Re: Toxic Pheromones?

[Randy or Deb Carey <carey@spacestar.net>]

IDMiamiBob@aol.com wrote:

> <snip>

>    I suppose it is reasonable that fish may also use "Scent Communication"
> in the water, and it would be reasonable to also refer to the responsible
> chemical "messengers" as pheromones. <snip>
>
> Bob Dixon

<also>

Russell /Susan wrote:

> As you may or may not know, almost all of the beasts in the Animal
> Kingdom (I'm still not sure about fish...it only stands to reason
> though) emit Pheromones, including humans.  <SNIP>

>    It is my theory (take it as you may) that fish, having a good sense
> of smell, do use pheromones on a conscious level.
>
> Thanks:     Russell
>

The use of pheromones has been well known for some time.

[1]  when ostariophysine fish (characins, catfish, barbs) suffer damage, they
emit  a "chemical alarm system, telling fish that  one of its congeners has been
attacked by a predator" (Characoids of the World, p.9).

[2] A neglected-but-important subfamily of the S. American tetras is known for
its pheromone producing glands:  Glandulacaudinae, a gland on the caudal peduncle
of the males.  The most well-known aquarium representative is the Swordtail
Characin, Corynopoma riseii (see Baensch I).

According to Gery (Characoids of the World, 1977), "The Glandulocaudinae have in
common certain male organs used to attract the females and to permit the internal
fertilzation of its eggs... All forms have a so-called caudal gland which is
supposed to secrete an attractive oder (like the musk gland of certain mammals),
..."  (We now know that the females receive and store the spermatores, but the
eggs are not fertilized until the female lays them, usually by herself).

Around the winter of  95-6, TFH published a series of articles by Dr. Weitzman
(Smithsonian) on the Glandulocaudins.  Several photos and a description of the
glands were included in the articles.   (Lucky me.  I am negotiating with
Dr.Weitzman to come to my club in March for two talks, one on the
Glandulocaudins. :-)

The phenomena is probably far more widespread, but I refer to the characins as
that is my "specialty."

- --Randy