Hoplisoma knaacki, more commonly referred to as Corydoras knaacki, is a species of Corydoras catfish. This species is named in honor of the ichthyologist Joachim Knaack. It's part of the diverse and popular Corydoras genus known for their peaceful nature and active behavior. Here's an overview of Corydoras knaacki:

Appearance

• Coloration: Corydoras knaacki typically has a light to medium gray body with distinctive black markings that often appear as spots or blotches along the sides and dorsal area. This pattern can vary among individuals, adding to their unique appearance.
• Size: They usually grow to about 2.5 to 3 inches (6 to 7.5 cm) in length, making them a medium-sized Corydoras species.

Behavior and Temperament

• Temperament: Corydoras knaacki are peaceful, social, and friendly fish, making them a great addition to community aquariums. They are non-aggressive and get along well with other small, peaceful fish.
• Social Behavior: They thrive in groups and should be kept in schools of at least 4-6 individuals. This helps them feel secure and encourages natural behavior, such as foraging and social interaction.

Tank Requirements

• Tank Size: A minimum of a 20-gallon (75 liters) tank is recommended for a small group of Corydoras knaacki. A larger tank will provide more space for swimming and better water quality.
• Substrate: A soft substrate, like fine sand or smooth gravel, is ideal to protect their sensitive barbels while they search for food on the tank floor.
• Water Conditions:
  • Temperature: 72-78°F (22-26°C).
  • pH: Slightly acidic to neutral, around 6.0-7.5.
  • Water Hardness: Soft to moderately hard water (2-12 dGH) is preferred.
• Aquascaping: Provide plenty of hiding spots with plants, driftwood, and rocks. Corydoras knaacki enjoys a well-decorated environment that offers both open swimming areas and sheltered spots.

Diet

• Omnivorous: Corydoras knaacki are omnivores and will readily accept a variety of foods. They should be fed a balanced diet of high-quality sinking pellets, along with live or frozen foods such as bloodworms, brine shrimp, and daphnia. Occasional vegetable matter can also be offered.

Summary

Corydoras knaacki (Hoplisoma knaacki) is a peaceful and active bottom-dweller that adds interest to a community tank. With proper care, including being kept in groups and provided with a suitable environment, they can thrive and display their full range of natural behaviors, making them a rewarding species for both beginner and experienced aquarists.