Siphonophores Characteristics,Type & 9 Facts You Should Know

Siphonophores are members of the Cnidaria, which includes corals, hydroids, and genuine jellyfish. Let us see their characteristics in brief.

  • Siphonophores are free-swimming or floating (pelagic) colonies. Sometimes the colony resembles a single animal, such as Physalia physalis.
  • Siphonophores colony is frequently held together by a long thread to which various types of specialist creatures are linked. Some digest food, while others utilise stinging tentacles to grab prey.
  • Siphonophores pass the food to the “stomach”, which ingest and digest it, providing sustenance for the entire colony.
  • Some siphonophores even emanate light.
  • Siphonophores are complex colonial hydrozoans made up of many medusoid and polypoid species.
  • Medusoid zooids produce translucent gelatinous floating bells (nectophores), floats (pneumatophores), or bracts, which operate as protective shields.
  • Siphonophores are Hydrozoa clade cnidarians that reproduce abiogenetic way to generate a colony of clonal, physiologically integrated, and physically linked animals. 

Let us discuss the life cycle, habitat, features, types and many other related facts of siphonophores in this article.

Siphonophores life cycle

Life cycle is the sequence of changes an organism undergoes including reproduction during its life time. Let us see the lifecycle of siphonophores in detail.

  • All zooids in a particular siphonophore colony are derived from a single fertilized egg. The egg grows into the protozooid, a polyp that gives rise to all of the colony’s zooids by budding.
  • The early stages of development of castanets are entirely unknown, however, certain physodes and calycophorans are known.
  • In the physonects, the protozooid elongates and thins. The pneumatophore develops at the end opposite the mouth, and the thin section becomes the colony’s stem.
  • The young stem develops two growth zones. These growth zones are the sites of both stem elongation and the formation of new zooids.
  • The nectophores develop in the development zone nearest to the pneumatophore and mature as they are transported down by the expanding stem.
  • The other development zone lies slightly below the oldest nectophore and gives birth to siphosome zooids, which are similarly transported down as the stem develops.
  • Calycophorans evolve similarly to physonects, but with a few key changes. The protozooid’s end opposite the mouth atrophies, and no pneumatophore emerges.
  • The formation of calycophoran nectophores is not totally known. In certain species, new nectophores bud from the base of older nectophores, but in others, they sprout directly from the stem.
  • The majority of calycophorans shed mature cormidia at the stem’s base.
  • Each cormidium lives apart from the rest of the colony, with its own feeding polyp, bract, and reproductive medusa. It is unclear how long this liberated cormidia, known as eudoxids, may survive in the environment.
  • Cormidium are unable to regenerate into a whole colony and can only produce new reproductive medusae.
  • Some zooids specialise in movement, whereas others specialise in eating, breeding, digesting, protecting, and so forth. Fertilized eggs hatch into the main-feeding zooid, which has a gas-filled float and divides into two growth zones during its life cycle.
  • Budding occurs in the growth zones. Most species create zooids from a single probud, which subdivides farther up the stem to yield several zooid kinds.
800px Siphonophore 8482692352
Image credits: Siphonophores by Bernard DUPONT (CC BY-SA 2.0)

Siphonophores types

There are around 200 distinct species of siphonophores recognised. Let us see their two most important types in detail.

Giant siphonophore

The functional elements of giant siphonophores, like other siphonophores, are extremely specialized. The giant siphonophore is bioluminescent, which means it generates light on its own. When it collides with anything, the stem lights brilliant blue. Some segments grab prey, some digest food, some breed, and yet others swim to control the action.

Pelagic siphonophore

Marrus orthocanna is one of the numerous deep-water siphonophores known collectively as a Pelagic siphonophore. This species has been seen by deep-water ocean explorers in manned submersibles at depths of up to 2000 meters (6600 feet). M. orthocanna, like other siphonophores, is a colony of specialized individuals known as zooids.

Siphonophores habitat

Siphonophore animals are actually colonies of genetically identical individuals known as zooids. Let us discuss their habitat in detail.

Siphonophores inhabit a wide range of habitat from near-coastal areas to the ocean twilight zone and the sea bottom. Some siphonophore species rarely live in a single site. Some species, on the other hand, are restricted to a certain depth range and/or location of the ocean.

What do siphonophores eat?

Siphonophores are extremely active creatures that move quickly through the water column. Let us check what they consume for living.

Siphonophores are thought to feed on copepods and other tiny crustaceans like decapods, krill, and mysids as they are predatory predators. Small fish can also be eaten. They also prey on smaller creatures such as crabs, mollusks, tiny fish, and larvae.

Where do siphonophores live?

The siphonophores are mostly differentiated by the shape of their swimming bodies and tentacles. Let us see where they live.

The majority of siphonophores reside in the deep water and may be found in all seas. Praya dubia, also called huge siphonophore, is an invertebrate found in deep water at depths ranging from 700 m (2,300 ft) to 1,000 m. (3,300 ft). Erena is also a deep-water creature.

They may also live in the open ocean. They are, however, so delicate that they are rarely spotted near the beach as the waves and debris are too much for them.

Are siphonophores jellyfish?

Jellyfish are solitary creatures that can swim freely and move across the water. Let us explore if siphonophores are jellyfish or not.

Siphonophores are not jellyfish though they have similar appearance and soft fragile bodies and tentacles. Jellyfish are solitary creatures that can move through the water and swim freely. Siphonophores are unable to travel through the water on their own. They are ocean drifters.

Why do siphonophores burst?

Siphonophores are aquatic creatures of the order Siphonophorae. Let us discuss the reason behind their rupture.

Siphonophores rupture when taken to the surface because their hydrostatic skeleton was kept together by water pressure greater than 46 MPa (460 bar).

Do siphonophores sting?

Siphonophores, sometimes known as jellyfish, are colonial pelagic hydroids that include the Blue Bottle. Let us see if they sting or not.

Siphonophores, like jellyfish, use tentacles to sting. The Portuguese man of war is the ultimate siphonophore. Its sting is agonizing. and continue to cause damage while floating around on their own. They are, indeed, hazardous.The majority of siphonophores have a strong and frequently excruciating sting.

Siphonophores facts

The siphonophore are members of the Hydrozoa class, which also includes other marine animals. Let us see some of their facts in brief.

  • Siphonophore has a large impact on deep-sea food webs.
  • The pulsing bells of siphonophores at the front, pull a lengthy chain of segments designed for feeding and defense.
  • Siphonophores are lethal beauties that use a net of tentacles to catch food and are key predators in ocean ecosystems.
  • None of the elements of siphonophores could work alone.
  • Each siphonophore is a colony of separate components known as “zooids,” which are formed as the siphonophore grows and remains linked together.
  • Siphonores are therefore multiorganisms that are identified as a colony. A colony is divided into three groups: cystenects, physonects, and calycophorans.
  • Some form rope-like chains as long as a whale. In this colony, each zooid has a specific function: some hunt prey, others digest it, while still others spawn, swim, and maintain the colony upright.


From the above article, it can be concluded that siphonophores develop and evolve in a totally different way than other huge, complex animals.

Read more about Medusozoa.

Also Read: