Larva Ikan (ichtyoplankton) merupakan tahapan awal dari daur hidup ikan dimulai dari perkembangan telur, larva dan juvenil, memiliki tingkat mortalitas tinggi dan peka terhadap perubahan lingkungan, predator, dan kesediaan makanan. Fungsi ekologis padang lamun sebagai daerah asuhan dan tempat berlindung bagi semua jenis organisme laut kecil, salah satunya larva ikan. Kerapatan atau tutupan padang lamun juga sebagai salah satu faktor pendukung melimpahnya organisme dan kekayaan di laut. Tujuan Penelitian ini untuk mengetahui kelimpahan dan distribusi larva ikan yang terdapat pada ekosistem padang lamun, serta mengetahui hubungan kelimpahan larva ikan dengan tutupan padang lamun di Perairan Prawean Bandengan, Jepara. Metode penelitian ini adalah metode deskriptif dengan penentuan lokasi sampling menggunakan purposive sampling methode. Lokasi penelitian pada 3 stasiun dengan pembagian kerapatan lamun yang berbeda (I = Padat ; II = Sedang ; III = Jarang) dan dilakukan sebanyak 3 kali pengulangan sampling di masing-masing lokasi. Pengambilan sampel larva ikan dilakukan dengan menggunakan larva net (P = 0,9 m ; L : 0,6m) dengan ukuran mata jaring 800 µm. Hasil penelitian ini ditemukan larva ikan sebanyak 5 famili yaitu Nemipteridae, Gerreidae, Gobiidae, Labridae, dan Mullidae. Famili larva ikan yang paling sering ditemukan adalah Nemipteridae. Rata-rata kelimpahan famili larva ikan pada Stasiun I sebesar 0,419 ind/m3, Stasiun II sebesar 0,205 ind/m3, dan pada stasiun III sebesar 0,069 ind/m3. Nilai rata - rata indeks keanekaragaman termasuk dalam kategori rendah sedang (0,65–1,37), indeks keseragaman larva ikan termasuk dalam kategori rendah-tinggi (0,33-0,65) indeks dominasi larva ikan menunjukan ada yang mendominasi pada tiga stasiun (0,28–0,30) dan indeks sebaran morisita yang dilakukan menunjukan bahwa sebaran larva ikan pada tiga stasiun merata. Fish larvae (ichtyoplankton) are the initial stages of the fish's life cycle starting from the development of eggs, larvae and juveniles, which have a high mortality rate and are sensitive to environmental changes, predators, and food availability. The ecological function of seagrass beds as nurseries and shelter for all types of small marine organisms, one of which is fish larvae. The density or cover of seagrass beds is also one of the supporting factors for the abundance of organisms and wealth in the sea. The purpose of this study was to determine the abundance and distribution of fish larvae found in the seagrass ecosystems, and to determine the relationship of abundance of fish larvae with cover seagrass beds in the waters of Prawean Bandengan, Jepara. This research method is a descriptive method by determining the sampling location using purposive sampling method. The research location was in 3 stations with a different distribution of seagrass density (I = Dense; II = Medium; III = Rare) and carried out 3 times repetition of sampling at each location. Sampling of fish larvae was carried out using larvae net (P = 0,9 m; L: 0,6m) with a mesh size of 800 μm. The results of this reasearch, found fish larvae of 5 families, namely Nemipteridae, Gerreidae, Gobiidae, Labridae, and Mullidae. The most common family of fish larvae was Nemipteridae. The average abundance of fish larvae at Station I was 0,419 ind/m3, Station II was 0,205 ind/m3, and at Station III was 0,069 ind/m3. The average diversity index was included in the low category (0,65 – 1,37), the uniformity index of fish larvae was included in the low-high category (0,33 – 0,65) the fish larvae dominance index shows that there are dominating at three stations (0,28 – 0,30) and the distribution index of distribution (morisita) conducted showed that the distribution of fish larvae at three stations was evenly distributed.
Mesozooplankton and Ichthyoplankton composition in two tropical estuaries of Bahia, Brazil