Have you ever wondered why some plants and animals live for so long relative to humans? An animal with one of the longest lifespans is the Greenland Shark, which can live up to 200 years. In fact, some have been found to live 400 years (One Kind Planet).
When it comes to plants, the Great Basin bristlecone pine has the longest lifespan in North America, and is the oldest non clonal tree on the planet (Wikipedia). A non clonal organism is one that reproduces sexually, rather than by cloning.
You’ll also find some long-lived animals under the waves as well. I like to bring your attention to the most primitive multi-cellular life form on earth.
The sea sponge is certainly high on the list of the world’s longest living organisms. When you wonder how long do sea sponges live and why, it’s wise to consider three aspects of this awesome creature’s life.
First, their environment must offer optimal conditions for growth; second the sea sponge’s natural defenses against invaders help them survive and thrive, and finally their rate of growth heavily impacts their life span.
Nice and Easy
Sea sponges live in relatively stable environments. This means their surroundings do not change significantly enough to bring about any disruption to their development. They remain fixed to wherever they happen to land during the larval stage and remain there for their entire existence. The few that manage to move do so on a cellular level. They do so slower than it takes grass to grow.
The coral where they live also changes very slowly, which adds to the stability of that ecosystem. The deep and calm waters of the deep are the type of habitat needed by the longest living sponges, because it ensures maximum and uninterrupted growth (NewScientist).
The more remote the sea sponge’s home is the better. At present, only humans seem to be the only threat to these sanctuaries. It seems only rational that a long life is heavily dependent on the unchanging steadiness of the world around us.
Back Off Pal!
Sea sponges are supremely adept at defending themselves against different threats. To protect themselves against predators, or even other sponges when the coral becomes too crowded, they produce powerful toxins. These chemicals also make them taste awful to would be consumers.
Invasion by toxic parasites is also a constant threat. The sponges’ own powerful toxins help to keep these invaders at bay and thus maintaining it’s health. Which will have a direct impact on the question of how long do sea sponges live.
Symbiotic microbes living within the sponge are responsible for producing these extremely effective substances that keep the host safe and thriving (SunSentinel). These natural chemicals have also become the new frontier against killer infections and diseases such as MRSA and cancer.
Maybe you have also noticed that sea sponges vary greatly. They differ in color, shape, texture and size. One feature that most related to how long a sea sponge lives (and any other animal for that matter) is their size.
Sea sponges can reach some remarkable proportions. One particular sponge discovered off the coast of Hawaii was measured to be as big as a minivan. Others have been found to be as tall an 8 story building.
When it comes to longevity Natural selection dictates that the larger a species of animal is the longer its lifespan. In part this is because the larger animals not only face less danger from predators, their aging process is actually slowed down (NCBI).
It also takes more time to grow larger; it makes sense that old age will come later to an organism which is taking longer to develop.
This is relatively easy to see when we notice the bigger whales are the ones living longer; as are the tortoises, which are the larger members of the order testudines to which turtles belong.
The larger the species of animal, the slower it will grow. When it comes to living longer, natural selection will favor the animals that grow large and thus take time to mature.
Bring Down The Hatches
In the event that the sea sponges’ environment becomes stressful for the sponge, it can encapsulate itself in a structure called a gemnule. While inside, the sponge has plenty of nutrients and protection to ride off what ever stressful event is occurring in its environment (USCB Scienceline).
This adaptation offers our resilient sea sponge with yet another way of surviving in an unpredictable world.
A sea sponge’s skeleton is made up of spicules. Besides providing the skeleton with structural support, these also discourage predators as they are too irritating to consume.
This remarkable organism has few predators to be concerned with. This is due to its remarkable array of defenses. It does not move very much, if at all, yet it has not had a good reason to do so in 600 million years.
One Way Or Another
The first organism to reproduce sexually were actually the sea sponges. That is, the original life form that procreated by way of the union of sperm and egg. Sea sponges are hermaphrodites; that is one sponge can produce both egg and sperm. This gives them yet another avenue to survive.
Sea sponges have another method by which to continue their lineage – they can clone themselves. As many who harvest them knows, sea sponges can be cut about an inch from their base and it will regrow into an entire new organism – even more robust than the original.
If a piece of a sponge happens to becomes severed from the host, drifts away, lands and attaches to a rock or coral, it will regrow into a genetically identical sponge.
Sea sponges have been surviving and thriving for six hundred million years. This alone affords them tremendous respect. They have evolved a host of different ways to protect themselves from the many threats that naturally exist.
The larger sponges naturally require more time to develop. Natural selection favors the larger sponges by slowing down the aging process, which results in them living longer.
Even when the environment becomes hostile, the sea sponge can further protect itself by encapsulating itself in a protective capsule that provides nourishment and protection until the environmental conditions improve.
To protect itself against predators such as fish, this versatile animal has the help of symbiotic microorganisms. They produce powerful toxins that deter predators and any other sea sponge that may decide to hunker down too close.
Spicules not only offer structural support for the sea sponge, they also protect by causing irritation for any potential predator.
Sea sponges have more than one way to procreate. In fact, these remarkable organisms were the first ever to do so by the joining of egg and sperm. A given sponge can act as the male or female while in reproduction.
These ancient creatures can also clone themselves. That is, if a part of the sponge becomes separated, it can reattach itself to another part of the coral or a rock and it will regenerate a genetically exact copy of the host sponge.
For all these reasons is why I believe that sea sponges can live for so long. They are true success stories that perhaps we humans can learn a thing or two from.
Do you own a sea sponge in a home aquarium? How long do they live in captivity? Are you amazed by how versatile sea sponges are? What do you think we can learn from these spectacular creatures?
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