Written by: Dan Colodney
The Cichlids of Lake Nicaragua - Part I
Lake Nicaragua in Nicaragua,
Central America contains a very diverse cichlid population. Some of these
such as the convict cichlid are quite common in the hobby and will be
known to many of you, while others are relatively rare and you may never
have heard of them. After reading this article, you may want to try your
luck with some of these and given appropriate tank size, I encourage you
to do so.
Lake Nicaragua, the
largest lake in Central America, is drained to the east into the Caribbean
by the Rio San Juan. A number of smaller rivers flow into the lake from
the surrounding courtryside; Lake Managua to the northeast, connects to
Lake Nicaragua via the Rio Tipitapa. With an average depth of only 40
feet on average, Lake Nicaragua contains several island chains of volcanic
origin which are surrounded by rocky habitats and additionally, numerous
swampy habitats. The lake has very low visibility which accounts for the
few submerged aquatic plant species represented here; Salvinia and Pistia
are among those found at the mouths of the inflowing rivers.

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Until a mere 8 million years
ago, Lake Nicaragua lay along a connection between the Pacific and the
Atlantic oceans, when the formation of the lake existed as an embayment
of the Caribbean Sea. Not until the Peistocene era did Lake Nicaragua
come to exist in its present form. This geology accounts for the tremendous
cichlid populations within the 'lake' and their composition among piscivore,
herbivore, omnivore and insectivore species.
Unlike the cichlid "flocks" of the Great Rift Lakes of East
Africa, not a single cichlid (except for Cichlasoma
labiatum) is endemic to the lake; Rather, they are also found in rivers
and streams in surrounding areas as well as in other parts of Central
America. Many of the species occupy specific ecological habitats. For
example, Neetroplus nematopus is an algae scraper and is found only in
areas which support a large algal population.
Cichlasoma nicaraguense forages for food over sandy substrates and is
limited to habitats between rocky areas which have a large sand bed.
Cichlasoma citrinellum on the other hand, is an omnivore and can be
found in a variety of habitats. When spawning however, all these species
require rocky habitats to provide shelter for eggs and fry.

Image courtesy of FishBase
Photo copyright: Kopic, G
Much
of the aquarium literature suggests that Central American cichlids should
be maintained in pairs. In fact, this doesn't at all represent the way
these cichlids are found in the wild where they are most often encountered
in large shoals comprised of several different species. Only when breeding
does 'pair' formation occur. By contrast, some piscivorous species such
as Cichlasoma dovii and C. managuense are solitary and only found together
during spawning season.

Parachromis managuense
Thus, when keeping Central
American species many hobbyists cannot provide conditions which duplicate
their natural environment and often keep 'pairs' of fishes that don't
get along together. This results in continuous stress and behaviour
which is neither normal nor healthy. Moreover, such fishes do not display
their best color, or live a normal lifespan .. much to the detriment
of the hobbyist who never gets to see these cichlids at their 'best'.
I've always maintained my Central American cichlids in groups of 6-8
in tanks of 75-150 gallons.
When maintaining cichlids
from Lake Nicaragua, it's important to feed them in a manner which duplicates
their behaviour in the wild. Cichlasoma rostratum for example, is a
sand sifter, finding food particles by sifting through mouthfuls of
sand and separating out that which is edible. Clearly, this species
should be maintained over a sand substrate to facilitate normal feeding
methods.
Amphilophus rostratus
Neetroplus nematopus is
an algae scraper which cannot display its normal feeding pattern if
no algal-encrusted rocks are provided in the aquarium. Yes, cichlids
are adaptable and can adjust to whatever diet is offered but if you're
going to keep a given species, don't you want to see its normal behaviour?
Why keep it otherwise.
Here's a list of those cichlids currently found in Lake Nicaragua together
with their feeding preferences and adult size:
- Amphilophus citrinellum - omnivore - 12 inches
- Amphilophus longimanus - herbivore, insectivore - 8 inches
- Amphilophus rostratum - herbivore, insectivore - 8 inches
- Amphilophus labiatum - herbivore, insectivore - 10 inches
- Archocentrus centrarchus - herbivore, insectivore - 8 inches
- Cryptoheros spilurum - insectivore - 6 inches
- Cryptoheros nigrofasciatum - insectivore - 6 inches
- Herotilapia multispinosum - herbivore - 6 inches
- Hypsophorys 'Copora' nicaraguense - herbivorre - 8 inches
- Neetroplus nematopus - herbivore - 6 inches
- Parachromis dovii - piscivore - 20 inches
- Parachromis loisellei - piscivore - 10 inches
- Parachromis managuense - piscavore - 20 inches
- Vieja maculicauda - herbivore - 12 inches
In part II of this series, I'll detail each cichlid found in Lake Nicaragua.
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