Earthworm dissection.

Because it is widely known, Lumbricus terrestris goes under a variety of common names. In Britain, it is primarily called the common earthworm or lob worm (though that name is also applied to a marine polychaete). In North America, the term nightcrawler (or vitalis) is also used. In Canada, it is also called the dew worm, or "Grandaddy Earthworm". Although this is not the most abundant earthworm, even in its native range, it is a very conspicuous and familiar earthworm species in garden and agricultural soils of the temperate zone, and is frequently seen on the surface, unlike most other earthworms. It is also used as the example earthworm for millions of biology students around the world, even in areas where the species does not exist.

Worms are critical for soil turnover and fertility. They eat dead plant material, and their burrows help aerate the soil and let water through easily. Worm casts (faeces) are rich in recycled plant nutrients that help maintain soil fertility.

This practise consists on two parts:

A) First, there is a theorical study of annelids, specifically earthworms (Lumbricus terrestris).

Complete your worksheet, using this page Earthworm virtual dissection to do the exercises.

In this link you have the Virtual earthworm dissection worksheet.

WITHOUT COMPLETING THIS WORKSHEET, THE STUDENT IS NOT DOING THE DISSECTION

B) The second part of this practice, consists on observing the external features of annelids, and the earthworm internal characteristics. The practice guide is available in both links.

Check this video of how to dissect an earthworm.


And this page about earthworms characteristics.

Heart dissection.

Before the practice, read the practice sheet and then complete this test about the heart dissection. I also link here two videos.





TEST

Bony fish dissection.

Living things are similar to and different from each other. When we look at the inside of a fish, we will learn that certain organs and systems in fish are similar to those in humans; and other organs and systems are not. Stomach contents can tell us much about a fish’s habit. The external anatomical features (outside body parts) of fish can also tell us a lot about a species-where it lives in the water, how it finds food, and how it protects itself from predators.

That's why today's dissection is going to be a really educational activity.

The following link, is the lab class sheet we are using. In it, it's described the fish anatomy, materials, protocol, and some exercises. First of all, WE MUST READ THIS SHEET, in order to do a proper practice.

Laboratory sheet Bony fish

I also attach a video link of the inner estructure of a bony fish. Check it, to be able to label your specimen.

To do this, we are using labelled needles/labels with the following names: liver, kidney, gonad, heart, intestine, stomach, swim bladder, caecum, spleen and fins.




Check thess two videos.

Bony fish structure video.


Student dissecting a perch.


Useful sources.

Glossary of fish terms
Fish structure and function
Gills and respiration


The results.

Juan M. and Nacho L. fish (Sparus aurata)

Daniel A. and Javier G. fish (Oncorhynchus mykiss)

Jorge G. and Pablo R. fish (Oncorhynchus mykiss)