Streaming Media
Presentation Abstract
The global success of the invasive European green crab (Carcinus maenas) is due, in part, to its broad diet, with over 140 different genera consumed worldwide. However, very little of this information comes directly from populations in the Salish Sea and it is unclear the degree to which green crab select prey vs consuming what is readily available. Additionally, almost nothing is known about the diet of graceful crab (Metacarcinus gracilis), a common, co-occurring native species which may compete with green crabs. Although studies have hypothesized that graceful crabs may specialize on soft-bodied prey, this study is the first to document the types of locally available prey consumed by both of these crab species, their prey preferences, and potential for competition. A range of common intertidal invertebrates were offered as prey, including small native crabs (Hemigrapsus spp. and Pagarus spp.), common bivalve species, snails, and isopods. Crabs were allowed to forage individually on each prey species with appropriate substrate at natural prey densities. As expected, green crabs were able to consume a wide variety of prey, with a preference for bivalves. Graceful crabs were also able to consume most prey species, including those with hard shells, although the probability of consumption increased with crab size. These results support the hypothesis that these two crab species may compete for shared prey resources and suggests that more work should be done to understand the potential impacts of invasive green crabs on a common, but under-studied, native crab in the Salish Sea.
Session Title
Poster Session 2: The Salish Sea Food Web and Cycles of Life
Conference Track
SSE14: Posters
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-posters-401
Start Date
26-4-2022 4:30 PM
End Date
26-4-2022 5:00 PM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Determining the prey consumption, preferences, and potential for dietary overlap between invasive European green crab and native graceful crab in the Salish Sea
The global success of the invasive European green crab (Carcinus maenas) is due, in part, to its broad diet, with over 140 different genera consumed worldwide. However, very little of this information comes directly from populations in the Salish Sea and it is unclear the degree to which green crab select prey vs consuming what is readily available. Additionally, almost nothing is known about the diet of graceful crab (Metacarcinus gracilis), a common, co-occurring native species which may compete with green crabs. Although studies have hypothesized that graceful crabs may specialize on soft-bodied prey, this study is the first to document the types of locally available prey consumed by both of these crab species, their prey preferences, and potential for competition. A range of common intertidal invertebrates were offered as prey, including small native crabs (Hemigrapsus spp. and Pagarus spp.), common bivalve species, snails, and isopods. Crabs were allowed to forage individually on each prey species with appropriate substrate at natural prey densities. As expected, green crabs were able to consume a wide variety of prey, with a preference for bivalves. Graceful crabs were also able to consume most prey species, including those with hard shells, although the probability of consumption increased with crab size. These results support the hypothesis that these two crab species may compete for shared prey resources and suggests that more work should be done to understand the potential impacts of invasive green crabs on a common, but under-studied, native crab in the Salish Sea.
