Re: [Killietalk] Inspecting killifish eggs in peat

[Brian Watters <bwatters at shaw_ca>]

Tom Isgro wrote:

>
> As I remember food should be no larger than the diameter of the
> eyes.  That being said, I've watched inch long Lucania goodei
> swallow whole bloodworms.
>
> Maybe the gape size is more realistic.  Just a thought.
>

I am sure that gape size is more realistic but in a practical sense, how do
you measure it, or even estimate it when you are dealing with, for example,
Aphyobranchius fry that may measure 2 mm or less total length ?

As an example of where gape size is clearly the most relevant measure,
consider N. ocellatus, the predatory Notho. It has relatively small eyes but
an enormous gape. When they hatch the fry are about 8 mm or more in length
(an estimate) and it is common to see one with another of its siblings half
way down its gullet. That is the reason they have to be separated from one
another within the first day or two after hatching. Interestingly, however,
as they grow their gape must become relatively smaller because they will not
eat any other Notho that is anywhere near their own size, and probably not
even a third of their length.
___________________________
Brian Watters
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E-mail: bwatters at shaw_ca

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