Trout Goodeid

Trout Goodeid (Ilyodon furcidens)

Also known as Mexclapique de Armería, Goldbreast Splitfin

A robust and attractively colored livebearing fish from the rivers and streams of Jalisco and Colima in western Mexico. Known for its distinctive yellow to orange “goldbreast” coloration on the belly and the males’ variable dark speckling and fin bands, this species is a favorite among goodeid enthusiasts. It is a strong swimmer that thrives in moderate to swift currents and makes an excellent choice for larger, well-oxygenated aquariums or outdoor tubs in warmer months.

Key Features

• Maximum Size: Up to 10.3 cm / ~4.1 inches SL.
• Appearance: Sturdy body with a greenish to grayish-brown back and a striking yellow to orange belly. Males are often more intensely colored, developing dark submarginal bands in the dorsal and caudal fins along with variable speckling or blotching on the body. Females are slightly larger and fuller-bodied. Males possess the characteristic goodeid splitfin (notch in the anal fin) and a larger dorsal fin.
• Fin Details: Males develop a noticeably larger and more ornate dorsal fin with the split anal fin typical of goodeids.

Aquarium Care

• Tank Size: Minimum 120 liters / ~30 gallons (larger preferred, low height recommended) for a group.
• Water Parameters: Cool to subtropical; 59–77°F (15–25°C), pH 7.0–8.5, moderate hardness. Moderate to swift current and high oxygen levels (>8 mg/L) are important. Provide gravel, rocks, roots, branches, and dense vegetation in corners for cover and grazing surfaces. A winter cooling period below 22°C helps regulate breeding.
• Diet: Primarily herbivorous grazer — readily accepts algae on rocks or décor, blanched vegetables (zucchini, spinach), and high-quality flake or pellet foods. Supplement with occasional live or frozen foods (brine shrimp, daphnia) for conditioning.
• Behavior: Peaceful, active, and not shy. Best kept in groups where they form schools and graze together. Live-bearing; females produce well-developed young. Fry survival is generally good with sufficient cover and food. Excellent for larger community tanks or species setups with other peaceful fish that appreciate current.

IUCN Status Least Concern (IUCN)

Average selling size: ~1.5"