Panulirus ornatus atau biasa disebut lobster mutiara memiliki nilai ekonomis tinggi bahkan diperdagangkan hingga pasar internasional jika dibandingkan dengan lobster tropis lainnya seperti (P. versicolor, P. Homarus) dan (P. polyphagus). Keberadaan spesies ini menjadi sesuatu yang harus dipertahankan sehingga upaya konservasi terhadap lingkungan biologi menjadi faktor penting. Tujuan penelitian untuk mengetahui hubungan panjang berat dan faktor kondisi lobster mutiara (P. ornatus) yang tertangkap jaring insang (Gill net) di Perairan Kota Tarakan. Metode penelitian menggunakan analisis hubungan panjang berat, rasio kelamin dan faktor kondisi. Metode pengambilan sampel menggunakan observasi berdasarakan purposive sampling dengan mengikuti nelayan Gill net. Pengambilan sampel dilakukan di perairan bagian Barat Kota Tarakan. Pengambilan sampel dilakukan selama 5 bulan dengan total tangkapan sebanyak 15 ekor. Pengambilan data berupa Panjang total (PT), berat total (BT). Analisa data menguji pertumbuhan dan faktor kondisi lobster mutiara dengan data pendukung seperti kedalaman, kecerahan dan salinitas. Hasil penelitian didapatkan rasio kelamin jantan dan betina yaitu 1 : 1,14. Pertumbuhan Lobster mutiara jantan dan betina bersifat allometrik negatif. Bentuk tubuh paling banyak di temukan pada lobster mutiara jantan memiliki bentuk tubuh gemuk sedangkan betina memiliki bentuk tubuh gemuk dan kurus.
Kata kunci: Pertumbuhan, Faktor Kondisi, Lobster Mutiara, P.ornatus, Gill net

Panulirus ornatus or commonly called pearl lobster has high economic value and is usually traded in the international market when compared to other tropical lobster such as (P. versicolor, P. Homarus) and (P. polyphagus). The existence of this species must become attention to be kept so the conservastion efforts on the biological environment become an important factor. The purpose of this study was to determine the relationship between weight-long and condition factors of pearl lobster (P. ornatus) caught in gill nets in the area waters of Tarakan City. The research method used the analysis of the relationship between weight-long, sex ratio, and condition factors. The sampling method used observation based on purposive sampling by following Gill net fishermen. Sampling was carried out in the area waters of the wastern part of Tarakan City. Sampling was carried out for 5 months with a total catch of 15 fish. Data collection was about total length (PT), and total weight (BT). Data analysis tested the growth and condition factors of pearl lobster with supporting data such as depth, brightness, and salinity. The results showed that the ratio of male and female sex was 1: 1.14. The growth of male and female pearl lobsters was negative allometric. The most common body shape found in male pearl lobsters has a fat body shape while the female has fat and thin body shape. Keywords: Growth; Condition Factor; Pearl Lobster; P.ornatus; gill net