Size distribution and growth patterns of banana prawn (Penaeus merguensis) in the shallow waters of Merauke District, Indonesia

The shallow waters of Merauke District, Indonesia, have biological resources such as banana prawns (Penaeus merguensis). However, studies on the size distribution and growth patterns based on habitat in the shallow water are limited. This study aims to answer what habitats are suitable for prawn fishing areas and as nursery grounds. Additionally, it aims to determine whether growth patterns differ in each habitat. The results showed that juvenile prawns were found in some habitats in March, related to the spawning season in the previous month. The increase in the size of banana prawns as sub-adults begins in April, with adult size being reached in different months in each habitat, due to increased water salinity and temperature decreases. The presence of adult prawns in estuarial habitats and sandy beaches at Lampu Satu in September was related to the spawning season. A decrease in size, from adult to juvenile prawns, was observed in estuarine habitats and sandy beaches in Lampu Satu, in mangroves in Yobar, and on sandy beaches in Payum. In contrast, adult prawns could be found in mangrove habitats in Bokem, from October to January, but in the sandy beach habitat of Payum, they can be found until February, and in the mangroves in Bokem, until December. This is due to the influx of fresh water, causing the spawning of adult prawns in the preceding month (namely September), to conclude. Juvenile prawns then take their place in areas adjacent to the estuary. The increase in size from March onward is due to the low supply of fresh water, a decrease in temperature, and a pH above 7. These conditions are signals for both sub-adults and adults to spread more widely, replacing juvenile prawns in some habitats. The growth pattern in all habitats for males and females were negative allometric (b