TY - JOUR

T1 - Effect of a generalist mesopredator on modular and unitary sessile prey associated with a foundation species

AU - Чава, Александра Ивановна

AU - Артемьева, Анна Васильевна

AU - Яковис, Евгений Леонидович

PY - 2024/5

Y1 - 2024/5

N2 - Unitary and modular sessile organisms both dominate in marine benthic communities, commonly preyed upon by the same generalist predators. The differences between unitary and modular defensive strategies may underlie the ways generalist predators control community structure, but this has never been empirically examined. We hypothesize that the individual size of an omnivorous mesopredatory shrimp affects the relative vulnerability of unitary and modular prey and hence translates into community structure. In a short-term laboratory microcosm experiment, we assessed the effect of the shrimp individual size on an epibiotic assemblage of red algae blades initially dominated by three species of modular bryozoans and a unitary serpulid tubeworm. We found that the individual size of a shrimp determines its effect on the prey community composition. Large shrimp stronger than small shrimp increased the proportion of unitary tubeworms among the epibionts surviving predation. While large shrimp reduced the proportions of all the three dominant bryozoan species, small shrimp, in contrast, mostly increased the proportion of a bryozoan species with the smallest modules and largest colonies. This bryozoan, like the tubeworms, demonstrated a higher survival rate with larger individual (colony) size. Yet, against large shrimp this bryozoan was outperformed by the largest tubeworms almost immune to predation. Partial predation by small shrimp modestly improved survival of the largest bryozoan colonies. Thus, relative vulnerability of unitary and modular prey is determined by the predator individual size. Our findings clarify the complex way the size structures of generalist consumers and their prey shape communities by affecting the species-specific relative performance of modular and unitary organisms. The demography of a foundation species and the competitive hierarchy can have additional effects by altering the balance of predation and competition.

AB - Unitary and modular sessile organisms both dominate in marine benthic communities, commonly preyed upon by the same generalist predators. The differences between unitary and modular defensive strategies may underlie the ways generalist predators control community structure, but this has never been empirically examined. We hypothesize that the individual size of an omnivorous mesopredatory shrimp affects the relative vulnerability of unitary and modular prey and hence translates into community structure. In a short-term laboratory microcosm experiment, we assessed the effect of the shrimp individual size on an epibiotic assemblage of red algae blades initially dominated by three species of modular bryozoans and a unitary serpulid tubeworm. We found that the individual size of a shrimp determines its effect on the prey community composition. Large shrimp stronger than small shrimp increased the proportion of unitary tubeworms among the epibionts surviving predation. While large shrimp reduced the proportions of all the three dominant bryozoan species, small shrimp, in contrast, mostly increased the proportion of a bryozoan species with the smallest modules and largest colonies. This bryozoan, like the tubeworms, demonstrated a higher survival rate with larger individual (colony) size. Yet, against large shrimp this bryozoan was outperformed by the largest tubeworms almost immune to predation. Partial predation by small shrimp modestly improved survival of the largest bryozoan colonies. Thus, relative vulnerability of unitary and modular prey is determined by the predator individual size. Our findings clarify the complex way the size structures of generalist consumers and their prey shape communities by affecting the species-specific relative performance of modular and unitary organisms. The demography of a foundation species and the competitive hierarchy can have additional effects by altering the balance of predation and competition.

KW - bryozoans

KW - community ecology

KW - consumer control

KW - epibiosis

KW - modular

KW - predation

KW - serpulids

KW - shrimp

KW - unitary

UR - https://www.mendeley.com/catalogue/580ff8a9-375e-3f6d-96b9-dfac01fe2425/

U2 - 10.1002/ece3.11413

DO - 10.1002/ece3.11413

M3 - Article

C2 - 38756683

VL - 14

JO - Ecology and Evolution

JF - Ecology and Evolution

SN - 2045-7758

IS - 5

M1 - e11413

ER -