A slug has two retractable pairs of tentacles. The upper pair of tentacles are called the optical tentacles and are the eyes of a slug. The optical tentacles have light sensitive eyespots on the end and can be re-grown if lost.
Sexually creative and equipped with eyes that can grow back if they somehow go astray, slugs might not be the cuddliest of all creatures - but they are very definitely interesting.
Mystery snails (Family Ampullariidae) are aquatic prosobranchs which possess structurally complex eyes at the tip of a cephalic eyestalk. No other sensory organs are found in association with this stalk. These snails possess the ability to regenerate the eye completely after amputation through the mid-eyestalk.
While their actual eyes might not be especially useful for seeing with, snails actually have light sense cells covering their entire bodies. This means that, even without eyes, they can sense when a shadow casts over them.
All slugs have two eyes on the end of long antenna and two smaller antennae below that are used to feel and taste it's surroundings.
Slugs and snails have two pairs of retractable tentacles on their head. The upper, optic tentacles, have light-sensitive eyespots on the ends. Each eye-stalk can move independently and can be re-grown if lost.
Many land snails have the ability to retract their eyes. The main reason for this is to keep them protected! It's similar to our ability to blink or close our eyes when we need to. If something is going to hurt your eyes, it's better to get them protected and secure.
Snails may have opioid responses and mussels release morphine when confronted with noxious stimuli. Both reactions suggest that these animals do, in fact, feel pain. While mollusks don't have brains per se, they do exhibit some nervous system centralization. They have several pairs of ganglia connected to a nerve cord.
Since snails only sleep for about 20 minutes at a time, it is simply best to wait for them to wake up on their own.
To wake mollusks and avoid large losses, increase the air temperature gradually several degrees per day, simulating natural warming. This will help avoid stress. In order to accelerate this process, water them with warm water. They will gradually feel the heat and begin emerging from the shells.
They have both female and male reproductive cells (they are hermaphrodite). They don't actually need to mate with another snail in order to reproduce, self fertilisation is possible. After mating they lay around 80 white eggs in a damp, underground nest.
Many species of freshwater snails are hermaphrodites, meaning they have both male and female sexual organs, and can reproduce asexually, meaning without the need for two snails. Others are hermaphroditic but often reproduce sexually.
lose them, they'll just grow a new one!... lose them, they'll just grow a new one!
Some sea slugs can live without their bodies. Cut their heads off, and the noggins can still survive for months, scientists recently discovered.
The ugly slug uses a relatively simple system of neurons to remember certain stimuli and react to them. For example, the slugs can remember being pinched in the gill, and they learn to react by withdrawing the gill.
Then the researchers tested the slugs' siphon withdrawal reflex 48 hours later. Sea slugs that had been shocked kept their siphons withdrawn for a significantly longer period of time than untrained sea slugs. This suggests that the conditioned sea slugs had formed a memory of their shocks. So far, nothing unusual.
How Long Can Snails Sleep? Certain land snails can sleep for up to three years in hibernation or estivation. Yes, it's true! Although this extended nap may sound appealing at first, it is actually caused by less-than-ideal conditions.
Being upside-down for short periods of time won't kill the snails, but it does leave them vulnerable to predation from tankmates, and they can't feed or do any other normal snail things. Some snails can flip themselves over like acrobats, but others may need a hand if they get stuck.
If your snail seems to be in a friendly mood, it will be okay to stroke its shell a little bit. Stroking or touching the shell is a great way to interact with your snail and to “play” with it.
Is it cruel to put salt on slugs? Slugs have pain receptors, so salt could be really painful for them. Some studies have shown that mollusks like slugs and snails still can feel pain, so coating them in salt and dehydrating them isn't the most humane.
Slugs do not bite in a traditional way. Yet, they use a ribbon-like organ to scrape rocks and other surfaces, which can include human skin. Slug bites are not as dangerous as you would think. Among the few occurrences of slug bites, only some people experienced tingling and pulsation in the bitten area.
“We don't know how much pain they feel when in contact with salt, but a slug or snail caught in granules will try to wiggle away while exuding a lot of mucus to clean their skin.”
Researchers were astonished to observe slugs in captivity cutting off their own heads after their bodies became infected with parasites. Within 3 weeks, the heads regenerate a whole, parasite-free body, though the bodies never grow back new heads.
If a slug is frightened or not active the slug will retract its head into the mantle for protection. The mantle also forms the respiratory cavity. In some slug species there is a small piece of shell in the mantle, this is because slugs have evolved from snails.
A slug may lift its tail and vibrate it back and forth as a means of scaring a potential predator. It may clamp its mantle to the ground to protect its head. To scare away predators, it may even squirt blood through its breathing hole!