Description

Hoplistoma axelrodi:

Axelrod’s Catfish Care Guide

Common Name: Axelrod’s Catfish, $\text{Axelrod’s Hoplo}$ Scientific Name: Hoplistoma axelrodi (often now reclassified as Dianema axelrodi in the hobby) Family: $\text{Callichthyidae}$ (Armoured Catfish family, which includes the $\text{Corydoras}$ genus) Origin: South America (specifically, the slow-moving tributaries of the $\text{Rio Meta}$ system in Colombia).

The name confusion often arises because H. axelrodi shares the peaceful temperament and shoaling behaviour typical of $\text{Corydoras}$. However, they have a distinct, more elongated, torpedo-like body shape compared to the chunky, rounded profile of most true $\text{Corydoras}$ species. Like their cousins, they are excellent, non-aggressive additions to a community tank.

Key Characteristics and Appearance

• Size: They typically reach a maximum adult length of 4$\text{to 5}\text{ cm}$ (approximately 2 inches).
• Appearance: This species is noted for its sleek body and elongated snout. They typically display a creamy brown or beige base colour patterned with distinct dark spots or blotches. They use their long, sensitive $\text{barbels}$ constantly to sift through the substrate for food.
• Temperament: Highly peaceful and social. They are shoaling fish and become stressed if kept alone.
• Activity: While active at night, they will readily emerge to feed during the day, especially if they are kept in a well-established group.

Aquarium Setup Requirements

These catfish thrive in setups that mimic their natural South American jungle river habitat—slow-moving, dark water with plenty of leaf litter and cover.

Tank Size and Substrate

• Minimum Tank Size: A $100\text{ litre}$ tank is the recommended minimum for a small shoal of at least five or six individuals. As bottom dwellers, the tank’s length and width (footprint) are more important than its height.
• Substrate: Fine river sand is absolutely essential. Using coarse gravel can quickly damage their delicate barbels, which they use to locate food. Damaged barbels can lead to infection and difficulty feeding.
• Decor: Furnish the tank with plenty of hiding places like bogwood, smooth river stones, and large leaf litter (e.g., Indian Almond leaves, which also release beneficial $\text{tannins}$). They love resting in shaded areas.

Water Parameters

H. axelrodi are adaptable but prefer soft, slightly acidic conditions for optimal health.

Parameter	Recommended Range
Temperature	22∘C to 26∘C (72∘F to 79∘F)
$\text{pH}$	$6.0$ to $7.5$ (Neutral or slightly acidic is best)
Hardness ($\text{GH}$)	Soft to Medium ($\text{dH }2\text{ to }12$)

Filtration and Flow

They require excellent water quality but dislike strong currents. A quality external or internal filter should be used, but ensure the water return is baffled or directed against the glass to create a gentle, diffuse flow.

Diet and Tank Mates

Dietary Needs

As opportunistic, omnivorous bottom scavengers, they require a varied diet to remain in peak condition.

• Staple: High-quality sinking pellets, wafers, and granules.
• Supplement: Offer frequent frozen or live treats like bloodworms, $\text{daphnia}$, and brine shrimp. This variety helps boost their immune system and encourages natural foraging behaviour.
• Feeding Tip: Always drop food directly onto the substrate after the main lights have dimmed or gone out, as this caters to their slightly $\text{nocturnal}$ nature and ensures faster fish don’t steal their dinner.

Compatibility

H. axelrodi are ideal community fish. They co-exist happily with most small, peaceful tropical species.

• Good Tank Mates: Small $\text{Characins}$ (like $\text{Neon}$ or $\text{Black Skirt Tetras}$), $\text{Rasboras}$, small $\text{Loaches}$, and $\text{Dwarf Cichlids}$ ($\text{Rams}$, $\text{Apistogrammas}$).
• Avoid: Large, overly aggressive, or overly boisterous species that might intimidate them or outcompete them for food.