How do hydrozoans protect themselves?

A variety of predators have the ability to consume the stinging cells of hydrozoans without triggering them. These predators then sequester the stinging cells in their body to defend them against their own predators.

What animals belong to hydrozoa?

Some examples of hydrozoans are the freshwater jelly (Craspedacusta sowerbyi), freshwater polyps (Hydra), Obelia, Portuguese man o’ war (Physalia physalis), chondrophores (Porpitidae), “air fern” (Sertularia argentea), and pink-hearted hydroids (Tubularia).

Are Hydrozoa triploblastic?

Recent interpretations of the medusary nodule (the structure that, from a polyp, gives rise to a medusa by a special type of budding) suggest that the Hydrozoa are triploblastic.

What are the characteristics of scyphozoa?

Scyphozoans exhibit the main characteristics of cnidarians. They have radial symmetry and are diploblastic, meaning that their body wall consists of the outer epidermis (ectoderm) and the inner gastrodermis (endoderm), which are separated by mesoglea. They have nematocysts, which are characteristic of the phylum.

Are Physalia colonial or solitary?

The Obelia are naturally found underwater in the ocean throughout the world. Portuguese Man O’ War (Physalia physalis) – also known as the bluebubble, bluebottle or the man-of-war, is commonly thought of as a jellyfish but is actually a siphonophore, a colony of specialized polyps and medusoids.

What body cavity does Cnidaria have?

Corals, sea anemones and jellyfish belong to a group of animals called cnidarians. They have a simple body consisting of a central gut cavity surrounded by tentacles. A jelly-like substance called mesoglea lies between the outer and inner layers of the body.

What is a unique feature of scyphozoa reproduction?

Key Points. Scyphozoans have a ring of muscles that lines the dome of their bodies; these structures provide them with the contractile force they need to swim through water. Scyphozoans have separate sexes and form planula larvae through external fertilization.

What is meant by phase behaviour of a hydrocarbon?

PHASE BEHAVIOUR OF HYDROCARBONS When fluids are produced from a subsurface reservoir to the surface both temperature and pressure are reduced. The P-T changes result in two kinds of phase change in the produced fluids: 1. Liquid may condense from the produced gas. Gas may evolve from the produced liquid.

What is the difference between hydrorhiza and hydrocaulus?

From hydrorhiza arises a vertical branching stem about 2.5 cm long which is known as a hydrocaulus. The hydrorhiza and hydrocaulus are hollow tubes. The hydrocaulus bears zooids or polyps on either side in a cymose formation.

What is a functional analysis of behavior?

A functional analysis of behavior is particularly useful with young children who are nonverbal or unable to self-report on their behaviors. It is also useful with adults who are unable to find insight into the cause of their behaviors.