Re: NANFA-L-- Chrosomus lifespan

Al G Eaton (sege7_2000-in-yahoo.com)
Sat, 3 Dec 2005 05:07:47 -0800 (PST)

I have personally heard Carol Johnston make this
claim, and it seems to hold true in the wild in some
populations during some years (personal observation).
In Beaver Creek, which is probably the southern most
population or close to it, the adults seem to rapidly
deteriorate and die after spawning (two occasions
support this and two don't). I think they expend so
much energy in spawning there and food may be
insufficient for them to recover, so they die. My own
observations are somewhat contradictory. I have seen
them in Beaver Creek just prior to spawning and then
not found a single adult specimen only weeks after
spawning, but lots of tiny tiny fry, which can be
easily identified by the red in the upper part of the
eye. All the adults I have caught there seem to be
the same size, so they are the same year class.
However, in Ft Payne populations and in Conasauga
River populations I have definitely seen more than one
year class in collections. In Ft Payne I have seen
three years of adults, the third year probably being a
rare exception as I only caught one lunker of that
class.

My own experience-in-home supports an aquarium life
span of around five years.

The mechanism for their rapid deterioration after
spawning hasn't been adequately explained to me,
though I remember Bruce S. writing about some of his
Centreville specimens spawning and then literally
falling apart before his eyes. My males did this at
age five.

Fish being annual in the wild and having a much longer
life span in captivity isn't an unusual occurrence.
Cardinal and Neon Tetras are annual fish in the wild,
but live much longer in captivity, when they have a
constant food source supply.

Klaus

--- Gerald Pottern <gbpottern-in-yahoo.com> wrote:

> Hi Todd - My original chrosomus (from centreville
> AL) lived-in-room temp for five years and spawned
> good eggs year-round (not continuously, but on & off
> without respect to season) from about age 2 to 5.
> Seasonal chilling is not required,-in-least for the
> warmwater pops (dunno -might be different in cool
> stream pops ??). My 2nd & 3rd generation rainbows
> behave simialrly. Spawning usually occurs in the
> morning, and the fish turn translucent hot pink with
> a bright silver lateral band just before & during
> spawning - looks like they have internal lighting.
> Apparently the melanophores all contract down to
> nothing so there's no trace of dusky color. Female
> bodies get even brighter than the males, but they
> have less blue-violet in the fins & head. They do
> lots of playful chasing & flashing all the time --
> so watch for that translucent change that indicates
> breeding (you may need sunglasses to watch). So
> who's claiming they die after spawning ? --gerald
>
> Date: Fri, 2 Dec 2005 12:42:21 -0500
> From: "Crail, Todd" <tcrail-in-UTNet.UToledo.Edu>
> Subject: NANFA-L-- Chrosomus firing up.
>
> Hi gang,
>
> My rainbow shiners are really showing the magenta
> flecks, the females
> look gravid and all of them are rooooosy. I can see
> a little lateral purple
> on the dominant males. How much pre-spawn flash
> have they done for you folks
> who've spawned them? Is this an indication of a
> spawn, or are they just
> feeling sassy and large? It's not like they got
> cold or anything (just down to
> 62 the last three weeks), so I'm not even sure the
> eggs will work if they do.
>
> I'm looking forward to the color and photographs,
> but not so much the
> swan song they apparently sing a week later. Fort
> Payne is a loooooooong
> way from here.
>
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/ visit http://www.nanfa.org Please make sure all posts to nanfa-l are
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