Seen here is a bass larvae with two heads. Thousands of such mutated animals were spawned at a fish farm in northern Australia likely due to contaminated water. Other animals at the Noosa River hatchery were also born with birth defects and death rates were abnormally high. From AFP:
"I have been working in aquaculture for 10 years and this is the first time I have ever seen anything like it," (said Matt Landos, an aquatic animal specialist and member of the Australian College of Veterinarian Scientists.)
Tests had excluded the presence of a virus or bacteria, leading Landos to suspect that pesticides from a neighbouring macadamia nut farm were to blame…
The Queensland state government said tests gave no indication that the macadamia farm was using the chemicals against the manufacturers' instructions.
"Contamination fears over two-headed Australian fish"