Redhook Myleus

Geographic Origin and Biotope: Amazon river basins (Orinoco, Rio Negro, etc.) in South America. Populates dense oxbow lakes covered by roots and flooded forests where plant cover is very heavy.

Taxonomy and Morphology: Redhook Silver Dollar (Myloplus rubripinnis / ex Myleus rubripinnis). Vegetarian "Pacu/Piranha" of impressive size. It has a flattened silver disk, but boasts a sickle or hook-shaped anal fin.

Social Behavior: Titanic Gregariousness (Schooling). Unlike small fish, fear in this beast translates into sprints that break heaters. Keeping a school of at least 5 mitigates panic and stops the group from breaking apart.

Coloration and Sexual Dimorphism: Shiny silver metallic shield (more ash-gray in adulthood). The hallmark is the huge fleshy anal hook of an intense carmine red (Red-hook). Males develop extended filamentous dorsal fins and a fringed anal lobe (females have a straight, clean red hook).

Aquarium Setup: Monster Tank (200+ cm / 80+ inches, 700 Liters / 185 Gallons). Do not waste money on furnishings: sharp branches will flay them in their sprints and they will destroy, eat or uproot ANY existing aquatic plant (even Anubias and Java Ferns or plastic!).

Diet and Feeding: Vegetable-mincing machine (Frugivore/Herbivore). They have powerful jaws with crossed flat teeth born to break hard pits. Feed massively with zucchini, peas, cucumbers, blanched lettuce or vegetable feed for koi carps.

Water Quality: Moderately acidic water (preferably tannic to reassure them), but they are pollution machines (Critical Bio-load). They suck in huge amounts of food and produce gigantic feces; double external/pond external filters are essential.

Compatibility and Tankmates: The perfect Dither-Fish for Super Cichlids. No South American or Central American cichlid (even Peacock Bass, Oscars or Jaguar Cichlids) can swallow this spiky silver flying saucer. Harmless to other species (if not tiny).

Aquarium Reproduction: Virtually absent due to lack of space (only in zoos or indoor public pools). Couples release eggs that sink amid the school during the wet season.

Risks and Diseases: Glass-breaker from light explosion. The sudden turning on of the neons above their tank unleashes a 25 cm (10 inches), one-pound bullet against the front glass, causing the animal's skull to fracture or the glass to crack (use LED Sunrise/Sunset or dim lights).