Meeting Abstract
Many fishes have evolved the ability to bury into sandy substrates. To bury themselves, fish must displace a volume of sand equal to the volume of their entire body. An animal’s burying ability depends on several factors, including body size, sand grain size, and sand density. The complex material properties of granular media make it difficult to mathematically model burial performance, so we need a breadth of empirical studies before we can move to models. We used larval Pacific lamprey, Entosphenus tridentatus, to experimentally explore how burial performance scales with body size. We observed that Pacific lamprey bury with a similar mechanism to that of sand lances (Ammodytes), and larval sea lamprey (Petromyzon marinus L.). That is, they begin burying by undulating rapidly to drive the head and about 1/3 of the body into the sand. Next, with their tails flat against the sand surface, they undulate the anterior portion of their bodies through the sand to drag their caudal regions completely under the substrate. To quantify the effect of body size on performance, we used high-speed video to record burial events of 12 lamprey (range: 8 to 63 mm in TL) and measured time spent burying. Total time to bury decreased with body length to the power of -1.393. This agrees with Quintella et al. (2007), who showed that in sea lamprey, larger animals buried faster.
