The swordsman in nature lives in Central America, Southern Mexico and Guatemala. It occurs both in mountain rivers with rapid currents, and in their lower reaches, as well as in lakes, swamps, lagoons. Swordsmen belong to the Pizelia family. Life expectancy can reach 5 years. The name of the fish is due to the special structure of their body. Fishes reach a length of up to 10 cm, males are slightly smaller than females, have “swords” on the caudal fin, males also have a special copulative organ - gonopodia, formed from the anal fin. In aquariums, swordsmen grow to such sizes only under very good conditions. Introduced to Europe in 1907 and became one of the most common for breeding in aquariums.
The natural basic color of males is light brownish-olive, on the back with a greenish tint. A carmine-red two-millimeter strip runs along the sides, and two narrower red stripes below and above it. The body casts a silvery sheen. The long "sword" is painted in yellow, green, orange, reddish colors and has a clear black border. Females are larger, painted paler, do not have a “sword”. In adult females, a "maturity spot" located in front of the anal fin is clearly visible. The swordsman has a long, flattened laterally body. Body color is very bright and elegant. As a result of selection of the swordsmen, fish of different colors with fins of various shapes were obtained.
An interesting feature of these fish is the ability to change sex, depending on the conditions of detention and the sex ratio of individuals in the aquarium. With a shortage of males, females change sex and accordingly the appearance and functionality of the anal fin changes.
Swordsmen are not whimsical in terms of nutrition. These are omnivorous fish, it is necessary to include both plant and animal food in the diet. Of plant foods, daphnia, bloodworms, artemia, and others are usually used, and flakes with spirulina and special algae tablets are usually the plant component. Swordsmen eat well dry food. These fish are prone to overeating and obesity, therefore, for prophylactic purposes they are advised to have a hungry day every few days. The diet should not be too monotonous, it is worth giving both live food, for example mosquito larvae, and granular.
Maintenance and care
The optimal conditions for keeping in the aquarium are: temperature range 20-26С, water acidity 7-8рН, and water hardness within 6-20dH. The minimum volume of the aquarium is at least 50 liters per family of one male and several, usually 3-4, females. It is recommended to close the aquarium tightly with glass or net, as the fish are very active and can easily jump out of the water. It is good if the backlight is organized and a water filter is installed. Swordfish are peaceful fish, get along well with neighbors such as neons, thorns, guppies, zebrafish, tetras, and bottom non-aggressive fish. However, they should not be kept in the same aquarium with fish that have veil fins to avoid being bitten by swordsmen. It’s good if there are aquatic plants and snails in the aquarium that collect leftover food to prevent rotting of the water. However, in the absence of aggression towards other species, males can show intolerance and hostility towards each other and arrange fights that lead to death. Based on this, in one aquarium it is worth keeping either one male for three or four females, or several males (but more than two) for a sufficiently large number of females.
Swordsmen are viviparous fish, one act of fertilization is enough to give birth to 6 generations of fry! Puberty is completed by 5-6 months of age. The duration of the female’s pregnancy is 4-6 weeks; the pregnant female has a dark spot in the anal fin. At a time, from 15 to 100 fry are born. In order to preserve the offspring that adults are actively hunting for, it is advisable to plant the pregnant female in a separate container and return to the general aquarium after spawning. A pregnant female swordsman is placed a couple of days before birth in a separate container (aquarium, jar) with a large number of small-leaved plants located both at the bottom and on the surface of the water. A sufficient amount of algae will serve the fry as a shelter from their own mother, who is able to destroy them. After childbirth, the parent must be placed in a common aquarium from the children.
An interesting fact: swordsmen of various breeds, when crossed among themselves, can produce offspring of a new color and fin shape.