Category: Sharks and Rays

Underwater Fact 153

Despite its name the ‘Common Skate’ is nowadays extremely rare.

Common SkateCommon Skate   ©

Skates are found in most parts of the world, from the shallow waters on the coast to depths of 2700 metres. They are flattened fish that look very similar to their well-known relatives: the rays.
The major difference between rays and skates is their reproductive strategy. Rays are live bearing (viviparous) while skates are egg-laying (oviparous).

The Common Skate or Blue Skate (Dipturus batis) is the largest skate in the world attaining a length of more than 250cm.
View full article »

Underwater Fact 145

Cownose Rays are known to take on long migrations in schools of thousands of individuals, moving northwards in late Spring and southwards in late Autumn. It is believed that this migration is initiated by the orientation of the sun and by water temperature.

 01-Cownose Rays migration, Gulf of MexicoCownose Rays migration, Gulf of Mexico   © Sandra Critelli

Cownose Rays can be recognised by their unusual bi-lobed head. Under the snout are two large fleshy lobes. These are often mistaken as the entrance to the mouth. The mouth however, is on the underside the fish.

View full article »

Underwater Fact 142

Manta rays have the largest brain to body weight ratio of any living fish.

View full article »

Underwater Fact 133

Sand Tiger Sharks are the only sharks known to come to the surface and gulp air. They store the air in their stomachs, which allows them to float motionless in the water while hunting.

Sand Tiger Shark   © Mark Fox

This Shark is not related to the Tiger Shark (Galeocerdo cuvier) however, it is a cousin of the Great White Shark (Carcharodon carcharias).
Despite its fearsome appearance and strong swimming ability, it is a relatively docile and slow-moving shark that will only attack a human when threatened.

View full article »

Underwater Fact 127

Most migratory sharks need to move to keep breathing, but the white-tip reef shark uses an ancient technique to rest during the day and save energy for hunting at night.

View full article »

Underwater Fact 124

The most northerly shark species alive is the Greenland Shark which grows to dimensions comparable to those of the Great White Shark. The species sacrifices its sharp eye sight to a rather unusual symbiotic relationship with a bioluminescent parasite that makes the sharks eyes glow in the dark.

Greenland shark   © Paul Nicklen for National Geographic

The largest member of the dogfish family, the Greenland Shark (Somniosus microcephalus) can grow to over 6 metres in length weigh up to one tonne. Females grow to be larger than males.
This shark prefers the icy waters of the North Atlantic and will usually only ascend from the depths if the surface drops to around 0.5 degrees Celsius.

View full article »

Underwater Fact 118

Great White Sharks generally don’t fight with one another for food. Instead, they will have “tail-slap” competitions until one gives up. The loser must continue the hunt for food elsewhere.

View full article »

Underwater Fact 111

One of the largest freshwater fish in the world is the Giant Freshwater Stingray. Its poison is most like that of a Rattlesnake.

View full article »

Underwater Fact 108

The Porcupine Ray is a species of stingray that does not have a venomous sting on its tail.

View full article »

Underwater Fact 104

Sharks can sense their prey through electroreception.
Tiny electrical signals are received from their environment via a series of pores peppered over the head, which are distributed in discrete patterns that vary from species to species.

View full article »

Copyright 2011 - 2015 Aqua Marine Life