These plecos might not clean up any algae, but they are an incredibly rewarding species to build an aquarium for. Paul Adonis explains how he keeps and breeds Hypancistrus seideli (L236).
Keeping Hypancistrus can be a rewarding experience, but breeding them successfully requires a little more understanding of their behaviour and specific requirements. Having spent time keeping and breeding the L236 cracked zebra pleco (Hypancistrus seideli), I've learned a lot about what makes these fish tick, from choosing the right breeding stock and setting up a dedicated aquarium to raising the fry.
A community tank pleco?
Hypancistrus species can work in community tanks, in fact that is exactly how I first started keeping them. They were in a tank with rummynose tetras, keyhole cichlids, Laetacara and a group of what are commonly referred to as Corydoras.
The L236 (my first Hypancistrus species) were supposed to be the show stoppers of the aquarium and they were… but not for long. The cracked zebra plecos looked remarkable while floating in their bag; I was amazed at their patterns. However, upon releasing them into the aquarium, it took almost three weeks for me to see them again and to know for sure that they were doing well in their new home.
I soon realised this was not the ideal setup to really show off these small, striking suckermouth catfish.
All photos by Paul Adonis unless otherwise stated.
A dedicated aquarium
Due to the nature of these fish, I think it’s best to keep them in dedicated setups. Add plenty of places to hide in the form of rock structures, ceramic caves, large seed pods and any other suitable hideaway, and push the water around the aquarium with some velocity to replicate the fast-flowing water they are found in.
They also appear to be far more social and brave when kept in good size groups. While they are not a 'shoaling fish', in my experience, they seem to follow the same safety in numbers strategy that so many of our favourite aquarium residents rely on.
In fact, their behaviour completely changed when I added a good-sized group to a dedicated tank with some small dither fish. They became the show stopper fish I thought they'd be in my community tank.
Feeding Hypancistrus: Understanding their unusual diet
Feeding Hypancistrus, such as the cracked zebra pleco, is easy and straightforward. They are not fussy eaters. These catfishes will accept most foods available on the market, but they prefer higher-protein, meatier foods which is at odds with what many people think of when they see a pleco.
Contrary to popular belief, not all plecos are algae eaters and, for Hypancistrus, even though algae can make a small part of their diet, they are not well suited to rasping algae off rocks. While a common Ancistrus will happily gorge itself on algae, Hypancistrus won't be so content if that is all that is offered.
As juveniles, they will graze on algae and biofilm, but as they reach adulthood, they tend to show less and less interest in vegetable foods. Some people still like to feed them courgette or various other vegetables, and I did the same when I started keeping them. However, I soon realised that it is somewhat unnecessary.
In captivity, offer a mix of prepared foods, including meaty catfish pellets, along with some frozen and live foods; bloodworm often goes down a treat.
When to feed your plecos
It is important to note that, like most catfish, Hypancistrus are nocturnal. Fry and juveniles will have a bigger appetite and therefore it's not uncommon to see them feeding during the day, especially if the tank is situated in an area with not too much foot traffic.
As they reach maturity, however, they’ll mostly feed overnight. So keep this in mind in case you decide to keep them with other fish, as it’s important to make sure that there’s enough food for them when the lights go out. Add some sinking pellets, wafers, or defrosted worms once your aquarium lights have turned off. Some light units will enable a blue light night mode which can be used during this time, allowing you to watch your Hypancistrus feed.
Do Hypancistrus need wood in their aquarium?
As for most plecos, aquarium safe wood can be added to the tank. It's not a must, but they do like to rasp on it if given the chance.
This is especially true while growing up, as the wood can be a good medium for growing biofilms and beneficial bacteria, which can be a great starting food for fry.
In fact, some types of wood, like honeycomb wood, are great options as it not only provides a surface for biofilms and algae to grow but it is also full of hidey holes for your young plecos to shelter in.
Juvenile Hypancistrus debilittera hiding in a piece of wood - Photo by Alex Bell
A young group or a proven pair?
Similarly to feeding, breeding Hypancistrus is not a complicated process as long as their requirements are met. The only problem is that if you start with a group of young fish and not a pair/group of known breeders, it will take a while for them to get to the spawning stage. This can mean anything from one and a half to two and a half years, depending on the species.
When I decided to focus on breeding the L236, I had two options: get an established breeding pair or get a group of young fish, grow them out and breed them once they reached maturity.
After weighing up the pros and cons of each, I decided to get a group of young fish and start from there. This can actually be beneficial if you are just starting out with this genus, as you’ll get a better understanding of the process of growing juveniles into adults, which will become very useful when it comes to rearing these fish from eggs into adults later on.
Buying proven breeding pairs could be a good option if you’re an experienced breeder and want to start straight away. Money wise, a breeding pair will cost you pretty much the same as it would cost you to buy a group of five or six young fish, but you'll likely get a successful spawning much sooner.
You should buy your fish from a source you trust, though, as some breeders can sell their old fish which have stopped breeding. This can be especially true for the H. zebra (L46), where the difference in age is hard to tell once the fish mature.
Tank setup for breeding Hypancistrus
Once you've got an established pair, trio (one male, two females) or a mature group, things start getting interesting.
To breed these fish, they need to be provided with caves. For L236, caves measuring up to 15 cm (6 in) long, 5 cm (2 in) wide and 4 cm (1.6 in) tall are a great option. The size of the cave can vary depending on the size of your fish. Some adults stop growing when they reach around 12 cm (4.7 in), but some males can get to 15 cm (6 in) and turn into proper beasts.
As a rule, I like to have 2–3 caves per fish, as males are territorial when they mature and will guard caves as part of their territory. Females are more docile; they will have their arguments every now and then but nothing too serious.
Once the males in your group have established a hierarchy, you shouldn't have problems as long as they have enough space and enough caves to use between them.
The caves can be placed right on the bottom of the tank, or on the substrate, and you can use slate, rocks or tiles to create layers and offer the fish more surface areas to graze on. All these decorations help to mark out their territories.
Choosing the right tank size
The tank size will depend on the number of fish you want to keep. A single pair for breeding could work in a 60-litre (13 gal) tank, whereas a group of five fish would need at least 90-litre (20 gal) tank.
My group of 10 adults, alongside around nine juveniles, is doing great in a 140-litre (31 gal) shallow tank measuring 120 x 40 x 30 cm (48 x 16 x 12 in), with some green neon tetras as dither fish and 40–50% weekly water changes.
Related article: Keeping and breeding the green phantom plec.
Water parameters and conditions
The L236 have been in the hobby for a while now and are fairly easy to breed. While there are reports of breeding them in tap water, this will depend on where you live. I prefer people to include actual parameters with their breeding records, as tap water varies so much.
I doubt I could have achieved breeding them using the London tap water, but remineralised RO water works great for me, aiming for soft and slightly acidic water. Water with a pH of 6–7 with less than 6°dH should work nicely.
High temperatures are certainly best; I keep my tanks at 28°C (82°F). I combine this with slightly soft water that avoids the extremes, and my TDS sits around 150–170ppm. With strong filtration and good food, it didn't take long for me to see some breeding behaviours.
I would add that the placement of your tank is important for breeding this species. They are shy, tending to hide at any sudden movement. If you can, place the tank in an area with not too much foot traffic.
My group first started breeding when my partner and I were on holiday for just over a week, and it is quite common for people to experience this. They enjoyed the quietness of our room and started breeding straight away.
The breeding process
When a female is ready to breed, she will choose a male and start showing interest in him by trying to occupy the cave he is in. For this to happen, the male will come out of the cave before trapping her within it. The trapping can last anywhere from a few hours to a week.
During this time, the male will be shaking vigorously – you'll be able to clearly see his tail shaking near the cave entrance – to encourage the female to lay her eggs. During this time, neither of them will leave the cave until the female is ready to lay her eggs.
Once ready, the male will allow her to turn around, leaving the cave to do so. Now her tail is at the back of the cave, the male will once again trap her inside.
As soon as she is ready to deposit the eggs, he will turn around as well to be able to fertilise them. You'll be able to see his head at the entrance of the cave, which is a good sign that spawning is occurring, as most of the time these fish will get in a cave head first.
Egg care and the male's role
After the eggs are fertilised, the male will let the female leave the cave and then proceed to guard and fan the eggs constantly for up to around two weeks, usually.
The eggs need seven days to hatch and the fry will need another seven days to fully absorb their yolk sac. This can vary depending on the temperature of the water; a higher temperature can mean a shorter time and vice versa.
It is not unusual for a male that spawns for the first time to eat the eggs or kick them out of the cave while he's guarding them. This can happen for a variety of reasons, such as lack of experience, eggs not being viable, the male getting disturbed by other fish or by us flashing the torch at them too often to check on his progress.
At the same time, an experienced male can spawn, guard the eggs for seven days and, after the eggs are removed, he can go again and trap another female. Once they're in the mood, they just keep going.
Another possibility is for a male to guard eggs and to trap another female at the same time. It doesn't happen often, but when it does, if successful, the male will be rearing two different batches from two different females at the same time.
Raising Hypancistrus fry alongside the adults
If your tank is set up for breeding, the fry can be left alone to leave the caves when they're ready, especially if the male that spawned is an experienced male.
After absorbing the yolk sac, the fry will fend for themselves in the tank. They will eat the biofilms naturally occurring in the tank and any tiny foods and particles that they can find.
The main benefit of this method comes when your breeding group is in a mature tank. The fry can constantly graze on natural food stuffs throughout the day and night, which can result in faster growth.
Raising fry separately
The other option is to remove the fry and keep them in a breeder box or grow-out tank. It will be easier to target-feed them, monitor their growth, whether they are eating, and if they remain healthy.
They can then be reintroduced to the parents’ tank, or moved to a larger grow-out tank as they grow.
The fry should be fed more often than the adults but in smaller portions. It's important to make sure that the food you feed is consumed in a short period of time. You do not want uneaten food slowly polluting the water, especially if the fish are kept in a much smaller grow-out tank or breeder box.
Which method is best?
I've raised fry using both methods, leaving the fry in the tank with their parents or in grow-out tanks, and I can't say I've seen a clear difference in terms of growth rate.
This being said, I personally prefer the grow-out tank method just because it can be easier to monitor the fry. Keeping them with their parents means they are often hiding and you will not see them that often until they reach 3 cm (1.2 in) and gain more confidence to be around their giant parents.
Final thoughts on breeding L236
Hopefully, sharing my journey with H. seideli L236 will help fellow hobbyists interested in the species have the courage to dedicate a tank to breeding a group of these beautiful Hypancistrus.
While I have only tried my methods with the L236s, it should work well for the majority of other Hypancistrus species that are commonly seen in the trade.
Cracked zebra pleco fact file
Scientific name: Hypancistrus seideli (L236)
Size: Usually up to 12 cm (4.7 in).
Origin: Brazil
Habitat: Found in fast flowing rivers with rocks and sandy substrate. Occasionally large pieces of wood may get trapped between the rocks but plants are generally absent from the habitat.
Tank size: 60 x 40 x 30 cm (24 x 16 x 12 in) for a breeding pair, 90 x 30 x 30 cm (36 x 24 x 24 in) for longer term housing of a group.
Water requirements: Soft and slightly acidic is ideal but a pH of 6.0 to 7.5 and a hardness below 12°H will work well for general care.
Temperature: 25–29°C (77–84°F)
Feeding: Omnivorous with a preference for high protein foods. Offer sinking prepared foods and plenty of frozen and live fare.
Availability & cost: Occasionally stocked by stores and if not currently available, they should be able to source them for you if you enquire. Prices often start at £60 for juveniles depending on quality.