Enneapterygius atrogulare – Blackthroat Triplefin
Enneapterygius atrogulare was first described by Albert Günther in 1873. This species belongs to the family Tripterygiidae, known as the three-fin blennies. The genus name “Enneapterygius” is derived from Greek, where “ennea” means “nine” and “pterygion” means “small fin,” referring to the distinctive fin structure of these fish. The species name “atrogulare” refers to the fish’s black throat, which is a distinctive feature. Their common name is Blackthroat Triplefin.
Synonyms:
Enneapterygius annulatus, Tripterygium atrogulare, Vauclusella atrogulare, Tripterygium annulatum, Vauclusella annulata.
Description
General External Characteristics:
Enneapterygius atrogulare is a small fish species with a maximum length of about 5 to 6 centimeters. The body of this fish is slender and elongated, with three clearly separated dorsal fins, which is characteristic of the family Tripterygiidae.
The color of the head and flank varies between the sexes. Males have a distinctive orange color with white saddle-shaped markings on the back and a black head. Females, on the other hand, are usually marbled brown with pale saddle-shaped markings. Both sexes have a dark vertical stripe at the base of the tail. The fins of males are often blackish, while females have a more uniform pale color.
Differences between Males and Females:
There are distinct physical differences between males and females. Males are often brighter in color, especially during spawning, when they take on a reddish hue with a black head. Females are generally less conspicuous, with a marbled brown color. No specific behavioral differences between the sexes have been documented.
Behavior and Temperament:
The Blackthroat Triplefin is generally a peaceful fish that often lives solitary or in small groups. They are not aggressive and usually exhibit shy behavior, often hiding among algae and rocks. These fish are bottom dwellers and are often found near the sea floor, especially in areas with abundant algae.
Biotope
Enneapterygius atrogulare is found mainly in the subtropical waters of the western Pacific, particularly around Australia and Tonga. They live mainly in coral reefs, estuaries and harbors, and are often found in shallow waters to a depth of about 5 meters.
Their natural habitat consists of areas with lots of algae and rocks, where they can hide and feed. The bottom of their habitat is often covered with algae and debris, which provides them with good shelter from predators.
Diet
Diet in the Wild:
Enneapterygius atrogulare feeds in the wild mainly on benthic algae, weeds and small invertebrates. Thus, this fish species is an omnivore that focuses on consuming both plant and animal material found on the sea floor.
Diet in the Aquarium:
In an aquarium environment, Enneapterygius atrogulare can be fed a diet similar to what they eat in the wild . This can consist of algae flakes, spirulina, and small frozen or live invertebrates such as artemia or mysis shrimp. It is important to offer a varied diet to ensure the fish gets all the nutrients it needs.
Reefsafe:
The Enneapterygius atrogulare is considered reefsafe, meaning they will not eat coral, polyps or shrimp found in a reef environment. Thus, they pose no threat to coral reefs and can be safely kept in a reef aquarium without harming corals or other reef inhabitants.
The Aquarium
Aquarium size:
To keep Enneapterygius atrogulare, an aquarium of at least 60 liters is recommended. This provides enough space for a pair of these fish. If you want to keep several pairs, it is wise to consider a larger aquarium, say 100 liters or more, to minimize territorial conflicts and provide adequate hiding places.
Aquarium setup:
The aquarium should be set up with plenty of rocks and algae, as these fish like to hide and feed in such environments. The use of live coral is not necessary, but it can contribute to a natural look. A substrate of fine sand is ideal because it mimics the fish’s natural habitat and makes it easier for the fish to hide.
Water parameters:
The best water conditions for Enneapterygius atrogulare are a temperature between 23°C and 25°C, a pH of 8.1 to 8.4, and a salinity of 1.020 to 1.025. These values provide a stable and healthy environment similar to their natural habitat.
Introduction to the Aquarium:
It is important to introduce this fish species into the aquarium only after it has matured properly. This means that the aqu arium must have had sufficient time to develop a stable biological balance, including the growth of algae, which are an important part of their diet.
Compatibility with Other Species:
Enneapterygius atrogulare can live well with other peaceful reef fish such as anemone fish, gobies, and blennies. However, it is important to avoid aggressive or much larger fish as they may intimidate or injure the triplefins.
Breeding in the Aquarium
There are no documented cases of successful breeding of Enneapterygius atrogulare in an ordinary aquarium.
Particularities
The Enneapterygius atrogulare, also known as the Blackthroat Triplefin, has some interesting features and peculiarities that provide further insight into this species:
- Colorful Differences Between Genera: As mentioned earlier, males and females of this species exhibit significant color differences. Males are often brighter colored with a distinctive orange hue and a black head, while females are a marbled brown color.
- Habitat and Behavior: These fish are often found in shallow waters, especially estuaries and harbors, and they prefer areas with lots of algae and rocks. They are not migratory and usually stay within their territory.
- Reproduction and Eggs: The eggs of Enneapterygius atrogulare are hemispherical and are attached with sticky threads that anchor them in the algae at nest sites. The larvae are planktonic and are found primarily in shallow, coastal waters.
- Ecological Role: This species feeds mainly on benthic algae and small invertebrates, giving them an important role in the ecosystem as a controller of algae and as prey for larger predators.
- Conservation Status: The Enneapterygius atrogulare is classified as “Least Concern” by the IUCN, meaning there are currently no major threats to their population.
- Morphological Characteristics: The species has a distinctive pointed snout and eyes placed high on the head. This, along with their three separate dorsal fins, makes them easy to identify.
- Geographic Distribution: This fish is endemic to Australia, occurring from northern Queensland to southern New South Wales, and has also been reported in Tonga.
Conclusion
The Enneapterygius atrogulare, or Blackthroat Triplefin is a fascinating species of fish especially suitable for experienced aquarists. Their specific habitat requirements, such as an environment with lots of algae and rocks, make them less suitable for beginners. They are peaceful and reefsafe, which makes them a good choice for reef aquariums. It is important to have a well-matured aquarium before introducing them.
Although there are no comprehensive reports on successfully keeping this species in captivity, their natural behavior and diet suggest that they can be challenging to care for. Their unique color differences between the sexes and preference for specific living conditions make them an interesting addition for specialized aquariums.
Author
John de Lange
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