Appearance and Characteristics:
The Common Bristlenose Catfish is the name given to the medium-sized, sturdy members of the Ancistrus species. They fall into the Loricariidae family of catfish, and hail from South America. Their name is derived, surprisingly, from the bristles that decorate the nose of the male of the species. Some sources claim that females may also display a smaller array of bristles on the lips, but I have found this to be completely untrue.
The colouration of this fish is a source of constant confusion, as hybridization within regional trades has resulted in a broad range of browns, greys, and greens in various mottled, spotty, and stripey patterns being common. These catfish are also capable of subtle changes of colouration in response to substrate, feeding, and emotional situations.
A mature Bristlenose Catfish reaches a length of about 10 cm, although they can get slightly bigger, and they live to well over 10 years of age!
Water Quality:
These are a remarkably tolerant catfish, very undemanding when it comes to water quality and parameters. The most important consideration is the oxygenation of the water. These fish come from fast moving water bodies, and require high concentrations of oxygen. Water movement and the addition of bubble stones will please these catfish, and they will often seek out the areas of the tank with the highest water movement or stream of bubbles. They are also capable of darting to the surface to gulp air directly, but this behaviour indicates that the oxygen content of the water needs to be improved quickly!
Close to neutral PH is preferable, but as aforementioned, hardness and PH are not crucial.
They are a tropical fish, and require a temperature of at least 24 degrees Celsius, but will happily live in a range from 23 to 29 degrees. Their ability to handle higher temperatures depends on the oxygenation of the water, as hotter water usually holds less oxygen.
Environment:
There are two important considerations when furnishing a tank for Bristlenose Catfish. Firstly, these fish require privacy, and need caves and plant thickets to feel secure. Males will take up residence in caves fashioned from rocks, ornaments, hollow wood, or terracotta pots, whilst females will generally find a quiet area of the tank, away from the males cave, and make her home deep in a thicket of plants.
The second consideration is stability. Once your Cats are happily ensconced in their new environment resist, at all costs, the urge to “fiddle”. Don’t adjust plantings and ornamentation. This will only stress your fish!
Bristlenose Catfish feel much more comfortable on a dark substrate, and although size is unimportant, the substrate mustn’t have any sharp edges. Likewise, and rockwork or ornamentation must be smooth. Male Bristlenose will choose the most unlikely spots to call home, and I have seen them choose depressions and caves that leave them cut and grazed.
The addition of driftwood is appreciated, and it has been suggested that these fish require wood to digest.
Diet:
The most important part of a Bristlenose diet is vegetation. These fish will rasp at algae, although it is usually simpler to feed algae tablets. They won’t turn to destroying plants if they are also given a variety of greenstuffs like lettuce, spinach, zucchini, and green beans. One of the easiest ways of filling their need for vegetables is frozen peas. These should be soaked in boiling water, and the MUST BE SHELLED! This can be time consuming, but I do mine whilst I am watching TV.
Whilst this species is considered to be vegetarian, they border on being omnivorous. They will clean up most flake and pellet foods that reach the bottom, and also enjoy bloodworms. I have observed young bristlenose diligently sucking snails from their shells.
Sexing:
As mentioned, the most obvious sexual difference is the bristles on the snout of the male. These may be sparse and delicate, or bushy and grotesquely ugly! A young fish will begin to develop these bristles at around three centimeters. Females are also slightly smaller, and develop a distinct rounding of the stomach when viewed from below. Males trail off much more gradually through the body to the tail, while the females have a more marked junction between broader abdomen and tail.
Breeding:
With correct feeding and STABILITY, these fish become the guppies of the Catfish world, happily producing a brood every four weeks or so.
If the catfish are comfortable in their environment it will only take a large water change with slightly cooler water and a big feed of bloodworms to induce the female to lay.
This is where the male’s cave comes into play. Usually he will tolerate no one, not even the female, coming near his home. When the female is ripe with eggs and in the mood, however, she will force her way in there. What follows is an uncomfortable looking jockeying for position in what is usually a ridiculously small space, during which the female releases up to fifty eggs, and the male releases her sperm. The whole process lasts about ten minutes. She then hightails it out of there, and the male’s true purpose in life begins.
A male Bristlenose Catfish is the most wonderfully dedicated father. For the next ten days he will not leave his cave at all. He simply fans ferociously with all his fins, ensuring a strong current of water over his eggs at all times.
The eggs hatch in about five days, and it has been suggested than the male helps to suck the shells off the babies. The hatchlings are tiny, about half a centimeter, orange egg sacks with a waving tail. Within another four days they have transformed into tiny replicas of mum and dad, and begin to move away. It can take up to a week for all the babies to have left home, and during this time dad will very occasionally dart out for a quick mouthful at feeding time, but never for more than about 30 seconds. He will wait until the very last baby has left before abandoning his parental duties. Babies do not need to be removed from the parents, as they will carefully forage around the tiniest young.
Commercial breeders often maintain a colony of one male and multiple females, all of which will lay in the one cave. I believe this is unnecessary, and very hard on the male, as the females may not lay at the same time.
Raising the free swimming babies is the most intensive part of the whole exercise for the aquarist. And the key to success is FOOD. And lots of it. Here is where bags of frozen peas become crucial. Once defrosted and peeled these should be mushed between the fingers and dropped into the tank, ensuring many small pieces scatter over the tank floor. Competition for food is tough, so don’t be light handed. Continue to add flake foods as well, and the occasional broken up algae wafers. Siphon the gravel every two days, and watch your babies grow!!!
Good luck!
Here is a pic of my male, resting on his cave, surrounded by his babies
A young male BN from above
A young male with his first clutch
Limegirl,
Wow! What an informative post and what lovely pictures! I plan on picking up a trio of Bristlenose cats once I'm relatively certain my relatively new, planted, fishless 29G is gill fluke-free (had a problem with the fish I used to cycle the tank).
Regarding quarentine, do you recommend any particular prophylactic medications before introducing new Bristlenose? I *REALLY* don't wanna have a parasite outbreak again!
Best,
Tony
In your first pic, limegirl, how old are those fry?