Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which rat stock is also known as the "hooded" rat?

1. Brown Norway

2. Long-Evans

3. Wistar

4. Sprague-Dawley

The correct answer is: Long-Evans

The Long-Evans rat stock is recognized as the "hooded" rat due to its distinct coat pattern characterized by a darker hood-like coloration over the head and shoulders, contrasted with a lighter body color. This unique appearance is a result of selective breeding, making Long-Evans rats easily identifiable and popular in research settings, particularly in behavioral studies. The specific coloration pattern allows researchers to study various aspects of animal behavior and physiology while offering a visually distinct model for identification. Other rat stocks, such as the Brown Norway, Wistar, and Sprague-Dawley, do not possess this hooded pattern characteristic of the Long-Evans rats. Brown Norway rats are known for their brown or agouti-colored fur, Wistar rats typically have a more uniform white coloration, and Sprague-Dawley rats are often albino with pink eyes. Understanding these differences helps clarify why the Long-Evans is specifically referred to as the "hooded" rat.