Meeting Abstract
9.4 Saturday, Jan. 4 08:45 The effect of climate-induced elevated seawater temperature on covering behavior in the echinoid Lytechinus variegatus. BROTHERS, C.J.*; MCCLINTOCK, J.B.; Univ. of Alabama, Birmingham; Univ. of Alabama, Birmingham brotce@uab.edu
Most species of regular echinoids lift materials such as stones, seagrass, or shells on to their aboral surface using their tube feet and spines. The functional significance of this “covering behavior” may include protection from UV radiation, preventing dislodgement from surge, and/or avoiding predation. Although studies have indicated that non-covering neuromuscular behaviors in invertebrates are sensitive to thermal stress, no studies to date have examined the potential impact that climate-induced elevated seawater temperatures may have on echinoid covering behavior. Individuals of L. variegatus were collected in Port Saint Joseph, FL and slowly adjusted over a period of one week to either 28°C (current summer seawater temperature) or 32°C (near-future climate-induced summer seawater temperature). A preliminary experimental trial was conducted to establish protocols for further experiments. Echinoids (n=4 per treatment) were each presented with fifteen identical covering items (1 cm diameter glass spherical beads) and then observed every four hr over a two day 48 hr period (12 hr light:12 hr dark cycle). Echinoid covering behavior (up to six beads per individual) was observed regardless of temperature treatment. There was no obvious difference between the number of beads held during light or dark periods. However, sea urchins exposed to 32°C required twice as long (8 hr) to initially cover than did urchins held at 28°C (4 hr). Based on these preliminary data additional experiments conducted at various time lengths and with larger numbers of individuals will be conducted to provide a rigorous assessment of potential impacts of future temperature rise on covering behavior in L. variegatus. Supported by Abercrombie and Kent Philanthropy and an Endowed Professorship to JBM.
