Although concerns about harvesting levels of the American Horseshoe Crab, Limulus polyphemus have prompted increased research into its ecology, current understanding of the species＇ foraging ecology is mostly limited...Although concerns about harvesting levels of the American Horseshoe Crab, Limulus polyphemus have prompted increased research into its ecology, current understanding of the species＇ foraging ecology is mostly limited to mid-Atlantic populations. This study elucidates the spatial and temporal pattern of Limulus foraging on an intertidal mudflat of a northern New Eng- land estuary. A novel survey method was used to monitor Limulus foraging activity without disturbing the sediment. A fixed 50 mx2 m transect was monitored with monthly surveys of the number of Limulus feeding pits from June to October 2009, May and June 2010. Snorkelling surveys were also carried out to observe individual behavior and examine the spatial scale of activity of individual animals. Results showed frequent and intensive use of the mudflat by foraging Limulus. Limulus were actively foraging within the survey area during all months surveyed. Foraging patterns exhibited a seasonal pattern with activity levels peaking in August 2009 and increased significantly towards the end of the study in June 2010. It was also shown that Limulus intertidal foraging persisted and peaked after the spring breeding season. Observations of foraging Limulus revealed that individual predators dig multiple pits within a single high tide, with little disturbance to the sediment in between. In addition to altering the perception of Limulus as a subtidal predator outside of the breeding season, findings from this study suggests a segregation of spawning and feeding habitats, thus underscoring the need to consider a wider range of critical habitats in the management of Limulus populations展开更多
基金the National Estuarine Research Reserve Graduate Research FellowshipUNH Marine ProgramNew Hampshire Seagrant
文摘Although concerns about harvesting levels of the American Horseshoe Crab, Limulus polyphemus have prompted increased research into its ecology, current understanding of the species＇ foraging ecology is mostly limited to mid-Atlantic populations. This study elucidates the spatial and temporal pattern of Limulus foraging on an intertidal mudflat of a northern New Eng- land estuary. A novel survey method was used to monitor Limulus foraging activity without disturbing the sediment. A fixed 50 mx2 m transect was monitored with monthly surveys of the number of Limulus feeding pits from June to October 2009, May and June 2010. Snorkelling surveys were also carried out to observe individual behavior and examine the spatial scale of activity of individual animals. Results showed frequent and intensive use of the mudflat by foraging Limulus. Limulus were actively foraging within the survey area during all months surveyed. Foraging patterns exhibited a seasonal pattern with activity levels peaking in August 2009 and increased significantly towards the end of the study in June 2010. It was also shown that Limulus intertidal foraging persisted and peaked after the spring breeding season. Observations of foraging Limulus revealed that individual predators dig multiple pits within a single high tide, with little disturbance to the sediment in between. In addition to altering the perception of Limulus as a subtidal predator outside of the breeding season, findings from this study suggests a segregation of spawning and feeding habitats, thus underscoring the need to consider a wider range of critical habitats in the management of Limulus populations
