Male Sea Urchins Don't Care Whose Eggs They Fertilize - Hybrids and Other Morphological Anomalies in Sea Urchins
David Pawson, National Museum of Natural History, Smithsonian Institution, Washington DC
29 Apr 2005
In sea urchins, reproduction seems straightforward, but there can be complications, of which three are described here. The first story deals with mirror-image sea urchins, in which the entire animal is back-to-front. What can these situs inversus animals tell us about inheritance - maternal and paternal? Gametes of echinoderms hybridize in the laboratory, but hybrid embryos don’t survive. Hybridization is apparently uncommon in the wild; adult hybrids are rare. The second story describes an extraordinary case of presumed inter-Order hybridization. The third story documents the discovery of adult inter-generic hybrids between sand dollars, and our laboratory-based attempts to duplicate these hybrids.