Order Siluriformes
Family Doradidae (Thornycatfishes)
Genus Acanthodoras.
Inhabit the waters of Guyana and the Amazon and Orinoco river basins. These fish are peaceful bottom-dwellers, spending the daytime in hiding and actively digging in the substrate for food at dusk. Can be kept in a community aquarium with a substrate of rounded sand, plants, and shelters made of rocks and driftwood.
— Chocolate Talking Catfish — Acanthodoras spinosissimus [Eigenmann, 1888]. Synonym: Doras spinosissimus. South America, freshwaters of Brazil, Colombia, and Peru. 10-13 cm. Body slightly elongated, wide and flattened, tapering towards the tail in the dorsal fin area. Head large, mouth terminal. Three pairs of barbels present. Hard bony plates cover more than half of the flank (missing only on the top and bottom of the caudal peduncle). Dorsal fin equipped with serrations, adipose fin small, caudal fin rounded.
Body coffee-brown with scattered dark brown spots. Light longitudinal stripes run along the body: the first along the flank from the eye to the base of the caudal fin, and the second along the back. Belly and lower part of the head light brown with uneven yellow lines and light dots near the anal fin. A distinctive feature is the presence of light spots on the dorsal surface between the dorsal and caudal fins.
Unpaired and pelvic fins dark brown with 2-3 white transverse bands. Caudal fin rounded. On the dorsal and pectoral fins, the first ray has transformed into a strong serrated spine that can inflict slow-healing wounds during capture. Males are smaller, brighter, with brownish barbels featuring light rings and distinct speckling, and a belly with white-brown spots. In females, the belly is brownish, and barbels are light yellow. Notably, their growth rate is twice as fast as that of males, which can only participate in spawning in their third year of life.
Peaceful fish. Requires an aquarium with dense thickets of live plants and various shelters (driftwood, rock caves, etc.). Prefers dim lighting and a thick layer of rounded sand substrate, where they eagerly dig in search of food. Can be kept in a community aquarium with dense live plants and shelters made of rocks and driftwood.
Compatible with various fish species. Inhabit the lower water layers. Become active at dusk. Like to hide in shelters. If these nocturnal and crepuscular fish do not find a sufficient number of hiding places in the aquarium, they may start burying themselves in the substrate.
Filtration, aeration, and water changes are necessary. Eats dry, live, and vegetable food (30% algae). Using fin vibrations, bone friction, and swim bladder contractions, they produce loud croaking-like sounds. These help the fish find partners and warn of danger. Reach sexual maturity unevenly: females at 1.5 years, males at 3 years. Lifespan 10 years. pH 6.0-7.5; dH 2-20°; T 22-26°C.
— Milky Catfish, Painted Talking Catfish, Chocolate Raphael, Chocolate Talking Catfish, Spiny Catfish — Acanthodoras cataphractus [Linnaeus, 1758]. Bolivia, Brazil, Peru, Colombia, Amazon River basin. 11 cm. Body slightly elongated, wide and flattened, tapering towards the caudal peduncle. The large flattened head features small eyes, a terminal mouth, and three pairs of barbels. Hard bony plates cover more than half of the flank (missing only on the top and bottom of the caudal peduncle). Adipose fin small, caudal fin rounded.
Main body coloration chocolate brown. Lower half of the head and belly light brown with uneven yellow lines and whitish dots near the anal fin. Orange longitudinal lines run along the body – one along the flank from the eye to the tail base and another along the back.
Fins light brown with chocolate-colored dots. Male is smaller and slenderer, more contrastingly colored, with a dark marbled belly and brownish barbels with light rings; female has a gray-brown belly and light yellow barbels. On the dorsal and pectoral fins, the first ray has transformed into a strong serrated spine that can inflict slow-healing wounds during capture.
Sometimes confused with Platydoras costatus. The easiest way to distinguish the fish is to look at the light-colored stripes on their flanks. In P. costatus, the stripes continue into the caudal fin and around the fish’s head, which is not the case in A. cataphractus.
Peaceful and hardy fish. Nocturnal in habits. By day, they hide in shelters or bury themselves in the substrate, becoming active at dusk. Can be kept in a community aquarium with rounded sand substrate, plants, and shelters of rocks and driftwood. Compatible with various fish species. Inhabit lower water layers. Love hiding in shelters.
Prefers dim lighting and a thick layer of substrate, where it eagerly digs for food. Consumes dry, live, and vegetable food (25%). Filtration, aeration, and weekly water changes are required. These fish can produce sounds somewhat similar to croaking, which help them find partners and warn of danger. Live up to 10 years in captivity. pH 6.0-7.5; dH up to 25°; T 22-27°C.
Agamyxis albomaculatus, Agamyxis pectinifrons.
Genus Nemadoras, Genus Orinocodoras, Genus Oxydoras, Genus Pterodoras, Genus Rhinodoras. 
