Quote:
Originally Posted by omard  Am wondering about the protective mucus blanket/bubble certain wrasses and other species known to form about themselves at night... 
Presumably a somewhat toxic covering to protect self while sleeping.
How do they do it? --- Do they blow a bubble and crawl inside? Is it a secretion all over body? Spit it out on surface then roll around in it.
Fish not designed to cover self with slime from mouth. If they do, can't imagine how it is done.
""...
Do they just shake it off or somehow crawl out of it when they wake up?
If toxic, could there be any adverse effect of this stuff floating around in a closed aquarium system?
Don't know if any answers to above...but for some reason I just got to thinking about...  |
Been browsing thru web for answers...here is what I have come up with...
(Answers.com) Animal Classification:
Labroidei II
(Damselfishes, wrasses, parrotfishes, and rock whitings)
Class: Actinopterygii
Order: Perciformes
Suborder: Labroidei
"...Parrotfishes, on the other hand, have their own presumably protective behavior. At night, these diurnal animals prepare for sleep by generating a tube of mostly clear mucus that surrounds the body. The tube forms in about 30–60 minutes. There is some debate over whether cocoon formation is a behavioral trait or simply the result of normal mucus secretions that accumulate because the fish is stationary. Either way, the mucus tube appears to provide the fishes with some protection from predators by masking them, and perhaps by surrounding them with an unpleasant-tasting barrier..." (Fishchannel.com)
"...
Fairy wrasses do form a mucus cocoon at night. Studies on parrotfishes, which also form a mucus sheath, have demonstrated that by enveloping their bodies in slime they may prevent olfactory stimuli from reaching nocturnal predators hunting nearby..."
(
Journal of Fish Biology)
Volume 39 Issue 3 Page 383-392, September 1991
(abstract...)
"...A histological and ultrastructural examination of the opercular gland of the cleaner-wrasse Labroides dimidiutus has demonstrated that the slimy envelope which covers the animal at night is mainly produced by large mucous goblet cells in a folded epithelium; there is a high number of acidophilic secretory cells. At the ultrastructural level, both cell-types open at the surface of the epidermis. Preliminary experiments with pilocarpine, atropine and the α-blocker propranolol reveal a neural regulation of mucus discharge. Also, the rich vascularization of the gland could indicate a hormonal control e.g. by prolactin. The secretory products of both types of goblet cells are discussed in relation to their possible antibiotic properties..."
(- no idea whatsoever above is saying???...but kind of sounds similar to what our wrasses do
)
The Bahamas: A Closer Look at the colorful and Unique Parrotfish
by Tim Smith
"...parrotfish retire to the reef bottom to sleep at night. Some burrow into the sand
like wrasses while some species of Scarus have developed the ability to secrete a filmy mucus cocoon. Some individuals also produce mucus cocoons under anoxic conditions.
The mucus envelope is secreted in thirty minutes and masks its scent, affording the parrotfish protection from coral reef night predators such as sharks and moray eels. Six series of experiments were performed to determine the effectiveness of the mucus envelope in reduction of predation using the common spotted moray eel and three species of parrotfish (Winn & Bardach, 1959). Only one of the parrotfish (Scarus croicensis) was capable of secreting a mucus cocoon. The results indicated an increased tendency for the moray eel to prey on the species of Sparisoma (apparently do not secrete mucus cocoons) rather than Scarus croicensis. The moray uses the senses of smell, taste, and touch in its feeding activities. A grasping reflex is initiated and the food is swallowed immediately upon touch.
In these experiments, the grasping reflex was not initiated when the head of the moray was exposed to the mucus..."
Please feel free to add to if you come up with anything else...
