Difference Between Bryozoans and Corals

The key difference between bryozoans and corals is that bryozoans are colonial aquatic animals that belong to phylum Bryozoa, while corals are colonial reef-building marine animals that belong to phylum Cnidaria.

Bryozoans and coral look similar. Both types of organisms are aquatic organisms that exist as colonial forms. They form a calcium carbonate skeleton connected to one another. Moreover, both types of animals have a crown of tentacles surrounding the mouth. However, these two groups of animals belong to two different phyla. In addition, corals are marine organisms, while bryozoans live in both marine and freshwater environments.

CONTENTS

1. Overview and Key Difference
2. What are Bryozoans 
3. What are Corals
4. Similarities Between Bryozoans and Corals
5. Side by Side Comparison – Bryozoans vs Corals in Tabular Form
6. Summary

What are Bryozoans?

Bryozoans or moss animals are colonial animals found in freshwater and marine water. Similar to corals, they form a calcium carbonate skeleton. But unlike corals, they do not build on top of one another’s skeleton. They belong to phylum bryozoa. There are about 5000 living species of bryozoans. They are hermaphrodites.

Bryozoans show several characteristics that are different from corals. They have an anus outside its ring of tentacles. It is an advanced characteristic shown by bryozoans. Moreover, there is a crown of tentacles surrounding the mouth of each bryozoan. Their tentacles don’t sting, unlike corals. Bryozoans do not have respiratory organs, heart or blood vessels. They absorb oxygen through their body wall and lophophores.

Bryozoans cause problems for boats and harbours. But, they are important organisms since they have a substance called bryostatin, which is believed to be a strong anti-cancer agent. Moreover, bryostatin is useful in treating Alz­hei­mer’s disease.

What are Corals?

Corals are reef-building marine organisms which are colonial animals. They are invertebrates which are colourful and fascinating. They have a wide variety of shapes and sizes as well. Corals have a calcium carbonate hard skeleton. However, there are also soft corals without a solid exoskeleton.

Corals belong to class Anthozoa of phylum cnidaria. Corals are sessile. They do not have a medusa stage. They have a polyp body type and feed on small animals. Moreover, they have tentacles with stinging cells called nematocysts. Although they have a mouth, they do not have an anus. Corals show both asexual and sexual reproduction and are hermaphrodites.

What are the Similarities Between Bryozoans and Corals?

• Bryozoans and corals are invertebrates.
• They are aquatic organisms and colonial animals.
• Both types of invertebrates form calcium carbonate skeletons connected to each other.
• They have tentacles as well.
• Moreover, they are hermaphrodites.

What is the Difference Between Bryozoans and Corals?

Both bryozoans and corals are invertebrate animals. Bryozoans belong to phylum bryozoa, while corals belong to phylum cnidaria. So, this is the key difference between bryozoans and corals. Bryozoans are more advanced than corals.

Moreover, bryozoans have an anus while corals do not have an anus – instead, their mouth works as an anus. Also, another difference between bryozoans and corals is that bryozoans tentacles don’t sting like corals.

Summary – Bryozoans vs Corals

Bryozoans and corals are aquatic invertebrates which make calcium carbonate skeleton. They are colonial animals having tentacles. However, bryozoans belong to phylum bryozoa while corals belong to phylum cnidaria. Moreover, corals are marine animals while bryozoans live in marine as well as in freshwater. Bryozoans are advanced animals than corals. Thus, this summarizes the difference between bryozoans and corals.

Reference:

1.” What Are Corals?” International Coral Reef Initiative, Available here.
2.”Bryozoa.” Wikipedia, Wikimedia Foundation, 23 Feb. 2020, Available here.

Image Courtesy:

1. “Bryozoans at Lorry Bay PB092314” By Peter Southwood – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Coral Outcrop Flynn Reef” By Toby Hudson – Own work (CC BY-SA 3.0) via Commons Wikimedia