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can some body give me some facts

2007-03-28 13:06:02 · 2 answers · asked by Sarita* : ) 2 in Pets Fish

2 answers

Predation

Anglerfishes are named for their characteristic method of predation, Angler being another word for fisherman. The anglerfish has three long filaments sprouting from the middle of its head; these are the detached and modified three first spines of the anterior dorsal fin. As with all anglerfish species, the longest filament is the first (the illicium). This first spine protrudes above the fish's eyes, and terminates in an irregular growth of flesh (the esca) at the tip of the spine. The spine is movable in all directions, and the esca can be wiggled so as to resemble a prey animal, and thus to act as bait to lure other predators close enough for the anglerfish to devour them whole. The jaws are triggered in automatic reflex by contact with the tentacle. (The netdevil anglerfish has similar growths protruding from its chin as well.)

As most anglerfish live mainly in the oceans' aphotic zones, where the water is too deep for enough sunlight to penetrate for photosynthesis to occur, their predation relies on the "lure" being bioluminescent (via bacterial symbiosis). In a related adaptation, anglerfish are dull gray, dark brown or black, and are thus not visible either in their own light or in that of similarly luminescent prey.

The wide mouth extends all around the anterior circumference of the head, and both jaws are armed with bands of long pointed teeth, which are inclined inwards, and can be depressed so as to offer no impediment to an object gliding towards the stomach, but to prevent its escape from the mouth. The anglerfish is able to distend both its jaw and its stomach (its bones are thin and flexible) to enormous size, allowing it to swallow prey up to twice as large as its entire body.

Some benthic (bottom-dwelling) forms have arm-like pectoral fins which the fish use to walk along the ocean floor. The pectoral and ventral fins are so articulated as to perform the functions of feet, the fish being enabled to move, or rather to walk, on the bottom of the sea, where it generally hides itself in the sand or amongst sea-weed. All around its head and also along the body the skin bears fringed appendages resembling short fronds of sea-weed, a structure which, combined with the extraordinary faculty of assimilating the colour of the body to its surroundings, assists this fish greatly in concealing itself in places which it selects on account of the abundance of prey.


Reproduction

Antennariidae: striated frogfish, Antennarius striatus
Linophrynidae: Haplophryne mollis
Chaunacidae: pink frogmouth, Chaunax pictus: B.K. Phillips
Ceratiidae: Krøyer's deep sea angler fish, Ceratias holboelliAnglerfish have a unique mating method. Since individuals are rare and encounters doubly so, finding a mate is a problem, especially at a time when both individuals are ready to spawn. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were females. These individuals were a few inches in size and almost all of them had what appeared to be parasites attached to them. It turned out that these "parasites" were the remains of male ceratioids.

When a male of one of these species hatches, it equipped with extremely well developed olfactory organs that detect scents in the water. They have no digestive system, and thus are unable to feed independently. They must find a female anglerfish, and quickly, or else they will die. The sensitive olfactory organs help him to detect the pheromones that signal the proximity of a female anglerfish. When he finds a female, he bites into her flank, and releases an enzyme which digests the skin of his mouth and her body, fusing the pair down to the blood vessel level. The male then atrophies into nothing more than a pair of gonads that release sperm in response to hormones in the female's bloodstream indicating egg release. This is an extreme example of sexual dimorphism. However, it ensures that when the female is ready to spawn, she has a mate immediately available.[2]

The spawn of the angler is very remarkable. It consists of a thin sheet of transparent gelatinous material 2 or 3 ft. wide and 25 to 30 ft. in length. The eggs in this sheet are in a single layer, each in its own little cavity. The spawn is free in the sea. The larvae are free-swimming and have the pelvic fins elongated into filaments. The males live off the female's bloodstream.


Consumption
In Europe, the tail meat is widely used in cooking and is often compared to lobster tail in taste and texture. It is therefore sometimes referred to as "poor man's lobster." The anglerfish is a culinary speciality in certain Asian countries. In Japan each fish sells for as much as USD$150. The liver alone, considered a great delicacy, can cost USD$100.

2007-03-28 13:14:29 · answer #1 · answered by FishFreak95 3 · 0 0

are you really trying to cheat on your homework on the internet?! this is hilarious!

2014-03-08 22:26:36 · answer #2 · answered by pat lewis 1 · 0 0

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