Earthworm (Pheretima posthuma) Dissection Manual - Download
For: Science Class 11 | Zoology
File Type: PDF
File Size: 142 KB
Download
Click on "Download" to Start downloading File.
Inside File:
Pre-lab Discussion:
The earthworm belongs to a group of animals called annelids (segmented worms). The body of an annelid is usually divided internally and externally into well-defined segments which may be separated from each other by membranous partitions. Except for the tail and head regions, all segments are essentially alike. Other members of this group include the clam worms and tube worms, which live in the ocean, and the leeches.
The earthworm belongs to a group of animals called annelids (segmented worms). The body of an annelid is usually divided internally and externally into well-defined segments which may be separated from each other by membranous partitions. Except for the tail and head regions, all segments are essentially alike. Other members of this group include the clam worms and tube worms, which live in the ocean, and the leeches.
The earthworm hunts food at night and thus has been called a "night crawler." it usually extends its body from the surface opening of a small tunnel which it makes by "eating" its way through the soil. The rear end of the worm's body remains near the opening while the head end forages for decaying leaves and animal debris.
It has been estimated that an acre of good soil contains over 50,000 earthworms. By their continuous foraging and tunneling these worms turn over 18 to 20 tons of soil per acre and bring over one inch of rich soil to the surface every four to five years. Thus, indirectly, the earthworm enriches farmland and provides for more food in a rapidly expanding population. .......................... Download File to read more...
Tags:
Biology