Yet other studies suggest that habitat preference (Sloan & von Bodungen, 1980) and distribution of most tropical
holothuroids on reef flats is related to shelter from wave action (Bakus, 1973).
mourlani, which is mainly found in association with asteroids and less so with
holothuroids (Parmentier, 2003).
Thus within this protected site we could test the hypothesis that intensity of human presence affects community structure of
holothuroids. The next 2 sites are ecologically and structurally distinct.
Similar results were reported for echinoid and
holothuroid metamorphosis (Chia and Burke, 1978; Burke et al., 2006; Nakano et al., 2006; Katow et al., 2009).
The structures reported in this study have been seen only in
holothuroid echinoderms.
Second, Strathmann et al., (1994) proposed that the ability to flexibly shift allocation could be of greater benefit for taxa that invested early in postlarval structures (e.g., echinoids, asteroids, and molluscs) than for those that develop postlarval structures closer to the time of metamorphosis (e.g., ophiuroids,
holothuroids).
This condition is also reported in viviparous
holothuroids (Miller, 1985; Frick et al., 1996).
The planktotrophic larvae of asteroids are morphologically similar to those of
holothuroids (Smiley, 1986), whereas the planktotrophic larvae of echinoids are similar to those of ophiuroids (Levin and Bridges, 1995).
(leviuscula?), and the
holothuroids Cucumaria miniata and Psolus chitinoides.
Several species of
holothuroids (sea cucumbers), all belonging to the order Aspidochirotida, possess a very specialized defensive system: the so-called Cuvierian tubules (Flammang, 1996).
In echinoderms, serotonin was first isolated in the gonads of adult asteroids (Welsh and Moorehead, 1960), and its cellular location has been documented in studies of the larval nervous system of echinoids, asteroids, and
holothuroids (Bisgrove and Burke, 1986; Burke et al., 1986; Bisgrove and Burke, 1987; Nakajima, 1988; Bisgrove and Raft, 1989; Nakajima et al., 1993; Moss et al., 1994; Chee and Byrne, 1997).
In this paper we test the prediction of bimodality in egg sizes in the two remaining classes, the
holothuroids and ophiuroids, which meet the criteria defined above, and we incorporate new data into the published egg size distributions of echinoids and asteroids (14).