Hoplisoma davidsandsi · Sand's Cory

Overview

Among Negro-basin catfishes with an oblique dorsal band, Hoplisoma davidsandsi has a forked band above the caudal peduncle and a pale orange area behind the facial stripe. Peaceful group housing in soft, acidic water suits this social species.

Distribution & habitat

It appears endemic to the Unini tributary of the lower Negro in Brazil. The type locality was called a whitewater area, although observations support a blackwater system. The wording may have referred to local rapids rather than sediment-rich white water.

Habitats are therefore presumed to include organically stained tributaries and flooded forest with low hardness, low conductivity, and acidic water. This remains a habitat interpretation rather than a precisely documented site description.

Aquarium setup

Fine sand is preferable; rounded gravel requires particularly good cleaning. Other decoration is flexible, provided sheltered spaces give the group security.

Diet & feeding

Related cory catfishes are generally foraging omnivores. Captive feeding commonly combines sinking prepared foods with small live or frozen bloodworms and aquatic worms.

Deliver a varied ration deliberately. Leftovers from other fishes are unreliable, and catfish cannot take over the task of cleaning the substrate.

Behaviour & compatibility

A peaceful and gregarious fish, it should have at least four to six conspecifics.

Sexual dimorphism

Females tend to be larger, rounder, and deeper-bodied once mature.

Breeding

Methods used for related catfishes can be followed, with approximately two males per female. When females are visibly gravid, a 50–70% change with slightly cooler water within the suitable range, plus increased oxygenation and movement, can stimulate spawning. Repeat daily if needed.

Eggs are usually attached to glass, although fine vegetation and fine-fiber mops should be available as alternatives. Separate adults and eggs afterward. Glass-bound eggs can be gently rolled free with a finger and moved into the same water with good aeration. Some breeders use a little methylene blue or one or two alder cones against fungus.

Incubation usually lasts three to four days. After yolk absorption, fry accept microworms and Artemia nauplii. A thin sand layer appears to reduce ailments compared with completely bare flooring, while careful water maintenance remains essential.

Notes

The forked dorsal band resembles that of Hoplisoma melini. In this species, the pale orange area between the facial mark and dorsal band, together with the absence of additional dark flank markings, helps establish identity.

Related armored catfishes use a modified intestine to supplement oxygen intake, explaining occasional surface gulps. Handle carefully around the pectoral spines: punctures can be painful, and secretions near their bases may be mildly toxic.