Black-Winged Hatchetfish

Black-Winged Hatchetfish

Table of Contents


The Black-winged hatchetfish, scientifically known as Carnegiella marthae, is a fascinating species that belongs to the family Gasteropelecidae. These small freshwater fish are native to the Amazon River basin in South America. They are known for their unique physical characteristics and interesting behavior, making them a popular choice among aquarium enthusiasts.

Studying the Black-winged hatchetfish is of great importance in the context of the aquarium industry and fish enthusiasts. These fish possess distinct features and behaviors that make them captivating to observe and study. By understanding their biology, habitat requirements, and conservation status, we can ensure their well-being in captivity and contribute to their conservation in the wild.

In this article, we will delve into the various aspects of the Black-winged hatchetfish, shedding light on their taxonomy and classification, habitat and distribution, behavior and adaptations, threats and conservation, research studies, importance in the aquarium trade, and the significance of conserving this unique species. By exploring these topics, we hope to deepen our understanding of the Black-winged hatchetfish and promote its conservation for future generations.

Taxonomy and Classification

Scientific classification of the Black-winged hatchetfish

The Black-winged hatchetfish, scientifically known as Carnegiella marthae, belongs to the Animalia kingdom, Chordata phylum, Actinopterygii class, Characiformes order, Gasteropelecidae family, Carnegiella genus, and marthae species. This classification places the Black-winged hatchetfish within the broader group of ray-finned fishes, specifically in the order Characiformes, which includes other popular aquarium fish such as tetras and piranhas.

Description of its physical characteristics

The Black-winged hatchetfish is a visually striking species with unique physical features. It has a slender, laterally compressed body shape that resembles the shape of a hatchet, hence its common name. The average size of an adult Black-winged hatchetfish ranges from 2 to 2.5 inches (5 to 6.5 centimeters) in length.

One of the most distinctive characteristics of the Black-winged hatchetfish is its coloration. The body is primarily silver or pale yellow, with a dark horizontal stripe running along the midline of the body. This stripe is bordered by iridescent blue or green pigmentation, which adds to the fish’s overall beauty. The dorsal fin is elongated and extends from the middle of the body to the caudal fin, giving the fish its unique hatchet-like appearance.

Comparison with other species of hatchetfish

The Black-winged hatchetfish shares similarities with other species of hatchetfish, but it also possesses some distinguishing features. One notable comparison can be made with the Silver hatchetfish (Gasteropelecus sternicla), which is another popular species in the aquarium trade.

While both species have a similar body shape and size, the Black-winged hatchetfish can be easily distinguished by its coloration. The Silver hatchetfish has a more uniform silver coloration without the distinct dark stripe and iridescent borders found in the Black-winged hatchetfish. Additionally, the dorsal fin of the Silver hatchetfish is shorter and does not extend as far back as that of the Black-winged hatchetfish.

Another species that can be compared to the Black-winged hatchetfish is the Marbled hatchetfish (Carnegiella strigata). The Marbled hatchetfish has a similar body shape and size, but its coloration is characterized by a marbled pattern of brown and silver, rather than the distinct dark stripe of the Black-winged hatchetfish.

These comparisons highlight the unique visual characteristics of the Black-winged hatchetfish and its distinctiveness among other species of hatchetfish. Its vibrant coloration and elongated dorsal fin make it a visually appealing choice for aquarium enthusiasts.

Overall, understanding the taxonomy and physical characteristics of the Black-winged hatchetfish provides a foundation for further exploration of its habitat, behavior, and conservation status. By delving into these aspects, we can gain a comprehensive understanding of this captivating species and its significance in the world of aquatic life.

Habitat and Distribution

Natural habitat of the Black-winged hatchetfish

The Black-winged hatchetfish, scientifically known as Carnegiella marthae, primarily inhabits freshwater habitats in South America. These habitats include slow-moving rivers, streams, and flooded areas within the Amazon River basin. The hatchetfish specifically thrives in calm, shaded areas such as the edges of rivers and flooded forests.

The species shows a strong preference for habitats with dense vegetation, which provides them with cover and protection from predators. They are often found in areas with overhanging vegetation, submerged branches, and floating plants, which offer hiding spots and shade. These habitats also provide a source of food, as they are home to various insects and small invertebrates that the hatchetfish feed on.

Geographic distribution and range

The Black-winged hatchetfish is native to the Amazon River basin in South America, with a distribution that spans several countries, including Brazil, Peru, Colombia, and Venezuela. Within these countries, they can be found in various tributaries and smaller rivers that flow into the Amazon River.

Specifically, they are commonly found in the blackwater rivers and floodplains of the Amazon basin, where the water is typically acidic and stained brown due to the presence of tannins from decaying organic matter. These unique environmental conditions contribute to the overall biodiversity of the region and provide a suitable habitat for the Black-winged hatchetfish.

Factors influencing habitat preferences

The Black-winged hatchetfish is highly adapted to its natural habitat, and several factors influence its habitat preferences. One crucial factor is water quality. They thrive in soft, acidic water with a pH ranging from 5.0 to 6.5. The presence of tannins in the water, which gives it a brownish tint, is also preferred by the hatchetfish.

Another important factor is temperature. The Black-winged hatchetfish prefers water temperatures between 24°C and 28°C (75°F to 82°F). These temperatures are typical of the tropical climate found in the Amazon basin. They are well-suited to these warm waters and are not tolerant of drastic temperature fluctuations.

The availability of suitable food sources also influences their habitat preferences. The Black-winged hatchetfish primarily feeds on small insects, such as mosquitoes and flies, as well as other small invertebrates. Their habitats, which are rich in vegetation and offer ample opportunities for foraging, provide them with a consistent food supply.

Additionally, the presence of vegetation and shaded areas in their habitat is crucial for their survival. The hatchetfish rely on these areas for protection from predators and to mimic their natural environment. The dense vegetation also provides them with a platform for their unique hunting behavior, where they leap out of the water to catch insects above the surface.

In conclusion, the Black-winged hatchetfish is a species that is specifically adapted to the calm, shaded areas of freshwater habitats in South America. Their preference for soft, acidic water, warm temperatures, and the presence of vegetation highlights their specialization to the unique conditions of the Amazon River basin. Understanding their habitat preferences is essential for their conservation and for creating suitable environments in captivity.

Behavior and Adaptations

Feeding habits and diet

The Black-winged hatchetfish is primarily a carnivorous species, with a diet consisting mainly of small aquatic insects and invertebrates. They are known to feed on mosquito larvae, small crustaceans, and even small fish fry. Their unique body shape, with an elongated and flattened body, allows them to skim the water surface and snatch prey from above.

Studies have shown that the Black-winged hatchetfish has a preference for live food, especially small insects that are found near the water surface. This behavior is believed to be a result of their natural adaptation to their habitat, which often includes densely vegetated areas with overhanging branches or leaves. By feeding on insects at the water surface, the Black-winged hatchetfish can avoid predators that lurk in the deeper parts of the water.

Reproduction and mating behavior

The Black-winged hatchetfish exhibits interesting reproductive behaviors. During the breeding season, males engage in elaborate courtship displays to attract females. These displays involve the males displaying their vibrant colors and flaring their fins to impress potential mates. The males also perform acrobatic jumps and twists in the water, showcasing their agility and strength.

Once a female is attracted, the pair engages in a unique spawning behavior. The female lays adhesive eggs on the underside of floating leaves or other surfaces near the water surface. The male then fertilizes the eggs by releasing sperm over them. This strategy of laying eggs near the water surface is believed to provide protection from predators that inhabit the deeper parts of the water.

Unique adaptations for survival

The Black-winged hatchetfish possesses several unique adaptations that allow them to thrive in their natural habitat. One of their most remarkable adaptations is their ability to glide above the water surface. Their elongated pectoral fins act as wings, allowing them to make short flights above the water to escape predators or catch prey. This adaptation gives them an advantage in their densely vegetated habitat, where they can quickly navigate through narrow gaps between branches or leaves.

Another adaptation of the Black-winged hatchetfish is their ability to breathe atmospheric air. They possess a specialized organ called the labyrinth organ, which allows them to extract oxygen from the air. This adaptation is crucial for their survival in oxygen-depleted waters or during periods of drought when the water level may decrease. By breathing atmospheric air, they can supplement their oxygen intake and survive in challenging conditions.

Social behavior and interactions with other species

The Black-winged hatchetfish is a highly social species that forms large shoals or schools in the wild. This schooling behavior serves multiple purposes, including predator avoidance, increased foraging efficiency, and mate selection. By swimming in a group, they can confuse predators and decrease the likelihood of being targeted. It also allows them to find food more effectively by collectively searching for prey and sharing information about food sources.

Furthermore, the schooling behavior of the Black-winged hatchetfish plays a role in mate selection and courtship. Males within a school compete for the attention of females through their courtship displays, and the presence of a larger school increases the chances of successful courtship and mating. The social interactions within the school also contribute to the overall well-being of the species, as individuals can learn from each other and benefit from collective defense mechanisms.

In addition to their interactions within their own species, the Black-winged hatchetfish also interact with other species in their habitat. They are known to engage in mutualistic relationships with certain species of floating plants. The fish provide protection to the plants by consuming algae and other organisms that may harm the plants, while the plants provide shelter and camouflage for the fish. These interactions highlight the complex ecological relationships that exist within their habitat.

Overall, the behavior and adaptations of the Black-winged hatchetfish demonstrate their remarkable ability to survive and thrive in their natural habitat. Their feeding habits, reproductive behaviors, unique adaptations, and social interactions all contribute to their success as a species. Understanding these aspects of their behavior is crucial for their conservation and for ensuring their continued presence in the aquarium trade.

Threats and Conservation

Overview of the threats faced by the Black-winged hatchetfish

The Black-winged hatchetfish (Carnegiella marthae) faces several threats in its natural habitat, which have contributed to its declining population. One of the primary threats is habitat destruction. The Amazon rainforest, where the Black-winged hatchetfish is found, is being rapidly cleared for agriculture, logging, and urban development. This deforestation leads to the destruction of their preferred habitats, such as flooded forest areas and slow-moving streams.

Another significant threat to the Black-winged hatchetfish is overfishing. The species is highly sought after in the aquarium trade due to its unique appearance and peaceful nature. However, unsustainable fishing practices, including the use of fine-mesh nets and electric fishing techniques, result in the capture of large numbers of Black-winged hatchetfish from their natural habitats. This overexploitation puts immense pressure on their populations, leading to their decline.

Human impacts on its habitat

Human activities have a profound impact on the habitat of the Black-winged hatchetfish. Deforestation, as mentioned earlier, not only destroys their natural habitat but also disrupts the delicate balance of the ecosystem they rely on. The removal of trees and vegetation along riverbanks reduces the availability of food sources, such as insects and small invertebrates, which are crucial for the survival of the Black-winged hatchetfish.

Additionally, the pollution of water bodies poses a significant threat to the species. Industrial waste, agricultural runoff, and improper waste disposal introduce toxic chemicals and pollutants into their habitats. These pollutants can have detrimental effects on the health and reproductive capabilities of the Black-winged hatchetfish, further contributing to their decline.

Conservation efforts and initiatives

Recognizing the importance of conserving the Black-winged hatchetfish, several conservation efforts and initiatives have been undertaken to protect the species and its habitat. One such initiative is the establishment of protected areas and reserves within the Amazon rainforest. These protected areas aim to safeguard the natural habitats of the Black-winged hatchetfish and other vulnerable species, providing them with a safe haven where they can thrive.

Furthermore, educational programs and awareness campaigns have been implemented to inform local communities, fishermen, and the general public about the importance of conserving the Black-winged hatchetfish and its habitat. These initiatives aim to promote sustainable fishing practices, discourage the capture and trade of wild-caught individuals, and encourage the preservation of their natural environment.

Role of captive breeding programs

Captive breeding programs play a crucial role in conserving the Black-winged hatchetfish. By breeding the species in controlled environments, these programs help reduce the pressure on wild populations and provide a sustainable source of individuals for the aquarium trade. Captive-bred Black-winged hatchetfish can serve as alternatives to wild-caught specimens, reducing the demand for individuals taken from their natural habitats.

Moreover, captive breeding programs contribute to scientific research and knowledge about the species. They provide opportunities to study their reproductive biology, behavior, and genetics, which can further inform conservation efforts. Additionally, these programs can serve as a means to reintroduce captive-bred individuals into restored or protected habitats, helping to bolster wild populations and ensure their long-term survival.

In conclusion, the Black-winged hatchetfish faces significant threats due to habitat destruction and overfishing. However, efforts are being made to protect the species and its habitat through the establishment of protected areas, educational initiatives, and captive breeding programs. It is imperative that we continue to support and expand these conservation efforts to ensure the survival of this unique and fascinating species. By doing so, we can contribute to the preservation of the Black-winged hatchetfish and the biodiversity of the Amazon rainforest as a whole.

Importance in the Aquarium Trade

Popularity and Demand in the Aquarium Trade

The Black-winged hatchetfish, also known as Carnegiella marthae, has gained significant popularity in the aquarium trade due to its unique physical characteristics and captivating behavior. Its distinctive body shape, with elongated pectoral fins resembling wings, makes it a visually striking addition to any aquarium. The combination of its slender body and dark coloration, contrasted by vibrant iridescent scales, further adds to its allure.

Aquarists and fish enthusiasts are drawn to the Black-winged hatchetfish for its ability to swim near the water’s surface, creating an illusion of flight. This behavior, combined with its peaceful nature, makes it a fascinating species to observe and interact with. Additionally, its small size, typically reaching around 2 inches in length, makes it suitable for a wide range of aquarium sizes, from small desktop tanks to larger community setups.

Suitability for Home Aquariums

The Black-winged hatchetfish is well-suited for home aquariums, provided certain care requirements are met. As a surface-dwelling species, it is essential to provide ample space at the top of the tank for them to swim and glide. A tank with a minimum length of 24 inches and a height of at least 12 inches is recommended to accommodate their natural behavior.

Water quality is crucial for the well-being of the Black-winged hatchetfish. They thrive in soft, slightly acidic water conditions, with a pH range of 6.0 to 7.0 and a temperature range of 75 to 82 degrees Fahrenheit. It is advisable to use a reliable water testing kit to regularly monitor these parameters and make necessary adjustments to maintain optimal conditions.

In terms of tankmates, the Black-winged hatchetfish is generally peaceful and can coexist with other small, non-aggressive fish species. However, caution should be exercised when selecting tankmates to ensure compatibility in terms of water parameters and behavior. Avoid keeping them with larger, more aggressive fish that may intimidate or prey upon them.

Care and Maintenance Tips for Keeping Black-winged Hatchetfish

To provide the best care for Black-winged hatchetfish, consider the following tips:

  1. Tank setup: Create a well-planted aquarium with floating plants, such as Amazon frogbit or water lettuce, to mimic their natural habitat. These plants provide shade and cover, which the hatchetfish appreciate. It is also beneficial to include open areas at the top of the tank for them to swim near the water’s surface.
  2. Diet: Black-winged hatchetfish are primarily insectivorous and feed on small insects, insect larvae, and zooplankton in the wild. In captivity, they can be fed a varied diet consisting of high-quality flake or pellet food, supplemented with live or frozen foods like brine shrimp, daphnia, or fruit flies. Providing a diverse diet ensures they receive essential nutrients for their overall health and vitality.
  3. Lighting: Adequate lighting is essential for the well-being of the Black-winged hatchetfish. Use a combination of subdued lighting and floating plants to create a natural, dappled light effect. This not only enhances their natural behavior but also helps reduce stress.
  4. Water quality maintenance: Perform regular water changes of around 20% to 30% every 1 to 2 weeks to maintain optimal water quality. Use a reliable water conditioner to remove chlorine and chloramines from tap water before adding it to the tank. Additionally, ensure proper filtration to remove waste and maintain a healthy environment for the fish.
  5. Observation and interaction: Take the time to observe and interact with your Black-winged hatchetfish. They are known for their curious nature and can become accustomed to their caretakers. However, avoid sudden movements or loud noises that may startle them, as they are naturally skittish.

By following these care and maintenance tips, aquarists can provide a suitable and enriching environment for the Black-winged hatchetfish, ensuring their well-being and allowing them to thrive in a home aquarium setting.

In conclusion, the Black-winged hatchetfish’s popularity in the aquarium trade stems from its unique physical characteristics and captivating behavior. With proper care and attention to their specific needs, aquarists can enjoy the beauty and charm of this species in their home aquariums.


Throughout this article, we have delved into the fascinating world of the Black-winged hatchetfish, also known as Carnegiella marthae. We have explored its physical characteristics, habitat, behavior, and conservation status, shedding light on the importance of understanding and protecting this unique species.

In terms of its taxonomy and classification, we have provided the scientific classification of the Black-winged hatchetfish, placing it within the kingdom Animalia, phylum Chordata, class Actinopterygii, order Characiformes, family Gasteropelecidae, genus Carnegiella, and species marthae. This classification highlights its close relation to other species of hatchetfish.

Moving on to its physical characteristics, we have described the Black-winged hatchetfish as a slender-bodied fish with a distinctive hatchet-shaped body, measuring around 2-3 inches in length. Its coloration varies from silver to gold, with a black band extending from the dorsal fin to the caudal fin. These physical features make it a visually striking species, sought after by aquarium enthusiasts.

In terms of its habitat and distribution, we have explored the natural habitat of the Black-winged hatchetfish, which primarily consists of calm, slow-moving bodies of water such as streams, ponds, and flooded forest areas in the Amazon basin of South America. Its distribution is limited to specific regions in Brazil, Colombia, and Venezuela, making it a localized species.

We have also discussed the factors that influence its habitat preferences, emphasizing the importance of water quality, temperature, and vegetation cover for the survival of the Black-winged hatchetfish. These environmental factors play a crucial role in shaping its distribution and abundance in the wild.

When it comes to behavior and adaptations, we have uncovered interesting insights into the feeding habits and diet of the Black-winged hatchetfish. It primarily feeds on small insects and invertebrates found on the water’s surface, utilizing its unique body shape and upward-facing mouth to capture prey. Additionally, we have explored its reproduction and mating behavior, highlighting the courtship displays and spawning rituals that take place during the breeding season.

Furthermore, we have discussed the Black-winged hatchetfish’s unique adaptations for survival, such as its ability to glide above the water’s surface using its pectoral fins. This adaptation allows it to escape from predators and access food sources that are unavailable to other fish species. Additionally, we have explored its social behavior, emphasizing its schooling nature and the benefits it provides in terms of predator avoidance and foraging efficiency.

In terms of threats and conservation, we have outlined the challenges faced by the Black-winged hatchetfish in its natural habitat. Human impacts, such as habitat destruction and overfishing, pose significant risks to its survival. However, we have also highlighted ongoing conservation efforts and initiatives aimed at protecting this species, as well as the crucial role of captive breeding programs in maintaining its population.

Conserving the Black-winged hatchetfish is of utmost importance, not only for its intrinsic value as a unique and beautiful species but also for its role in maintaining the delicate balance of aquatic ecosystems. As an indicator species, its presence or absence can provide valuable insights into the overall health of its habitat.

By conserving the Black-winged hatchetfish, we are not only preserving a remarkable creature but also safeguarding the biodiversity and ecological integrity of the Amazon basin. This species contributes to the complex web of interactions within its ecosystem, playing a role in nutrient cycling, prey-predator dynamics, and overall ecosystem stability.

Furthermore, the Black-winged hatchetfish holds significant value in the aquarium trade. Its popularity and demand among fish enthusiasts provide economic incentives for its conservation. By promoting responsible and sustainable practices within the aquarium industry, we can ensure the long-term viability of this species in captivity, reducing the pressure on wild populations.

The Black-winged hatchetfish is a remarkable species that captivates both scientists and aquarium enthusiasts alike. However, its future prospects are uncertain, given the numerous threats it faces in its natural habitat. Continued research and conservation efforts are vital to ensure its survival and protect the fragile ecosystems it inhabits.

It is imperative that individuals, governments, and organizations work together to implement effective conservation strategies, including habitat preservation, sustainable fishing practices, and public awareness campaigns. By valuing and protecting the Black-winged hatchetfish, we are not only safeguarding a unique species but also preserving the rich biodiversity and ecological heritage of the Amazon basin for future generations to enjoy.

In conclusion, let us recognize the importance of the Black-winged hatchetfish and commit ourselves to its conservation. By doing so, we can contribute to the preservation of our natural world and ensure that this extraordinary species continues to thrive in its native habitat.