1.Dark-field, multiple-exposure photographs of live spermatozoa of a number of echinoderms were analysed. 2. Bends develop at the base in pairs, as they do in flagella with symmetrical waveforms. However, the angles of these bends do not cancel, so that microtubular sliding-of up to over 50% of that associated with bend propagation-is transferred distally. This sliding implies that (a) microtub...

1. Twenty-two sterols were identified in the starfish Asterias rubens (Phylum, Echinodermata; Class, Asteroidea). 2. The major 4-demethyl sterols had a Delta(7) bond and the C(27) compound 5alpha-cholest-7-en-3beta-ol predominated over other mono- and di-unsaturated sterols belonging to the C(26), C(27), C(28) and C(29) series. 3. Small amounts of cholest-5-en-3beta-ol and 5alpha-cholestan-3bet...

DNA barcoding has proven an effective tool for species identification in varied groups of marine invertebrates including crustaceans, molluscs, polychaetes and echinoderms. In this study, we further validate its utility by analyzing almost half of the 300 species of Echinodermata known from Canadian waters. COI sequences from 999 specimens were assigned to 145 BINs. In most cases, species discr...