Class Hydrozoa Flashcards

What phylum does Class Hydrozoa belong to?

What organisms are included in Hydrozoa?

Hydrozoas are mostly freshwater organisms.

Hydrozoas mostly have a _____ and _____ life cycle.

What does the attached colony of Obelia include?

What do reproductive polyps in Obelia produce?

What do medusas produce in the Obelia life cycle?

What happens after fertilization in the life cycle of Obelia?

Class Hydrozoa Overview

Belongs to the Phylum Cnidaria, which includes diverse marine and freshwater organisms.
Characterized by a life cycle that often features both polyp and medusa stages, with some exhibiting only the polyp form.

Notable Members

Contains genera like Hydra (found in freshwater) and Obelia (primarily marine).
Hydrozoans can either be solitary or colonial, depending on the species.

Marine and Freshwater Habitats

Most Hydrozoans are marine, crafting intricate relationships with their aquatic ecosystems.
Hydra stands out as an exception since it inhabits freshwater environments.

Life Cycle of Obelia

Start with an attached colony comprising specialized feeding polyps and reproductive polyps.
The reproductive polyps are responsible for producing medusas, which are the free-swimming phase of the life cycle.
Medusas generate either sperm or eggs, facilitating sexual reproduction.
Fertilization leads to the formation of a larva that swims, anchors itself, and grows into a new colony.

Test your knowledge of Class Hydrozoa with these flashcards. Learn about the unique characteristics, life cycles, and classifications of hydrozoans. Dive into the facts about this fascinating class in the phylum Cnidaria.