Xiphophorus hellerii — Golden Sunset Swordtail
Family: Poeciliidae
Origin: Central America — native to rivers and streams in Mexico, Belize, and Honduras
Size:
Males: Up to 12 cm (4.7 inches)
Females: Up to 15 cm (6 inches)
Lifespan: 3–5 years
 
Natural Habitat
Environment: Warm, slow to moderately flowing rivers, streams, and ponds with dense vegetation
Water Conditions: Clear or slightly turbid water with moderate current and plant growth
Temperature Range: 22–28°C (72–82°F)
 
Physical Description
Body Shape: Elongated and slender with a signature "sword" extension on the male's tail fin
Coloration:
Bright golden-yellow body with red and orange undertones
Often features sunset gradients on fins and body
Fins: Extended lower caudal fin ray in males; females lack the swordtail but are larger-bodied
Note: This is a selectively bred color variant of the wild-type Swordtail, prized for its vivid golden hues and peaceful nature.
 
Aquarium Care
Tank Size: Minimum 75 litres (20 gallons); larger for mixed groups
Water Parameters:
pH: 7.0–8.3
Hardness: Moderate to hard (10–30 dGH)
Temperature: 22–28°C (72–82°F)
Water Flow: Moderate
Substrate: Fine gravel or sand
Décor: Planted tanks with open swimming areas; floating plants and hiding spots recommended
Filtration: Standard with good surface agitation
 
Diet
Type: Omnivorous
Preferred Foods:
High-quality flakes, micro pellets, spirulina-based foods
Frozen or live brine shrimp, bloodworms, daphnia
Blanched spinach or zucchini as occasional treats
Feeding Frequency: 1–2 times daily
 
Behavior & Tank Mates
Temperament:
Peaceful and social
Males can be mildly territorial with each other
Compatible Tank Mates:
Other livebearers (platies, mollies), tetras, Corydoras, rasboras, danios
Avoid aggressive or fin-nipping species
Behavior Notes:
Enjoy swimming in upper and mid levels of the tank
Best kept in groups with a ratio of 2–3 females per male
 
Breeding
Spawning Method: Livebearer
Breeding Conditions:
No special triggers needed; prolific breeders
Provide plants or hiding areas for fry
Fry Care:
Gestation: ~28 days
Fry are free-swimming at birth and can be fed crushed flakes or baby brine shrimp
Separate fry from adults to increase survival rate
 
Conservation Status
IUCN Status: Not Evaluated (wild-type populations)
Notes: A colorful and hardy choice for both beginner and experienced aquarists. Their vibrant coloration and lively behavior add energy to any community aquarium