Find a Fish
Billfish skeleton
A billfish skeleton at Garden Bay, 12 km south of Batemans Bay, New South Wales, 1999. Photo © M. Middleton. View larger image.
A 1.8 m long billfish skeleton in a cave at Barrenjoey Headland, Sydney, New South Wales, April 2007. Photo © D. Musumeci. View larger image.
Above and below: A billfish vertebra found on the rocks by C. Stanyer, at Birubi Point, Port Stephens, New South Wales, October 2003. Photo: S. Reader © Australian Museum. View larger image.
Billfishes include the marlins, sailfishes, spearfishes and swordfishes.
The vertebrae of billfishes can be recognised by the expanded flanges. These flanges are modified neural (dorsal) and haemal (ventral) spines. The flanges of each vertebra are overlapped by bony projections (the anterior zygapophyses) from the vertebra immediately behind. This results in a stiffening of the vertebral column, which improves swimming efficiency.
The top image shows a billfish skeleton found at Garden Bay, 12 km south of Batemans Bay, New South Wales. The skeleton is most likely from a marlin. The "skull-like" bone at the left of the image is the cleithrum. In life, this bone supports the pectoral fin. It has been moved into its current position for the photograph.
The bottom two images show a billfish vertebra. It is probably from a marlin or swordfish.
Related links
- Marlin dorsal fin spine enquiry
- Marlin skeleton enquiry
- Black Marlin fact sheet
- Blue Marlin fact sheet
- Swordfish fact sheet
Further reading
- Nakamura, I. 1985. Billfishes of the World. An Annotated and Illustrated Catalogue of Marlins, Sailfishes, Spearfishes and Swordfishes known to Date. FAO Species Catalogue. Vol. 5. FAO. Rome. Pp. 65.
