This study was carried out to determine the reproductive biology characterizations of the tiger tooth croaker (Otolithes ruber) in Iraqi marine water northwest of the Persian Gulf. Test organism – Otolithes ruber, a total of 221 fish and around (8.1– 46.6 cm) in length were collected using bottom gill net and trawl. An upward trend was observed in the gonadosomatic Index (GSI) in March. It found that the sex ratio of females was more than males during the breeding season. Five stages of the sexual development of the gonads were identified. The length at first maturity (Lm₅₀) was 27 cm. The absolute fecundity rate of O. ruber is 436636 eggs. The months of January and February recorded the predominance of the developing stage of females, which will participate in reproduction. The breeding period was determined from March to April, reproduces once a year. The results of the study support the dynamic applications of O. ruber stock, which will help in the management choices for a sustainable stock for future generations.