https://doi.org/10.4081/jlimnol.2014.1036
Hatching response to temperature along a latitudinal gradient by the fairy shrimp Branchinecta lindahli (Crustacea; Branchiopoda; Anostraca) in culture conditions
Accepted: 30 July 2014
HTML: 777
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Authors
Branchinecta lindahli is a broadly distributed fairy shrimp, reported from a range of temporary wetland habitat types in arid western North America. This species’ eggs hatch after the habitat dries, refills from seasonal rain, and receives a strong cold shock during the winter low temperatures. I studied phenotypic variation in temperature responses in cultures collected from four populations across 8° of latitude with low average temperatures ranging from -8 to 8°C. Time to maturation, mature body size and first clutch size decreased, as temperature increased, with only minor body size variability at mortality, regardless of culture origin. No variation in individual egg size was observed, demonstrating that body size is sacrificed to produce at least a few normal eggs during unfavourable years. Latitudinal variation in hatching temperature demonstrated a pattern of adaptive significance, with some overlap between regional temperature hatching cues. Phenotypic hatching temperature and growth rate responses may cause genetic segregation, selecting one cohort for warmer, dryer years and one cohort for cooler, wetter years. Drier year selected cohorts can exploit habitats that have shorter hydroperiods even in wet years. This may lead to population specialisation and speciation by adapting to more extreme habitats
