My Big Fat Lemon

The mucus cocoons made by some reef-dwelling fish protect the sleeping animals from being bitten by the louselike parasite Gnathia aureusmaculosa, the marine isopod shown here.Nico Smit

Tallying each fish’s blood-engorged parasites showed that the mucus acts as a slimy sea version of bug netting: 94 percent of fish without cocoons had bites, versus 10 percent of fish with intact cocoons. The cocoon-challenged fish also had far more bites on average than their counterparts, the researchers report in a paper to appear in Biology Letters.

Making the mucus cocoon, which begins at the fish’s mouth and envelops the entire body within an hour, is an efficient protection strategy, costing a mere 2.5 percent of the fishes’ daily energy budget, the researchers estimate. This is relatively cheap, compared with scraping yourself on rocks or sand, avoiding areas with parasites or seeking parasite-eating cleaner http://best-hair-loss-products.net fish (which the fish do during waking hours).

Keeping bugs at bay is a new role for fish mucus — the thinner slime layer employed by some species appears to protect against UV rays and pollutants, or can aiding in maintaining the proper balance of electrolytes and fluids.

Presented with a choice between cocaine and food, female rats choose the drug while male rats go for the grub, a new study finds. The result may help clarify differences in addiction between men and women, scientists reported November 14 at the annual Society for Neuroscience meeting.

Colleagues trained rats to press one lever to receive food or a separate lever to receive cocaine. Later, the rats were presented with the food lever and the cocaine lever at the same time.