How long do starfish live?
Starfish is the common name given to the species of the Class of asteroids (Asteroidea): an extensive group of animals belonging to the Phylum of echinoderms, whose main characteristics are five-radial symmetry, a flattened body, and the presence of five arms or even more.
Although this common name, starfish or sea stars, is exclusive to the member species of the Class of asteroids, its use is often mistakenly extended to the Class of ophiuroids. Although this meaning is commonly accepted, it is still wrong.
Generally, these particular marine animals are classified as fish when, in fact, they are not. Interestingly, as members of the phylum echinoderms, the starfish are close relatives of sea urchins, sea cucumbers, and sand dollars, and not of fish since these belong to another phylum (Chordata Phylum).
Currently, more than 2,000 species of sea stars are known from the world's oceans, which, although very similar in shape, differ in longevity. Larger species usually live much longer than smaller ones because of the biological advantages and chances of survival that their size confers.
The sea stars are a class (Asteroidea) of the echinoderm phylum composed of approximately 1,900 species, which usually rest on the seabed of all the world's oceans without exception.
In other words, it is possible to find starfish in all latitudes, from the tropics to the polar regions, resting on the ocean floor, either in the warm intertidal zone or in the frigid and hostile abyssal depths (20,000 feet below sea level).
Given such biological capabilities, it is not surprising that starfish have unusual reproductive behavior.
In conclusion, the asteroids (sea stars), as a class of species, do not have a single life cycle but rather vary according to the species.
For this reason, if the central question of this section is to be answered, one of the best alternatives would be to establish an upper and lower limit between the oldest and least long-lived species of asteroids:
Lifespan of starfish in captivity
Starfish are often kept in aquariums and other controlled environments, where they can be observed up close. In captivity, the lifespan of a starfish can vary greatly depending on the species and the quality of care they receive.
Some species, such as the common sea star (Asterias rubens), have been known to live for up to 35 years in captivity.
Others, like the chocolate chip sea star (Protoreaster nodosus), may only live for a few years. Larger species such as the Acanthaster planci (crown-of-thorns starfish) can live up to 25 years or more under optimal conditions in captivity.
Factors that can affect the lifespan of starfish in captivity include water quality, temperature, and diet.
Starfish require clean, well-oxygenated water to thrive, and they may become stressed or sick if the water is not properly maintained.
In addition, some species of starfish have specific dietary requirements that must be met in order for them to live a long and healthy life.
Captive starfish are also less prone to diseases, parasites, and injuries, because of the controlled conditions and regular monitoring by marine biologists or aquarists.
Lifespan of starfish in the wild
On average, most species of starfish live between 5 to 10 years in the wild. However, this can vary greatly depending on the species and the environment in which they live.
Some species, like the sunflower star (Pycnopodia helianthoides), may live for up to 10 years or more. Others, like the northern sea star (Asterias vulgaris), may only live for a few years.
One factor that can affect the lifespan of starfish in the wild is predation. Starfish are a favorite food of many marine predators, including birds, fish, and other invertebrates.
Another factor that can affect the lifespan of starfish in the wild is environmental stress. Starfish are sensitive to changes in temperature, water quality, and other environmental factors, and may become stressed or sick if these conditions are not optimal.
Climate change and other human activities can also have a negative impact on the health and lifespan of starfish and other marine organisms.
Where do starfish live?
Like all species belonging to the echinoderm phylum, Sea stars are biologically incompatible with freshwater habitats. In other words, asteroids can only live in bodies of salt water; for this reason, they can only be seen in oceans.
As for the distribution and habitat of asteroids in the oceans, it seems to have no limits. Starfish can withstand the warm waters of tropical regions and the frigid waters of polar regions without any problem, as well as the abysmal pressure prevailing in the abyssal region.
What do starfish eat?
Given such a diversity of species, it is not appropriate to describe the diet of starfish under a single adjective since each species shows different eating behaviors.
Thus, depending on its species and the environmental conditions in which it develops, a starfish can feed on:
- Coral polyps
- Decomposing organic matter
- Surrounding organic nutrients in water currents produced by sea sponges
- Sea stars (some species may exhibit cannibalistic behavior)
Interesting facts about starfish
Next, we show you seven (7) fun facts about starfish:
- Starfish are not fish; they are not even close to being considered as such. These particular marine animals do not belong to the extensive phylum of chordates to which fish belong but to the echinoderms.
- There are currently 1900 species of starfish alive and distributed throughout the oceans of the world without any exception. While most starfish share the same characteristics, some have unique and distinctive traits. For example, the sunflower star (Pycnopodia helianthoides) is distinguished by its incredible wingspan, size, and speed.
- Don't be fooled by its appearance! Sea stars are predators. The star sunflower, for example, is one of the most feared predators on the sea floor.
- Each one of the arms of this species is identical to the other. Likewise, these contain the vital programs of the sea stars. Under their arms, it is possible to observe small flexible appendages in the form of tubes, which the starfish use to move and transport food to their mouths.
- Oddly enough, starfish's eyes are not located on their central disc but at the end of each arm. Although its vision system is not exactly the best in the entire marine world, it allows it to obtain enough information to orient itself, identify structures and find food.
- Starfish don't have brains! Instead, asteroids have a complex nervous system that runs through their entire body.
- Like some lizards and salamanders, starfish master autotomy, in other words, voluntary amputation. This ability allows them to detach a part of their body at will to escape from their predators. After a while, the starfish can regenerate the lost limb.