First, in regard to appearance, as a family,
the cichlids are as colorful as any other
fishes, saltwater or fresh. It’s just that we
are used to seeing only the most colorful
of the different families in an aquarium.
The family takes a backseat to no other in
the looks department—even though it is
certainly true enough that some species are
real clock-stoppers! Really, these fish tend
to take the prizes in both directions: most
beautiful and most grotesque.
Another thing that attracts tropical
fish hobbyists is that they can relate to
these fish because they seem to move with
purpose, and they are the only large family
in which every single species provides
parental care of some sort. As humans, we
tend to empathize with these animals in
their efforts to protect and care for their
young. It is particularly touching to watch
two cichlids coordinate in the biparental
defense and care of their fry. Other fish
families have species that exhibit some
parental care, but cichlids are the masters
in this department.
The cichlids are biologically interesting,
too, and that fact makes them the darlings
of scientists, who study them for several
reasons. One is to try to understand why
cichlids are so successful in terms of the
number of species. The cichlid family may
be the most successful vertebrate family
known, so scientists are naturally curious
to discover why.
Another reason scientists study cichlids
is that their behavior is so complex, making
them a gift from nature to ethologists
(scientists who study animal behavior).
There are so many things to learn.
In the case of biparental cichlids, there
have been many studies of how the parents
communicate with each other in the defense
and care of their brood, and how they even
communicate with the fry. And amazingly,
many species actually exude a specialized
body slime that feeds the young, much
like mammals produce milk—although in
the case of cichlids, both male and female
provide the food. For most cichlid species
that do this, it is a supplementary food. The
young find food on their own, although not
without help, as the parents herd them to
promising feeding areas and stir them up
with their ventral fins. In the case of discus,
though, the body slime is an essential first
food, so most discus breeders leave the fry
with the parents.
At the first sign of trouble, a female Egyptian mouthbrooder Pseudocrenilabrus multicolor
victoriae opens her mouth, signaling her fry to retreat back to her buccal cavity.
Discus and angelfish, the “king and queen” of freshwater aquarium fish, are in many
ways typical cichlids.