Candiru

Vandellia cirrhosa

FAMILY

Trichomycteridae

TAXONOMY

Vandellia cirrhosa Valenciennes, 1846, probably South America.

OTHER COMMON NAMES

Spanish: Candirú.

PHYSICAL CHARACTERISTICS

Length 1 in (2.5 cm). Body naked and very elongate; dorsal fin short, without a pungent spine, its origin posterior to pelvic fins; adipose fin absent; anal fin origin behind dorsal fin base, short; mouth narrow and suckerlike, inferiorly located; lower jaw toothless; mental barbels absent; eyes without free margins; opercular bones with spines. With a yellowish tinge or almost transparent.

DISTRIBUTION

South America in the Amazon River basin.

HABITAT

Freshwaters. Benthic, burrows in sandy bottoms.

BEHAVIOR

Parasitic, enters the gill cavity of larger fishes, frequently long-whiskered catfishes, to suck blood.

FEEDING ECOLOGY AND DIET

An obligate parasite that in captivity refuses any kind of food. However, it attacks a living fish by entering the gill chamber when inhaled water is expelled. Once in place, the candiru lodges itself using its opercular spines, bites off tips of host's gill filaments, and gorges with flowing blood. The candiru's body can distend considerably, and after few minutes of feeding it drops off to the bottom, where it burrows or just remains quiet.

REPRODUCTIVE BIOLOGY

Nothing known.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

Known to enter the urogenital openings of bathers, usually if they happen to urinate under water. The candiru swims up the flow of urine, possibly mistaking it for the water flow from a gill cavity. After penetrating as far as possible, the fish locks its opercular spines into position. This has obviously serious consequences for both the fish and the person, since the candiru can only be removed by surgery. Humans in its range protect themselves by wearing tight clothing when swimming (and by refraining from urinating underwater).