Simply speaking, animals without backbone or vertebral column are invertebrates. Humans have backbones and are not invertebrates, in fact humans are vertebrates. You would be surprised to know that invertebrates and not vertebrates (despite humans being vertebrate) dominate the animal kingdom in terms of numbers. 95% of known animal species fall in the category of invertebrates and vertebrates are a rarity in animal kingdom.

When one thinks about spineless creatures (invertebrates) then automatically creepy and crawly creatures led by snakes takeover the mind but you will be surprised to know that snakes are not invertebrates and have spine. Snakes like humans are rare members of animal kingdom. All vertebrates are descendants of the same progenitor while certain invertebrates are more closely linked to vertebrates rather than other invertebrates because they belong to diverse and sometimes unrelated families.

Some notable invertebrates
1. Bobbit worm – It is a bristle worm that that inhabits warm marine environments and is at times found amid coral reefs. While it can be sighted in the Indo-Pacific, the Atlantic Ocean is its most important habitat. Four inches to 10 feet is its length range. It can reproduce asexually by separating into multiple segments just like various other bristle worm species. This is why withstanding attacks from predators becomes easy for them. They are ambush predators and use antennae to detect prey.

2. Giant Isopod – Don’t go by their terrible looks, giant isopod are harmless invertebrates that can be sighted scuttling about in the ocean’s depths nibbling on dead items that drift down from above. It is an aquatic crustacean species belonging to the Isopoda order and is distantly related to shrimp and crabs.

3. Amazonian giant centipede – Amazonian gigantic centipede belongs to Scolopendra genus of centipedes. It is world’s biggest species of centipede (12 inches length). Bodies of Amazonian giant centipedes can have up to 21 or 23 segments. This creepy species is prevalent in South America and the southern Caribbean. These are real creepy characters.

In dark, wet areas like under leaf litter or beneath rocks, the Amazonian giant centipede can be found in tropical or subtropical rainforests as well as tropical dry forests. It is a carnivore that eats any other animal that it can dominate and kill with its brute strength and deadly venom. It is strong enough to defeat small vertebrates like lizards, frogs, snakes, bats, and even birds in addition to other invertebrates including insects, spiders, millipedes, scorpions, and even tarantulas. The venom of this centipede has caused at least one recorded human fatality. So, if you find yourself in the Amazon, be mindful of where you step!

4. Vampire squid – These creepy looking invertebrates inhabit deepest parts of temperate and tropical waters. These little cephalopods survive in these areas of the ocean with very little amount of oxygen by making use of its bioluminescent organs. They can grow up to one foot in total.
These are only few of the numerous species of invertebrates that include coconut crabs, tailless whip scorpions, giant weta, bigfin quid, Japanese spider crab and irukandji jellyfish.