Badis siamensis

Overview

The peninsular Thai badid Badis siamensis has dark flank marks arranged in roughly horizontal rows and a small or absent tail-peduncle blotch. Slow feeding and a retiring nature coexist with strong male territoriality, favoring a well-covered species aquarium.

Distribution & habitat

Records are restricted to west-draining river systems of Peninsular Thailand in Ranong, Phang Nga, Phuket, Krabi, Trang, and Satun.

The natural habitat has not been confirmed. Relatives commonly occupy shallow, slow streams and pools with dense marginal or submerged vegetation. That provides a comparison rather than a verified collection-site description for this species.

Aquarium setup

Arrange smooth stones, roots, and branches over sand or gravel, with floating plants and leaves forming separate retreats. Attached Microsorum, Taxiphyllum, and Anubias are optional. Strong illumination and forceful filtration are unnecessary.

Provide caves with coconut shells or accessible clay pots, spreading them out and breaking sight lines for multiple males. This species favors somewhat warmer and steadier temperatures than many congeners, so marked seasonal cooling used for northern relatives should not be transferred automatically.

Diet & feeding

The genus takes small aquatic crustaceans, worms, insect larvae, and zooplankton. Dry foods may be rejected. Regular small live or frozen Artemia, Daphnia, and similar prey remain important, even after acceptance improves. Check that slow feeders get food before their companions consume it.

Bloodworms and Tubifex are associated with obesity and health problems and are best excluded from the routine menu.

Behaviour & compatibility

A dedicated aquarium is preferable, using a pair or one male with several females where space is limited. It is not a shoaling species. Several males need separate territories and caves with effective visual barriers.

Potential companions should be peaceful upper-water fishes that do not dominate feeding. Avoid large active species and similar territorial bottom dwellers. Keep other Badis species apart because hybridization is possible. Ornamental shrimp, particularly their young, may be eaten.

Sexual dimorphism

Females are smaller, duller, and rounder. Mature males are more elongated with slightly extended fins.

Breeding

Members of the genus form temporary pairs for cave spawning, with males providing care. A dedicated breeding arrangement improves fry survival. Give every male a cave and condition the adults with live and frozen foods.

Typical generic observations include stronger male colors, increasing rivalry, and occasional mouth-locking as females are drawn into caves. Batches commonly contain roughly 30–100 eggs. The male then excludes the female and guards and fans the brood. Hatching follows in about two to three days. Young become free-swimming around six to eight days old and may remain near the cave for another week.

Adults, including the father, may subsequently eat dispersing fry, so separation becomes useful. Feed initially inactive fry microworms, adding Artemia nauplii once they swim in the water column.

Notes

Older literature may use Badis badis siamensis. Its horizontal flank markings contrast with the more vertical pattern of Badis ruber, whose tail-peduncle blotch is larger. Badis khwae lacks these rows of flank marks.

The caudal-fin base offers another distinction: this species has faint patches, B. ruber has three small dark spots, and B. khwae has a dark bar. Assess the combined pattern and locality rather than one isolated mark.