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