specific ecological niches than their simpler multicellu-
lar ancestors. Although it is probably one of the reasons,
this alone cannot explain this kind of development.
Seeing and being seen may have played a very decisive
role. Seeing is one of the most pioneering and far-reach-
ing inventions of nature, as it promotes the emergence
of predators/prey structures with evolutionary contests,
thus generating tremendous dynamism in species for-
mation. The fact is that highly developed eyes with lenses
are also about 540 million years old, so their genesis co-
incides neatly with this Cambrian species explosion.
It is still unclear whether very different eye types
in animals are all based on a kind of primal eye or are
completely independent of each other. When we peer
into our aquariums, it is mind-boggling to realize that
there are numerous different eye types looking back at
us, including those of fishes, crabs, snails, octopuses,
and mussels. Are all these eye types, which functionally
differ from each other and have different abilities, of
monophyletic origin? Or has nature invented the eye
multiple times (polyphyletic origin)? As the following
article documents, eyes are fascinating, and attempting
to see the world as our fishes and other animals see it
can be a powerful tool in aquatic husbandry.Lori’s Anthias (Pseudanthias lori):
eyes with ancient beginnings. Fishes
first appear in the fossil record
around 530 million years ago.