Dear Dan,

I'm not used to Nucella lamellosa (as i live in Brazil), but in
many cases size variations is caused by disponibility of food.
And sculpture (varices, teeth, etc) are related to wave exposure
or current.
Colder waters normaly make animals bigger (more phytoplancton,
more food), and still waters make animals with better grown
sculpture.

Predators are indeed a factor that influence the shape of
shells. This kind of selection is relatively common.

As for collors patterns, they are influenced by genetics (albine
animals, etc) but shell collors are directely related by what
the animal eat (that's why animals in aquarium have distinct
colors than those in nature).

See ya,

Fabio Wiggers
Universidade Federal do Rio Grande do Sul
Porto Alegre - Brasil

 --- Dan Yoshimoto <[log in to unmask]> escreveu: > Dear
Friends,
>         A couple of weeks ago I posted a question about
> Nucella lamellosa
> and the variations (varieties/forms) as I was giving a talk to
> our shell
> club here in Eureka, California.  After last night I have even
> more as the
> members were curious about the species also.  As most of them
> had only seen
> the form Nucella lamellosa lamellosa (Gmelin, 1791) because
> that's what
> most shell shops sell, they we awed at the number of forms
> that can be
> found, within 100-200 miles from here.
>         As children we always asked the big question, "WHY?"
> and as adults
> our curiosity seem to wane abit and "Why?" is used less often.
>  Poor us!!
> But last night the questions were in every mouth.  Here are a
> few of them
> and if there are folks out there that may have some answers,
> I'll print
> them in our next Lost Coast Shell Club Newsletter.
> 1. Seeing various sizes in the species, (some from deeper
> waters and others
> intertidal), is there a reason for this difference?  Is there
> an advantage
> to a bigger size... for the animal?  No, not the
> collector/dealer.
> 2. Having many color variations and color banding, as are
> found in Northern
> Vancouver Island, Canada, is there a cause of this, besides
> genetics?  (For
> those interested in Port Hardy specimens photo, please e-mail
> privately)
> 3. Some of the specimens (usually with narrow aperture, thick,
> heavy
> shells) are there uses/causes for the "teeth" that are inside
> the outer
> lip?
> 4. In many of the locations there are very few color forms,
> and at times,
> only white or only brown, is this a type of evolutionary
> selection because
> of predator choices? (Birds, Crobs, Octopi,Sea stars) When I
> find
> populations of few or only one color forms, I usually find in
> the area
> several species of large crabs with strong pincers and
> specimens that have
> been broken in similar ways.
> 5. Could the color variations in Nucella be foorms of sexual
> dimorphism?
> Speaking of "sex" (oh boy) are Muricids hermaphroditic and are
> the egg
> cases carrying veligers or shelled "walk-outs"?
>
>         As you can see, the questions posed are similar to
> those asked by
> the Elementary/Jr. High school students where I give talks. As
> the members
> in the club had so many good questions, and I wasn't sure of
> the answers, I
> am asking your indulgence in asking for some answers.
>
>         My question, also a bit elementary, is, "Has anyone
> done a DNA
> Analysis for comparison of the many forms of the species
> Nucella lamellosa?
> Not much has been done with this species since 1915 (Dall) and
> the new
> technologies may give us some new answers.
>         Thank you for your answers, in advance.
> Dan Yoshimoto
> p.s. e-mail address is
>
> [log in to unmask]         if you's like to see the Port
> Hardy Nucella
> lamellosa variations photo, even with 4 purple specimens.
>
> Dan, Hiromi & Kuma Yoshimoto
> 1164 Vista Dr.
> Eureka, California
> 95503-6018
> U.S.A.

Yahoo! Mail - o melhor webmail do Brasil
http://mail.yahoo.com.br