Re: [Killietalk] Annual Fundulopanchax

[LeeH920226 at aol_com]

In a message dated 11/1/06 12:33:39 PM, GregNski at cs_com writes:

<< Annualism, if defined as the ability of the eggs to enter a resting state 
under adverse conditions, is a binary attribute (meaning it is or it isn't; 
you can't be "semiannual" any more than you can be "semi-pregnant").  But that's 
just the old Biologist in me speaking. >>

Hmmm! Most "non-annuals" have eggs that can be kept on peat for storage or 
shipment and will not hatch unless submerged. They do not normally exhibit 
diapause, yet they exhibit a pause in development. I guess the definition of 
diapause "a period of physiological enforced dormancy between periods of activity" 
(Webster's new Collegiate Dictionary) suggests that diapause occurs in the case 
of the non annuals as well. That definition does not introduce the concept of 
obligatory nor does the known practice of water incubation of well defined 
annuals. So what is the bottom line? The eggs will develop or pause in 
development depending on the conditions regardless of what the natural process is in 
the wild. Whether the fish is in an obligatory state in nature to exhibit 
annualism is variable with every species and location. Many so-called annuals such 
as Cynopoecilus melanotaenia probably sometime hatch without drying in nature, 
but also tolerate a dry period.

Lee Harper
Media PA
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