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Abstract: In this study, we estimated the extent of asexual reproduction and genotypic diversity at the intra- and interspecific levels in sponges of the genus Chondrilla in the Caribbean and along the coast of Brazil. Allozymes were used to identify the genotypes of specimens of Chondrilla in each location. The four species studied displayed a large variation in the extent of clonal reproduction and genotypic diversity, with the two species from the Bahamas having a greater proportion of asexually produced individuals than those along the coast of Brazil. Conspecific Brazilian populations of Chondrilla sp. had large differences in clonality: the population from a heterogeneous environment and under the influence of a strong upwelling had little clonality (7%), whereas the population located 350 km south along the coast, in a more homogeneous and temporally stable environment, had a five-fold larger (39%) proportion of asexually derived individuals. Finally, we were able to confirm that, besides fission, the genus Chondrilla displays a second mode of asexual reproduction, by fragmentation of teardrop shaped individuals. [Copyright &y& Elsevier]

The azooxanthellate sun corals Tubastraea coccinea and T. tagusensis have invaded and dramatically changed rocky reef habitats along the Brazilian coast. Management of invaded areas has brought discussions on its potential negative effects regarding species dispersal, including those related to fragmentation. Although fragmentation has been observed in unmanaged localities, here we experimentally tested the sun coral ability to regenerate from undifferentiated coral tissue to fully functional polyps in response to differences in food supply, temperature, and fragment size. In general, survival and successful regeneration were high and markedly similar for both species. However, while percent of tissue retraction/reorganization (a proxy of metabolic cost) responded to fragment size and temperature, mouth development was faster in fed fragments. Together, our findings indicate that sun coral fragments may regenerate at temperatures that lead to extensive bleaching in native scleractinians that harbor Symbiodinium . Although no doubts remain about the necessity and efficacy of the management of invasive Tubastraea spp., recovery of undifferentiated coral tissue to fully functional polyps may contribute to their invasion success and should be taken into account during management efforts. [ABSTRACT FROM AUTHOR]