I’m still very, very busy. 10 hours a day, I’m on campus. 2 hours a day, I do stuff for my lab practical and I kind of try to sleep 8 hours at least. That leaves 4 hours to shower, eat, relax and … write something up for Steemit.
I’m doing my best but especially the fiction stories need a lot of concentration (even more so if they contain something scientific). I hope you enjoy my other stuff anyway, even if it’s sometimes a bit shorter!
Today, I’ll present you another animal I dissected a while ago: The Earthworm, lumbricus terrestris!
Bought from a fishing shop, these specimens were destined to be eaten alive. We killed them by pouring a mixture of ethanol and formaldehyde over them to give them a quick and hopefully painless death.
Dissecting the earthworm was kind of satisfying because everything looks just so … in order.
The worm consists of mostly homologous sections, that’s why only the upper part is cut open in the picture.
At the very tip, there should be the brain but it’s so tiny that you probably can’t really see it. It’s below the pink pin, a little bit to the left. Two tiny, white dots.
Can you see the pink-ish stuff between the yellow and the black pin at the top? That’s the pharynx which connects mouth and esophagus of the worm. From there on a grey-ish brown tissue goes all the way straight down, that’s the intestines.
The yellow-ish “balloons” are the so called seminal vesicles which are right above the non-visible seminal receptacles. Do you know what that implies?
The Earthworm is both male and female. Some animals that are both can inseminate themselves. The Earthworm can’t, that’s why it needs the seminal receptacles: They collect the “sperm” from another earthworm.
Below that it’s just organs for digestion, nothing spectacular.
On the sides, you can see thin, white lines. Those are the segments you can see from the outside. Between them are, also not visible, the metanephridia which are basically the worm’s kidneys.
Now, to some fun facts!
The common earthworm can live up to 6 years, so if you give your kid one when they graduate they can have a great pet throughout college!
All around its body, the worm has tiny bristles which it uses to move. They also feel very interesting if you try to pet a dry worm. We were strongly advised to take off our gloves and feel the worm when we were working with it in the lab.
In the USA, there are several invasive earthworm species brought over from Europe and Asia which has effects just as harmful as other invasive species. In Minnesota, there aren’t even any native earthworms. They were probably ground to death by glaciers. I’m serious, look it up in the source I linked below.
Stuff I learned during the lab practical
*Picture was taken by me *
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