REPRODUCTIVE CYCLE, SIZE AT MATURITY AND FECUNDITY OF GIURIS MARGARITACEUS IN LIMBOTO LAKE
ARAFIK LAMADI (a,b*) Dewa Gede Raka Wiadnya (c), Maheno Sriwidodo (d), Feni Iranawati (d)

a) Doctoral Program, Faculty of Fisheries and Marine Science, University Brawijaya. Jl. Veteran, Malang 65145, East Java, Indonesia. Email: arafik_lamadi[at]student.ub. ac.id
b) Department of Aquaculture, Fisheries and Marine Science Faculty, Universitas Negeri Gorontalo. Jl. Jendral Sudirman No. 6, Gorontalo 96138, Gorontalo, Indonesia. Tel./fax.: +62-435-821125. Email: arafik_lamadi[at]ung.ac.id
c) Department of Fisheries and Marine Resources Utilization, Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran, Malang 65145, East Java, Indonesia
d) Department of Aquaculture, Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran, Malang 65145, East Java, Indonesia
e) Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran, Malang 65145, East Java, Indonesia

Abstract

Understanding the reproductive biology particularly sexual maturity, reproductive cycle and fecundity of fish is useful for fisheries management. Unfortunately, there is no information about reproductive biology of Giuris margaritaceus in Limboto Lake. 614 specimens of the fish were collected over a 12 month. Their length varied between 6.5 and 20.9 cm. The fecundity ranged between 3,356 and 114,424. Male and female fish reached first sexual maturation at different size, 9.9 and 10,7 cm, respectively. This information is needed to determine the lowest acceptable harvest length of this fish under the management aim to enter all female fish for reproduction minimum one time in their life. We estimated the reproductive period of Giuris margaritaceus applying oocytes diameter, histological examination of ovaries and monthly mean GSI. All of these methods gave a consistent result about that Giuris margaritaceus could spawn throughout the year, with peaks in July and November. Based on this result, Giuris margaritaceus spawners can be protected during July and November for entering the reproductive stock. The results of this study might facilitate future efforts at fine tuning fishing effort for a proper management of Giuris margaritaceus.

Keywords: Reproduction, Sex ratio, gonado somatic index, snakehead Gudgeon, huluu

Topic: Aquatic Ecology and Conservation