Maximum size : 15 cm

Spotted Hoplo Catfish - Megalechis thoracata : Complete Fish Profile & Care Guide

Table of contents


Spotted Hoplo Catfish (Megalechis thoracata) are a fascinating and visually striking addition to any aquarium. These peaceful and intelligent fish are highly adaptable and hardy, making them an excellent choice for both novice and experienced aquarists alike.

While more prominent individuals can become a bit boisterous in a community setup due to their digging behaviour and nocturnal activity, they are not predatory and will coexist peacefully with larger, more aggressive species. Complementary tankmates for Spotted Hoplo Catfish may encompass medium-sized representatives of the Barb family, substantial Rainbowfish species, larger Devario species, medium-sized or deep-bodied Tetra species, as well as medium to large-sized Rasbora species. Additionally, the inclusion of Severum Cichlids and analogous counterparts can be considered.

It is crucial to recognize that Spotted Hoplo Catfish exhibit spirited feeding behaviour. Consequently, during feeding sessions, it is advisable to distribute sustenance concurrently across various locations within the tank to ensure equitable access to nourishment for all other cohabiting fish. However, smaller fish should not be kept with them as they will likely become a midnight snack. Spotted Hoplos are highly social and should be kept in groups of at least five individuals, although larger groups are even better for their well-being.

The diligent care of Spotted Hoplo Catfish necessitates vigilant monitoring, particularly during the pairing and spawning phases, as the male may exhibit heightened aggression, potentially necessitating the relocation of other fish inhabitants. Juvenile specimens may find suitable accommodation within a 4-foot long aquarium, but the spatial demands of adults mandate a more expansive habitat.

Creating an optimal environment involves the provision of a soft sand substrate, which proves gentle on their lengthy sensory barbels, alongside the incorporation of abundant shaded refuge opportunities amidst well-anchored bogwood, rocks, and robust aquatic vegetation. Given the proclivity of Hoplo Catfish for excavation, it is imperative to ensure the structural stability of aquarium arrangements. Lighting should be subdued to prevent excessive brightness, potentially diffused through the inclusion of floating plant species. For enhanced observation of this primarily nocturnal species during the late evening hours, the installation of a blue moonlight tube is highly recommended.

Despite their perceived adaptability to suboptimal conditions in the wild, it is imperative to uphold stringent aquarium maintenance and water change protocols. Spotted Hoplo Catfish thrive in environments characterized by high oxygen levels and substantial water current, underlining the significance of these factors in their care regimen.

The primary body colour of the Spotted Hoplo Catfish is a beautiful shade of brown, adorned with small dark spots of varying shapes and sizes scattered throughout. The creamy-white abdomen complements this pattern, while the dorsal and tail fins are small and triangular in shape. In addition, the males have a more triangular pectoral fin, while the females have an oval one. In rare cases, an albino variety can be found in the hobby, featuring a milky colour with dark spots on the body.

Spotted Hoplo Catfish Photos

Sexual Dimorphism

The process of distinguishing between male and female Spotted Hoplo Catfish is relatively simple. Males that have reached sexual maturity will display a thickened first pectoral ray that varies in colour from orangey-brown to scarlet. Additionally, the male's belly may take on a more bluish hue during breeding conditions. Conversely, females are typically fuller-bodied, with more rounded fins compared to males.

Quick Facts

Scientific NameMegalechis thoracata
Year Described1840
Other NamesBlack Marble Hoplo, Hoplo Catfish, Port Hoplo Catfish
OriginsRussia , Brazil , Suriname
Max Size15 cm
Aquarium LevelBottom
DifficultyBeginner - Intermediate
Best kept asGroups 5+
Diet & FeedingOmnivore
ReproductionBubble Nester
LifespanUp to 10 Years

Water Parameters

Water TypeFreshwater
pH 5.5 - 8.5
GH 1 - 20
Ideal Temperature
63 - 82
17 - 27

Natural Habitat

The Spotted Hoplo Catfish, a captivating and unique freshwater fish, can be found in various regions across South America. This species has adapted to living in the sluggish and murky waters of the Amazon, Orinoco, and Upper Paraguay River basins, as well as the coastal rivers of the French Guianas and the Mana River. They are also prevalent in the northern part of Brazil. In their natural habitat, Spotted Hoplo Catfish prefer to reside in calm, almost stagnant waters, including rivers, swamps, ponds, and flooded regions. These environments are typically covered in dense vegetation, which provides them with shelter and an ample food supply.

 Orinoco - Venezuela
Venezuela Flag
 Paraguay River - Brazil
Brazil Flag


Breeding the Spotted Hoplo Catfish is relatively easy, as these fish are bubble nesters. The males reach sexual maturity between 18 months to two years old, and you can induce spawning behaviour by changing the water in the tank with cooler water. It is recommended to set up a separate breeding tank with plenty of floating plants to support the male's bubble nest, which he will build on the water's surface. It is also essential to minimize the surface movement from filtration to avoid destroying the nest.

To encourage spawning, the breeding pair should be conditioned with plenty of live and frozen foods and a significant water change of colder water. Once the female lays her eggs in the nest, the male will guard and defend them, and it may be necessary to remove the female from the breeding tank to avoid aggression from the male.

The eggs usually hatch around 48 hours after being laid, and it is best to remove the male from the breeding tank at this point to prevent him from eating the fry. The fry becomes free-swimming after three or four days and can be fed with freshly hatched brine shrimp initially, progressing onto fry foods such as crushed flakes and pellets as they develop.

Diet & feeding

To maintain optimal health and vibrancy, providing the Spotted Hoplo Catfish with a diverse and nutrient-rich diet is crucial. These omnivorous fish are not overly finicky and will readily consume a range of high-quality flakes, granules, sinking pellets, and wafers. In addition, supplementing their diet with occasional servings of live or frozen fare, such as bloodworms, brine shrimp, insect larvae, and earthworms, can be highly beneficial. With a well-rounded diet, these catfish will thrive and exhibit their full range of natural behaviours and colours.

Other Other Catfish of interest