The purpose of the earthworm dissection is to provide you with basic dissection experience, as well as to begin an introduction into gross anatomy to be coordinated with your lecture notes.
Scientific Classification: Squid belong to the order Teuthoidea of the class Cephalopoda. The common squid of the east North Atlantic coast belongs to the family Loliginidae and is classified as Loligo vulgaris.
Objectives:
• Describe the appearance of various organs found in the squid.
• Name the organs that make up various systems of the squid.
Materials:
Dissecting kit and pins, gloves, forceps, lab apron, scissors, paper towel, scalpel, water, dissecting probe, preserved squid, hand lens, dissection tray.
Purpose:
In this lab, you will dissect a squid in order to observe the external and internal structures of squid anatomy.
Background:
The squid is one of the most highly developed invertebrates. Some of the animals structures explored in this lesson illustrate the ways in which the squid has adapted to life in the ocean. Its streamlined body and jet propulsion which occurs as the squid squeezes water out of its body through its siphon, make the squid a fast, active predator. This animal also has a very good defense mechanism.
· All mollusks have a soft body with a special covering called the mantle, which encloses all of the body organs such as heart, stomach and gills.
· Squid can be as small as a thumbnail, or as large as a house. The giant squid, Architeuthis, can measure 60 ft. in length and weigh three tons!
· Squid have ten arms, which are wrapped around the head. Eight are short and heavy, and lined with suction cups. The ninth and tenth are twice the length of the others, and are called tentacles. Suction cups are only on the flat pads at the end of the tentacles.
· Squid feed on small crustaceans, fish, marine worms, and even their own kind! They use their tentacles to quickly catch their prey, which is pulled in by the arms and down to the radula, or beak, which uses a tongue-like action to get food to the mouth so it can be swallowed whole.
· Squid are a major food source for many fishes, birds and marine mammals.
· Squid produce a dark ink that they use to escape from predators. When a squid is startled, the ink is released through the anus, and the cloud of inky water confuses the predator while the squid swims away.
· After mating, a female squid will produce 10-50 elongated egg strings, which contain hundreds of eggs each. In many species, the parents will soon die after leaving the spawning ground. The egg strings are attached to the ocean floor, are left to develop on their own, and hatch approximately ten days later.
Procedure:
1. Put on gloves and a lab apron if possible.
2. Place squid in the dissecting tray & rinse off the excess preservative. Identify the dorsal side and the ventral side. Turn the squid dorsal side up, as shown in the diagrams.
3. Use a hand lens as you observe all parts of the squid, externally and internally.
4. Using the attached diagrams, dissect the squid to reveal and explore the various structures and organs.
5. Dispose of your materials according to the directions from your teacher.
6. Clean up your work area and wash your hands before returning to class.
For example a structure of a worm.
No comments:
Post a Comment