A Sex Camera at the White Shark Trust?

One of the biggest challenges in the field is identifying the sex of the White Sharks we observe. Both male and female Sharks have a pair of pelvic fins situated between the pectoral ("wings") and the caudal fin ("tail") on the ventral side of their body. In male Sharks the pelvic fin is differentiated in an extra two extensions called claspers. A clasper is not a penis, but rather a simple tube-like extension strengthened by cartilage, which channels the sperm into the female during copulation. Shark's mating process involves internal fertilization.

These claspers are located on the belly side of the male Sharks (see picture above), and can be very small especially on the younger Sharks. Unless the Shark is turning on its side or back, the pelvic region remains very difficult to observe properly. This pelvic area becomes even more difficult to observe under a cloudy sky due to the reflection at the surface of the water or when the water visibility is reduced. to date, we have been able to identify only around 50% of the Shark's sex with absolute certainty.

Hence, in April 2004, the White Shark Trust invested in a small pencil camera connected to a small LCD screen. The camera is mounted on a pole which is used to position the camera to film the pelvic area from below. One assistant is usually handling the pole and camera aiming at the belly of the Shark from below, while another assistant is carefully scanning the LCD screen to see the pelvic fin area for the presence or absence of claspers. This process takes place once the Shark has been identified through body markings and / or photo identification. At present, we do not have any digital video recording device which would enable us to record the footage for further analysis. Hopefully, we will manage to secure some additionnal funding to purchase a DV recording device in the future.

The LCD screen has been encased in a small Pelican case on which a plexiglass window was added. This case is completely sealed from water and will protect the delicate LCD screen.
One of our assistants (Ben Westrope above) is handling the pole on which the pencil camera is attached.
A second assistant (Giacomo Palavicini above) is carefully watching the screen as the camera is aimed at the belly side of the Sharks as they swim past the boat.
We would like to thank Eagle Technology based in Cape Town for their support and assistance with this system which they have supplied to us at a reduced rate.

The following equipement is used:

E-LM500 5" TFT Video LCD Monitor

E-506EHPSC-DN Underwater Camera