Shane's World Right Reproduction Right L174 and L316, two small and similar Hypancistrus species

Article © Janne Ekström, uploaded January 01, 2002.

I've kept these two small species for some years now and they are both very charming little species with an "innocent" look; maybe this is because, compared to other members of the same genus, these two species have quite small eyes which make them look timid. They both have a very variable patterning. Although the majority of L174 individuals look similar to one another (they are commonly seen with rounded, almost equal-sized dots) you can also find them spotted or striped with a mixture of dots and spots either over the entire body or just their fins. L174 is a small species and will not grow bigger than just under 10cm. The base colour varies depending on size and mood from light grey over beige to steel grey or very dark grey with a dark brown pattern. In breeding condition, the male will look very dark with a less contrasting pattern than the female.

L316 are even more variable and not a single individual will look the same. Individuals could be striped, spotted or display both spots and stripes; the stripes themselves can also vary from thin lines to broad bands. However, most members of the species share the same striped dorsal and caudal fin in black and white.

The base colour of L316 is black with a pattern ranging from pure white in youngsters to the adults' more bluish grey tinge. Even in this species the females' pattern is more distinct in the adults. The easiest way to distinguish them from similar black and white species is the size of their eyes that are very small compared to their heads; both these two species share these small brown eyes. L316 is a small species too and will not grow any larger than just above 10cm, slightly bigger then L174.

L174L174 Hypancistrus sp. female

L316L316 Hypancistrus sp. female

The males in both species share odontodal growth that, in these species, covers the whole body from the head to the caudal peduncle. This growth can be so heavy that the males almost look singularly colored and incredibly sticky. Once adorned, males never entirely lose this growth if kept in good conditions. They will in fact grow larger during the breeding season. By virtue of their lack of odontodal growth, the females invariability look more attractive than their male counterparts in adulthood.

L174L174 Male shows odontode growth

L316L316 Male covered with odontodes

L316L316 Male covered with odontodes which makes the contrasting pattern almost disappear

L316L316 Female showing the differences in the shape of her body

L174 is mature from just above 5 cm and L316 from around 6-7, cm but it's better to wait and let them grow a little bigger before attempting to breed them. When they start to spawn they will do so regularly and, like many other species, their own growth will slow during this time. If the aim is to hold and breed them in their own tank they will use all the energy in the breeding process, spawning all year around with corresponding cessation in growth. In a community tank this is not likely to happen. To prevent this they need a break from time to time and I suggest allowing them to breed three times before giving them two months recuperate before further spawning.

Setting up the breeding tank
Before placing fish in the breeding tank you need to know that you have specimens of both sexes. If the fish are just starting to mature or are not showing any great visible differences (often the case if they are newly imported and you have just bought them) there are other ways to sex the fish. The shape of the body is one distinguishing feature if they are big enough; from above, males are broadest across the head in line with his eyes, while the female is broadest between the pectoral fins. In this way, the female looks more pointed then the male's more stubby shape.

Examining the genital papilla is not the universal answer to gender determination many people would suggest; before full maturity it's very hard to see any differences between the sexes because, when not fully developed, the genital papilla looks very similar between sexes.

L174L174 Male genital papilla

L174L174 Female genital papilla

The male's genital papilla is elliptical in shape and rounded, while the female's is more elongated and finished with a flap. In adolescent fish, or fish in poor condition, both look pointed, and of equal size rendering this visual aid useless.

Tank set-up for breeding
For these small species I use a 130 L tank that measure 95x40x36 cm (that's a volume of around 130L), which is perfect for a group of 1 male and 2-3 females. However, they will breed in smaller tanks if kept as a pair. The sole current comes from a power head that pumps 1800 L/h placed on one side with the outlet near the surface and the inlet near the bottom. The current hits the other side and in that way you force the current down near the bottom of the tank when it returns to the pump. Place the cave intended as the breeding nest close to the place there the current turns back at an angle of 30 degrees - if you do that a strong current will face the entrance of the cave but not reach inside it. For these species I use caves that are 15 cm deep with an entrance 4 cm wide and 2.5-3 cm high. The following water parameters were used in the breeding tanks for these species: pH 6.8-7.2 conductivity 280-300 µS, temperature 27-29°C.

I use sand or fine gravel for bottom substrate. In some of the pictures you can see that I previously used larger gravel because I thought it was needed for the heavy currents (initially I thought sand would drift too much). I soon opted for a much finer size in all tanks, using 2 mm fine gravel instead. I learned everything depends on how I place the power heads and how strong they are (in small tanks sand is very difficult to use). Caves of the right size for the male are placed where the current turns back towards the power head. This means on the opposite side turned with the entrance against the current in an angle of circa 30 degrees and not facing the power head. A few larger stones and pieces of wood are also placed in the tank; both to provide hiding places, but also to disrupt the current so calmer areas are created where food collects and can be eaten. I placed a trio with one male and two females in just such a tank.

Water quality and food are the only important things to concentrate on. I provided clean, frequently changed water together with frozen food such as Cyclops, brine shrimp and my home made shrimp mix, together with a staple food; either granulated or tablet food made for the hobby.

The females become full and ripe with eggs in a short time and will visit the male for inspection of his cave. If she feels satisfied and ready, they will spawn. The male stimulates the female to release her eggs with high frequency vibrations (like a bumblebee), while sitting on her back blocking her escape. This is the typical breeding behavior for the genera Hypancistrus, Peckoltia and the dwarf Panaque. It is interesting to note they not only share the odontodal growths on the body but they also share reproductive behavior.

L174L174 Male in front of his cave

L316Pair of L316 spawning; male covers the female

When the female has deposited her eggs, the male lets her out of the cave and begins to tend the new eggs. There can be between 10-20 eggs (L174) or 10-25 eggs (L316) depending of the size of the female; my breeders are not fully grown yet so perhaps the species can lay even more than this. During the time he is guarding the eggs, the male turns them around from time to time in order to keep them clean, and if there are any eggs that remain unfertilized he will eat them so they do not become fungused. Under his care the eggs will hatch after 5-6 days, which is considered normal for this genus. However parameters like temperature and other, as yet unknown conditions, can delay hatching by several days. This occurred with the L174 Hypancistrus in my case; it took 8 days for them to hatch each time even though the temperature differed 2°C. I believe this is not a normal duration because I have heard from other successful breeders that their hatchings took place after 5 days.

The eggs hatch singly sometimes with hours between them and can occasionally be fanned out from the cave by the male in the course of his nesting duties. Such fry will be lost unless they are removed and placed in a rearing container. As long as they have a yolk sac other aquarium citizens will consider them as food. Although I have found such abandoned fry surviving a few times, it is just a lucky fluke that they have not been found before becoming free swimming. Once free swimming they are left unmolested. It takes from 10 to 14 days for the fry to consume the yolk sac but before that I usually empty the cave and place them in a rearing container. If I wait until they are free swimming they are very hard to get out of the cave and even though they look so small, they have a strong mouth to resist my attempt to re-house them. I have found that if I empty the cave at an early stage it disturbs the male much less. If I do it at one or two days after hatching it take less then a minute to empty the cave of fry and replace the cave exactly. Nevertheless, this is still distressing for the male and the shorter time taken the better; he recovers very fast and is normally ready the next day to breed with the next female; this is not the case if I linger over emptying the cave.

L316L316 Fry one day old

L174L174 Fry one day old

L174L174 Fry 5 days old

L316L316 9 days old

L174 & L316L316 and L174 fry 20 days old

L316L316 Fry 18 days old

L174L174 Youngster 6 month old

L316L316 Youngster 5 month old

Maintaining the fry
After the yolk sac is consumed the fry are quite big and able to eat chopped frozen brine shrimp, micro-food or crushed carnivore tablets. They should stay in the rearing container for the first two weeks so it's easy for them to find the food, and so they get a little stronger before they are moved to their own small tank. In two weeks they appear not to have grown much from the 16 mm they were when the yolk sac was consumed, but they will look a little fatter and stronger after this time if they have eaten well. They are strong enough to be moved to their own tank filled with water from the breeding tank to make it easier for them to acclimatize.

When I first started to breed plecos I used a thin layer of fine gravel in the raring tanks and I had no problems raising them, but after I read about other breeders that use no substrate I tried that technique. If nothing else, it made it easier to vacuum and keep the tank clean from waste and foods. In no time at all I started experiencing problems keeping my fry alive; one by one, with a day or so between they started to die. In the beginning I thought the problem was the water rather than any disease because there was too few dying, but the deaths never stopped how much water I changed. I can't tell for sure what was going wrong but I have my ideas about what caused the problem; after some months a bacteria film built up on the bottom glass which feels like a thin slimy coat to the touch. My thoughts about this are that the bacteria consume lots of oxygen and their end product is nitrogen which makes first, lower millimeters of water low in oxygen and high in levels of nitrogen instead. Small fry that live on the bottom practically swim, breathe and live in just this layer; their mouth and gills are, at most, 1 mm up from the bottom glass. Their oxygen level starts to decrease in their blood and the immune system weakens until they fall prey to bacteria or die from high levels of nitrogen in their blood; they are essentially "drowning". The first symptom is faster breathing followed by the loss of fin parts as bacteria attack them. I also think that the symptoms of gas, making their bellies look like a balloon is caused by the same condition; fluid containing high levels of nitrogen fills their stomachs.

Today I use a thin layer of fine gravel in all my raring tanks and since resuming with that procedure I have not had any more problems like this, of course, some fry or youngsters will die during the time you raise them but it's not common any more.

A few slates or small pieces of wood should be placed in the tank with the fry so they have something to hide under; in an empty tank they will hide in the corners and be too wary to search for food in such an open area. They need to feel secure when feeding and not, they will starve and the survival rate will fall drastically. I feed them twice a day in the afternoons and evening, or, if I have the time, I feed them in the morning and evenings and change water every second day. They are slow growers like all Hypancistrus species and reach around 4 cm after 6 months. After a year they are around 6 cm; L174 can be a little smaller. If they are sorted by size and placed in different tanks you can get them to grow a little faster so it depends a little how you care for them, in my case I have always more fry then tanks so they have competition for food for some time before I sort the biggest out. Small Panaque fry share this growth rate with Hypancistrus but Peckoltia fry do not, they grow much faster and reach a mature size in 16-18 months. There are many similarities between these three genera and the growth rate seems to be the only feature that they do not share completely when it comes to behavior and environment.

These three genera are broad fit three levels of dietary requirement; the dwarf Panaque are mainly herbivores, Peckoltia are the next stage and are accomplished omnivores, before the Hypancistrus as the final step living mainly as carnivores. This would give you an idea what to feed to keep them in the best condition and care, make them breed and thrive.

There is further information on this species on the Cat-eLog page.

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