BRYOZOAN STUDIES 2019 Growth geometry and measurement of growth rates in marine bryozoans: a review Abigail M. Smith1* and Marcus M. Key, Jr.2 1 Department of Marine Science, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand [*corresponding author: email:
[email protected]] 2 Department of Earth Sciences, Dickinson College, P.O. Box 1773, Carlisle, PA 17013-2896, USA ABSTRACT measuring and reporting growth rate in bryozoans The relationship between age and size in colonial will ensure they are robust and comparable. marine organisms is problematic. While growth of individual units may be measured fairly easily, the growth of colonies can be variable, complex, and INTRODUCTION difficult to measure. We need this information in Bryozoans are lophophorate aquatic invertebrates order to manage and protect ecosystems, acquire which typically form colonies by iterative addition bioactive compounds, and understand the history of of modular clones (zooids). Freshwater species environmental change. Bryozoan colonial growth are uncalcified; the majority of marine species are forms, determined by the pattern of sequential calcified, so that there is an extensive fossil record of addition of zooids or modules, enhance feeding, marine bryozoan colonies. When calcified colonies colony integration, strength, and/or gamete/larval grow large, they can provide benthic structures dispersal. Colony age varies from three months to which enhance biodiversity by provision of sheltered 86 years. Growth and development, including both habitat. Agencies who wish to manage or protect addition of zooids and extrazooidal calcification, these productive habitats need to understand the can be linear, two-dimensional across an area, or longevity and stability of these structures.