Biomineralization in bryozoans: present, past and future

Area of Science:

• Paleontology
• Marine Biology
• Biomineralization Studies

Background:

• Bryozoans are aquatic invertebrates with biomineralized skeletons, shaped by over 500 million years of natural selection.
• Their skeletal formation processes are less understood compared to related phyla like Brachiopoda and Mollusca.
• Bryozoan skeletons exhibit unique intricacies, with calcareous skeletons evolving independently in Stenolaemata and Cheilostomata clades.

Purpose of the Study:

• To review the significance of biomineralization in bryozoans.
• To explore skeletal ultrastructures, mineralogy, chemistry, and organic components.
• To examine the evolutionary history of biomineralization in relation to seawater chemistry and global changes like ocean acidification.

Main Methods:

• Literature review of bryozoan biomineralization.
• Analysis of skeletal ultrastructures, mineralogy, and chemistry.
• Examination of evolutionary trends and responses to environmental changes.

Main Results:

• Bryozoan skeletons feature distinct wall types and diverse ultrastructural fabrics (laminated, prismatic).
• The Cheilostomata clade uniquely biomineralizes aragonite and exhibits prismatic fabrics.
• Skeletal composition (aragonite, Mg content) varies latitudinally, increasing in tropical waters.
• Responses to past seawater chemistry changes are unclear, but future ocean acidification threatens calcification and growth.

Conclusions:

• Bryozoan biomineralization is complex, with evolutionary and environmental influences.
• Ocean acidification and warming present significant challenges to bryozoan skeletal integrity and function.
• Further research is needed to address key questions in bryozoan biomineralization.