the ratio between females and males is about 1.3:1. In terms of growth, the fish significantly increase in length and weight during their first year of life, with females reaching a length of 11.3 cm and males reaching 11.15 cm. Maturation also begins after one year; however, after sexual maturation, both sexes' growth rate decreases. Spawning rates increase in March and fall down after April. During the spawning season, the GSI value of males is larger than females, but the mass of the female gonads is slightly greater than their male counterparts. Species within genus Atherinosoma Three species of Atherinosoma (A. presbyteroides, A. enlongata, A. wallacei) are located in South-Western Australia. A. presbyteroides is a primarily marine species that can also live in estuaries, A. enlongata is only found within an estuary, and A. wallacei is found in both estuary and inland waters. Atherinosoma presbyteroides have a lifespan of one year, and its length ranges from 25 to 75 mm. Specifically, females are about 69.1 mm while males are 59.1 mm in length when they reach sexual maturity. Smaller fish are present throughout the year, which means that breeding occurs over a long period of time. This species primarily lives in estuaries, so their breeding occurs there, but as the fish mature, they travel to the ocean and spawn there. Spawning begins from August to November due to the GSI of the fish being significantly high in both males and females. However, younger fish have their GSI relatively high during April and May, indicating that spawning may occur in the Spring. Atherinosoma enlongata is found in Australia’s south-western estuaries and ranges from 40 to 78 mm in length. Fish are usually bigger in size during the summer months than winter months. The lifespan of this species is about one year, so the fish grow significantly during their first months of life. When sexual maturity is reached, females are about 68.9 mm in length while males are 54 mm. The gonadosomatic index (GSI) for both males and females increases after August and remains high until December, indicating their breeding period is around these months. Atherinosoma wallacei has a lifespan of one year, and its length ranges from 25 to 50 mm; females are longer than males. When sexual maturity is reached, females have an average length of 54.8 mm, and males have an approximate length of 44.7 mm. Additionally, the number