http://www.collembola.org/publicat/morpholo/ovary.htm
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Last updated on
2024.08.10
by Frans Janssens
Frans Janssens,
Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Abstract.
Skin pigmentation has been a neglected diagnostic character given it is quite
variable in instars of the same species. But also due to complexities caused
by metabolic issues such as the presence of eggs in the ovaries of female reproductive instars.
Here we will explore the effect of the colour of the yolk rich eggs in the ovaries
on the appearance of the habitus colouration.
To be completed.
Introduction
Fig.Ifu. A light colour form of Isotomurus fucicolus from Belgium
2024.08.03 © Huskens, M.-L.
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The ovaries of the adult female reproductive instar of Collembola
are typically filled with yolk rich eggs.
The yellow colour of the yolk may affect the appearance of the lateral
and ventral
colouration in habitus images of light or poorly pigmented specimens
(fig.Ifu).
To be completed.
Reproductive system
To be completed.
Reproductive instar versus feeding instar
Contrary to Insecta, adult Collembola keep on moulting.
During the adult phase two distinct types of instars occur.
The reproductive instar in which the gut is empty.
The feeding instar in which the gut is filled with ingested food.
Only in the reproductive instar the intrinsic colouration of the species
can be observed.
In the feeding instar the colouration may be obfuscated by the colour of the
food in the midgut.
But in adult female reproductive instar the ovaries
are typically filled with eggs.
The broad lateral longitudinal yellow stripe observed in
a light colour form of Isotomurus fucicolus is not skin pigmentation,
but it is the colour of the
yellow yolk in the eggs present in the ovaries
as seen through the translucent body (Fig.Ifu).
To be completed.
Discussion
To be completed.
Conclusion
To be completed.
Acknowledgements
We would like to thank, in alphabetical order,
Marie Louise Huskens
for their kind permission for using their respective photographs
as illustrations.
References
