Reproduction characteristics, survival rate and sex-ratio of four brine shrimp Artemia sauna (Linnaeus, 1758) populations from Tunisia cultured under laboratory conditions

Artemia has a remarkable genetic variability that can be expressed in various phenotypic characteristics, such morphometry, growth rate, reproductive isolation or molecular composition. This study presents reproduction characteristics, survival rate and sex-ratio of four Artemia sauna populations from Tunisia cultured under standard conditions. Results show that both low (17.8% and 30.6% in Megrine saltwork and Sabkhet Sijoumi, respectively) and high (83.9% for Sahline saltwork) values were recorded for the percentage of total oviparous offspring. The offspring per brood varied from 70.3 +/- 41.9 (Megrine saltwork) to +/- 73.6 +/- 51.4 (Sabkhet El Adhibet). Broods per female varied between 3.1 +/- 0.9 (Sahline saltwork) and 4.5 +/- 1.2 (Megrine saltwork), and time between broods ranged from 5.7 +/- 1.1 to 6.5 +/- 2.2 days for Megrine and Sahline, respectively. Statistical analysis (one-way analysis of variance, Tukey's HSD test, p < 0.05) revealed no significant differences between reproductive traits of the four studied populations except for mean of oviparous and oviviparous offspring per female (F=9.158, p < 0.05), and brood per female (F=4.779, p < 0.05). The survival rate of the four studied A. salina populations fluctuated between 31.4% and 64.5% for Megrine and Sahline saltwork, respectively. However, the sex-ratio showed that for Megrine saltwork and Sabkhet El Adhibet, males predominated with 1: 0.90 and 1 : 0.97 (males : females), respectively. The comparison between our results and those reported of other Anemia populations showed that the offspring per brood of Tunisian Artemia are comparable to A. persimilis but different to A. sauna from Abu Kammash (Libya) and A. urmiana (Urmia Lake, Iran), and that days between brood, are similar to A. sauna from Abu Kammash, A. sinica and polyploid A. parthenogenetica, but different from A. persimilis and A. franciscana.