Top 10 Colonial Organisms
While many living things live their lives in organized groups, some take socialism to strange extremes; some link their bodies together to essentially build one large body, others may produce young physically adapted to fill specific roles.
Related to jellyfish and anemones in the phylum Cnidaria, a coral colony typically consists of several hundred tentacled “polyps” duplicating themselves and building an elaborate calcerous “skeleton” for protection. Most colonies are either entirely male or entirely female, and will release eggs or sperm into the water to mate. This results in microscopic, swimming larvae, which eventually settle and begin to clone themselves into new, independent colonies. Most corals are actually carnivorous, stinging tiny planktonic organisms with their sticky tentacles. The stony or “hard” corals are known for building the environments we call reefs, home to thousands of other unique animal species.
Resembling slugs with hairy, branching tentacles, Pterobranchs filter food from the water and form colonies of “clones,” much like coral polyps, often secreting a network of hard tubing. Individual zooids can crawl about freely within the colony, but are connected to one another by thin “cables,” quickly retracting if disturbed. What makes the Pterobranchs even stranger than corals is that these slimy, slithering weirdos are “hemichordates,” closer to us vertebrates than to invertebrates like worms and jellyfish.
True chordates more directly related to vertebrates, Pyrosomes are a form of tunicate or “sea squirt,” their saclike adult bodies constantly pumping water in and out as they trap and digest plankton. Many tunicates grow together in colonies, but Pyrosomes join together to form mobile, gelatinous tubes, propelled by hundreds or even tens of thousands of individuals. The largest of these colonies can be wide enough for a human to swim through – and up to a hundred feet or more in length.
Most bee species are actually solitary, but bees are most famous for their “eusocial” species, meaning those who live in organized communities with both reproductive and non-reproductive castes. In a typical social bee colony, a single queen is fertilized by a harem of male drones, producing hundreds of sterile, female workers who collect pollen and nectar for the entire colony, often made from their own special secretions of “beeswax.” Larvae are usually fed “royal jelly” before switching to pollen and honey, but larvae who continue to consume only jelly will develop into new queens and eventually leave the hive with their own swarm of workers. Though famous for their ability to sting, only a minority of species possess these weapons, and only the non-reproducing females; the stinger is a modified ovipositor, sort of like a sharpened, venomous vagina.
Also called Ectoprocts or “moss animals,” these tiny, aquatic filter feeders grow together in a variety of bizarre colonies. Most individual “zooids” are devoted entirely to feeding, but some species may produce special defensive zooids resembling beaked “heads” on swiveling necks or box-shaped “moustraps.” Since defensive zooids must be fed by the rest of the colony, they’re only grown in response to danger, practically overnight. A few species form fully mobile colonies, with specialized zooids acting as “feet.” Others have special reproductive zooids whose bodies house larvae, and many species even produce faster growing, “empty” bodies just to claim territory as quickly as possible.
Cousins to the bees and even closer to the wasps, ants are arguably the most successful animals on Earth, far more aggressive than most other colonial organisms and outcompeting many other species large and small with their superior numbers. Many are capable of cultivating their own edible fungi, plant life or even insect “cattle.” Some may link their bodies together to form temporary bridges, rafts and protective barriers. Some can even overwhelm and kill vertebrates thousands of times their size, in some cases driving nearly all other life from their territory. Whatever problem a colony may face, only a single member needs to find the solution and the rest will follow, thousands of workers and soldiers collectively solving problems like a single massive, mobile brain…a mobile brain with a million teeth.
Whereas many ants seem like a formidable army of conquerors, termites are more like futuristic, utopian pacifists. Symbiotic microorganisms allow termites to derive sustenence from plant cellulose, making them some of the few creatures that can feed entirely on wood. Other species may simply grow their own gardens of symbiotic fungi as food, but in any case, termites are virtually never aggressive or carnivorous. Instead, they spend most of their lives sealed within their nests, some of which put human engineering to shame with their complex, high efficiency architecture. While termites share the same castes as ants – queens, workers, soldiers and a winged reproductive caste – they are actually categorized as a highly unusual group of cockroaches.
3. Mole Rats
The only known vertebrates with a colonial structure like that of ants or termites are two species of “mole rat” or blesmol, the famous Naked mole rat and lesser known, fuzzier Damaraland mole rat. These bizarre rodents build subterranean communities where the “queen” is kept fertilized by her own sons, while her daughters are sterilized by hormones in her urine and function as a worker caste. Naked mole rats are especially well adapted to this insect-like existence; their own carbon dioxide turns their tunnel systems into a highly toxic and constantly hot environment, but their lack of pain reception and a “cold blooded” metabolism (unique among mammals) allow them to thrive comfortably in these hostile conditions.
2. Pistol Shrimp
The Alpheidae or “pistol shrimp” are well known to marine biologists for their amazing biological weaponry; one of the two front claws is highly enlarged, and rather than functioning as a pincer, its joints have evolved to generate a sort of “sonic blast” when snapped shut, capable of paralyzing fish and even breaking glass. Most of these impressive invertebrates live solitary lives, but a few species are the only eusocial crustaceans and only eusocial sea life known to man. These bees of the sea employ living sponges as their “hives,” with a single queen and up to several hundred offspring, including both a worker caste with normal claws and a soldier caste bearing the group’s trademark snapping cannons.
Close cousins to the corals but far more elaborate, Hydrozoa are made up of attached individuals so specialized that they function more like organs forming one “body,” blurring the line between a colony and a single animal. The most famous Hydrozoan is the Portuguese Man O’ War, which consists of four different polyps: one forms the gas filled “float” while others form the venomous tentacles, stomach-like feeding polyps and special reproductive polyps. Other hydrozoan species may form stationary coral-like colonies, swimming chains and many other strange shapes. Some in the deep ocean are luminous, and one even dangles bright lures to attract its prey.
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More from Jonathan Wojcik at bogleech.com