Re: NANFA-- Hellbender questions

Steffen Hellner (steffen_at_hellner.biz)
Mon, 12 Jan 2004 21:23:26 +0100

>>>> Yes, they are large, can live longer than 50 years (every fire slamander
> can
> as well, recorded up to 52 years in captivity). Compared to human
> aging-potential and maturing they4re fast!<<<
>
> --- Compared with the taxa commonly cultivated by aquarists (killifish,
> livebearers, shiners, darters), they're slow and logistically problematic.
Yes, it all depends on what you compare. The secret of statistics.
>
>
>>>> Limited dispersal information is
> limited itself as hardly anybody has really studied if and how far the can
> migrate.<<<
>
> --- Adults occassionally migrate long distances (up to 3500 m) but most
have
> restricted movements. Home ranges < 350 sq m are documented for a
> Pennsylvania stream, < 100 sq m in the Niangua River, Mo. Check out
> citations in "Salamanders of the United States and Canada" by James W.
> Petranka.
Interesting, I4ll look that up.

>>>> The genetic differences even between the two subspecies are not
> substantial (if I interpreted available literature correctly). The latter
> would make it easier replacing specimen/transferring to nearby
> populations.<<<
>
> --- It is unclear whether the two forms are species or subspecies. It is
> very clear that genetic differences ARE substantial. An allozyme study in
> 1977 indicated little variation among populations but a 1993 mtDNA study
> indicated 15 different haplotypes for 21 populations studied. Haplotypes
> were clustered geographically (by drainage or state), but some were
> apparently absent from nearby streams within the same drainage. It may be
> "easy" to replace or transfer specimens but it may not be genetically
> advisable. see Eric Routman's "Mitochondrial DNA variation in
> Cryptobranchus...." in Copeia 1993(2): 407-416. [Note for sturgeon
> enthusiasts - genetic resolution of pallid and shovelnose sturgeon was also
> obscured by early allozyme data, and clarified by later DNA data]
This is absolutely new to me and the more interesting. Will surely read this
up asap.

>>>> ...the topic in general is the same as for many NANF.<<<
>
> Perhaps, but I am unaware of any large, long-lived, slow-to-mature T&E NANF
> that have been successfully propagated by private individuals.
I know about many salamanders successfully propagated by private
individuals. Of course logistics is a challenge but as for hellbenders it is
fairly easy. Crayfish, fish and even frogs are fairly easy to get compared
to all that insect stuff for other amphibia and reptiles. Our salamanders
and newts as well take 3+ year to be mature and some more years to be fully
grown. That is a particular excitement to spend a long time with a "pet"
(not in the meaning of puppies, please!). Longer than any dog, cat or
hamster. Only turtles and parrots can cope with that.

>From this perspective, my future hellbenders may as well be there when I am
already goen. That4s a problem.

Steffen
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