Info: Composition of Whale Dorsal Fins

Michael Williamson (
Mon, 1 Mar 1995 19:05:08

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Date: Wed, 01 Mar 1995 18:59:09 -0500 (EST)
From: Michael Williamson <WHE_WILLIAM@FLO.ORG>
Subject: Info: Composition of Whale Dorsal Fins
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From:	SMTP%"MARMAM@UVVM.BITNET"  1-MAR-1995 17:11:51.09
Subj:	Collagenous fins/flukes
Date:         Wed, 1 Mar 1995 09:26:59 -0500
Reply-To:     Marine Mammals Research and Conservation Discussion
Sender:       Marine Mammals Research and Conservation Discussion
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From:         Alastair Watson <AWATSON@OSUVM1.BITNET>
Organization: Oklahoma State University
Subject:      Collagenous fins/flukes
X-To:         MARMAM Res&Consv Discus <>
To:           Multiple recipients of list MARMAM <MARMAM@UVVM.BITNET>
1 March 1995
Recent postings discussing Orca dorsal fins have raised an issue
concerning the histological make-up of cetacean dorsal fins and flukes.
Without doubt these structure are "stiff" but this does not necessarily
require that they be formed from bone or cartilage ... although it is
said at Sea World and other places and in texts that cetacean dorsal fins
and flukes consist of cartilage.
My question is: Is there histological evidence to support this statement?
In my gross examinations of a minke whale and several smaller odontocetes
I have not seen anything that resembles cartilage in either the dorsal
fin or flukes.  The dense connective tissue collagenous core is very firm
and provides a rigid support to these appendages.
"The flukes and dorsal fin consist of an inner core of connective tissue
fibre ... The collagenous tissue matrix is firm ..." p. 146
Elsner, R., et al. 1974. Functional circulatory anatomy of cetacean
appendages.  In, Harrison, R.J. ed. Functional Anatomy of Marine Mammals,
vol 2:143-159.
If there is cartilage in the fin/flukes, I would appeciate knowing of
the evidence and reference, if not, let us support the collagen that
supports us, Orcas and all.
Alastair Watson
College of Veterinary Medicine
Stillwater, OK