Hypancistrus seideli

Seidel's Pleco, also known as L329, is a small and attractive member of the suckermouth catfish family from South America. Unlike the common pleco, this species stays a manageable size, typically not growing larger than 10 cm. This makes it a great choice for aquariums of 60 liters or more. Its body is flattened, which helps it navigate currents and hide in tight spaces on the tank bottom. It lives exclusively in freshwater.

This fish is an omnivore, meaning it eats both meaty foods and plant matter. It's not a true algae-eater, so you'll need to feed it a varied diet of sinking pellets, wafers, and occasional frozen or live foods to keep it healthy. Because it's a bottom dweller, make sure food reaches it, especially in a community tank.

Seidel's Pleco is generally peaceful but can be territorial towards other plecos, so providing plenty of caves and hiding spots is essential. It can get stressed by very large or hyperactive tank mates, so it does best with calm, similarly sized fish. It's considered of medium difficulty to care for, making it suitable for aquarists who have some experience in maintaining stable water conditions. With proper care, this interesting pleco can live for up to a decade.

Hypancistrus seideli, L329, is a desirable Loricariid for the experienced hobbyist due to its manageable size and interesting behavior. A minimum tank of 60 liters is suitable for a single individual, but a larger footprint is recommended to accommodate its territorial nature, especially if keeping multiple specimens. The aquascape should replicate its natural riverine habitat. This includes a substrate of sand or fine, smooth gravel and an abundance of hiding places created with rockwork, driftwood, and dedicated pleco caves (slate or ceramic). Providing more caves than fish is a key strategy to diffuse aggression. A moderate water flow is crucial, not only for recreating its natural environment but also for ensuring high levels of oxygenation, as this species has a medium oxygen demand. A canister filter with a spray bar or a strategically placed powerhead can achieve this effect.

Water parameters should be kept stable within the fish’s preferred warm, soft, and acidic range. Stability is more important than chasing exact numbers, but success is most often found in water that mimics its South American origins. Its classification as a medium-difficulty fish stems from this need for pristine and consistent conditions. With a medium rate of waste production and a bioload factor of 3.5, it places a moderate strain on the aquarium's ecosystem, necessitating a mature nitrogen cycle and a regular schedule of water changes. Monitoring Total Dissolved Solids (TDS) is beneficial, with a target around 150 ppm indicating the clean, soft water it thrives in.

As an omnivore with a preference for protein, its diet must be varied. It is an active biofilm consumer, constantly grazing on surfaces for microorganisms, but this is insufficient for its total nutritional needs. A high-quality sinking pellet or wafer should form the staple of its diet, supplemented several times a week with frozen or live foods such as brine shrimp, daphnia, and bloodworms. Unlike many Ancistrus species, a diet primarily of algae or vegetables will lead to poor health.

For tank mates, choose peaceful species that occupy the middle and upper water columns, such as small characins (tetras) or rasboras. Avoid boisterous fish that may outcompete the L329 for food or cause stress. Breeding requires special conditioning, typically involving a high-protein diet and simulated rainy seasons through large, cooler water changes. As a cave-spawner, the male will select a tight-fitting cave, trap a female inside to spawn, and then guard the eggs until they hatch.

Hypancistrus seideli is a species within the family Loricariidae, a diverse group of Neotropical catfishes. Taxonomically, it is classified under the order Siluriformes. The designation 'L329' originates from the L-number system, used as a provisional identifier for undescribed Loricariids in the aquarium trade prior to its formal scientific description. This species belongs to the genus Hypancistrus, which is distinguished from other genera like Peckoltia or Ancistrus by its dentition and a more carnivorous feeding ecology.

Ecologically, H. seideli originates from river systems in South America characterized by moderate water flow. Its preference for a pH range of 5.0-7.0, low water hardness (dGH 1-10), and a temperature between 26-30°C suggests it inhabits clear or blackwater environments with low mineral content. Its IUCN status is Not Evaluated (NE), indicating a lack of formal assessment of its population status in its natural habitat. In its biotope, it functions as a benthic omnivore. Its role as a biofilm consumer involves grazing on aufwuchs, which consists of a complex community of algae, bacteria, and other microorganisms, supplemented by opportunistic predation on small invertebrates.

The species' physiology is well-adapted to its environment. Its depressiform (dorso-ventrally flattened) body shape is a hydrodynamic adaptation for a benthic existence in flowing water, reducing drag and allowing access to narrow crevices for shelter. Its metabolism and oxygen consumption are moderate for a fish of its size, but these rates increase at the higher end of its temperature range, necessitating well-oxygenated water. The specified bioload factor of 3.5 provides a quantitative measure for advanced aquarists to calculate stocking levels and required filtration capacity, reflecting its nitrogenous waste output from a protein-rich diet.

Reproductive biology is typical for the genus. It is a paternal cave-spawner, and successful propagation in captivity requires specific environmental triggers beyond standard husbandry. These 'special conditions' often involve simulating seasonal changes, such as a drop in temperature and conductivity via large water changes, which induces spawning behavior. Male territoriality intensifies during this period, focusing on the defense of a chosen spawning cave.