Sphyrnid Sharks in GURPS

The sphyrnids, or hammerheads, are very similar to the carcharhinid sharks, except for one bizarre feature - a large boomerang shaped structure that mounts the eyes on the ends. The purpose of this structure is unknown - it may provide lift when swimming, aid in maneuverability, or provide a larger surface for the remarkable elctroreceptive abilities common to all sharks.

Hammerheads have a lower bouyancy than most sharks. All sharks are very slightly heavier than water, so have a tendancy to sink. This is countered by the lift forces generated by the forward motion of a swimming shark as water flows over the wing-like pectoral fins. It may be that the "hammer" is neccessary to compensate for the hammerhead's reduced bouyancy. Hammerheads are constantly swimming from the moment of birth until they die. They use the ram pressure created by their motion through the water to force oxygenated water past their gills. If they stop swimming, they find it more difficult to breathe. Perhaps, like some carcharhinids that swim almost continuously, they can breathe if stationary by "gulping" water past their gills - but this actually takes more effort than swimming!

Game Statistics

choose a species:
Species tiny
10 kg
25 kg
50 kg
100 kg
150 kg
300 kg
600 kg
enter weight (kg)
Great hammerhead

Smooth hammerhead

Scalloped hammerhead


The radio button entries in the table above give realistic sizes of the species of that row. If you want a specimen outside that range, enter the weight in kg manually.

Marking the T? checkbox will give you the stats in template form with all costs listed, otherwise you get a stat sheet as for a character.

Marking the HR? checkbox will print the information using all my house rules. Otherwise, the stats will be as compatable with plain vanilla GURPS as possible (although several custom advantages and disadvantages will be present, see my Traits page).

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