Wobbegongs spend most of their time on the sea floor and hunt mostly at night using an unusual sit-and-wait ambush strategy
Wobbegongs spend most of their time on the sea floor and hunt mostly at night using an unusual sit-and-wait ambush strategy

Many sharks are colour blind

The PhD study bt Dr. Susan Theiss showed that the wobbegong visual system contains only a single class of cone photoreceptor. Cone photoreceptors are the retinal cells that are used for vision under bright light conditions, whereas as rod photoreceptors are used in dim light.

These previous studies looked at opsins, which are light-sensitive proteins found in the photoreceptor cells of the retina. Rod opsins are used in low light and produce a black and white image, while cone opsins are used in bright light, and often to see colours.

Papua New Guinea: Tufi, New Ireland & Milne Bay

Is there another country anywhere with so much diversity? The six million inhabitants of this nation of mountains and islands are spread over 463,000km2 of mountainous tropical forests and speak over 800 different languages (12 percent of the world total). Papua New Guinea occupies half of the third largest island in the world as well as 160 other islands and 500 named cays.

Papua New Guinea: Unity in Diversity

I’ve been on the road for 36 hours now, and I’m pretty much on the other side of the world from where I started back in rain drenched England. At last, I’m approaching the final legs of the journey—just a short one-hour flight to go.

Things have gone smoothly so far, I’m thinking, as I wander up to the check-in desk for the last leg of my trip. “The flights full,” the attendant tells me, “You’ll have to wait until tomorrow.

South Georgia

South Georgia is the most well-known of the Falkland Islands, also called Islas Malvinas. It lies nearly at the end of the world in the Southern Atlantic Ocean. To find this place on the map, draw an equilateral triangle with one vertex on Cape Horn and another on the Antarctic Peninsula. The third vertex in the east is our destination.