Esmaeilius arakensis · Arak Toothcarp

Overview

Esmaeilius arakensis is a small Iranian spring-dwelling toothcarp formerly traded under provisional Namak labels. Its size does not prevent vigorous breeding pursuit. A dedicated group with clear provenance is preferable to mixing visually similar relatives.

Distribution & habitat

It appears limited to a few natural springs near Arak within the closed Namak basin, outside the saline lake itself. The type locality is a shallow spring-fed pool over mud and gravel, without higher submerged plants but with rushes and cattails at the margins.

During fieldwork the water was nearly still and the habitat showed human pollution. These observations demonstrate vulnerability rather than conditions to reproduce in an aquarium.

Aquarium setup

Plan at least about 120 × 30 cm for a group. Abundant fine spawning mops and filamentous algae interrupt sightlines and supply egg attachment sites. Females and subordinate males need relief from dominant males.

Marine salt at about 1–3 g/L is used for maintenance; ordinary moss or hornwort may struggle. Substrate is optional, with inert sand and gravel suitable, and filtration should be gentle. Outdoor care can work where the climate is appropriate, with several hours of natural light benefiting color and condition.

Diet & feeding

Relatives consume small crustaceans, worms, insect larvae, and similar prey, plus algae and plants. Dry foods should be accompanied by regular live or frozen brine shrimp, Daphnia, and bloodworms, particularly during demanding spring and summer reproduction. Include a quality plant-enriched formula where filamentous algae are absent.

Behaviour & compatibility

Keep a separate, single-species locality group with two or three females per male. Water requirements and strong breeding activity make conventional community housing unsuitable. Layout should allow pursued fish to move out of sight.

Sexual dimorphism

Males show silver bars toward the rear, sometimes two or three pale tail bands, and whitish edges on the dorsal, anal, and tail fins. Front dorsal rays are dark, paired fins yellowish, and dark blotches often mark the dorsal and anal bases. Larger, plainer females carry dark flank blotches and whitish fins.

Breeding

Its strategy suits unstable small habitats: life is usually shorter than three years, maturity is early, and reproductive effort is high. Repeated spawning typically runs from April to November, with April and August peaks. Males defend temporary territories, and eggs attach by fine threads to algae or other material.

Adults may eat eggs and fry, so inspect the medium daily. Move egg-bearing fragments with fine forceps without touching the eggs, or replace entire mops every few days. Match incubation water to adult temperature and chemistry. Hatching generally takes seven to fourteen days. Free-swimming fry can take brine shrimp nauplii and microworms immediately.

Notes

Namak and Namak River are historical trade designations. Several Iranian relatives look similar. Male bars and large female blotches aid recognition but cannot replace reliable source information.