Primary utricle structure of six Halimeda species and potential relevance for ocean acidification tolerance
Abstract Variations in utricle morphology may be responsible for different tolerances to ocean acidification (OA) within the macroalgal genus Halimeda , an important sediment producer on reefs. However, differences in species’ utricle morphology and their relationship to calcification and crystal fo...
| Published in: | Botanica Marina |
|---|---|
| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Walter de Gruyter GmbH
2017
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1515/bot-2016-0055 http://www.degruyter.com/view/j/botm.2017.60.issue-1/bot-2016-0055/bot-2016-0055.xml https://www.degruyter.com/document/doi/10.1515/bot-2016-0055/xml https://www.degruyter.com/document/doi/10.1515/bot-2016-0055/pdf |
| Summary: | Abstract Variations in utricle morphology may be responsible for different tolerances to ocean acidification (OA) within the macroalgal genus Halimeda , an important sediment producer on reefs. However, differences in species’ utricle morphology and their relationship to calcification and crystal formation have not been well articulated. In the present study, we characterized the utricle morphologies of six Halimeda species. Primary utricle ultrastructure was quantitatively and qualitatively compared to tissue inorganic content and crystal microstructure. Morphologies differed across species and several morphometric relationships were revealed. Primary utricle size (r 2 =0.70) and diffusion pathway length (r 2 =0.87) had inverse relationships with inorganic content based on regression analyses, and corresponded to crystal microstructure form. Species with large utricles and long diffusion pathways contained more narrow (~0.15 μm) aragonite needles and minimal micro-anhedral crystal formations. In contrast, species with small utricles and short diffusion pathways elucidated aggregates of micro-anhedral crystals and wider aragonite needles (~0.30 μm). Species’ utricle characteristics generally corresponded to specific evolutionary lineages. Thus, characteristics of Halimeda utricle morphology may control long-term adaptive responses to OA, an idea articulated in the broader literature. |
|---|