CW009 Green Laser Cory (Osteogaster sp.)

Common Name

Green Laser Cory
Also known as Green Stripe Cory and Peru Green Stripe

Scientific Name and Label Usage

Most sellers list this fish as Corydoras aeneus “Green Stripe” CW009 or Corydoras sp. CW009. The CW009 code is a community placeholder for an undescribed but distinct Peruvian lineage closely related to the aeneus group. Keeping the CW009 tag preserves the identity of this specific green-striped population and avoids confusion with other domestic green forms.

Origin and Habitat

Wild specimens come from Peru, primarily the Marañón and Ucayali river systems near Iquitos and Pucallpa. They inhabit quiet tributaries, flooded forest margins, and soft sandy runs under heavy shade with abundant leaf litter and submerged wood. Water is typically soft and mildly acidic. The signature neon-green stripe glows brilliantly against dark leaves and fine sand.

Temperature and Water Conditions

Preferred range: 74–77 °F (23–25 °C). Tolerates 70–80 °F (21–27 °C) when oxygen is high. Wild pH usually 6.0–7.2. In captivity, stability is far more important than exact wild values (except for dedicated breeding). Use soft silica sand to protect barbels, strong filtration with gentle to moderate flow, and good surface agitation for oxygen.

Appearance and Size

Base color olive to bronze with a subtle metallic sheen. The vivid electric-green dorsal stripe—from snout to caudal peduncle—is the star feature and intensifies dramatically under aquarium lighting as the fish settle in. Adult size: 6–7 cm (2.25–2.75 in). Females are deeper-bodied; males are slightly slimmer. Fresh imports often appear muted until well-fed and relaxed.

Diet in the Wild

Sand-sifting micropredator that forages insect larvae, tiny worms, microcrustaceans, and organic detritus in leaf litter—very similar to other aeneus-group members.

Feeding in Captivity

Daily staple: quality sinking micro-pellets and wafers. Several times weekly offer live/frozen baby brine shrimp, daphnia, cyclops, and finely chopped blackworms to boost color and condition. Feed small amounts the school can finish quickly. A thin layer of fine sand encourages natural sifting behavior and keeps barbels healthy.

Behavior and Tank Setup

Peaceful, highly social bottom-dwellers—best kept in groups of 6 or more (larger groups show more confidence and activity).

• Tank size: 20-gallon long or larger
• Substrate: soft silica sand
• Décor: leaf litter, driftwood, shaded plant clumps
• Flow: gentle to moderate with strong oxygenation

Compatible with any small, peaceful community fish that won’t outcompete them for food.

Breeding

Overview & Conditioning

CW009 spawns like aeneus but is often more selective and less prolific. Many breeders find very soft, tannin-rich water and seasonal cues essential. Separate sexes for a week, feed heavily with live/frozen foods, then perform several small, slightly cooler water changes at 74–75 °F (23–24 °C) to simulate rains.

Spawning Sites

Provide fine-leaved plants, yarn mops, and clean glass panes. Females deposit adhesive eggs on these surfaces while males fertilize in the classic T-position.

Incubation & Fry Care

Parents may eat eggs—move eggs to a small hatching box with matching water, gentle air stone, and a touch of tannin (methylene blue optional). Eggs hatch in 3–5 days at breeding temperature. Start fry on infusoria or fine powdered food, then transition to newly hatched brine shrimp and microworms. Maintain pristine water with tiny, frequent changes and high oxygen.

Seasonal Push

Green Lasers often respond strongly to a series of soft, cooler water changes and lower conductivity—especially wild-caught or recent descendants.

Quick Facts

• Scientific label: Corydoras aeneus “Green Stripe” CW009 / Corydoras sp. CW009
• Origin: Peru – Marañón & Ucayali drainages
• Adult size: 6–7 cm (2.25–2.75 in)
• Temperature: 74–77 °F (23–25 °C) preferred
• Wild pH: 6.0–7.2; stability key in captivity
• Temperament: peaceful schooling bottom-dweller
• Diet: sand-sifting micropredator; quality sinking foods + live/frozen supplements
• Breeding: adhesive egg-layer; often needs soft, tannin-rich water and seasonal cues

Tropical Fish Co. Notes

Rarity and specialness. This is one of those fish that stop people in their tracks—the stripe really does glow, and it looks even wilder over dark leaves and wood. True CW009 groups are still wild-collected from Peru and arrive in waves. If you breed them, think rainy season, keep meticulous records, and enjoy the ride. When a school of Green Lasers cruises across the front glass like a neon parade, you remember exactly why you keep Corys.