The Four-lined Pimelodus Pimelodus blochii is a very handsome and hardy fish. When young its color is a pretty silver gray striped over with a darker gray which aptly gives them their name. While the term Pimelodus literally translates into “fat tooth”, the first part of its common name comes from the four lateral stripes on the flanks. Though this is there appearance when young, they often loose the striping as adults and becoming a more dusky gray. Other common names it is known by include Four-lined Pimodella, Dusky Pimelodid, and Bloch’s Catfish.

The Bloch’s Catfish has a flat-fronted nose and long flowing barbels. These characteristics lend themselves to the more generalized common names of Antenna Catfish and Flat-nosed Catfish. Like the other long-whiskered catfishes of the Pimelodidae Family, it locates its food by smell and by probing with its antennae. The Four-lined Pimelodus especially likes worms of all kinds and some of its favorites are bloodworms and earthworms.

The dorsal fin of the Four-lined Pimelodus has a strong, rigid spine with saw-edged tips that act like barbed hooks. It used to be thought that the spine was poison, as it is on a number of catfishes. But more recently several authors have said this is probably not true.

The Four-lined Pimelodus is moderately hardy, but needs an aquarium of at least 55 gallons or more. They swim in the lower portion or bottom of the aquarium and should be provided places to hide during the day. They are nighttime feeders but are not fussy about their food. They will eat most anything though have a preference for meaty foods, especially worms. In oxygen depleted waters, the Four-lined Pimelodus can change almost entirely to surface breathing. In the aquarium it will occasionally go to the surface to breath air through its intestinal respiratory system. These fish can also be kept in brackish water.

Four-lined Pimodella catfish are generally peaceful and can be kept in a community aquarium. However they are hearty feeders and will snack on any fish small enough to fit in their mouths. Larger active tetras, most barbs, gouramis, rasboras and other similar fish will be fine. Graceful fish types, like angelfish, may be bothered by the prodding of their barbels, especially after dark when these catfish are searching for food. They can be kept singly or in a group of their own kind, as well as with other catfish species like Plecostomus, Loricaria, Corydoras, Acanthodoras, and even larger cichlids.

The Four-lined Pimodella is often confused with its relative the Pictus Pimodella or Pictus Cat Pimelodus pictus. However the Four-lined Pimelodus doesn’t have the spotted patterning of the Pictus catfish. Also it is a much larger catfish, reaching  about 8 inches (20 cm) in the aquarium while the Pictus Pimelodus only reaches only about 4 1/2 inches (11 cm) in the aquarium.

Scientific Classification


Four-Lined Pimelodus – Quick Aquarium Care

Aquarist Experience Level:Intermediate
Aquarium Hardiness:Moderately hardy
Minimum Tank Size:55 gal (208 L)
Size of fish – inches14.0 inches (35.56 cm)
Temperature:68.0 to 79.0° F (20.0 to 26.1&deg C)

Habitat: Distribution / Background

The Four-lined Pimelodus Pimelodus blochii was first described by Valenciennes in 1840. They inhabit much of South and Central America, from Panama to Brazil. They are found in the Amazon and Orinoco river systems, as well as the Gulf of Paria and throughout much of Guyana. The first part of their common name comes from the fact they have four lateral stripes on their flanks, while the latin term Pimelodus means “fat tooth”. Other common names they are known by include Four-lined Pimodella, Dusky Pimelodid, Bloch’s Catfish, Antenna Catfish, and Flat-nosed Catfish.

The adaptable nature of the Dusky Pimelodid allows them to exist in brackish and freshwater conditions. They prefer moderately fast flowing river systems and are found near the bottom where they locate and hunt for food. They feed on insects and very small fish, but will also scavenge for fruit and ‘leftovers’. Four-Lined Pimelodus are gregarious and enjoy the company of their own kind.

Pimodella catfish is a common phrase used to describe a number of species that are members of either the Pimelodella genus or the Pimelodus genus. At one time these two genera were both classed as members of the Pimelodidae Family. However the taxonomy of the Pimelodidae family has been going through much revision. The Pimelodella genus has been moved into the Heptapteridae family while the Pimelodus genus remains in the Pimelodidae Family. Within the clade revision these two families are members of a Superfamily called Pimelodoidea.

  • Scientific Name: Pimelodus blochii
  • Social Grouping: Groups – Four-Lined Pimelodus are gregarious.
  • IUCN Red List: NE – Not Evaluated or not listed


The Four-lined Pimelodus is a moderately large sized catfish, reaching up to about 14 inches (35 cm) in the wild. In the aquarium it will generally reach about 8” (20 cm). Its base color is silver gray, which is striped over with a darker gray that gives them their apt name. As they mature, they often lose this striping and turn into a washed out gray tone. As with most catfish, they have flattened undersides and triangular flanks, leading up to their sharp, pointed dorsal fin. Their antennae are extremely long, allowing them to navigate in murky conditions and find the coordinates to nearby food. There are many color variances of this species which makes them hard to identify, but whether any subspecies exist are unknown at this point.

  • Size of fish – inches: 14.0 inches (35.56 cm) – They usually only obtain about 8” (20 cm) in the aquarium.
  • Lifespan: 8 years – They generally live 8 to10 years, but have been reported to live up to 15 years in the aquarium.

Fish Keeping Difficulty

These catfish are not hard to keep if proper conditions are met. They require aquariums 55+ gallons and can be messy, so frequent cleanings are required. They are unfussy about water parameters and will eat nearly anything. They become hardy if these conditions are met when they are first transferred to a new aquarium.

  • Aquarium Hardiness: Moderately hardy
  • Aquarist Experience Level: Intermediate

Foods and Feeding

Four-lined Pimelodus are omnivores that are far from fussy. They will happily consume most fish foods, but they do prefer meaty foods, especially worms. Their scavenger instincts will make them easy to feed. They’ll eat all kinds of live, fresh, and flake foods as well as pellets, tablets, and any foods that reach the bottom region of the tank.

To keep a good balance give them a high quality flake food or pellet everyday. It there is a lot of foods available, they will often gorge themselves until a prominent belly is showing. Don’t be alarmed, it is normal for them to do this and they can live off that type of feeding for up to a week. They will very happily take the treat of bloodworms or earthworms.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Most of Diet
  • Feeding Frequency: Daily – Offer a high quality flake food or pellet everyday, however if they are given the opportunity to gorge themselves on available foods, they will, and then they may go for up to a week without additional feedings.

Aquarium Care

The Four-lined Pimodella requires no special aquarium maintenance. They like opaque, blackwater such as is found in slow moving parts of the Amazon, but they do well in most reasonable aquarium environments. The recommended water change is 10 – 15% every week or 25% bi-weekly to keep up with the bio-load.

  • Water Changes: Weekly – Water change of 10 – 15% every week, 25% or more bi-weekly to keep up with the bio-load.

Aquarium Setup

A minimum 55 gallon aquarium is recommended for the Dusky Pimelodid. Pimelodus blochii prefer spacious aquariums with ample swimming space. Yet they also need numerous hiding places, like slate or driftwood, to make these generally nocturnal fish feel secure. Smooth gravel or sand is the best type of substrate for these catfish so they do not damage their antennae. Water parameters don’t have to be specific, they can range quite drastically without affecting them. This is partially due to their ability to adapt between freshwater and brackish water habitats.

  • Minimum Tank Size: 55 gal (208 L)
  • Suitable for Nano Tank: No
  • Substrate Type: Sand/Gravel Mix – Preferably a sand or fine gravel substrate.
  • Lighting Needs: Low – subdued lighting – Moderate lighting is okay if there is floating plant cover or numerous dark hiding spots.
  • Temperature: 68.0 to 79.0° F (20.0 to 26.1&deg C)
  • Range ph: 6.0-7.5
  • Hardness Range: 4 – 10 dGH
  • Brackish: Sometimes – These fish move between brackish waters and freshwater in nature.. They can tolerate brackish water but it is unclear if this is good for a long term.
  • Water Movement: Moderate
  • Water Region: Bottom – Sometimes in the lower reaches of middle area of the aquarium as well.

Social Behaviors

Four-Lined Pimelodus are usually peaceful, gregarious fish, existing well in peaceful to semi-aggressive communities. They will, however, consume small fish like Neon Tetras and will sometimes nip at slow, longer finned fish if they become bored. Graceful fish types, like angelfish, may be bothered by the prodding of their barbels, especially after dark when they search for food. Larger active tetras, most barbs, gouramis, rasboras and other similar fish will be fine.

They can be kept singly or in a group of their own kind, as well as with other catfish species like Plecostomus, Loricaria, Corydoras, Acanthodoras, and even larger cichlids. Keeping them in group helps to keep them preoccupied with each other and avoid harassing other fish.

  • Venomous: Unknown – There is conflicting literature on the subject of the possibility of this fish having venom in its spines.
  • Temperament: Semi-aggressive – Some fish will be bullies although overall they are agreeable fish.
  • Compatible with:
    • Same species – conspecifics: Yes – They will nip at the fins of the same species, but generally cause little harm.
    • Peaceful fish (): Safe – Don’t keep with fish that are much smaller since these catfish are predaceous.
    • Semi-Aggressive (): Safe
    • Aggressive (): Monitor
    • Large Semi-Aggressive (): Safe
    • Large Aggressive, Predatory (): Threat
    • Monitor
    • Shrimps, Crabs, Snails: May be aggressive – May consume small snails and shrimp.
    • Plants: Safe

Sexual differences

There is no known way to sexually differentiate these fish – males may grow larger.

Breeding / Reproduction

The Four-Lined Pimelodus have not been successfully bred in aquariums. In the wild the Pimelodus blochii are seasonal breeders. Spawning occurs only once a year during the rainy season, and only for a short period of time.. They are thought to migrate upstream during reproduction. The female lays an average of 50,000 eggs which are fertilized externally.

  • Ease of Breeding: Unknown – This fish has yet to bred in home aquaria.

Fish Diseases

Four-Lined Pimelodus have no specific diseases associated with them. If proper conditions and acclimating methods are met they tend to be hardy fish. Like most catfish,being scaleless it makes them difficult to treat, particularly if they get Ich. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.

Because they are a scaleless fish, catfish can be treated with pimafix or melafix but should not be treated with potassium permanganate or copper based medications. Malachite green or formalin can be used at one half to one fourth the recommended dosage. All medications should be used with caution.


Four-Lined Pimelodus are not hard to obtain, but are only occasionally found in pet stores. Special orders or online orders might be required. They are moderately priced.



 Pimelodus blochii (Image Credit: Ictiologia Universidad Católica de Oriente, Wikimedia Commons CC BY-SA 2.0 Generic)