish can still perform many of the same behavioral tasks as mammals, making direct comparisons between the two groups possible. “Anything that you can place in the form of a multiple-choice question, you can actually study with the archerfish,” says Ronen Segev, a neuroscientist at Ben-Gurion University of the Negev in Israel.

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"Object discrimination isn’t the only surprising thing that archerfish seem to be able to do without a cortex, and archerfish as a group remain a fruitful source of research ideas, says Shai Gabay, an evolutionary neuroscientist at the University of Haifa in Israel. Gabay’s lab uses archerfish to complement his research on the human brain and to challenge what he calls a “cortico-centric bias” in the neuroscience literature. His team has argued that archerfish respond to stimuli in a volitional manner—that is, by processing and acting on information in a way that goes beyond purely reflexive reactions—and preliminary work suggests that the animals engage in prosocial behaviors such as food sharing. In findings recently presented at a conference by a member of Gabay’s lab, the team found that an archerfish will consistently choose a target that rewards both itself and a passive tankmate with food, so long as the chooser receives at least as much as its neighbor. While it was thought that a highly evolved brain that includes a cortex was needed for social behaviors, “now we can see very complex social behaviors even in fish,” Gabay tells The Scientist, suggesting that alternative mechanisms can lead to sociality."

Comment: they are just like humnan archers. What this means it is the design of the archerfish neurons that allow this degreee of cognition. No. it is not just brain size but the neuron design.