Girardinus Metallicus Stats InfographicGirardinus Metallicus is a peaceful livebearer species hailing from the brackish waters of Cuba and Costa Rica. Commonly known as black chin livebearer and metallic fish due to a dark line running from the chin across its shiny body, this spectacular species is a great choice for community tanks.

Nonetheless, improper Girardinus Metallicus care in an aquarium set up can lead to unwanted consequences, which is why we have got this guide ready for you.

In this article, not only will we be addressing how you can care for the tiny species, but also list its ideal tank mates, breeding possibilities, and diet.

Girardinus Metallicus Stats: Important Facts & Figures

Shimmering in gorgeous silver to gold colors under the right light, the metallic girardinus is a much sought after species. As a matter of fact, you will find them being referred to by several names at pet shops.

Hence, don’t be surprised when the striking striped fish you notice in one shop is being sold as black chin livebearer or metallic livebearer, and metallic topminnow, metallic girardinus, or Girardinus Metallicus in others. They are all the same species of livebearer fish.

Moreover, if you are planning to bring a school of Girardinus Metallicus home, you better take a look at the important stats below, to know them better first.

Quick stats:

Scientific name Girardinus Matallicus
Family Poeciliidae
Origin Central America: Cuba and Costa Rica
Coloration A golden sheen that appears metallic in light with silver diamond shapes spreading across the body laterally. It has a black spot on the mid-center of the dorsal fin. Their mouth, underside of the chin, chest, stomach and tail also feature black blotches that differ from one fish to the other.
Strata Top to mid-level dwellers in ponds and streams
Size Up to 2.0 inches (Adult Male)

Up to 3.5 inches (Adult Female)

Life Span 3 to 5  years
Temperament Peaceful Fish
Diet Omnivorous
Tank Size 20 – 55 Gallons, depending on size of school
Temperature 22-25°C
pH 6.0-8.0
dH 9.0-19.0° H – medium hardiness


Order: Cyprinodontiformes
Family: Poeciliidae
Genera: Girardinus
Species: Girardinus metallicus

Girardinus Metallicus Care in Aquariums

Girardinus metallicus know as black chin livebearer and metallic fishThe metallic livebearer is an attractive choice for fish keepers, not only in terms of the appearance of the species but also because of its ease of care. Besides, the fish is fond of eating algae, too. Hence, a perfect fit for all kinds of aquariums. In other words, the black chin livebearer requires no special treatment while in captivity inside a community fish tank.

However, there certainly are some factors that you need to keep in mind if you are going to add these fish to your aquarium anytime soon.

Keep scrolling as we take you through the important bits one by one:

– Aquarium Size

Being tiny creatures, a tank measuring 18 x 12 x 12 inches tends to be sufficient for the Girardinus Metallicus. This is a minimum of 10 gallons. However, a larger tank of up to 55 gallons can be chosen in case you wish to house a larger school of the breed or add in some tank mates with them.

Moreover, a larger aquarium will make it easier for you to care for the fish and give them more room to swim around. The species can actually feel stressed if confined to a limited space despite girardinus metallicus size. Also, make sure to secure the fish tank with a lid to prevent them from jumping out which they are likely to do if scared.

– Livebearer Tank Set Up

Girardinus metallicus tend to flaunt their best colors when kept in a dark bottomed fish tank decorated to match their natural habitat. It is, therefore, vital for aquarists to make sure that they include live plants as an important addition to the metallic livebearer tank. Such plants serve as both shelter and food for the fish.

You can also add a variety of floating and stemmed to plants as well as sandy or gravel substrate. This will help in keeping the aquarium environment as natural as possible.

Besides, male metallic girardinus can be quite aggressive in their pursuit of the opposite gender. It is, therefore, advisable to provide good hiding spots for the females for additional care by adding driftwood, rocks, and sticks.

– Ideal Water Conditions

Livebearer fish are inhabitants of brackish water bodies like lakes, streams, and ponds. Therefore, it is understandable that to provide utmost care, you need to ensure that the water should be medium hard, clear, well-oxygenated, and sluggish.

Here are the water parameters you should be adhering to for optimal Girardinus Metallicus care:

  • Temperature: 22-25°C
  • Hardness: Moderate
  • pH Levels: 6.0 – 8.0

Furthermore, you can easily create mild brackish water in the aquarium by adding in 2 tablespoons of marine salt for each gallon of water. Use a hydrometer to keep check of the desired range and ensure a weekly 50% water change. This will reduce nitrogenous waste in the aquarium and is crucial for their longevity.

Girardinus Metallicus Tank Mates: The Best Ones

Metallic Girardinus has a peaceful temperament and goes well with most other species. However, mixing it with tank mates of similar genes is not advisable as this is likely to result in hybridization of the black chin livebearer.

Also, considering girardinus metallicus size, you need to take special care of not including larger breeds in the same tank. Doing so will only result in all of your metallic fish falling prey to its bigger tank mates.

Here are some compatible species to serve as excellent tank mates for your girardinus metallicus:

Nonetheless, it is best to consult an expert before adding tank mates as the survival rate of different species varies in freshwater and brackish water aquariums. In case you intend to keep the fish with their own kind only, a ratio of 1 male every 3 females is suggested so as to prevent aggression.

Girardinus Metallicus Breeding

Livebearer fish can easily reproduce in captivity without additional help from their owner. All they require is a densely planted aquarium that has ample hiding spots for the newborns to hide before they can swim safely with the rest.

The male Girardinus Metallicus tilts its body to chase the female to fertilize it. Pregnant females can be recognized by a large dark spot that appears at the back of her belly as her abdomen enlarges in a couple of weeks.

Furthermore, the female metallic girardinus has the ability to store sperm for a year and lay fry in broods of 15 to 30, every 28 days without the need of insemination multiple times.

Regardless, pregnant metallic fish can be put in a breeder net in an attempt to save their fry from getting treated as food by other tank mates. A better option to take care would be to put the pregnant fish in another tank until it gives birth.

The parent fish may or may not become cannibalistic towards its babies. Hence, you can either scoop the fry into another tank or provide them with ample hiding places like Java Moss and floating plants to escape into.

Girardinus Metallicus Diet: What do they Eat?

Being omnivores, black chin livebearers need both meaty foods and plant matter in their diet to stay healthy. The best way to care for their diet in an aquarium set up is to rotate their daily feed, providing variations, and making sure not to overfeed. The ideal feeding regime for these creatures should be not more than twice daily.

They usually thrive on aquatic vegetation, algae, insect larvae, detritus, and diatoms in the wild, whereas in captivity they readily accept a diet of dry flake food, pellets and occasional live and frozen food such as daphnia, bloodworms, and brine shrimp as treats.


In this article, we have compiled all important facts related to Girardinus Metallicus care, tank mates, breeding, and diet. By now, you should have a clear idea of how to set up an aquarium or community tank for these docile metallic fish.

Here’s a quick summary of the guide, in case you missed anything above:

  • Black chin livebearerThe metallic girardinus is a native of Cuba and Costa Rica regions, mainly found in brackish water bodies such as streams, ponds, and lakes.
  • They make a charming addition to aquariums of size 10 gallons and up. The fish tank, however, should be densely planted to replicate their natural environment.
  • Livebearer Fish need moderate-hard water conditions to survive in, a temperate between 22 – 25°C, and an alkalinity level of 6.0 to 8.0.
  • It is essential to maintain a 50% water change in the fish tank every week to keep the water free from nitrogenous waste.
  • These brackish water fish do fairly well in moderately hard freshwater. Hence, their tank mates must be chosen accordingly to the water conditions and girardinus metallicus size.
  • Its best tank mates include rainbowfish, rasboras, tetra fish, bumblebee gobies, corydoras, and danios – among others.
  • The male fish chases the female to seek its consent for mating. It then takes approximately 28 days for the impregnated female to give birth.
  • It is vital for the aquarium to have sufficient hiding places for the fry to seek shelter until it is safe enough to swim with other tank mates. For optimal care, the pregnant females can also be put into a separate tank until they lay the eggs.
  • Girardinus metallicus are an omnivore species that prefer a high-protein diet, along with plant based food. They feed on aquatic plants, algae, larvae and diatoms in the wild and survive well on dried flakes, pellets, live and frozen food in aquariums.

All in all, these pretty little fish are bound to capture anyone’s attention with their shimmery sheen glistening from inside a perfectly set up fish tank. With their non-fussy temperament and easy care routine, these metallic fish are an excellent choice for beginner as well as experienced aquarists.

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