Behavioral Characteristics of the Juvenile Japanese Surf Clam Pseudocardium sachalinensis in response to Sand Erosion and Deposition Associated with Oscillatory Water Flow

Abstract

This study examined the behavioral characteristics of juvenile Japanese surf clam Pseudocardium sachalinensis in response to sand erosion and deposition under laboratory conditions, then estimated the fluid conditions critical to wash the clams out of the sand. The juveniles started burrowing down ward into sand when their burying depth decreased to less than 1.5 times the shell length due to erosion , and moving upward when the depth increased to more than 2.5 times the shell length due to deposition of sand. Burrowing and climbing actions of the juvenile continued until the depth reached 1.7-2.1 times the shell length once again. The burrowing and climbing speeds were about 1.8 times higher than the speed of erosion or deposition of sand. It was concluded that the juveniles would maintain their po sition actively in order to avoid being washed out or buried too deeply by adapting their behavior to the dynamic conditions of sand movement. The juveniles were washed out of the sand when the erosion speed exceeded 3.5 mm/min, and such erosion occurred when oscillatory water flow speeds over a sandy bottom with median particle diameter of 0.3 mm exceeded more than 45 and 55 cm/s at periods of 4 s and 8 s, respectively.

Burrowing ability as a key trait in the establishment of infaunal bivalve populations following competitive release on an extensive intertidal sandflat

“…There, some high burrowing ability would be required for juvenile clams to maintain themselves in the sediment. It has been reported that high burrowing ability is a critical trait for infaunal bivalves to survive in unstable sediment habitats (Alexander et al, 1993;Breum, 1970;Brock, 1979;Kakino, 2000;Sakurai and Seto, 1998;Stanley, 1970). The laboratory experiments of the present study have clearly demonstrated that BRI of the two successful clam species (Me.…”

“…Their burrowing ability is a key trait in determining post-(larval) settlement survival. Bivalves in the sediment column can be expelled onto the surface by abrupt sediment erosion induced by intense hydrodynamic forces (Brock, 1979;de Montaudouin, 1997;Lundquist et al, 2004;Sakurai and Seto, 1998;St-Onge and Miron, 2007). Juveniles are more vulnerable to sediment erosion than adults due to limited burrowing depths (Lundquist et al, 2004;St-Onge and Miron, 2007).…”

Vulnerability assessment of nearshore clam habitat subject to storm waves and surge

“…According to previous investigations, the clam burrows downward when the burying depth was eroded to less than 1.5 times the shell length, while moving upward when overburden with 2.5 times the shell length. The comfortable burying depth might be roughly estimated as 1.7–2.1 times the shell length 44 , 45 . Based on these biological propensity, we directly link the clam’s mortality to the sediment layer changes as the indicator of benthic ecosystem stability and hydrodynamic strength during a storm.…”

The potential of marine bivalve Spisula sachalinensis as a marine temperature record

“…Previous research on the species has been guided by its commercial im- portance, focusing on its nutritional value and optimal growth and spawning conditions (e.g. Golikov and Scarlato, 1970;Kato and Hamai, 1975;Lee et al, 1996;Sakurai and Seto, 1998;Sasaki, 1981;Sasaki and Ohta, 1999;Tabakaeva and Tabakaev, 2017;Takahashi and Yamamoto, 1970).…”