(No common name)

FAMILY

Phallostethidae

TAXONOMY

Neostethus bicornis Regan, 1916, Kuala Langat, peninsular Malaysia.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

Small, transparent fish, with urogenital and anal openings placed far anteriorly. Dramatic sexual dimorphism. Males have a complex, asymmetrical structure, the priapium, derived from the pectoral and pelvic girdles and used in reproduction.

DISTRIBUTION

Peninsular Malaysia, Singapore, Thailand, Borneo, Palawan (Philippines).

HABITAT

Fresh and brackish water.

BEHAVIOR

Forms small schools in shallow water near the shore.

FEEDING ECOLOGY AND DIET

Planktivorous.

REPRODUCTIVE BIOLOGY

The male violently swims into the female and knocks her onto her side, gripping her with his ctenactinia, two elongate bones that are part of the priapium. He then attaches a bolus of sperm over her oviduct and swims in rapid spirals and forward bursts that may break the surface of the water, apparently in an effort to break free from the female.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

None known.