Effect of the snail Ilyanassa obsoleta (Say) on dynamics of the amphipod Corophium volutator (Pallas) on an intertidal mudflat

We studied the spatial distributions of mud snails (Ilyanassa obsoleta) infected by two trematodes, Lepocreadium setiferoides and Gynaecotyla adunca, on a macrotidal mudflat in the Minas Basin, Bay of Fundy. Snails, as first intermediate hosts, were castrated by both parasites, and we found no evidence of sex differences in parasitism. Similar to previous work, prevalence of L. setiferoides in I. obsoleta increased exponentially with host size (and age). Unexpectedly, prevalence of G. adunca decreased over the largest size classes of snails, a result that may be due to several causes. Distributions of both parasites across the intertidal zone differed from previous accounts in that snails infected with L. setiferoides were found only in the middle of the intertidal zone, whereas prevalence of G. adunca increased exponentially moving seaward. Several species of polychaetes could be infected by L. setiferoides in the laboratory and may act as appropriate second intermediate hosts, whereas only the amphipod Corophium volutator served as a second intermediate host for G. adunca. Finally, the vertical distributions of I. obsoleta infected by either species of trematode overlap with distributions of apparent or known second intermediate hosts.

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Crawling behaviour of the amphipod Corophium volutator and foraging by Semipalmated Sandpipers, Calidris pusilla

Canadian Journal of Zoology ◽

10.1139/z89-066 ◽

1989 ◽

Vol 67 (2) ◽

pp. 457-462 ◽

Cited By ~ 34

Author(s):

J. Sherman Boates ◽

Peter C. Smith

Keyword(s):

Nova Scotia ◽

Food Intake ◽

Lunar Cycle ◽

Intertidal Mudflat ◽

Sharp Reduction ◽

Corophium Volutator ◽

Quantitative Evidence ◽

Qualitative And Quantitative ◽

Calidris Pusilla ◽

Semipalmated Sandpipers

During late spring and summer, the crawling behaviour of the amphipod Corophium volutator was studied on an intertidal mudflat in the Minas Basin, Nova Scotia. On average, less than 1% of the population crawled on any tide and these individuals tended to be large adults that were predominantly males. Animals emerged as the tide receded but most had crawled into burrows after 25 min. The crawling behaviour did not seem to be related to the lunar cycle as was expected; however, there was a sharp reduction in crawling activity (from 36.3 to 1.2 amphipods/m2) in July that coincided with the arrival of Semipalmated Sandpipers, Calidris pusilla, an abundant seasonal predator. The proportion of males in the amphipod population declined during the period when sandpipers were present. It appears that both a change in amphipod behaviour and depletion of the animals most prone to crawling may contribute to the observed reduction in crawling activity. Qualitative and quantitative evidence show that sandpipers were attracted to the tide edge where crawling amphipods were relatively abundant and that they increased their food intake by doing so.

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Trophic dynamics of a mud snail [Ilyanassa obsoleta (Say)] population on an intertidal mudflat

Estuarine Coastal and Shelf Science ◽

10.1016/s0302-3524(82)80006-6 ◽

1982 ◽

Vol 14 (6) ◽

pp. 663-686 ◽

Cited By ~ 25

Author(s):

Steven F. Edwards ◽

Barbara L. Welsh

Keyword(s):

Trophic Dynamics ◽

Intertidal Mudflat ◽

Ilyanassa Obsoleta ◽

Mud Snail

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Sedimentological and Biological Changes in the Windsor Mudflat, an Area of Induced Siltation

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f80-178 ◽

1980 ◽

Vol 37 (9) ◽

pp. 1387-1397 ◽

Cited By ~ 10

Author(s):

Ted R. Turk ◽

Michael J. Risk ◽

Roy W. M. Hirtle ◽

Ross K. Yeo

Keyword(s):

Organic Carbon ◽

Water Content ◽

Macoma Balthica ◽

Biological Characteristics ◽

High Water Content ◽

Intertidal Mudflat ◽

Organic Carbon Content ◽

Corophium Volutator ◽

Tidal Power ◽

Shell Size

The causeway-induced mudflat at Windsor, Nova Scotia, was studied to determine the effect of rapid sedimentation on the sedimentological and biological characteristics of an intertidal mudflat. Compared to typical Minas Basin mudflats, the Windsor flat has high water content, (50% vs. 30% wet wt, approximately) small grain sizes, and elevated organic carbon content (0.82% vs. 0.24% dry wt). The two principal infaunal species of the Windsor flat, the amphipod Corophium volutator and the clam Macoma balthica, are less abundant than in nearby typical flats (~840 vs. ~13 000/m2 and ~640 vs. ~1500/m2, respectively), while the polychaete Heteromastus filiformis is particularly abundant at Windsor. Macoma balthica at Windsor grow faster and have a shorter lifespan (~6 yr vs. ~13 yr) than at other Minas Basin flats. Compared to other Minas Basin Macoma, the weight of Windsor Macoma increases more slowly with increasing shell size, possibly an adaptation to the more fluid Windsor sediments.These sedimentological and biological characteristics exist at Windsor nearly 10 yr after the start of flat development and show little tendency to approach typical mudflat characteristics. Our results indicate, therefore, that secondary productivity of Macoma and Corophium could be reduced by about two-thirds for at least a decade in existing Minas Basin mudflats that are covered by Windsor-type sediments as a result of the construction of a tidal power dam.Key words: Bay of Fundy, tidal power, sedimentation, water content, organic carbon, infauna, Corophium volutator, Macoma balthica, growth, mortality

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