The spider crab Maja brachydactyla Balss, 1922 is a species with high commercial value and it is suitable for aquaculture. Larval culture has been recently studied, but their environmental requirements are poorly known. In this work, the influence of temperature, light (intensity and photoperiod) and salinity over the larval development has been studied. We quantified the effect of the above mentioned variables on the ratio to zoeae that moult to megalopa, the ratio of megalopa that moult to juveniles, time of development and the growth measured as changes elemental composition (CHN). Larvae were obtained from broodstock animals distributed in 2,000-L tanks under constant temperature (18.5±1.0 ºC), salinity (35±1 ‰) and photoperiod (12L:12D). Larval rearing experiments were carried out in 500 mL glass beakers at an initial density of 60 zoea L-1 and 20 megalopa L-1. Daily the water of larvae was changed and feeding with Artemia nauplii. Five experiments were carried out: (Exp-I) at temperatures 15, 18, 21, 24, 27 and 30 ºC (constants: 12L:12D, 100 lux, 35‰); (Exp-II) at photoperiods 0L:24D, 8L:16D, 12L:12D, 16L:8D and 24L:0D (constants: 21 ºC, 300 lux, 35‰); (Exp-III) at light intensity (0, 300, 1000 and 3000 lux) (constants: 21º C, 12L:12D, 35‰); (Exp-IV) light effect over settlement and metamorphosis to the first juvenile stage (photoperiods: 0L:24D; 12L:12D) (constants: 21º C, 35‰); (Exp-V) the effect of salinity over the development (25, 30, 35, 40 and 45‰) (constants: 21 ºC,12L:12D, 1000 lux). Survival and the duration of development were lower at higher temperatures (Exp-I), but where no significant effects on the C:N ratio. Photoperiod and light intensity (Exp-II and Exp-III) did not affect in zoeal development; but the duration of development to the megalopa stage were shorter, without effects on C:N ratio. Photoperiod (Exp-IV) did not produce consistent effects on settlement. Salinity (Exp-V) did not affect the duration of development, but only the zoea reared at 30, 35 and 45‰ survived to megalopa stage, and only at those reared at 35‰ complete the metamorphosis to juvenile. In summary, the most important factors are the temperature and salinity used for larval maintenance. Photoperiod and light intensity have modest effects on larval development, especially during the megalopa stage

World Aquaculture Adelaide, Create, Nurture, Grow, 7-11 June 2014, Adelaide, South Australia.-- 1 page, 1 figure

Peer Reviewed