During mating season, male midshipman fish will hum almost incessantly to attract females. The end result of a successful serenade is a nest of newly hatched larvae like the ones seen above.
These golden hatchlings are about 10 to 14 days old. The young are still attached by adhesive disks on the bottoms of their yolk sacs to a pinecone that was in the nest where the mother laid its eggs.
A July 2008 study of midshipman fish larvae showed that the neural circuit for vocalizing develops across a brain region that includes the base of the hindbrain and the upper spinal cord—the same region this circuit appears in other vertebrates.