Small Bills

Q: I took this photo of a 400-plus-pound blue marlin landed at the Hawaiian International Billfish Tournament. Its bill is very unusual - short and curved upward. It's not broken, but thin and pointed. How do you explain this? Would it handicap the fish in any way? - Mark Quarteman, San Francisco, California

A: The odd-looking bill is probably a natural variation or mild birth defect, depending on whether it was caused by a genetic mutation or an injury at an early age. From the uniform shape, the cause is more likely genetic than traumatic.
Many billfish live quite well with broken or misshapen bills. It's true that billfish use their bills to advantage, to stun or impale prey and in aggression against enemies such as sharks and sport-fishing boats, but the lack of a long bill places the marlin in no worse a situation than other fish, such as the shortbilled spearfish, for example.