Electronic Theses and Dissertation

Lingula sp. adalah salah satu genus dari filum Brachiopoda yang berada di zona interdal atau daerah yang masih dipengaruhi oleh pasang surut air laut. Tujuan dari penelitian ini untuk mengetahui struktur populasi Lingula sp. melalui pendekatan sebaran ukuran, hubungan panjang dan berat, faktor kondisi, kepadatan dan pola sebaran dengan parameter fisika dan kimia serta substart di Perairan Silo Baru Sumatera Utara. Metode yang digunakan dalam penelitian ini adalah metode purposive sampling. Hasil penelitian menunjukkan sebaran ukuran di Perairan Silo Baru jika digabungkan maka didapati selang kelas terbanyak terdapat pada selang kelas 49-52 mm (20 individu). Pola pertumbuhan Lingula sp cenderung membentuk pola allometric negetif, yang merupakan pertambahan panjang lebih cepat dibandingkan pertambahan bobot. Kepadatan Lingula tertinggi terdapat pada minggu pertama dengan nilai rata-rata 4.5 ind/m2. Sedangkan kepadatan Lingula sp yang terendah terdapat pada minggu ketiga dengan nilai rata-rata 3.0 ind/m2. Pola penyebaran Lingula sp. pada ketiga minggu bersifat seragam, dengan indeks morisita (Id) di minggu pertama 0.970, dan di minggu kedua 0.904, sedangkan di minggu ketiga 0.805. Faktor fisika-kimia lingkungan perairan tergolomg normal dan menunjang kehidupan Lingula sp. di Perairan Silo Baru. Kondisi substrat yang berteksut pasir juga sangat berpengaruh terhadapat pertumbuhan Lingula sp.
Kata Kunci : Lingula sp., struktur populasi, Perairan Silo Baru

Lingula sp. is one of the genera of the phylum Brachiopods which are in the interdal zone or areas that are still affected by sea tides. The purpose of this study was to determine the population structure of Lingula sp. through the approach of size distribution, length and weight relationship, condition factors, density and distribution patterns with physical and chemical parameters and substart in the Silo Baru Waters of North Sumatra. The method used in this research is purposive sampling method. The results showed that the size distribution in Silo Baru Waters, when combined, it was found that the largest class interval was in the class interval of 49-52 mm (20 individuals). The growth pattern of Lingula sp tends to form a domestic allometric pattern, which is the increase in length faster than the increase in weight. The highest Lingula density was in the first week with an average value of 4.5 ind/m2. Meanwhile, the lowest Lingula sp density was found in the third week with an average value of 3.0 ind/m2. The distribution pattern of Lingula sp. the three weeks were uniform, with a mortality index (Id) in the first week 0.970, and in the second week 0.904, while in the third week it was 0.805. The physico-chemical factors of the aquatic environment are classified as normal and support the life of Lingula sp. in New Silo Waters. The condition of the sand-textured substrate also greatly influences the growth of Lingula sp. Keywords: Lingula sp., population structure, New Silo Waters