Fish: More than meets the fry?
When you think of fish, intelligence isn’t usually the first thing to pop into your head. Their short memory spans, which can be as little as 3 seconds, probably don’t help their cause.
Taken/Pixabay
Recently, though, it has become apparent that fish can be trained to do simple math problems like adding and subtracting. Research conducted in Germany has shown that cichlids – tropical fish often found in home aquariums – and stingrays can observe small quantities and know how many things are there without actually counting, kind of like how a human can look at a bowl of apples and know about how many are in it.
Fish, once thought to be not very smart, may be on the same level of intelligence as birds, suggested Vera Schluessel, PhD, of the University of Bonn’s Institute of Zoology, and associates.
“Successful fish showed abilities far above chance level, specifically in the stingrays. Again, this raises the question of what abilities fish may be capable of if being asked the ‘right’ question,” the researchers said in Scientific Reports.
They tried to teach the cichlids and stingrays how to add and subtract by recognizing colors: Blue meant to add one and yellow meant to subtract one. Gates were set up and when the fish chose a correct answer, they were rewarded with food. Although it took many sessions for the fish to completely catch on, they did figure it out eventually.
If fish are smarter than we thought, maybe we can stop paying for math tutors for our kids and just have the family goldfish do it.
For earthworms, not all plastics are created equal
Everything living on the earth has to deal with pollution in some way, including earthworms. Not only have they have adapted to eating plastics found in soil, they have preferences.
Piqsels
The earthworm is a little creature with a big job. The materials and minerals they munch on as they go through the earth get recycled through their tiny bodies to create more fertile soil for things to grow – making them the hidden heroes of every garden. But what about soil that’s full of microscopic plastic pieces? Well, turns out earthworms will eat that too, investigators from Nankai University in Tianjin, China, reported in Environmental Science & Technology.
The researchers looked at how these eating machines were digesting the plastic and found that they actually have preferences. Soils with bio-based polylactic acid (PLA) or petroleum-derived polyethylene terephthalate (PET) particles were a hit. Another test showed that the worms broke the PLA particles down into smaller fragments than the PET ones. So at least the “healthier” option agreed with them more. More work is needed, however, to determine if the worms are being harmed by all the waste they’re digesting.
So what does this mean for the evolution or even survival of this unsung hero of the planet? Scientists still need to dig into that question. No pun intended.