Posts tagged Jonathan Couch
Thornback ray (Raja clavata) and thornback ray skeleton
Like sharks, rays and skates have fully cartilaginous skeletons, which provide a stable structure but more flexibility than bone. You can see that, much like fish, rays have defined, er, rays, in their fins. The difference is that while fish tend to have a few unconnected rays and a taught taut tissue between them, the Rajiforms (skates and rays) have many, many rays, which are all connected perpendicularly by collagen. The body is then formed around these rays, which propel the Rajiforms forward in an undulating (wave-like) motion.
A history of the fishes of the British Islands. Jonathan Couch, 1863.
![Eqalussuaq [Inuit] - Somniosus microcephalus (The Greenland Shark)
The Greenland shark is big, slow, and an apex predator of the sea. Despite its top speed of not over 2 mph (and this fast only in short sprints - it generally moves under 1 mph), it is still the second-largest carnivorous fish on Earth, and has been found with polar bear, reindeer, narwhal, and even other sharks in its stomach. Of course, although the Greenland shark is decent at hunting sharks, (sleeping) seals, and fish in the water, the polar bear and reindeer remains are from carrion that drifted to the bottom of the ocean. It’s an opportunistic predator, and will try to eat almost anything in its path.
Over 90% of the arctic Greenland sharks are hosts to the parasitic copepod Ommatokoita elongata (seen in the illustration), which has evolved to permanently attach themselves to the corneas of the genus Somnosius. They absorb nutrients through the blood vessels in the eyes and corneal fluid, and cause serious vision impairment in those affected by their presence. However, since the Greenland shark lives up to 7,200 ft (2,200 m) below the surface, it has little use of eyesight to begin with, and is believed to be largely unharmed by the presence of eyeball-sucking copepods tagging along on their corneas.
A History of the Fishes of the British Isles. Jonathan Couch, 1868.](http://25.media.tumblr.com/tumblr_m6d3m7q53t1qk931ho1_400.jpg)
Eqalussuaq [Inuit] - Somniosus microcephalus (The Greenland Shark)
The Greenland shark is big, slow, and an apex predator of the sea. Despite its top speed of not over 2 mph (and this fast only in short sprints - it generally moves under 1 mph), it is still the second-largest carnivorous fish on Earth, and has been found with polar bear, reindeer, narwhal, and even other sharks in its stomach. Of course, although the Greenland shark is decent at hunting sharks, (sleeping) seals, and fish in the water, the polar bear and reindeer remains are from carrion that drifted to the bottom of the ocean. It’s an opportunistic predator, and will try to eat almost anything in its path.
Over 90% of the arctic Greenland sharks are hosts to the parasitic copepod Ommatokoita elongata (seen in the illustration), which has evolved to permanently attach themselves to the corneas of the genus Somnosius. They absorb nutrients through the blood vessels in the eyes and corneal fluid, and cause serious vision impairment in those affected by their presence. However, since the Greenland shark lives up to 7,200 ft (2,200 m) below the surface, it has little use of eyesight to begin with, and is believed to be largely unharmed by the presence of eyeball-sucking copepods tagging along on their corneas.
A History of the Fishes of the British Isles. Jonathan Couch, 1868.
A blog for all biological and medical ephemera, from the age of Abraham through the era of medical quackery and cure-all nostrums. Featuring illustrations, history, and totally useless trivia from the diverse realms of nature and medicine.
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