Wednesday, June 26, 2013

Anglerfish

A fish that fishes!

The anglerfish has no distinct shape.  It looks like a tattered shopping bag, with a skin like an old rag.  It has no particular color, but many colors arranged in irregular patches.  It is, in fact, hard to distinguish when it rests on the sea bottom.  As it is disguised, it gently raises a long spine from its dorsal fin.  On the end of the spine is a bit of skin - a true fishing line, complete with bait!
When a little fish comes to see if this might be something good to eat, in a split second it is gobbled up, sucked in by the great current of water created when the anglerfish opens its huge mouth.  This happens so quickly that the jaws seem to not move at all.

Some anglerfish, like those of the Ceratioid group (Ceratiidae, or sea devils), employ an unusual mating method. Because individuals are presumably locally rare and encounters at least doubly so, finding a mate is problematic. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were female. These individuals were a few centimetres in size and almost all of them had what appeared to be parasites attached to them. It turned out that these "parasites" were highly reduced male ceratioids. The presence of multiple males breeding with a single female makes this a good example of polyandry. At birth, male ceratioids are already equipped with extremely well-developed olfactory organs that detect scents in the water. The male ceratioid lives solely to find and mate with a female. Yeah, that sounds like a simple life, eh?

There are, in all the seas of the world, hundreds of different types of anglerfish.  I once read that there are over 350 types, but who knows, by now there may be even more that have been discovered since then.  The best known is the fishing anglerfish, or turbot, much sought after as a food fish.  Only the tail is eaten, which is fortunate, because the head is so ugly (large and flat with a toothy, protruding lower jaw) that it would take away anyone's appetite upon first sight; ha!
The head and jaw make up a third of the length and most of the weight of this fish.
Anglerfish live on the sea bottom at depths that vary from species to species.  They move by making little jumps on their short, stubby fins.  They hunt without moving, attracting little fish with their "fishing lines," so to speak.

Image Credit: http://en.wikipedia.org/wiki/File:Representatives_of_ceratioid_families.jpg

Related Blog Post:  The 'John Dory' Fish

---End of Post "Anglerfish"

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