Vitellogenesis, oocyte maturation pattern, spawning rhythm and spawning frequency in &lt;i&gt;Otolithes ruber&lt;/i&gt; (Schneider, 1801) (Sciaenidae) in the Kuwaiti waters of the Arabian Gulf

Stephen Dadzie

doi:10.3989/scimar.2007.71n2239

Abstract

Vitellogenesis, oocyte maturation pattern, spawning rhythm, spawning frequency, batch fecundity and oocyte diameter-frequency distribution of the tigertooth croaker, Otolithes ruber (Schneider, 1801) in Kuwaiti waters were investigated from March 1999 to February 2000 and from January to May 2005, using histological and morphological methods. Oogenesis is described in four phases: vitellogenic, mature, spent and regressed. Vitellogenesis, in turn, is described in three classes: early vitellogenic, mid-vitellogenic and late vitellogenic. Development of the yolky oocyte is an asynchronous process resulting, by the time of oocyte maturation, in a clear differentiation between a ready batch of oocytes (ready for spawning) and a reserve pool. Consequently, O. ruber is capable of spawning multiple times during the reproductive season. Spawning frequency estimates, based on the final oocyte maturation (FOM) method indicated that the species spawns once every 2.8 days, while the estimates based on the post-ovulatory follicle (POF) method indicated a spawning every 2.2 days, during a 5-month spawning season lasting from January to May. Batch fecundity (BF) was significantly positively correlated with both ovary-free body weight (OFBW) (p 2 = 33%) than was OFBW (r 2 = 19.9%). Batch fecundity was also significantly different between March and April (p 0.05). Relative batch fecundity was 716 eggs/g OFBW; thus, estimates for potential annual relative batch fecundity were 10024 eggs/g OFBW using the FOM method for spawning frequency estimation, and 7876 eggs/g OFBW using the POF method. The oocyte diameter-frequency distribution analysis revealed a multimodal distribution, confirming the evidence of multiple spawning.

Highlights

Representatives of the family Sciaenidae are widely distributed in the tropical and subtropical waters of the Indian, Atlantic and Pacific oceans (Trewavas, 1977; Longhurst and Pauly, 1987)
The reproductive biology of many sciaenid species has been documented across the Gulf of Mexico (Merriner, 1976; DeMartini and Fountain, 1981; Lowerre-Barbieri et al, 1996; Brown-Peterson and Warren, 2001; Brown-Peterson et al, 2002), in South African waters (Griffiths, 1996, 1997; Fennessy, 2000) and in the West African coast of Benin (Pillai, 1983), only scant information is available from the Arabian Gulf and the Indo-West Pacific (Hussain and Abdullah, 1977; Abu-Hakima et al, 1983; Dadzie and Abou-Seedo, 2004)
The present report on oogenesis in O. ruber is restricted to a brief characterisation of four phases: vitellogenesis, mature, spent and regressed

Summary

Introduction

Representatives of the family Sciaenidae are widely distributed in the tropical and subtropical waters of the Indian, Atlantic and Pacific oceans (Trewavas, 1977; Longhurst and Pauly, 1987). The reproductive biology of many sciaenid species has been documented across the Gulf of Mexico (Merriner, 1976; DeMartini and Fountain, 1981; Lowerre-Barbieri et al, 1996; Brown-Peterson and Warren, 2001; Brown-Peterson et al, 2002), in South African waters (Griffiths, 1996, 1997; Fennessy, 2000) and in the West African coast of Benin (Pillai, 1983), only scant information is available from the Arabian Gulf and the Indo-West Pacific (Hussain and Abdullah, 1977; Abu-Hakima et al, 1983; Dadzie and Abou-Seedo, 2004). Dadzie and Abou-Seedo (2004) described the testicular structure and spawning only in the males Apart from these reports, no other studies have been carried out on O. ruber either locally or regionally

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