Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!husc6!cmcl2!phri!lonetto
From: lonetto@phri.UUCP (Michael Lonetto)
Newsgroups: sci.bio
Subject: Re: Octopus....fish, reptile or what?
Message-ID: <2797@phri.UUCP>
Date: Thu, 16-Jul-87 17:24:31 EDT
Article-I.D.: phri.2797
Posted: Thu Jul 16 17:24:31 1987
Date-Received: Sat, 18-Jul-87 09:00:53 EDT
References: <596@xn.LL.MIT.EDU>
Reply-To: lonetto@phri.UUCP (Michael Lonetto)
Organization: Public Health Research Inst. (NY, NY)
Lines: 24

In article <596@xn.LL.MIT.EDU> avi@XN.LL.MIT.EDU (Avi Weiss) writes:
>I was wondering whether an octopus is a fish or a reptile? Or prehaps
>some other class? Correct answers would be most appreciated!!
>      ---avi (avi @ xn.ll.mit.edu)



The octopi, along with squids and cuttlefish, are all mollusks.  I don't
have my guide to taxonomy around so I can't be any more specific.  One
interesting sidelight to the classification is that the octopus/squid 
group has extremely well developed eyes, which show a surprising similarity
to vertebrate eyes (certainly far closer than any other invertebrate).

These animals also have very fast, complex nervous systems, once again
on a par with vertebrate systems.  Interestingly, the speed is achieved
without myelination of the nerve axons (the system used in vertebrates).
Instead, the axons are enormous in size (hence the use of the "giant" 
squid axon in neurotransmission studies.

ML
-- 

Michael Lonetto    UUCP:(allegra!phri!lonetto) 
USMAIL: Public Health Research Institute, 455 1st Ave, NY, NYioneto)S