WWW.WAS.ORG • WORLD AQUACULTURE • DECEMBER 2024 43 FIGURE 1. Wild collected adult V. seheli. production of fry must be established; however, to date there are no protocols or reports on the hatchery techniques for this species. Therefore, this trial was designed at the Aquaculture and Marine Studies Center (AMSC), Abu Al Abyad Island, Abu Dhabi, UAE, to standardize hatchery production techniques and support conservation and aquaculture initiatives. The results of these first trials are presented in this article. Wild Brood Stock Collection, Quarantine and Maintenance A total of 125 adult blue spot mullet (Figure 1) averaging 0.75Kg (0.50 – 1.3 kg) were collected from around the waters of Abu Al Abyad Island, from December 2023 through February 2024. The fish were carefully removed from gill nets without damaging them and immediately transferred to a 500 L tank with seawater and oxygen kept inside the boat. A mild dose of anesthetic (5 ppm AQUI-S®1) was administered in the tank to prevent the aggressive jumping behavior of the fish. Only a maximum of 8-10 fish were collected during each fishing trip. The fish were then transported to the quarantine facility of the AMSC. At arrival all fish were given an injection of Oxytetracycline at a dose of 10 mg/kg before they were introduced into quarantine tanks. Depending on collection site salinity, the fish were stocked in the quarantine tanks at 45 or 50 ppt salinity. Beginning the second day after stocking, the salinity in each tank was reduced by 5 ppt daily until it reached 5 ppt and then gradually increased to reach the desired salinity of 35 ppt for maintaining the fish during the The blue spot mullet (Valamugil seheli), locally known as Biah Arabi, occurs throughout UAE waters and is one of the most common species in the local fish markets. The fish has a high commercial importance and attains a price of US $ 8/Kg. There is also considerable interest for the species during the spawning season for the exploitation of their roe to produce dry bottarga, a highly valued-added product. Considered as a luxury food in many parts of the world, this product commands a very high price (US $ 204/Kg). A stock assessment study considered this species as fully exploited as of 2010, and indicated that the catch has declined by about 86 percent over the previous 11 years (Ralph et al. 2021). V. seheli schools in shallow coastal waters and forms large shoals at sea during the spawning season. Adults as well as juveniles feed on various algae, diatoms, foraminiferans, and detritus associated with sand and mud (Moorthy et al., 2000; Saleh, 2008). In the southern Arabian Gulf spawning occurs from February to April and the age and size at sexual maturity for males and females are 4.5 years and 38 cm, and 4 years and 41.8 cm, respectively (IUCN 2012). The blue spot mullet and the flat head grey mullet, Mugil cephalus, are the most cultured species of mullet in the world. However, most mullet aquaculture activities in the Mediterranean, Southeast Asia, Taiwan, Japan and Hawaii rely on the use of wild seed either due to the lack or insufficient supply of hatchery produced seed and associated high prices (Saleh 2008). Hatchery production techniques for the grey mullet (M. cephalus) are utilized on a limited scale and no techniques are as yet developed for commercial supplies at economical prices. For aquaculture of the blue spot mullet to succeed, sustainable First Induced Spawning and Larval Rearing of Wild-Caught Blue Spot Mullet, Valamugil seheli (Forsskal 1775) in the Emirate of Abu Dhabi, United Arab Emirates Omer M. Yousif, Krishnakumar Menon, Balamurugan Vadivel, John Antony and Trig T. Ali (CONTINUED ON PAGE 44)
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