Boulengerella cuvieri: Not a Gar but a Pike Characin

 

I have a fish at my place that fishkeepers almost always mistake for a Gar; they see it in its tank and just pass it by. However, when I talk about it, they always pause and listen to what I say and give the fish a second look. This is the Boulengerella cuvieri, a Pike Characin from tropical South America, found in the Amazon Basin, Rio Amazonas, Rio Tocantins, Río Orinoco, Essequibo River, Oyapock River, and the rivers of Amapá, and Pará, Brazil.

The mistake is quite understandable as the Boulengerella cuvieri shares many similarities with the Spotted Gar (Lepisosteus oculatus), Long Nosed Gar (L. osseus), and the Short Nosed Gar (L. platostomus). All are long and slender fish with long snouts housing a set of impressive teeth.

 

THE DIFFERENCES

But similarities end there. The Gars are a primitive freshwater fish of the order Lepisosteiformes and family Lepisosteidae, native to the North American continent, while the B cuvieri is from the order Characiformes, which in layman’s terms means it is a tetra belonging to the family Ctenoluciidae. It originates from the South American continent.

The genus Boulengerella or the Pike Characins are named after Belgian-British zoologist George Albert Boulenger. Five species of Boulengerella have been described, with B cuvieri being one and the four others being B lateristriga, B lucius, B maculata, and B xyrekes. All are quite rare in the Philippines, and stocks are normally low in number when we do get some. Thus Filipino fishkeepers are not familiar with these Pike Characins.

B cuvieri was named after French naturalist and zoologist Jean Léopold Nicolas Frédéric Cuvier after it was first described by German biologist Johann Baptist Ritter von Spix and Swiss-American biologist Jean Louis Rodolphe Agassiz during their expedition to the Amazon. Although Spix died in 1826, Agassiz finished the work and was published in 1829.

The B cuvieri is a long and slender fish shaped very much like a pencil, a trait common to many gar-like fish. Its base body color is silver with a dark horizontal stripe that starts from the mouth, runs through the eyes, and ends at the peduncle. It has a forked tail with rather thick lobes. The tail may or may not be dark in color. The head is barracuda-like; it appears large for its slender body. The eyes are big, and the snout is long with menacing teeth that outline the mouth. A key feature of the mouth of the B cuvieri is knob-like flesh at the tip of the snout.

The fins of the B cuvieri are clear. The dorsal fin is small and located far behind with the small fleshy adipose fin next to it. Pectoral fins are also small. The ventral fins are located below the dorsal and the anal fin behind it.

It is said that B cuvieri grow to a maximum size of 80 centimeters or about 32 inches in the wild. Pictures of B cuvieri caught by anglers show a big slender fish that is silver in body color with a dot at the peduncle and a big orange tail. This quite different from the description above of a juvenile that we almost always encounter here in the Philippines.

CARE, TEMPERAMENT, AND FEEDING

Coming from the Amazon River, the B cuvieri, which is also known as the Bicuda, prefers pH between the range of 5.0 to 7.5 and water hardness between 18 to 215 ppm. A temperature of 22 to 30°C is also preferred. These water parameters are very common under Philippine conditions.

B cuvieri is a carnivore and must be given meat in its diet. But it prefers eating live fish in captivity. With hard work and perseverance, the B cuvieri may be taught to eat non-live meaty food.

It is normally a timid fish that almost always stays put in its area of the tank. It gently hovers about in that position by independently moving its pectoral and dorsal fins about. The movement of these fins also allows it to move gently forward or backwards.

But this is, of course, when it is relaxed. When startled, it becomes skittish, making darting movements and jumping around the tank. Thus, it would be wise to keep the tank fully covered because you might one day find it dead outside the tank.

Feeding time is another opportunity to see how fast this fish can swim. It generally stays put, hovering peacefully about in the tank. But once a fish small enough to fit its mouth is dropped in the tank, it will cautiously approach it then make a lightning-quick strike when within striking distance. You will be amazed to see how fast this timid fish swims when food is offered.

Generally, even if the B cuvieri is a fish eater, I find it to be a gentle fish and it can be kept with other peaceful fish that are not small enough to be considered food. It hardly bothers other members of a community tank, mostly staying at the top portion. Avoid keeping B cuvieri with more aggressive fish like Peacock Basses, cichlids, or the more aggressive catfishes as the B cuvieri is considered a ‘gentle’ monster fish. I do not observe any aggressive conspecific behavior with the four B cuvieri I have in the tank, so they may be kept in a small school as well.

Keeping B cuvieri successfully in the tank needs no special fishkeeping skills. They are quite hardy and not demanding in their needs. Have an ample sized tank with the appropriate filter. Perform a 30% water change weekly to keep water conditions in check. Feed them properly and you should be rewarded with healthy B cuvieri which you can enjoy in your tank.

The B cuvieri should be a good addition to a community tank with exotic fish. It definitely has a special appeal because of its pike-like appearance. It is peaceful, yet it shows its monster fish appeal during feeding time. Unfortunately it is not a popular fish in the country and thus, availability is a challenge. But if you chance upon some in your favorite fish store, it should be a good choice for your tank.

 

This appeared in Animal Scene magazine’s January 2017 issue.