Subject: Spermaceti organ of the sperm whale

Lori Mazzuca (lorim@soest.hawaii.edu)
Sat, 17 May 1997 10:16:08 -1000 (HST)

Dear Steve,
	Thank you for your question and information about the
use and/or purpose of the spermaceti organ of the sperm whale.  I have
learned as you have, that it is used primarily for echolocation purposes.
I do not know if any further work has been done in the diving area, but
if anyone would know it would be my dear friend Robbins Barstow.  He knows
everything there is to know about the sperm whale.  I have cc'd this
message to him, and now you have his address.  My hope is that you will 
connect with him and as a result pass the information along to Whalenet.
(This is the last day my page will be up.)  Good luck and I applaud your
staying up to date in teaching!  Aloha-Lori

 On Sat, 17 May 1997, Steve Leslie wrote:

> 
> Lori,
>      In 1979, Malcolm R. Clarke wrote an article about the adaptive 
> significance of the huge spermaceti organ of the sperm whale in Scientific 
> American.  While the organ has all the characteristics of, and is described 
> in marine biology texts, as an organ for generation click pulses for 
> echolocation, Clarke suggested that buoyancy control may be a primary 
> purpose of the organ.  Where the organ evolved as an organ for echolocation, 
> he suggests that this is perhaps an example of preadaptation, with the organ 
> becoming useful in an entirely different context by serving to regulate 
> buoyancy during the long deep dives of the sperm whale.  In his analysis of 
> the anatomy and physiology of the sperm whale, he suggests that cooling the 
> spermaceti oil, either through vasodilation or through taking cool seawater 
> into the right nasal passage, would result in increasing density which 
> enables the sperm whale to dive through the thermocline and lie in wait for 
> giant squid.
> It would seem that the organ might serve both purposes, echolocation and 
> buoyancy control, so long as any water taken into the nasal passage to cool 
> the spermaceti oil could also be expelled to allow air to circulate past the 
> monkey's muzzle and create click pulses for echolocation.
>      In the intervening years since Clarke's article, has there been further 
> discussion in the literature, or any consensus among cetologists about his 
> hypothesis?  Is Clarke still involved in whale research, and if so where is 
> he now?
>      I teach marine biology in high school, and use this article because I 
> think it presents an excellent example of scientific thinking, but don't 
> know if the hypothesis has ever been further tested or refuted.  Marine 
> biology texts seem to focus on echolocation for the spermaceti organ.  Any 
> thoughts or updates would be appreciated.
> 
> Best wishes,
> Steve Leslie
>