Girardinus metallicus
Metallic Girardinus
Classification
Poeciliidae
Distribution
Costa Rica, Cuba.
Habitat
It can be found in streams, ponds and ditches. The water is commonly stagnant and often brackish.
Maximum Standard Length
Male 30-40 mm, female 40-60 mm.
Aquarium SizeTop ↑
18″ x 12″ x 12″ (45x30x30cm)
Maintenance
A well-planted tank with some floating cover is ideal for this species. Water should be medium hard and alkaline or brackish.
Water Conditions
Temperature: 72-81°F (22-27°C)
pH: 6.5-8.0
Hardness: 8-20 dH
Diet
Omnivorous and the diet should include small frozen, live and dried foods with a high vegetable content.
Behaviour and CompatibilityTop ↑
Peaceful but does appreciate brackish conditions, so tankmates should be chosen with care. If keeping in hard freshwater, then hardy corydoras, tetras and small rainbowfish are good choices. In a brackish setup G. metallicus can be kept with bumblebee gobies and other small species.
Sexual Dimorphism
Males possess a gonopodium and are smaller in size than females. Male fish also have a black ‘stripe‘ which runs from the mouth along the underside of the fish into the gonopodium.
Reproduction
Very easy if soft, acidic water conditions are avoided. Reproduces in standard livebearer fashion. As with other species, the males can be somewhat incessant in their pursuit of females, so we recommend that several females should be kept to every male in order to dissipate this. Areas of dense planting will also help. Gestation takes around 24 days and broods of between 15-30 fry can be expected. The adult fish will predate on the young so the best method of raising them is to remove the gravid female to a separate tank and allow her to give birth there, before returning her to the main aquarium. The use of breeding nets or traps is not recommended as their small size is not suitable for raising fry. The fry are quite large and will accept brine shrimp nauplii or powdered flake from birth. They should also be fed vegetable matter such as blanched spinach or spirulina. They grow very quickly if fed 2-3 times per day.
NotesTop ↑
This species was introduced into the aquarium trade in the early 20th century but disappeared soon after. It subsequently reappeared in a Berlin zoo in 1965 and has been available from specialist breeders ever since. It occasionally appears for sale in aquatic shops.
February 15th, 2016 at 8:59 pm
Hello.
I have a collony of Girardinus metallicus. The size of the fish is exagerated. The male is very small, 2cm. The female is 4cm big maximum. This is very strange that every website give the same “giant” proportions to this fish, even from people who brood them. But my and other aquarius I know who have this fish accord to his way smaller proportions.
February 16th, 2016 at 9:14 am
Hi Stalker, agree with you. This profile is in need of revision which we will do asap. For now, I have changed the sizes as a temporary measure.
February 16th, 2016 at 9:43 am
You did it quick, did you compared my observation with others? At your place I wouldnt be so fast to believe someone on the internet.
February 16th, 2016 at 1:32 pm
Hi, I’ve observed this species in the wild at several localities in Cuba and all adult specimens were within the range 30-50 mm. Have never seen an aquarium specimen larger than that either, and the books I have concur as well. Think most websites give sizes in TL whereas we use SL here on SF, so perhaps that explains the discrepancy? Will add some images of natural habitats and wild individuals when I update the profile fully.
February 16th, 2016 at 2:51 pm
TL, SL?
February 16th, 2016 at 3:05 pm
Sorry, TL = Total length (including the caudal fin), SL = standard length (to base of caudal fin). The latter is what we use.
February 16th, 2016 at 8:57 pm
The caudal fin is not that large in this species, my 2cm is TL for male.
June 7th, 2018 at 6:26 pm
My G. metallicus like to eat the algae growing off of silk plants. Crushed up earthworm and spirulina pellets are also popular. Like most livebearers they are pigs, they’ll eat basically anything. I used to keep mine with B. mahachaiensis and they were not bothered by them. Mahachaiensis may show aggression towards them so make sure you have a backup if you keep those two species together. The female metallicus are very pretty!
If you need more images, I have pictures of my group here: https://elemental-kiss.tumblr.com/tagged/my-metallics.