Fish Keeping and Aquascaping Blog

February 3, 2010

Keeping and Breeding The Swordtail Fish

Filed under: Uncategorized — Prabhu M @ 4:57 pm
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Hello. This is my post on keeping and breeding the swordtail fish. If you are new to the swordtail fish or if you are looking for more info on breeding and caring for the swordtail fish, then you have hit the right page.  This post will go over the profile and characteristics of the sword tail, and look at it’s care and requirements. I will also discuss about breeding them and raising their fry ( i.e. baby fish ).

The Swordtail fish ( scientific name : Xiphophorus helleri ) is one of the popular aquarium fish. The name Swordtail is derived due to the unique sword-like tail seen in adult males. These fish are very active in the aquarium, hardy and easy to keep and come in a variety of colour , hence making them a popular choice for newbie’s in Aquarium keeping.

Swordtail Male

Now let’s look at some of the common profile specification of the Swordtail :

a) Common Name : Swordtail fish
b) Scientific name : Xiphophorus helleri
c) Origin : Commonly found in the flowing waters of Central America
d) Preferred Water Temperature : 22C – 28C
e) Preferred pH of water : 7-9
f) Max Size : Can grow upto 4 inches in the aquarium
g) Compatible Tank Mates : Generally Peaceful. Hence suited for a community aquarium with non-aggressive tankmates.
h) Breeding Class : Livebearers ( i.e Swordtails do not lay eggs, but give birth to live young ones )

Swordtails found in the wild are generally green ( olive green ) in colour with the sword being yellow with black or brown borders. Cross Breeding in captivity by fish farms and hobbyist has given many strains of Swordtails with varying colours like red, red velvet, red wag tail, marigold, pineapple colour, black, etc . Different strains like Lyretail a.k.a. ‘Double Sword’ and ‘high fin’ are also available, giving the aquarist numerous options to choose from.

Swordtails are very active and lively in the aquarium and unlike other fish, move around all levels of the aquarium ( i.e. They can be seen moving in the bottom , middle and upper layers of the tank ). Hence you need to house them in an aquarium which has adequate swimming space. Higher activity in the aquarium leads to higher oxygen comsumption by the fish, and hence they need a well aerated aquarium . This is also seen from the fact that they are usually found in fast flowing streams of Central America, which are rich in dissolved oxygen.
Swordtails are good jumpers and could jump out of the tank when they are disturbed, stressed or scared. Hence it is advisable to keep your swordtails in a tank which has a cover ( hood ) and keep the tank in an area with minimal noise and disturbance. Keeping the tank in an area with minimal noise and disturbance is necessary to have stress free and healthy fish, irrespective of the kind of fish you house in your aquarium. Another trait I have noticed in my years of swordtail keeping is that they seldom jump in a planted tank. They get a sense of security in a well planted ( read densely planted ) tank, and hence are not disturbed or stress easily in a planted tank. I have lost quite a few fish due to their jumping habit whenever I forgot to put the cover on my breeding and grow-out tanks. On the contrary, I have seldom seen them jump in my display tank, which is heavily planted.

Sexing of the fish : Swordtails are sexually dimorphic, i.e. you can identify the sex of the swordtail fish by their external appearence. The male of the species develops a distinct ‘Sword’ in it tail fin as it matures, while the females do not. Also, the mature males show a distinct male sex organ near the anal fin, called the ‘Gonopodium’. It is through this gonopodium that the males deposit their sperms into the females during mating. The above two features are a sure shot way to distinguish a male swordtail from a female swordtail. Other differences are in their relative size, while the males are thinner and look elongated, the females are more round and grow a little larger and longer than the males.

Now, why am I talking about sexing the fish so early in the post. Shouldn’t it come under the breeding section ?! The reason for this is simple. Swordtail males tend to become territorial as they mature. When there are fewer females in the tank, the males tend to fight with each other for these females ( or rather for the ‘right’ to mate with them 🙂  ). Hence it is advisable to purchase more females than males when you visit your pet store. I know that this would mean fewer fancy sword’s since the females do not develop a sword, but that’s the least you can do for a peaceful aquarium . The generally accepted practice is to have 3 females for every male swordtail in an aquarium. Swordtail breeders generally have 5 females  for every male ( so as to keep the male always  busy 🙂 )

To be continued…….


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