Hastatus Cory Catfish – Corydoras hastatus

The Hastatus Cory Catfish (Corydoras hastatus) is one of the smallest and most fascinating Cory-type catfish in the freshwater aquarium hobby. Its miniature adult size, peaceful temperament, active schooling behavior, and distinctive tail marking make it an excellent choice for planted community aquariums featuring other small, peaceful fish.

Also known as the Tail Spot Pygmy Cory, Tail Spot Cory, Dwarf Corydoras, or Pygmy Cory Catfish, this species has a slender silver-gray body and a bold dark spot at the base of the tail surrounded by a lighter area.

Unlike many traditional Cory catfish that spend most of their time directly on the substrate, Corydoras hastatus frequently swims in open water. A healthy school may hover around plants, move together through the middle of the aquarium, and then return to the substrate to forage.

Taxonomy note: This species has traditionally been known throughout the aquarium hobby as Corydoras hastatus. Under newer scientific classification, the accepted combination is Gastrodermus hastatus. Both names refer to the fish commonly sold as the Hastatus Cory Catfish.

Hastatus Cory Catfish Care Information

What Does a Hastatus Cory Catfish Look Like?

The Hastatus Cory Catfish has a tiny, streamlined body that is generally translucent silver, gray, or light olive. Its subtle coloration helps the species blend naturally into planted freshwater environments.

The most recognizable feature is the bold black spot at the base of the tail. This dark marking is typically bordered by a pale or whitish crescent, creating a high-contrast tail pattern that gives the species its common name, Tail Spot Pygmy Cory.

Hastatus Corys also have relatively large eyes, a forked tail, and a more streamlined body shape than many bottom-oriented Cory species—features that suit their unusually active midwater lifestyle.

Why Is It Called the Tail Spot Pygmy Cory?

The common name Tail Spot Pygmy Cory comes from the distinctive black marking located at the base of the tail. The specific name hastatus refers to a spear-like shape, describing the appearance of the dark caudal marking.

This tail spot is one of the easiest ways to distinguish Corydoras hastatus from other dwarf Cory species such as Corydoras pygmaeus and Corydoras habrosus.

Do Hastatus Corys Swim in Midwater?

Yes. Corydoras hastatus is unusually adapted for midwater swimming compared with most traditional Cory species.

A group may hover together around plants, swim through open areas, rest on leaves, and form small schools several inches above the substrate. They still forage along the aquarium floor, but they spend a significant amount of time away from the bottom.

Their relatively large eyes, more terminal mouth position, streamlined body, and strongly forked tail are all associated with this more open-water lifestyle.

Hastatus Cory vs. Pygmy Cory

The Hastatus Cory (Corydoras hastatus) and Pygmy Cory (Corydoras pygmaeus) are separate dwarf Cory species, although both frequently swim above the substrate.

Hastatus Corys are most easily recognized by the large black spot at the base of the tail. Standard Pygmy Corys instead display a prominent dark horizontal stripe extending along much of the body.

Both species remain very small and display active schooling behavior, making them popular choices for aquarists interested in miniature Cory catfish.

Hastatus Cory vs. Dwarf Salt and Pepper Cory

Hastatus Corys also differ from the Dwarf Salt and Pepper Cory (Corydoras habrosus).

Corydoras habrosus has a more traditional Cory body shape with dark mottled markings and spends considerably more time directly on the substrate. Hastatus Corys are more streamlined, have a distinctive tail spot, and spend much more time swimming in open water.

Hastatus Cory Behavior & Group Size

Hastatus Corys are peaceful, highly social schooling fish and should not be kept alone. We recommend keeping at least 6 Hastatus Cory Catfish, with 10 or more preferred whenever aquarium space allows.

Larger groups generally encourage more confident behavior and create a much more natural-looking display. A healthy group may move together between the substrate, aquarium plants, and open midwater areas throughout the day.

Because Hastatus Corys are extremely small, they should not be housed with large or aggressive fish that may view them as prey or consistently outcompete them for food.

Like other Cory-type catfish, they may occasionally make a quick trip to the surface to gulp atmospheric air before returning to the group. Occasional surface visits are normal Cory behavior.

Ideal Aquarium Setup for Hastatus Cory Catfish

Although Hastatus Corys are tiny, they are active schooling fish and benefit from significantly more swimming space than their body size might suggest. An aquarium around 15 gallons or larger with a footprint of approximately 24 × 12 inches or greater is recommended.

A fine sand substrate is ideal, although smooth rounded fine gravel can also be used when kept very clean. These fish still spend part of their time foraging along the substrate with sensitive barbels.

Live plants are especially useful for Hastatus Corys. Dense planted areas, floating plants, driftwood, and shaded sections provide security, while open spaces between plants allow the group to display its characteristic midwater schooling behavior.

Are Hastatus Corys Good for Nano Aquariums?

Hastatus Corys are often described as nano fish because of their tiny adult size, but extremely small nano aquariums are not ideal.

These fish need room for a proper social group and enough horizontal space to school through the water column. A longer aquarium around 15 gallons or larger is generally a better choice than very small desktop tanks.

When planning an aquarium for Hastatus Corys, prioritize swimming footprint and group size rather than choosing the smallest possible tank based only on the fish's body length.

Hastatus Cory Water Parameters

Hastatus Cory Catfish generally do well at temperatures around 68–79°F (20–26°C) with a pH of approximately 6.0–7.5.

More important than constantly adjusting the aquarium to reach one exact number is maintaining clean, stable water conditions. Keep Hastatus Corys in a fully cycled aquarium with appropriate filtration, good oxygenation, and regular water changes.

Because these fish are very small, deteriorating water conditions can affect them quickly. Ammonia and nitrite should remain at zero, and sudden changes in temperature or water chemistry should be avoided.

What Do Hastatus Cory Catfish Eat?

Hastatus Corys are omnivorous micro-foragers and should receive a varied diet containing appropriately sized foods.

Small sinking pellets and finely sized prepared foods can form part of the diet, but this species also naturally feeds in the water column and benefits from small live or frozen foods.

Suitable foods may include:

• Baby brine shrimp
• Small live or frozen daphnia
• Microworms
• Finely sized bloodworms
• Small sinking micro pellets
• Other appropriately sized micro foods

Hastatus Cory Tank Mates

The peaceful personality of the Hastatus Cory Catfish makes it an excellent option for carefully planned freshwater community aquariums containing other small, peaceful species.

Potential tank mates may include nano rasboras, small peaceful tetras, small pencilfish, peaceful dwarf fish, other compatible dwarf Cory species, and freshwater shrimp in appropriately planned aquariums.

Avoid large predatory fish, aggressive species, and highly competitive feeders. Even otherwise peaceful larger fish may intimidate these tiny Corys or prevent them from receiving enough food.

Why Choose Hastatus Cory Catfish?

• Tiny adult size of approximately 1–1.3 inches
• Distinctive black tail spot with pale border
• Unique bottom-to-midwater schooling behavior
• Peaceful temperament for small community aquariums
• Excellent choice for planted freshwater setups
• Active schooling behavior when maintained in a proper group
• Interesting alternative to Pygmy Cory and Habrosus Cory
• One of the most distinctive dwarf Cory species

Hastatus Cory Catfish FAQ

What is a Hastatus Cory Catfish?

Hastatus Cory is a tiny South American Cory-type catfish traditionally known as Corydoras hastatus. It is recognized by its small size, distinctive black tail spot, peaceful temperament, and frequent midwater schooling behavior.

Is Corydoras hastatus now Gastrodermus hastatus?

Yes. Corydoras hastatus is the traditional scientific name and remains widely used in the aquarium trade. Under newer scientific classification, the currently accepted combination is Gastrodermus hastatus.

How big do Hastatus Cory Catfish get?

Adult Hastatus Corys generally reach around 1–1.3 inches, making them one of the smallest Cory-type catfish commonly kept in freshwater aquariums.

How many Hastatus Corys should be kept together?

Keep Hastatus Corys in a group of at least 6 fish. Groups of 10 or more are preferred when aquarium space allows and can encourage stronger schooling and more confident behavior.

What temperature is best for Hastatus Corys?

A general recommended aquarium temperature range for Hastatus Corys is approximately 68–79°F (20–26°C), with a pH around 6.0–7.5.

Do Hastatus Corys swim in the middle of the aquarium?

Yes. Hastatus Corys spend a significant amount of time swimming away from the substrate. They frequently school through the lower and middle portions of the aquarium and may hover around plants or open-water areas.

Is Corydoras hastatus the same as Corydoras pygmaeus?

No. Hastatus Cory and Pygmy Cory are separate species. Hastatus Corys are most easily recognized by the prominent black spot near the base of the tail, while Pygmy Corys typically display a dark horizontal stripe running along much of the body.

Is Corydoras hastatus the same as Corydoras habrosus?

No. Corydoras habrosus is the Dwarf Salt and Pepper Cory and spends much more time directly on the substrate. Hastatus Corys have a distinctive tail spot and are considerably more adapted to midwater schooling.

Can Hastatus Corys live in a nano aquarium?

Despite their tiny size, Hastatus Corys are active schooling fish and should not be crowded into extremely small nano tanks. An aquarium around 15 gallons or larger with a footprint near 24 × 12 inches gives a proper group much more useful swimming and schooling space.

Are Hastatus Cory Catfish peaceful?

Yes. Hastatus Corys are very peaceful social fish and work well with other small, non-aggressive freshwater species that share compatible water conditions.

What do Hastatus Cory Catfish eat?

Hastatus Corys are omnivorous micro-foragers. Feed appropriately sized prepared foods along with small live or frozen foods such as daphnia, baby brine shrimp, microworms, and finely sized bloodworms.

Where do Hastatus Cory Catfish come from?

Hastatus Corys have a broad South American distribution and are found within the Amazon and Paraguay River basins, including populations in countries such as Brazil, Bolivia, Paraguay, Argentina, and Uruguay.

Do Hastatus Corys clean the aquarium?

Hastatus Corys naturally forage for small foods around the aquarium, but they should not be considered aquarium maintenance animals. They require intentional feeding with appropriately sized foods along with regular water changes and normal substrate cleaning.