Stock Status and Growth Parameters of Pronghorn Spiny Lobster ( <i>Panulirus penicillatus</i> ) in the Prigi Waters, South Java Sea, Indonesia

ABSTRACT Lobster ( Panulirus spp.) is an important fisheries commodity in Indonesia for local and international markets. According to Minister of Marine Affairs and Fisheries (MMAF) Decree Number 19/MMAF/2022, the utilization level of lobsters in the Indonesian Fisheries Management Area (FMA 573), including Prigi Waters, has been “over‐exploited” status with the utilization rate ( E = 2.0). Similarly, the Marine and Fisheries Agency of Trenggalek Regency, East Java Province reported that the lobster annual catch has decreased by 3.28 tons from 2021 to 2022. Meanwhile, data and information regarding lobster fisheries are limited in this area. This study aims to evaluate the utilization status of the pronghorn spiny lobster ( Panulirus penicillatus ) in Prigi Waters based on parameters of growth and Length‐Based Spawning Potential Ratio (LB‐SPR). Data on catch and effort for the lobster fishery from January 2021 to December 2023 were sourced from local collectors. Meanwhile, the biological parameters of P. penicillatus were directly measured from fishers' catches between October 2023 and January 2024, resulting in a total of 2115 individual samples. This study revealed that P. penicillatus catches in Prigi Waters were dominated by legal‐sized individuals (&gt; 60 mmCL). The growth pattern is negative allometric. The growth parameters of this species were L ∞ = 133.74 mm and k = 0.50/year. The exploitation rate ( E ) was 0.57/year, and the spawning potential ratio was about 30%, indicating a “fully exploited” status. Therefore, this study recommends maintaining the level of fishing effort targeted at P. penicillatus , and replacing the illegal fishing method of compressor diving with traps.