Biological aspect of double-spined rock lobster (Panulirus penicillatus) in Wonogiri Regency waters, Central Java, Indonesia

Abstract

Spiny lobsters (Panulirus spp.) are an economically important species in the fishery industry and continuously being exploited, particularly in the South of Java. Lobsters in Wonogiri Regency waters have decreased in number, and the average size lobsters caught is also getting smaller. Double-spined rock lobster (Panulirus penicillatus) is the dominant species caught by the fishermen but has limited biological information. The objective of this study is to identify several factors affecting double-spined rock lobster (P. penicillatus) population in terms of growth parameters, mortality rates, and exploitation rates. This study was conducted in August 2018-January 2019. The analysis uses the FAO-ICLARM Stock Assessment Tool (FISAT II) program. The growth rates (K) of P. penicillatus male and female lobsters are 0.32 year-1 and 0.37 year-1. The mortality rates (Z) 2.35 year-1 for males and 2.84 year-1 for females. The exploitation rate of males 0.77 and females 0.77 and 0.78, respectively. It has exceeded the optimal level (0.5) and reached overfishing value. The management of lobster fisheries needs to be done by several approaches, including a reduction of fishing efforts and prohibited from catching lobster in berry (with eggs) conditions to sustain their population naturally.