Research Abstract

Distribution of two species of Holothurians, Holothuria atra and Stichopus chloronotus, based on distance from shore at Lizard Island, Great Barrier Reef, Australia

Distribution patterns based on distance from shore were studied in two species of holothurians (Holothuria atra and Stichopus chloronotus) on a beach of Lizard Island, Great Barrier Reef, Australia. All data were collected using thirty one hundred meter belt (two meter) transects. Species name and distance from shore were recorded. There were 186 individuals found of H. atra (n=54) and S. chloronotus (n=132). The mean distance to the shoreline for H. atra was 72.48±14.37 meters; whereas, the mean distance to the shoreline for S. chloronotus was 61.33±13.25 meters. The two species had significantly different distributions in relation to distance from the shore (p<0.001). The densities of H. atra and S. chloronotus were 0.009 m^-2 and 0.022 m^-2, respectively. The main factor influencing these distributions may be water movement.