Is the timing of spawning in sparid fishes a response to sea temperature regimes?

Published spawning seasons of sparid fish were investigated to determine if there were consistent patterns that could be related to large-scale physical variability, and whether these relationships were species-specific or characteristic of higher taxonomic groupings. For individual species, genera and the family Sparidae as a whole, there was a consistent pattern; spawning at lower latitudes was concentrated close to the month of lowest sea surface temperature, while spawning at higher latitudes was more variable with greater deviations from the month of minimum sea surface temperature. The distribution of sparids may be limited by a lack of tolerance of one or more early life-history stage to high water temperatures, so targeting spawning to the coolest part of the year could be a tactic allowing maximum penetration into warmer waters. Such a link between the physiology of early life-history stages and timing of spawning could have direct consequences for patterns of distributions over a number of taxonomic scales. If there are similar constraints on the reproduction of other species, even minor increases in water temperature due to global warming that may be within the tolerance of adults, may impose constraints on the timing of spawning, with flow-on effects for both species and whole ecosystems

Lamprey spawning migration

During recent decades, new insights regarding the spawning migration of lampreys have been gained due to advances in technology and growing interest in this key life history phase. The development of miniaturized active and passive transmitters has led to detailed information on the timing and extent of lamprey migrations. These tools, together with sophisticated laboratory experiments, have provided fertile ground for studies of lamprey migratory physiology and behavior. New molecular tools have been applied to questions of population structure and philopatry, while the identification of lamprey pheromones has illuminated heretofore unimagined mechanisms of migration and orientation. Interest in spawning migration has been spurred by the growing need to restore native lamprey populations and the equally pressing need to control invasive sea lamprey in the Laurentian Great Lakes. While important advances in anadromous lamprey biology have been achieved, gaps remain in our understanding of marine movements, species-specific differences, mechanisms of orientation, and the factors controlling passage success. Moreover, with the exception of the landlocked sea lamprey in the Great Lakes, research on the spawning migrations of the strictly potamodromous species (i.e., those that are parasitic in fresh water and the non-parasitic “brook” lampreys) is sorely lacking, seriously compromising our ability to assess what constitutes barriers to their migration