Starfish
Conservation status
Starfish - Scientific Name - Asteroidea
There are well over 1,600 species of Starfish or Sea Stars – which are in fact invertebrates and not fish at all. They are classified as echinoderms, alongside urchins and sponges.
The Sunflower Sea Star (Pycnopodia helianthoides) is Critically Endangered on the IUCN Red List. From 2013 to 2017 the species (and over 20 other Sea Star species) were devastated by a global outbreak of sea star wasting syndrome. The IUCN determined a 90.6% decline from historic to current population sizes and estimated that 5.75 billion were killed by the disease which constitutes the biggest marine disease outbreak on record. There is evidence that rising sea temperatures contribute to the seriousness of the disease and there are ongoing local outbreaks. The decline of Pycnopodia impacts ecosystems – for example resulting in sea urchin overgrazing on kelp forests which provide crucial habitats for marine species as well as sequestering carbon dioxide from the atmosphere.
Overview
Sea Stars are generalist predators and, in some areas, considered to be keystone predators (regulating local ecosystems). Sea Stars are very vulnerable to rising sea temperatures due to climate change. In addition, as they breathe through their skin they are also at risk from declining oxygen levels.
There is evidence that Sunflower Sea Stars may also be threatened by bycatch, the trade of dried Pycnopodia, and ‘log dumping’.
Sea star species live across the world in all oceans – in intertidal zones, rock pools and rocky shores, coral reefs, in kelp and seagrass beds, and on sandy ocean floors. They vary in size and colour and most species have a spiny skin and 5 arms – although some have up to 50. Each arm has an eye spot at its tip which allows the Sea Star to distinguish between light and dark. The underside of a Sea Star is covered in hundreds of suckers/tube like feet which help them to move across rocky or sandy surfaces. Sea stars can extend their stomachs out of their mouths to capture their prey and begin digestion before returning their stomachs to the inside of their bodies. They don’t have a centralized brain (as we know it) – rather a decentralized nervous system – a network of nerves and neurons distributed throughout their bodies. This network allows a Sea Star to move, think, learn, remember and process information, and sense and respond to their environment. It also enables them to regenerate lost or damaged limbs. They have a water vascular system rather than blood circulating around their bodies. Sea Stars can feel pain and act collectively.
Because of its resilience, adaptability, and ability to regenerate Starfish feature in folklore, indigenous and Eastern philosophies and belief systems. For example, to symbolize the stages of life, death and rebirth, to highlight that life is a continuum beyond death or loss, or as a symbol of reincarnation and the journey of the soul through many lifetimes.
https://mythologyworldwide.com/the-sacred-starfish-regeneration-and-resilience-in-folklore/
https://www.iucnredlist.org/species/178290276/197818455
https://www.natgeokids.com/uk/discover/animals/sea-life/starfish-facts/
https://planetfish.org/do-starfish-have-brains/
https://enviroliteracy.org/how-do-starfish-think/