Xenentodon cancila is not often seen in your Local Fish Store, and when it is seen, it is sometimes called a “Freshwater Gar.” While it looks somewhat like a gar, with it's long beak and sharp teeth, it is actually a needlefish, and it's most common (common) name is Asian Needlefish. It is also sometimes called Silver Needlefish, and in Hawaii, where it has established an invasive population in a reservoir, it is known as a “Stickfish.”
This is a common fish throughout it's south east Asian native range, from Sri Lanka to the Mekong Delta in Vietnam. It lives in a variety of environments, from briskly moving streams to monsoon inundated floodplains and the still water bodies left behind by these events. They frequently live in groups, and will pair off for mating. They live almost entirely within the top few inches of water, hunting and eating pretty much anything they can fit in their mouths. They are voracious predators of smaller fish, aquatic invertebrates and terrestrial insects that have bad enough luck to fall into the water near an Asian Needlefish.
Asian Needlefish are an intriguing fish to keep in the home aquarium. They can be kept in planted tanks, or not. Honestly, what happens in the bottom ¾ of almost any fishtank won't really matter to the Needlefish. What they do like is some surface vegetation for cover, and a big enough footprint to swim around a bit. A display could honestly be ten inches deep as long as it was four feet long. A minimum tanks size for a small group should be four feet by 2 feet, and as they grow up, six feet by two or more feet would be more appropriate. They are best kept in a group of 3 or more individuals, though they must all be about the same size, and we'll revisit this point momentarily. They can be fed a wide variety of high protein foods; chopped seafoods, blackworms, bloodworms, and mysis make good meals. Many people also feed live earthworms, mealworms and crickets; live fish can be fed, though they should come from a sterile culture and generally be “gut loaded.” Over time, Needlefish can be taught to accept floating pellets which is an easy way to ensure a complete nutrient profile when added to live and or frozen foods. A diet like this also means that aggressive filtration and regular water changes are an important part of keeping these fish healthy long term.
Xenentodon cancila can be bred in the home aquarium and it is within the capabilities of many hobbyists to successfully raise the fry. Males and females can be distinguished by the males black fringed fins and the hump that develops on their back just behind their head as they come into spawning condition. They don't need to be paired off as long as you have a male and a female, they will pair, court and spawn in a very interesting display. The female only lays one egg per day, and will do so for weeks at a time. There is no parental care. In a community tank, these eggs and fry are beyond likely to get eaten and so would need to be removed to succeed in raising them. Fry can eat artemia basically immediately after hatching. As mentioned previously, the Asian Needlefish is a cannibal and they will eat the young, and the young will also eat other young if the size differential allows it (and this size differential is surprisingly small). All these factors mean that while this is very achievable in the home aquarium, production of these fish is too slow to allow for consistently available aquacultured specimens and so sustainable wild harvest is important to their viability in their native environments.
The Asian Needlefish (Xenentodon cancila) is one of freshwater aquariums coolest oddball fish. They offer the home aquarist a surprisingly peaceful (but hungry for smaller fish) predator for the top of the water column in their aquariums. With an interesting and achievable spawning behavior in the home aquarium, they offer intrigue beyond just their fascinating looks. If you are interested in getting a group of sustainably harvested Asian Needlefish, ask your LFS about getting you some from Aquatropic today!