Posts tagged sea

scienceyoucanlove:

Helmet Jelly - Periphylla periphylla

The umbrella is usually higher than wide. It may reach a height of 35 cm and a diameter of 25cm. The tip is pointed or dome-shaped. The large, red or orange stomach occupies the upper part of the umbrella. The 12 thick, orange tentacles can be more than 50 cm long. There is no information about a polypoid stage.

Habitat:

This is a common deep sea species. At locations dominated by strong tidal currents, forcing water from 200 metres or more up towards the surface, they can be encountered at any depth. At some locations this phenomenon is highly seasonal. An example is Lurefjorden (Hordaland) where water from 200 metres depth is forced into the fjord through a shallow (20 metres) and narrow (200 metres) sill entrance. In april every year, a large number of helmet jellies comes with the tide. At at other locations, like Skarnsundet, in the Trondheim Fjord, you may find them at any time of the year. Here the entrance is more than 200 metres deep and much wider than in Lurefjorden, so most of the helmet jellies pass below the common scuba diver. The maximum recorded depth is 2700 metres.

Distribution:

The helmet jelly is a cosmopolitan and widespread in the Atlantic Ocean, except in the Arctic. The Trondheim Fjord seems to be north of the “official” distribution area, but the helmet jelly does not know that.

source



Octopus in Hand
I captured this photo of an Octopus in Kauai while diving. As you can see, the dive masters hand is not touching it. He was only stopping its retreat just long enough for a quick shot. I was lucky enough to position myself for this photo with my housed canon SLR digital camera.



Photograph by Danny Bergeron

Octopus in Hand

I captured this photo of an Octopus in Kauai while diving. As you can see, the dive masters hand is not touching it. He was only stopping its retreat just long enough for a quick shot. I was lucky enough to position myself for this photo with my housed canon SLR digital camera.
Photograph by Danny Bergeron

Photos by Shawn Heinrichs at Mexico’s Isla Mujeres, site of the world’s largest aggregation of whale sharks. Measuring up to fifty feet long (compare to the thirty foot boat seen here), whale sharks are extremely docile creatures. They are listed as vulnerable by the international union for conservation of nature and natural resources, and these photos were taken to promote the message that the economic benefits of shark tourism outweighs the value of the shark fin trade.

Regarding the first and third photos, Heinrichs noted, “to get a shot like this requires a lot of technical know-how and experience because focusing on an object above and below the water at the same time is challenging,” adding, “getting the horizon line level and water off the lens is an exercise in patience and determination. (more whale shark photos)


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