KARAKTERISTIKMORFOLOGI DANHUBUNGANMORFOMETRIK OTOLITH DENGAN UKURAN IKAN LEMURU (Sardinella lemuru Bleeker, 1853) DI SELAT BALI

Abstract

Otolith telah digunakan secara luas untuk kajian taksonomi, pertumbuhan, umur dan kekerabatan populasi ikan dari perairan yang berbeda. Penelitian ini bertujuan untuk mengetahui hubungan morfometrik otolith dan ukuran ikan lemuru serta karakteristikmorfologi otolith. Sampel dikumpulkan dari Selat Bali padaApril hingga Juli 2015. Pengujian statistik juga dilakukanmenggunakan uji-t berpasangan dua arah pada selang kepercayaan 99% untuk menentukan signifikansi hasil pengukuran morfometrik antara otolith kanan dan kiri. Hubungan parameter morfometrik dan ukuran ikan dianalisis menggunakan persamaan regresi linear dan eksponensial. Karakteristik morfologi otolith disajikan secara deskriptif dan dipertegas dengan nilai indeks-indeks bentuk menggunakan 6 deskriptor. Hasil penelitian menunjukkan bahwa tidak ada perbedaan yang signifikan pada pengukuran morfometrik otolith kiri dan kanan. Ukuran otolithmemiliki korelasi isometrik dengan pertumbuhan ikan dimana panjang otolith (OL) menjadi indikator terbaik untuk mengestimasi ukuran individu ikan. Otolith ikan lemuru memiliki ciri-ciri morfologi yang konsisten seperti halnya ikan dari genus Sardinella, khususnya sulcus acusticus, rostrum dan antirostrum. Nilai indeks bentuk yangmenegaskan ciri-ciri morfologi otolith juga dijelaskan.Otoliths widely used to determine taxonomy, growth, age and population structure of fishes. This study aims to determine the relationship between otolith morphometric to fish sizes and morphological characteristic of otolith. Data were collected from April to July 2015 in Muncar, Bali Strait. The statistical tests using two tails ttest paired sample also implemented to examine differentiation between left and right otolith measurement. The linear regression and exponential equation used to examine otolith morphometric parameter to fish size. Otolith morphological characteristics presented descriptively and emphasized using 6 descriptors of shape indices. The results showed no significant differences between left and right otolith. The otolith-fish size relationship was isometric. An OL (length of otolith) found as the best indicators to estimate the original size of fish. The otolith has specific morphological characteristics, in particular sulcus acusticus, rostrum and antirostrum were similar with other species from Sardinella genus. Shape indices also provided to confirm the morphological otolith.

Bioecological Aspects of Snakeskin Gourami (Trichopodus pectoralis) in the Flooded Swamp Waters of Bilah River, Labuhanbatu Regency

“…Sarma (2015), stated that the relationship between the length and weight of fish is essential in the development of swamp fishery to show the relationship between population dynamics, growth patterns, fish stocks, gonad development, and general condition of fish, body shape comparisons of different groups of fish. Wujdi et al (2012) also mentioned that the growth pattern of fish could be determined from the value of the constant b from the relationship between the length and weight of the fish. If b=3, the growth is isometric (length gain is proportional to weight gain).…”

The Size and The Shape of Sagittal Otolith of Redtail Scad, <i>Decapterus kurroides</i> Blekeer 1855 from Kema Bay, North Minahasa Regency, North Sulawesi, Indonesia

“…There were 6 parameters of the shape indices calculated from the size of the otolith ( (Wujdi et al 2016;Ladroit et al 2017), formfactor (FF) = (4πAO)/OP 2 , roundness (RO) = (4OA)/(∏OL 2 ), circularity (CI) = OP 2 /OA, rectangularity (RE) = OA/(OL*OW), ellipticity (EL) = OL-OW/OL + OW and aspect ratio (AR) = OL/OW. Difference in otolith size and shape index between the left and the right ones was analyzed using pair t-test, while the difference in the otolith size and shape between sex was tested with t-test.…”

“…Otolith pairs of juvenile redtail scad was symmetrical. Wujdi et al (2016) stated there was no real difference between the size of the left and right otolith or symmetrical of lemuru fish (Sardinela lemuru) in the Bali Strait, as well as for anchovy (Engraulis encrasicolus) in Black and Marmara Sea (Zengin et al 2015), Scad (Decapterus muroadsi) in the Kema Bay of North Sulawesi (Manginsela et al 2017), Decapterus muroadsi scad in Manado Bay (Umar et al 2019), Selar crumenopthalmus from Kema Bay (Mamuaya et al 2017a andTaliawo et al 2018), Cakalang (Katsuwonus pelamis) in Bitung (Mamuaya et al 2017b) and in Manado (Mogea et al 2019). Otherwise, otolith pairs of female and male difference size or asymetrical like otolith of plaice Pleuronectes platessa and turbot, Psetta maxima (Helling et al 2005).…”

“…Wright et al (1990) have firstly reported it on Stolephorus heterolobus in Java Sea, then on several species of eels (Anguilla spp.) around Sulawesi waters and others (Arai et al 2000(Arai et al , 2003Sugeha et al 2001;Kuroki et al 2005;Lee et al 2008;Chino & Arai 2010), bluefin tuna (Thunnus maccoyii) around Bali waters (Shiao et al 2009;William et al 2013;Farley et al 2014), Chinese herring (Tenualosa toil) around Sumatera waters (Milton & Cheney 2001), red snapper (Lutjanus erythropterus) around Nusa Tenggara waters (Fry & Milton 2009), Bali sardinella (Sardinella lemuru) around Bali waters (Wujdi et al 2016), skipjack tuna (Katsuwonus pelamis) in the southern waters of Java and the Sulawesi Sea (Wujdi et al 2017(Wujdi et al , 2018Mogea et al 2019), and Selar crumenophthalmus in Manado Bay (Bahri et al 2018). Otolith study does not merely aim to get information on fish aging and fish growth but also to identify or discriminate the fish stock.…”

Biometric Analysis of Otolith (Sagitta) for the Stock Separation of Skipjack Tuna Katsuwonus pelamis (Linnaeus, 1758) Landed at Tumumpa Coastal Fisheries Port Manado, North Sulawesi

“…Secara klasik, otolit digunakan untuk menduga umur dan pertumbuhan individu ikan, tetapi menurut Campana dan Casselman (1993) (Wujdi et al, 2016;Ladroit et al 2017): Circularity (Cir) = OP/OA 2 ; Rectangularity (Rec) = OA/(OL*OW); Form-Factor (FF) = (4*π*OA)/OP 2 ; Roundness (Rnd) = (4*OA)/(π*OL 2 ); Ellipticity (Ell) = (OL-OW)/(OL+OW); Aspect Ratio (AR) = OL/OW. Untuk membandingkan ukuran rata-rata otolit maupun indeks bentuk otolit antara kiri dan kanan digunakan uji-t sampel berpasangan.…”