Science, Tech, Math › Science Slowest Animals on the Planet Share Flipboard Email Print Science Biology Organisms Basics Cell Biology Genetics Anatomy Physiology Botany Ecology Chemistry Physics Geology Astronomy Weather & Climate By Regina Bailey Biology Expert B.A., Biology, Emory University A.S., Nursing, Chattahoochee Technical College Regina Bailey is a board-certified registered nurse, science writer and educator. Her work has been featured in "Kaplan AP Biology" and "The Internet for Cellular and Molecular Biologists." our editorial process Regina Bailey Updated August 13, 2019 In the animal kingdom, it can be dangerous to be a slow-moving creature. Unlike some of the fastest animals on the planet, slow animals can't rely on speed to avoid predators. They must use camouflage, distasteful secretions or protective coverings as defense mechanisms. Despite the dangers, there can be real benefits to moving slowly and having a "slow" approach to life. Slow-moving animals have a slower resting metabolic rate and tend to live longer than animals with faster metabolic rates. Learn about five of the slowest animals on the planet: 01 of 05 Sloths Ralonso/Moment Open/Getty Images When we talk about slow, invariably the conversation will begin with the sloth. Sloths are mammals in the family Bradypodidae or Megalonychidae. They don't tend to move very much and when they do, they move very slowly. Due to their lack of mobility, they also have a low muscle mass. By some estimates, they only have approximately 20% of the muscle mass of a typical animal. Their hands and feet have curved claws, allowing them to hang (typically upside down) from trees. They do much of their eating and sleeping while hanging from tree limbs. Typically female sloths also give birth while hanging from tree limbs. The lack of mobility in sloths is used as a defense mechanism against potential predators. They camouflage themselves in their tropical habitat to avoid being spotted. Since sloths don't move much, it has often been reported that some interesting bugs live on them and algae even grow on their fur. 02 of 05 Giant Tortoise Mint Images - Frans Lanting/Getty Images The giant tortoise is a reptile in the family Testudinidae. When we think slow, we often think of a tortoise as evidenced by the popular children's story, "The Tortoise and the Hare" where slow and steady wins the race. Giant tortoises move at a rate of less than a half a mile per hour. Although very slow, tortoises are some of the longest-lived animals on the planet. They often live beyond 100 years with some having reached over 200 years old. The giant tortoise relies on its huge size and enormous tough shell as protection against would-be predators. Once a tortoise makes it to adulthood, it can live for a very long time as giant tortoises have no natural predators in the wild. The biggest threat to these animals is a loss of habitat and competition for food. 03 of 05 Starfish John White Photos/Moment/Getty Images Starfish are star-shaped invertebrates in the Phylum Echinodermata. They usually have a central disc and five arms. Some species may have additional arms but five is the most common. Most starfish don't move quickly at all, only managing to move a few inches per minute. Starfish use their hard exoskeleton as a defense mechanism to protect against predators such as sharks, manta rays, crabs and even other starfish. If a starfish happens to lose an arm to a predator or an accident, it is capable of growing another through regeneration. Starfish reproduce both sexually and asexually. During asexual reproduction, starfish and other echinoderms are able to grow and develop into a completely new individual from a detached part of another starfish or echinoderm. 04 of 05 Garden Snail Auscape/Universal Images Group/Getty Images The garden snail is a type of land snail in the Phylum Mollusca. Adult snails have a hard shell with whorls. Whorls are turns or revolutions in the growth of a shell. Snails don't move very fast, about 1.3 centimeters per second. Snails typically secrete mucous that helps them to move in some interesting ways. Snails can move upside down and the mucous helps them to adhere to surfaces and resist being pulled from said surfaces. In addition to their hard shell, slow-moving snails use the mucus to protect against predators as it has a foul smell and unpleasant taste. In addition to these defense mechanisms, snails sometimes play dead when they sense danger. Common predators include small mammals, birds, toads, and turtles. Some consider snails as pests as they can feed on common foods growing in gardens or in agriculture. Other individuals consider snails to be delicacies. 05 of 05 Slug Esther Kok/EyeEm/Getty Images Slugs are related to snails but don't typically have a shell. They are also in the Phylum Mollusca and are just as slow as snails, moving at about 1.3 centimeters per second. Slugs can live on land or in the water. While most slugs tend to eat leaves and similar organic matter, they have been known to be predators and consume other slugs as well as snails. Similar to snails, most land slugs have pairs of tentacles on their head. The upper tentacles typically have eye-spots on the end that can sense light. Slugs produce a slimy mucus that covers their body and helps them to move around and adhere to surfaces. The mucus also protects them against various predators. Slug mucus makes them slippery and difficult for predators to pick up. The mucus also has a bad taste, making them unappealing. Some species of sea slug also produce an inky chemical substance that they excrete to disorient predators. Though not very high on the food chain, slugs play an important role in the nutrient cycle as decomposers by consuming decaying vegetation and fungi.