SPAIN, D. D. *; PERALTA, M.; Dominican University of California: Sinking in Sand – An Examination of Burrowing in Sea Cucumbers (Holothuroidea: Echinodermata)

There are over 1,400 species of sea cucumbers living in marine environments worldwide. Yet, there are few descriptions of the burrowing process of infaunal holothuroids. This study provides a detailed description of burrowing in the infaunal dendrochirotid, Thyonella gemmata. Specimens were placed in small plastic containers with sand or gravel and artificial seawater. Burrowing was recorded using both real-time and interval recording features on a Sony digital camcorder. Analysis of the recordings showed that specimens burrow by using peristaltic waves originating on opposite ends of the body. Burrowing was only initiated after the anterior and posterior regions of the body were elevated. Afterwards, peristaltic waves were initiated at both ends of the body and traveled towards the midsection of the animal. Thus, the midsection of the body was buried first with the remainder of the body gradually being pulled under the sediment. This analysis will be combined with descriptions of burrowing methods used by other sea cucumber species in order to generate a more comprehensive account of burrowing in infaunal holothuroids.