Corydoras hastatus is also called Diamond Tail Cory and Dwarf Cory. In Latin Hastatus means spear-shaped. It belongs to the subfamily Corydoradinae of the family Callichthyidae. It is originally found in South Africa, Amazon, Brazil, and Paraguay.
Its habitats include marginal channels, swamps, blackwaters, floodplain lakes, and smaller water canals with shallow, clear, or murky environments with substrates of clay and mud. Corydoras hastatus lives in waters with no vegetation and also waters with a dense growth of aquatic or floating plants.
The body of Corydoras hastatus is usually more extended than other Corydoras species. Its color is glowing white to olive. Some individuals of this species have a thin black stripe on the sides from behind the head to the tail. Its belly is white and has a white crescent at the base of the tail and a black spot inside it.
Corydoras hastatus can grow in length up to 1.4 inches (3.5 cm), but the average length reaches only 1.0 inches (2.5 cm). Its body is covered with boney plates instead of scales like in the other catfish species. It has two rows of bony plates going down each side and two large plates cover its head. That’s why they are called ‘armored’ fish.
It has a very sharp barb right under each eye, and a large one in front of its dorsal fin. This helps the fish to defend itself from predators. This barb contains a poison gland that causes a sting like a jellyfish. It gives a lot of pain to the stung predator.
Male Corydoras hastatus are smaller than females; their bodies are slim and light and their dorsal fins are more pointed than females.
Females usually grow larger. They become sexually mature before the males and after growing into adults, their bodies become broader and larger than males.
Corydoras hastatus has a very strong sense of smell which lets them find the food particles buried in the sand at the bottom of the tank. Moreover, their eyes are different than common fish which never blink. These fish are known to ‘blink’ their eyes and one can observe them blinking. They also can tilt their eyes down to check the substrate for food.
Behavior and Compatibility
Corydoras hastatus is a social and peaceful fish. That is why they need to be kept in a group of at least 4-6 individuals. The ideal number is 10 or over for this fish to feel safe and no stress.
Selection of tankmates should be made among those which are not aggressive species. The small size of the male Corydoras hastatus makes it not matching with larger aquarium fish in the limited environment of a tank. They can easily become prey for larger fish or get hurt seriously.
Fish of small size that mostly swim on the surface or in mid-water would be a good choice as tank mates. Danios, small rasboras, hatchet fishes, pencil fishes, lamp-eye killifish, and the blue-eye rainbowfish are all peaceful tank mates which are also convenient. Several small characins naturally living in the same habitat of the Corydoras hastatus would also do well in a community tank.
pH: 6.0 – 7.5
Temperature: 20 – 26 °C
Hardness: 2-11 dGH
Proper Tank Conditions
A tank with 60 cm by 30 cm dimensions should be dedicated if a population of 6 to 12 Corydoras hastatus will be present. The substrate with fine sand or small gravel should be well maintained. Sharp and large gravel can lead to injuries in Corydoras hastatus and if their barbs are injured and infected they face difficulty in finding food. In most cases, that kind of injury leads to death in Corydoras fish due to infections and starvation. Corydoras hastatus do not live in salty water. Therefore the tank water should not be let go salty or no salt should be added. The tank could be well planted with pieces of bogwood and also different types of large leave plants such as Cryptocoryne plants to feel relaxed and safe.
During the spawning season, the tank water should be maintained more acidic, softer with lower alkalinity. This would reduce the percentage of infertile eggs increase the survival rate of the fry after hatch.
Corydoras hastatus is easy to keep and breed fish. All three types of miniature cories will eat just about anything tiny enough to fit in their mouths and sinks to the bottom of the tank.
Corydoras hastatus are carnivorous and eat small size crustaceans in nature. In the aquarium, they will eat brine shrimp, small size bloodworms, tubifex worms, grindal worms, daphnia, and other small size crustaceans. They also eat any dead shrimp or shrimp fry in the tank. Catfish pellets or wafers and protein-rich flake foods are good choices since they sink to the bottom. It should be noted that vegetable-based food is not suitable for Corydoras hastatus.
Frozen foods of tiny size live foods would be a good choice such as frozen copepods, frozen baby brine shrimp, rotifers, and other tiny foods. Also, micro worms could be chosen since they are easy to breed and their size is excellently fitted Corydoras hastatus.
A combination of a variety of foods rather than just a single type of food every day would be preferable. Hobbyists recommend feeding newborn Corydoras hastatus fry with 100 percent live foods (microworms, vinegar eels, or newly hatched brine shrimp) which is essential for healthy growth. On the other hand, adults and juveniles can eat baby brine shrimp, flakes, micro worms, and small size pellet foods.
The breeding of Corydoras hastatus is not complicated. A ratio of two or more males for each female should be maintained for the best fertilization. When the females are ready with eggs, 50 to 70 percent of the tank water should be changed with cooler and softer water (3 to 5 °C cooler), aeration and water flow in the tank should be increased to induce the spawning by replicating their natural habitat.
Spawning starts with the male fish chasing one another while the male competes for a position with another. The winning male mates with the female several times. After each spawning session one or two eggs are laid. Once the spawning started in a breeding tank, more pairs of fish also form and start spawning at the same time.
A few drops of methylene blue should be added to protect the eggs from the fungus after spawning. The eggs will hatch after 3 to 4 days according to the water temperature. The fry can eat live food like micro worms, daphnia moina, rotifers, protozoans, etc. The fry are not very easy to take care of but are less susceptible to sicknesses. Even in a community tank planted well with proper hiding spots, the fry will start appearing suddenly without any extra care.
Many hobbyists separate the fry from the adults to give them more chances to grow into adults safe and healthy with proper feeding. But, as long as the adults are fed sufficiently, they would not prey on young fish and can be kept together with the newly hatched fry.