Lesson plan

Physostome

to the gut in a common rudd. Physostomes are fishes that have a pneumatic duct connecting the gas bladder to the alimentary canal. This allows the gas bladder to be filled or emptied via the mouth. This not only allows the fish to fill their bladder by gulping air, but also to rapidly ascend in the water without the bladder expanding to bursting point. In contrast, fish without any connection to their gas bladder are called physoclisti. The physostome fish encompass the bichirs, gars, a number of carps, trouts, herrings, catfish, eels and the lungfish. While the gas bladder in fish mainly serves as a buoyancy organ, some physostomes (though not all) can use their gas bladder as a lung, allowing them to live from atmospheric oxygen in conditions where aquatic oxygen levels have dropped to a point which would kill other fish.

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Article summary

to the gut in a common rudd. Physostomes are fishes that have a pneumatic duct connecting the gas bladder to the alimentary canal. This allows the gas bladder to be filled or emptied via the mouth. This not only allows the fish to fill their bladder by gulping air, but also to rapidly ascend in the water without the bladder expanding to bursting point. In contrast, fish without any connection to their gas bladder are called physoclisti. The physostome fish encompass the bichirs, gars, a number of carps, trouts, herrings, catfish, eels and the lungfish. While the gas bladder in fish mainly serves as a buoyancy organ, some physostomes (though not all) can use their gas bladder as a lung, allowing them to live from atmospheric oxygen in conditions where aquatic oxygen levels have dropped to a point which would kill other fish.

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Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  3. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

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Key claims and bibliography are generated from the same tracked claims and sources as the article page.