Meeting Abstract
Cartilaginous fishes experience indeterminate growth, where both brain and body grow continually throughout their lives. This characteristic suggests that environmental conditions may impact overall development of the brain. Since neural growth has been linked with life history traits such as life span, reproductive output, mate selection, ability to avoid predators and find prey, changes in brain size and/or brain organization can have functional implications on the fitness consequences of environmental change in these species. The effects of increased rearing temperature were studied on brain development in the little skate (Leucoraja erinacea). Eggs cases were collected from a breeding stock of L. erinacea and placed into either ambient or 5° above ambient seawater conditions, and neonates were placed into a nursery tank at the same rearing temperature after hatching. To better understand how brain size and organization may be affected after exposure to increased temperatures, brains were imaged using magnetic resonance imaging (MRI) and brain region volumes were compared between the two treatment groups. Trends indicate differences in brain size between treatment groups and are particularly localized to the telencephalon and olfactory bulbs (F1,15 = 4.56, p<0.05). Results from behavioral studies of neonate L. erinacea were combined with neuroanatomical data to study the possible connection between increased rearing temperature and behavioral abnormalities in these skates. Determining the effects of increased temperature on neural phenotype and behavior aids in understanding the consequences of environmental stressors on brain development in this species and will indicate how they may fare in a changing climate.
