Australian researcher Leonardo Guida was cleaning an aquarium in April when he saw several baby rays floating in the water. Noting that the mother stingrays had just given birth, he began recording the baby rays when he saw an “oddly shaped, pale object floating in the water”. That odd object turned out to be a stillborn baby ray fetus – with two heads! Two-headed rays (and sharks) are a rare birth defect that arises when the neural tube in a single fertilized egg is duplicated. There has been an increase in shark and ray birth defects over the past few years but nobody is quite sure what is causing the anomalies.
According to Scientific American:
“The bay has recently undergone extensive dredging to enlarge shipping channels, resuspending contaminated sediment into the ocean, according to the study. This development, combined with the fact that rays eat bottom-dwelling creatures, may have exposed these animals to significant levels of pollutants.”