When we think about the speed that animals travel, usually we think of the fastest animals. We imagine horses, or the big cats like cheetahs and leopards, or wolves. But some of the slowest animals on the planet can be equally as fascinating.
Some, like the sea anemone may not look like an animal at all. There are others that look like fruit, or can hide in a shell. Some that have no bones and move using only muscles and mucus. There are lots of fascinating animals that are very, very slow. Let’s take a look at some of the slowest animals in this post.
10 Of The Slowest Animals
Sea Anemone (Order: Actiniaria)
- Size: From 1.5 cm to 1 meter in length.
- Speed: 0.001 km/h
They may look like a fancy type of corral, or sea plant, sprouting from rock on the sea bed, but Sea Anemones are in fact marine invertebrates, and a relative of jellyfish and hydra. While some anemones may float near the surface of the water, most of them are found attached to a hard surface near the sea floor.
While many anemones will stay anchored to the same spot for very long periods of time, the can and do move when the need arises. The movement however is so slow, that like the sun setting, it would be hard to perceive with the naked eye. It can be observed far easier with photography using a time lapse. This motion is performed by ‘creeping’ around on their base very slowly, along the surface to which they are attached.
If they want to move further and at a pace, they can detach their base from the object to which they are anchored, and drift or glide to a new location.
Garden Snail (Cornu aspersum)
- Size: Shell can be up to 4 cm in diameter and 3.5 cm high, and large enough to accommodate the body.
- Speed: 0.001-0.045 km/h
Snails are some of the slowest animals and the Garden Snail is amongst the slowest of them all. These little creatures use their shell rather than their speed as a means to escape their predators. As such, being able to move fast is not as important as it is for many other species. When threatened, they simply slither their bodies up into their shell and remain there until the threat has passed.
To move, these little creatures contract and relax muscles in their ‘foot’, and excreta a type of mucus to create locomotion. The process is very slow. On average, a garden snail will move around 1 meter in an hour but have the potential to move as fast as 47 meters per hour in times of extreme stress or need. It’s unclear how long they can maintain that type of top speed.
Starfish (Class: Asteroidea)
- Size: Range from 1.5 to 102 cm across the species.
- Speed: 0.009 km/h
Starfish is a broad description of all star shaped fish in the class ‘asteroidea’, of which there are over 1900 species around the oceans of the world. These marine vertebrates usually have a central ‘disc’ with 5 ‘arms’, though some are known to have more. There are some that have 6 or 7 and in rare examples, up to 15 limbs!
Like some other animals (axolotls for example) some starfish are able to regenerate limbs if they come to any damage, and sometimes shed them as a form of defence, only to grow them back later. They are important sea creatures, with some even being considered keystone species in their habitat.
There are some species of starfish, such as the sand star (Luidia foliolata) that can reach up to 2.8 meters per minute (0.168 km/h) but the majority can only travel at a fraction of this. The prime example being the leather star (Dermasterias imbricata) which can only manage up to 15 cm per minute (0.009 km/h).
Seahorse (Genus: Hippocampus)
- Size: 1.5 to 35.5 cm
- Speed: 0.015 km/h
There are 46 species of seahorse in the genus ‘Hippocampus‘, all of which are small fish with a peculiar tail and appearance. While their coil shaped tails make for an attractive feature, they don’t make a good swimming aid. Rather than swimming with purpose and finesse, seahorses, rely on drifting and gliding through water, steering with pectoral fins and flapping their dorsal fin to move with very little propulsion.
Across the species they can vary in size considerably, but they all share the common trait of being poor, vertical swimmers. They are another animal that has camouflage rather than speed as their main method of defence. Some species are as slow as 1.5 meters per hour when swimming, so it is to their advantage to find safety in stillness and their environment rather than evasion.
Sloth (Suborder: Folivora)
- Size: 58-70 cm
- Speed: 0.12 – 0.24 km/h
There are two different types of sloth, the two-toed sloth and the three-toed sloth. In both cases, they are incredibly slow, and spend most of their time hanging in the trees. These animals are equipped with very strong limbs from hanging and climbing, and only come down to ground roughly once per week! Their bodies are not nearly as well developed for terrestrial travel as they are for hanging in the tree canopies.
On the ground, they are capable of reaching around 2 meters per minute, and this increases to 3 meters per minute (0.12 km/h) in the trees. When desperate, sloths are capable of traveling as fast as 6 meters per minute (0.24 km/h) but they can only maintain this for short periods.
Sloths have an incredibly slow metabolism, and any exertion of energy is a real drain for them. Sloths don’t eat much, but despite this, they are almost always full. In most cases, they will only travel at around an average of 38 meters per day! They will only generally move faster if threatened, in pursuit of a mate, or for those that like the water, when swimming.
Galapagos Giant Tortoise (Chelonoidis niger)
- Size: 61 – 150 cm across the species
- Speed: 0.299 km/h
All tortoises are slow, but the Galapagos giant tortoise may be the slowest reptile on Earth. There are 13 extant subspecies of these behemoths, and the largest of them all can reach up to a staggering 417 kg in weight. The subspecies range across a variety of different islands, both size and longevity do seem to be effected by their habitat.
Not only are they huge, but the are incredibly long lived, with some reaching twice the age of the average human! They have been recorded reaching over 170 years of age more than once.
They may be big, and they may live long but they certainly do not move fast. While some of the smaller giant tortoises may be able to reach toward 1.92 km/h, the largest Galapagos giant tortoises travel at around 0.299 km/h (0.2 mph). Most of their traveling takes place while foraging through the day, after basking in the morning sun to heat up their shell and regulate their cold blooded temperature.
Caterpillar (Larval form of the Order: Lepidoptera)
- Size: From 0.1 – 14 cm across the species.
- Speed: 0.36 km/h
Caterpillars come in a variety of different shapes and sizes, representing the larval form of all butterflies and moths in the order Lepidoptera. They are mostly herbivorous, but some are insectivores and these little animals are found across the world on every continent except Antarctica. Some are rare, while others are more common. There are those that live in vegetation close to ground, and those that live higher up in the trees, munching on leaves.
Some caterpillars have been observed moving regularly at around 360 meters per hour. When threatened they can nearly triple their top speed to evade a predator, but they can’t maintain that for very long. Widespread as they are, caterpillars are a common prey for many species on land and from the air, an easy target with little protection. That is, with exception of the poisonous caterpillars!
They have a very different method of moving than most other animals, because they don’t have any internal bones. Rather they have an exoskeleton on the outside of their bodies. Instead, they grip with their boneless legs, and move by squeezing muscles in a sequence of contractions, using an undulating wave motion. This movement is often referred to as ‘inching or ‘crawling’ in ‘rectilinear’ locomotion.
Banana Slugs (Genus: Ariolimax)
- Size: 15-26 cm across the species
- Speed: 0.48 km/h
When you hear the word slug, the most common thing people think of are the black slimy creatures laying waste to the vegetation in their garden or yard. But in fact, the term is commonly used to describe any shell-less terrestrial gastropod mollusc. There are many different Orders, Suborders, Families and superfamilies that contain abundant species of land slug, and they can come in a variety of different colors and sizes. Not just the ones eating all the lettuce in your yard!
One particular genus, Ariolimax, have very distinctive coloring which has led to them commonly being called banana slugs. There are 5 different species and they all, in their own way, look like small ripe bananas.
One thing they all have in common, is that they are all pretty slow. The average speed of a banana slug, is around half a kilometer per hour. Like snails, to whom they are closely related, they move through making muscle contractions in their ‘foot’ to create locomotion. They are however, faster than their snail cousins, likely due to the fact that they don’t have to carry around their home of a shell around on their backs.
This genus represent some of the largest slugs in the world, with one of the species, the Pacific banana slug, reaching up to 26 cm in length.
The Slow Loris (Genus: Nycticebus)
- Size: 18 to 38 cm across the species
- Speed: 1.89 km/h
There are 8 extant species of slow loris found across their range, which extends across southeast Asia, from Bangladesh to the island of Java. Their closest relative is the pygmy slow loris, and they are also closely related to the slender loris that lives west of their range, in India and Sri Lanka.
These small animals are the only primate in the world that have a venomous or toxic bite. They use this as a defence mechanism from predators but also when resolving disputes with competitors. When threatened, these animals are far more likely to freeze than flee, which is a good thing because they are not fast at all. The average nocturnal hunt, takes these omnivorous animals around 8 km (5 miles) across the night, and they travel at speeds of up to around 1.89 km/h.
Gila Monster (Heloderma suspectum)
- Size: Up to 51-56 cm in the largest examples.
- Speed: 2.4 km/h
Gila monsters are known for being amongst the slowest lizards in the world. These venomous lizards are native to areas in southwest USA and northwest Mexico. They actually get their name from the Gila River Basin in Arizona and New Mexico where populations were once abundant.
They are a medium sized lizard, reaching as much as 56 cm long, and they are capable of killing and eating prey up to a third of their size (50% their size when they are young). Their closest relatives are the beaded lizards from Central America.
While gila monsters are well equipped for hunting, with a good strong body and venomous bite, they are slow out of the box. They are however known to have good endurance. Despite this, they rarely travel far. In one research project, they were observed moving around 210 metres across a whole day. This increased to around 1 km in some rare cases. Even during their most active season, they only spend around 10% of their time active, and the rest underground in burrows or shelters.
When they do hunt, or move their nomadic home, they have been observed at speeds of up to 2.4 km/h and this is usually in a short burst in pursuit of prey.
What Is The Slowest Flying Bird In The World?
Both the American Woodcock and Eurasian Woodcock are capable of flying at incredibly slow speeds during their courtship rituals when performing for potential mates. They have been observed flying as slow as 5 km/h, however, even during migration these low flying birds have been spotted averaging (26 to 45 km/h). So even during long flights these birds are very slow for birds in flight.
What Is The Slowest Mammal In The World?
As mentioned in the list above, all sloths are slow, but the three-toed sloth also boasts the title of being the slowest mammal on Earth.
They are slightly smaller than their two-toed cousins, and have a slightly different diet too. It is the difference in diet that some suggest may give the two-toed variety the edge when it comes to moving faster.
What Is The Slowest Fish In The World?
We know from our list that seahorses are slow, but the slowest of them all is the dwarf seahorse. These tiny seahorses are the slowest fish anywhere in the world.
They are recorded in the record books (Guinness) as being the slowest with a speed as slow as 150 cm per hour. Which for a fish in water, is obscenely slow!