Fish Haematological Techniques: Severing the Caudal Peduncle

Unit 2 - Collection of Blood

Severing the Caudal Peduncle	1 of 5 NEXT

This sampling technique is suitable for smaller fish (eg. less than 10 cm), and in many cases may be the only option because the blood vessels are small and blood volumes are very low. It should be noted that it is sometimes quite difficult to collect blood efficiently using this method. As coagulation tends to occur rapidly, the blood sample must be collected immediately after the tail is severed. In this procedure the fish is killed to obtain the sample (the term "sacrifice" is used to describe this act). Sacrifice the fish by administering an overdose with an anaesthetic solution.
*Definitions*
ANAESTHETIC: In the case of fish, chemicals used to relax and facilitate handling, surgery and spawning procedures. Commonly used agents include tricane methane sulfonate (MS-222), benzocaine and quinaldine which are widely used in handling freshwater fish. Ethylenglycol-monophenylether is an anaesthetic agent more suitable for marine fish species. It is usually administered by immersing fish in a bath solution blood.