Jurnal Iktiologi Indonesia (Indonesian Journal of Ichthyology)
Vol 18 No 2 (2018): June 2018

Otolith shape indices of skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) from the Indian Ocean

Arief Wujdi (Loka Riset Perikanan Tuna Jl. Mertasari No.140, Banjar Suwung Kangin, Sidakarya, Denpasar, Bali. 80223)
Maya Agustina (Loka Riset Perikanan Tuna Jl. Mertasari No.140, Banjar Suwung Kangin, Sidakarya, Denpasar, Bali. 80223)
Irwan Jatmiko (Loka Riset Perikanan Tuna Jl. Mertasari No.140, Banjar Suwung Kangin, Sidakarya, Denpasar, Bali. 80223)



Article Info

Publish Date
18 Jun 2018

Abstract

Skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) plays an important role in terms of the marine ecosystems as preyed-upon by shark, billfish, and larger tunas. In order to determine food chain system, there was a gap information as digested skipjack tuna difficult to be identified. This study aimed to determine shape indices to describe the otolith shape of skipjack. The morphometry data were collected from 253 pairs of skipjack tuna’s otolith during February, April, August, and September 2016 from four fishing ports namely Binuangeun, Sadeng, Prigi, and Labuhan Lombok. The data normality and homogenity also determined using Kolmogorov-Smirnov and Levene test respectively. In addition, right and left otolith morphometry were investigated using paired T-test. The shape indices were calculated using six descriptors including form factor (FF), roundness (RO), circularity or compactness (C), rectangularity (Rt), ellipticity (E), and aspect ratio (AR). Multivariate test using MANOVA and Tuckey test also implemented to investi-gate variation among locations. The results showed that the data were distributed normally and homogenly. There were also not significantly difference on otolith morphometry between left and right side (P>0,05). Shape indices also pro-vided in this paper. Skipjack tuna’s otolith has performed as non-rounded, closed to oval, elongated, and irregular surface. Abstrak Ikan cakalang, Katsuwonus pelamis (Linnaeus, 1758) berperan penting dalam ekosistem perairan laut, yaitu mangsa bagi jenis hiu, kelompok billfish, dan tuna berukuran besar lainnya. Dalam hal mengungkap hubungan pemangsa dan mangsa dalam suatu rantai makanan, seringkali terjadi kekosongan informasi karena sulitnya mengidentifikasi ikan yang telah tercerna. Penelitian ini bertujuan untuk menentukan bentuk morfologi otolit ikan cakalang berdasarkan nilai indeks bentuk. Data morfometri dikumpulkan dari 253 pasang otolit ikan cakalang pada bulan Februari, April, Agustus, dan September tahun 2016 di empat tempat pendaratan ikan, yaitu: Binuangeun, Sadeng, Prigi, dan Labuhan Lombok. Data morfometri otolit diuji normalitas dan homogenitasnya masing-masing menggunakan uji Kolmogorof-Smirnov dan Levene. Uji T berpasangan juga diterapkan untuk memastikan signifikansi perbedaan antara morfometrik otolit kanan dan kiri. Penghitungan indeks bentuk menggunakan enam deksriptor, yang meliputi form factor (FF), roundness (RO), circularity atau compactness (C), rectangularity (Rt), ellipticity (E), dan aspect ratio (AR). Analisis multivariat menggu-nakan MANOVA dan uji Tuckey juga diterapkan untuk menentukan perbedaan morfometri otolit dari masing-masing lokasi. Hasil menunjukkan bahwa data tersebar normal dan homogen serta tidak terdapat perbedaan yang signi-fikan pada morfometri otolit kanan dan kiri (P>0,05). Penelitian ini juga menyajikan nilai indeks bentuk yang menjelas-kan bentuk morfologi otolit ikan cakalang, yaitu memiliki karakteristik cenderung oval, memanjang, dan memiliki per-mukaan yang tidak beraturan.

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Journal Info

Abbrev

jii

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology

Description

Aims and Scope Aims: Jurnal Iktiologi Indonesia (Indonesian Journal of Ichthyology) aims to publish original research results on fishes (pisces) in fresh, brackish and sea waters including biology, physiology, and ecology, and their application in the fields of fishing, aquaculture, fisheries ...