Effect of Incubation Temperature on Survival, Growth and Oxygen Consumption of Developing Brine shrimp (Artemia franciscana)

Abstract

Brine shrimp (Artemia franciscana) are commercially harvested aquatic crustaceans that naturally inhabit inland and costal hypersaline environments. Brine shrimp are highly adaptable to such abiotic environmental fluctuations and exhibit the ability to survive in salinity concentrations ranging from 10–200 parts per thousand (ppt), and water temperatures ranging from 10–35°C. To assess the effect of the environment on development, we examined whether various incubation temperatures (20°C, 25°C and 30°C) directly affect morphological and physiological phenotypes of developing brine shrimp during a 40 day period from hatch to late juvenile/adult stages. Morphology was assessed throughout development using measurements of brine shrimp total body length (top of the median eye to the posterior of the caudal furca) and third appendage length (body's midline to the tip of the third swimming appendage). Developmental instar stage and survival were also recorded. Oxygen consumption rate (Vo2) was used as a functional measure of energy use throughout development. We found survival significantly decreased throughout development (P < 0.001). Survival to 40 days post hatch (dph) was similar at 20°C and 25°C, but no brine shrimp survived at 30°C beyond 30 dph. While a two‐way ANOVA indicated temperature had a significant effect on total body length (P = 0.002) and length of the third appendage (P < 0.001), temperature was not significant when examined on each developmental day. Therefore, the effect of developmental day was examined for all temperatures combined. Both total body length and length of the third appendage displayed trends of increasing length with development for all temperatures combined (P < 0.001 for both). Instar stage significantly increased with developmental day (P < 0.0001), but temperature only had a significant effect on development until 11 dph. The interaction between incubation temperature and developmental day for whole animal Vo2 was not significant (P=0.074), and thus the slope of whole animal Vo2 against developmental day did not differ between temperatures. Mass‐specific Vo2 was also not strongly affected by temperature, but brine shrimp showed a peak in mass‐specific Vo2 around 15 dph. The minimal temperature effect on development, morphology, growth, and Vo2 suggest that developmental brine shrimp metabolically compensate for temperatures within the range of 20–30°C, which likely reflects the variable thermal environment they live in.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.