Pike cichlids of the genus Crenicichla make very interesting and challenging aquarium residents. The following article is a brief introduction to this genus of South American cichlids.

Pike Cichlids are a group of South American fishes of the genus Crenicichla. They inhabit the freshwaters lakes, streams, rivers and pools of most of the Amazonian rivers, but there are many species found in Colombian, Venezuelan and Guyanan waters to the north of the Amazon. To the south, there are representatives of the genus all the way down to coastal regions of central Argentina. Basically, they are found east of the Andes, from the island of Trinidad in the north to the area around the Argentinian Rio Negro just north of Patagonia.

These fish are predominantly warm water fishes, with a few notable exceptions such as Crenicichla lacustris of Argentina and Crenicichla scotti of Uruguay. Crenicichla or Pike cichlids as their name implies, are mostly predatory, consuming small fish for prey. There are a few exceptions, as usual, such as Crenicichla compressiceps and C. cyclostoma from the rapids of Eastern Brazil that are specialized insect eaters.

Most Pike cichlids have an elongated body and a wide, protrusible mouth - features common to many predatory fish. There are some sedentary Pikes such as C. jegui that spend most of their time waiting for prey to swim by, at which time they lunge and grab the hapless fish. Predatory fish vary in their level of activity. To compare with saltwater fish, Pikes are somewhere between Rockfish and Barracuda in style and activity. Most Pikes position themselves near sunken tree stems, rocks and substrate, giving a quick, short but spirited chase to catch prey. Keeping Pikes in aquaria requires that you remember this fact. Housing them with fish less than half their size is inviting trouble - driven by instinct, they will attempt to eat the smaller fish even if the smaller fish cannot be easily swallowed.

Pikes come in many sizes. There are manwy dwarf Pikes that don't grow longer than 3-4 inches. They possess most of the color and interesting behavior of their larger cousins but remain small enough for aquarists to enjoy without giving up much floor space for fish tanks. Then, there are many medium-sized Pikes that reach a maximum size between 6 and 10 inches. And finally, there are lunkers, growing to 18-24 inches. There is a Pike for everyone. While Pikes have a reputation worse than that of Central American Cichlasoma sp., for tearing up other fish and destroying their environment, the truth is not that macabre. While Central American cichlids sometimes enjoy redecorating their environment, jaw structures of Pikes are not physiologically equipped to move and pull or tug. They usually do not dig up plants as much as Cichlasomines.

Aggression can be a problem with Pikes if you are not careful. Use caution when it comes to choosing tankmates. Most aggression is reserved for members of the same species; choosing tankmates of the same size can minimize this kind (conspecific) of aggression. Housing them with species of different shape and color can reduce aggression with other species. When all else fails, it's time for PVC. Addition of PVC tube sections wide enough to comfortably fit the Pikes into, seems to reduce aggression tremendously. I always make sure there are more PVC tubes than Pikes. Species that can't stand the sight of each other often will coexist in a tank furnished with numerous PVC tubes. Of course, these tubes are not exactly natural or attractive but they are sometimes the only way out. If you can find similar hollow pieces of driftwood, you can have aesthetics and practicality.

Tank size for Pikes is largely dependent on the maximum size of the particular fish. Dwarf species like C. notophthalmus, C. regani and C. urosema can be kept in tanks as small as 30 gallons. Some dwarves like C. compressiceps, while remaining small, are fairly aggressive and need more room - I wouldn't keep them in anything smaller than a 55-gal. tank. Slightly bigger but relatively peaceful species like C. cf. menesezi, C. geayi and C. britskii can be maintained in 55-gal. tanks. Most of the rest require tanks in the 75 to 125 gals. range. Large species like C. johanna, C. lugubris and Orange Pikes (C. sp. Xingu I) need 125-gal. or larger to exhibit their normal repertoire of behavior. I usually purchase fish that can be raised in a 55 or 240 gal. tanks since those are the sizes of tanks I have available. While raising Dwarf Pikes in a larger-than-necessary tank may seem excessive, it is very rewarding - they exhibit natural behavior that you'd never see in small tanks.

Water quality is usually not a critical issue for the medium-sized, spangled Pikes of the saxatilis-group; they are hardy and can happily live and breed in most treated tap water. The same goes for the Froghead Pikes formerly known as Batrachops. The large, small-scaled Pikes of the lugubris-group and the dwarf species need better water quality, since they are usually found in low-pollution, low-bacteria black waters of the Amazon. A regimen of large, partial water changes and powerful biological filtration should take care of these fish. Lax water quality management leads to "hole-in-the-head" disease in some large Pikes. The dwarves simply die if you don't keep the nitrogen levels in the water low.

While none of them require soft, acidic water for day-to-day living, the black water species usually need water with pH and hardness resembling their native habitat - pH of 5 to 6 and extremely soft to successfully breed. I have spawned many of the Spangled Pikes in hard, alkaline water but spawning occurred only with frequent, large water changes.

Feeding Pikes is usually not a problem, tank-raised Pikes happily accept prepared foods but fish imported from the wild are often difficult to feed - they demand live or frozen meaty foods. Juveniles imported from the wild can be converted onto pellets much faster than adults can. Keep in mind that these are predatory fish and feed them a varied diet frozen crustaceans, fish, live earth worms and live fish. Even specimens that accept pellets should be fed frozen and live foods regularly. Feeding a diet lacking in certain unknown minerals has also been pointed at as being the cause of hole-in-the-head disease. A variety of foods is key.

Reproduction of Pike cichlids in aquaria, unfortunately, does not occur frequently enough. It is not because these are difficult to breed, but because so few people try breeding them. The easiest group to get to spawn in aquaria is the saxatilis-group (Spangled Pikes). I believe Dwarf Pikes and the giant Pikes of the lugubris-group are more difficult due to their water requirements (see above). Of course, you see fry of Dwarf Pikes being offered for sale more often than those of the 'Giants' do, not because the dwarves are easier to spawn, but because they are easier to house and provide for due to their sizes.

Breeding lugubris-types requires a fairly large tank (A pair of C. lugubris belonging to Frank Warzel spawned in a 75-gal. tank but he claims that it is the smallest tank they'd breed in.) Providing large quantities of soft, acidic water can be an expensive proposition if you live in an area with hard, alkaline water. Wayne Leibel spawned, C. marmorata in a 150-gal. tank. As far as I know, he's the only American to have succeeded in breeding any of the lugubris-group. I believe that if enough people make an effort at proving the space, water-quality and dietary requirements of these large Pikes there'd be many more breeding reports. C. lugubris, C. marmorata and C. vittata are the only large Pikes that have been spawned (to the best of my knowledge) in aquaria. The laying of eggs without successful hatching of fry has been reported in C. phaiospilus, C. sp. Xingu I and C. acutirostris.

Pikes are cave-spawners, laying their adhesive eggs somewhere where it would be difficult for you to see. The female is responsible for the care of eggs and the male guards the immediate region against intruders. The eggs hatch in about 3-4 days and the fry are free-swimming in another 3-4 days, depending on the temperature. The fry are fairly large and can be fed newly hatched brine shrimp as their first food. Fry growth is very fast and if not segregated by size, the resulting cannibalism can lead to a highly biased sex ratio in some species, particularly in the saxatilis group. □