|
|
|
Livebearers
/ Poeciliidae / Swordtail
Swordtail
Xiphophorus helleri | Pictures
Synonyms: Mollienisia
helleri,
Xiphophorus brevis,
X. jalapae,
X. rachovii,
X. strigatus
Physical description: The Swordtail is an elongated species with a slender body.
Males possess a characteristic, sword-like
appendage formed by the lower rays of the caudal fin.
The original form imported to the hobby has an olive green back with
greenish-yellow flanks.
A reddish stripe, bordered by greenish areas, extends from the the snout to the caudal
fin.The
fins are greenish, while the sword is variable.
Most Swordtails available today differ in coloration do to years of
selective breeding.
Size/Length: Males to 4" (10 cm), females to 4.7" (12 cm)
Similar species: Other Xiphophorus
species
Habitat: Occurs in a wide range of habitats in Central America; Mexico, Guatemala, Belize,
and Honduras.
S: all
Aquarium: A tank measuring 20" (50 cm) with a capacity of 10 gallons (38 L) is only suitable
for young fish under 2.8" (7 cm) in length.
If adult fish are kept in a tank this size, aggressive tensions may
be present.
A 28" (71 cm) tank with a volume from 20-25 gallons (76-95 L) is more suitable.
Leave
open swimming areas and use planting along the back and edges of the tank.
A cover of floating plants can be used
to provide refuge for fry.
Water chemistry: pH 7.0-8.3 (7.3), 10-30 dH (15), 68-82°F (20-28°C)
Social behavior: A fish recommended for a community tank having fish that can tolerate neutral to alkaline
water conditions.
Older individuals, especially males, will become combative in cramped conditions.
It
is best to keep one male with two or three females.
Suggested companions: Colisa
, Trichogaster
, other Xiphophorus
, Corydoras
, loricarids, tetras tolerant of hard water
FOOD: Flake; small pellets; live; worms, crustaceans, insects, insect larvae.
SEX: Males are smaller, possess a gonopodium, and have a sword-like appendage on the caudal
fin.
Breeding techniques: After a gestation period of four to six weeks, the mother gives birth to 50-120 young.
Suggest
separating the pregnant female from other fish.
The fry are eagerly consumed by the parents and other fish.
The
fry measure about 0.3" (8 mm) when they are born, and grow quickly.
Breeding potential: 3.
An easily bred fish, although the young are hard to protect unless a breeding trap or other
means of refuge is used.
Remarks: Many different color morphs are available including red, green, red-eyed, albino, neon,
Lyre-tail,
Wag tail, Simpson, and the Tuxedo.
Besides these many cultivated forms, there are a number of separate
wild populations with varying colors and patterns.
Swordtails are known for undergoing "sex-reversals," when
females appear to become males.
This occurs most commonly to to five months after birth and in old females.
When
this change occurs early in life, a male is simply going through late development.
Sometimes old females develop male characteristics
after they are no longer fertile.
Difficulty of care: 1.
Swordtails are fish that are suitable for a beginner's community tank.
Recent articles about fish
Overfishing may hurt Amazon forest trees
(2/5/2008) Overfishing is reducing the effectiveness of seed dispersal by fish in the Brazilian Pantanal, reports Nature. The research suggests that fishing practices can affect forest health.
Scientists find fish that literally lives in trees
(10/17/2007) Scientists have found a fish that literally lives in trees, according to research published in The American Naturalist and highlighted in New Scientist Magazine.
Piranhas originated when Amazon was flooded by seawater
(12/4/2007) South America's piranha family of fish -- notorious as eaters of flesh -- can be traced back to a single ancestor which dispersed when the Amazon was flooded by seawater some five million years ago, report researchers from the Institut de Recherche Pour le Developpement (IRD). Today piranhas are exclusively freshwater fish found from the Orinoco River basin in Venezuela to the Parana in Argentina.
|
|
|
