I’ve grown up admiring Blue starfish (Blue Sea Star / Linckia Laevigata) not only in the lagoon but also on the rocks across the coastline of the Cook Islands. Interestingly starfish historically are seen to be simple invertebrates. Their eyes are relatively simple and they lack a brain. They are the opposite to one of my favourites the Eagle rays – with one of the biggest brains of all animals. Researches say it’s hard to know if they can even see, which is what largely prevents the invertebrates from wandering too far.
Because it is not a fish but an echinoderm – more closely related to sea urchins. Marine Biologists have renamed the beloved ‘Starfish’ name with ‘Sea star’. This said I grew up thinking of them as Starfish so will continue to call them this 😉
They are Carnivores and have a lifespan of up to 35 years. They are 4.7 -9.4 inches in size and weigh up to 11 pounds. Their relative size is that of a teacup. There is a population of 2,000 species of sea star living in our world’s oceans. In the Cook Islands the main species is the ‘Blue Starfish’. With the five-arm varieties being the most common. Interestingly there are species however with 10, 20, and even 40 arms (I would love to see this).
For shelter/protection they have bony skin, which protects them from the majority of predators. And their striking colours (seriously Wow) often camouflage them or scare off potential attackers.
Starfish are famous for their ability to regenerate limbs, and in some cases, entire bodies. This is done by housing most if not all of their vital organs in their arms. Some require the central body to be intact to regenerate, but there are a few species which can grow an entirely new starfish just from a portion of a severed limb.
They have an amazing ability to consume prey outside their bodies. They use their tiny, suction-cupped tube feet to pry open clams or oysters, and their cardiac stomach emerges from their mouth and oozes inside the shell. The stomach will then envelop the prey to digest it, before finally withdrawing back into the body.
They are known to be preyed on by pufferfish – also common in the Cook islands waters.
Warning courtesy of my Dad ‘Be careful if you see a starfish. It will make your eyes sparkle and your loved ones fall more in love with you. ‘