Fish Scales Preparation and Characteristics

Dr. Nagaraj from the Regional Institute of Education, Mysore, explains the preparation of temporary mounts of fish scales. The video covers the types of fish scales, including placoid, ganoid, cycloid, and ctenoid, and their unique characteristics. It also details the materials required and the step-by-step technique for mounting scales. The video concludes with a summary and self-evaluation of the learning process.

What is the primary function of fish scales?

• To aid in swimming

• To provide protection and camouflage

• To help in breathing

• To attract mates

Which type of fish scale is characterized by a tri-radiate shape?

• Placoid

• Cycloid

• Ctenoid

• Ganoid

What is the outer layer of ganoid scales made of?

• Keratin

• Chitin

• Ganoin

• Calcium

Which fish species are known to have cycloid scales?

• Sharks

• Perch

• Salmon

• Rays

What distinguishes ctenoid scales from cycloid scales?

• Presence of a nucleus

• Presence of teeth at the posterior end

• Lack of growth lines

• Thicker structure

Which chemical is used to dissolve muscle protein in the preparation of fish scales?

• HCl

• NaOH

• H2SO4

• KOH

What is the purpose of using alizarin red in the fish scale preparation technique?

• To dissolve the scales

• To clean the scales

• To stain the scales for better visibility

• To harden the scales

What is the role of glycerin in the mounting process of fish scales?

• To stain the scales

• To dissolve the scales

• To provide a medium for mounting

• To clean the scales

Which tool is used to pull out scales from the fish skin during preparation?

• Scalpel

• Forceps

• Brush

• Scissors

What is the final step in observing the prepared fish scales?

• Boiling the scales

• Observing under a microscope

• Mounting with a cover glass

• Staining the scales