Introduction
A. splendens is one of a family of
viviparous fish known as goodeids.
Goodeids are also known as splitfins because of the distinctive
shape of the male's anal fin. This has evolved into a primitive
copulatory organ called an andropodium. These fascinating fish are
sometimes called true livebearers. This is because, unlike the
popular guppies and swordtails, the females nourish the young via an
organ similar to the mammalian umbilical cord (the
trophotaeniae). In addition,
females are unable to store sperm, and must mate after giving birth
to become pregnant again.
All goodeids come from central Mexico and are
considered to be endangered. Some species are thought to be extinct
in the wild and are maintained only in the tanks of enthusiasts.
This family thus offers the aquarist an excellent opportunity to
contribute to a worthy conservation effort.
A. splendens is one the most attractive
members of the family and consequently it's probably the most
popular. A robust and active fish, the dominant males catch the eye
when flashing their yellow tails at the females. Like most of the
goodeids however, it has a deserved reputation for fin-nipping and
occasionally its aggression leads to the death of weaker tank mates.
Distribution & Availability
Limited to a small area of the Ameca river basin
in Mexico. A red-listed species which,
depending on which reference you use, is either extinct in the wild
or critically endangered. Not generally offered for sale in shops
but widely available at club auctions and by mail order.
Description
Males - up to 7cm. Typical Goodeid shape
with the dorsal and anal fins positioned well to the rear of the
bodies. The flanks are silvery grey and dappled with metallic
scales. The caudal fin is terminated in a black, then a yellow band.
Anal fin modified into an andropodium.
Females - up to 12cm though probably
smaller in most aquariums. Silver body with black spots. Has been
described as being like a miniature salmon.
Requirements
A boisterous fish in common with many Goodeids
and best kept in a species tank. Deep Sea World visitor attraction
at North Queensferry in Scotland has a colony co-habiting with a
large group of piranhas.
Tank size: 90cm minimum.
Decoration: needs a lot of room for
swimming and plenty hiding places as dominant males will bully
smaller individuals as well as harass females.
Temperature: 25-28oC
pH: 7-8
Hardness: not too soft, 5-20odH
Feeding
An omnivore that will eat just about anything.
Requires a diet high in vegetable matter and will graze on algae.
Use a good quality flake food and supplement with vegetables such as
peas and spinach. Offer frozen or live food weekly.
Breeding
Breeding A. splendens is not difficult.
Kept in a colony, the females will naturally fall pregnant.
Gestation is around 60 days and before giving birth the females are
huge. After dropping around 10-15 fry, the females resemble a
deflated balloon.
The fry are large (up to 2cm) and after a day or
two will be eating much the same diet as the adults. Some adults
will chase and occasionally kill fry but I never witnessed one being
eaten. I always removed fry to prevent any unnecessary deaths. They
can be reintroduced into the colony when they are around 3cm, which
they will reach in about one month.
It's an amazing sight to see such large fry. Of
additional interest is the fact that they are born with their little
umbilical cords still attached. These drop off within a day or so.
USA Show standards
Size: Males 7cm, females 8.5cm
Breeding category: D
Show class: AO
Summary
If you have the space to keep a colony of these
fascinating fish then I recommend them. Lively and attractive, they
deserve more attention.
References
Baensch, Fischer (1997):
Aquarium Atlas
Photo Index (1-5)
Fishbase
species summary
The IUCN
Red List of threatened species
Personal observation
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