Variation in purple sea urchin ( Strongylocentrotus purpuratus ) morphological traits in relation to resource availability

PeerJ

article

Joshua G. Smith¹  Sabrina C. Garcia¹ 

[1] Department of Ecology and Evolutionary Biology, University of California

关键词: Resource allocation;    Food limitation;    Growth;    Echinoidea;    Morphology;    Sea urchin;   

DOI  :  10.7717/peerj.11352

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Flexible resource investment is a risk sensitive reproductive strategy where individuals trade resources spent on reproduction for basic metabolic maintenance and survival. This study examined morphological variation in herbivorous sea urchin grazers across a mosaic landscape of macroalgae dominated habitats interspersed with patches of sea urchin barrens to determine whether sea urchins shift energy allocation in response to food limitation. Extensive underwater surveys of habitat attributes (e.g., sea urchin density, algae cover) were paired with detailed laboratory assays (e.g., sea urchin dissections) to determine how resource abundance affects energy allocation between reproductive capacity and body structure in the purple sea urchin, Strongylocentrotus purpuratus. We found that: (1) sea urchins had a more elongate jaw structure relative to body size in habitats void of macroalgae (i.e., barrens), (2) sea urchin reproductive capacity (i.e., gonad index) was lower in barrens and the barrens habitat was primarily comprised of encrusting algae, and (3) sea urchin jaw morphology (i.e., lantern index) and reproductive capacity (i.e., gonad index) were inversely related. These results suggest that sea urchins respond to macroalgae limited environments by shifting energy allocation between reproductive capacity and modifications of the foraging apparatus, which may explain the ability of sea urchins to acquire food in resource-limited environments.

【 授权许可】

CC BY