For free-spawning marine invertebrates, the egg is the unit of maternal investment in offspring. For many taxa, there is a major life-history trade-off between production of many small, nutrient-poor eggs in high-fecundity species and fewer large, nutrient-rich eggs in low-fecundity species. In echinoderms, the switch from small eggs in species with ancestral-type feeding larvae to large eggs a...

Most echinoderms display seasonal or other temporal cycles of reproduction that presumably result from the complex interplay of endogenous and exogenous signals. Various environmental, chemical and hormonal factors, acting directly or indirectly, individually or in combination, have been proposed to cue, favour or modulate a suite of reproductive functions from the onset of gametogenesis to gam...

A comprehensive analysis of the mitochondrial gene orders of all previously published and two novel Antedon mediterranea (Crinoidea) and Ophiura albida (Ophiuroidea) complete echinoderm mitochondrial genomes shows that all major types of rearrangement operations are necessary to explain the evolution of mitochondrial genomes. In addition to protein coding genes we include all tRNA genes as well...

An analysis of early coelom development in the echinoid Holopneustes purpurescens yields a deuterostome body plan that explains the disparity between the pentameral plan of echinoderms and the bilateral plans of chordates and hemichordates, the three major phyla of the monophyletic deuterostomes. The analysis shows an early separation into a medial hydrocoele and lateral coelomic mesoderm with ...

An analysis of early coelom development in the echinoid Holopneustes purpurescens yields a deuterostome body plan that explains the disparity between the pentameral plan of echinoderms and the bilateral plans of chordates and hemichordates, the three major phyla of the monophyletic deuterostomes. The analysis shows an early separation into a medial hydrocoele and lateral coelomic mesoderm with ...

Food web structure, particularly the relative importance of bottom-up and top-down control of animal abundances, is poorly known for the Earth's largest habitats: the abyssal plains. A unique 15-yr time series of climate, productivity, particulate flux, and abundance of primary consumers (primarily echinoderms) and secondary consumers (fish) was examined to elucidate the response of trophic lev...

Abstract Until now, the earliest fossil echinoderms have been predominantly known from early Cambrian of Laurentia and West Gondwana. Here, we describe Sprinkleoglobus extenuatus gen. et sp. nov. Chengjiang biota (Cambrian Series 2, Stage 3) Yunnan Province, China. The overall profile theca morphology ambulacra clearly establish it as an edrioasteroid echinoderm. This represents first discovery...

Hobson & Rees, 1955) and served to identify them by synthetic as opposed to degradative means. Throughout the species investigated the phosphokinases predicted by the previous results were all proved to be present and capable ofphosphorylating the expected base. As was reported for some of the echinoderms (Needham & Baldwin, 1937), several annelids, e.g. Glycera gigantea, Nerei8 diversicolor an...

Locations of the 5S rRNA genes (rDNA) are usually considered to be helpful, as generally invariable chromosome markers, especially if chromosome banding is not possible. The genes have been defined in about 90 invertebrate species, and were found linked to other multigene families in genomes of some nematodes and arthropods (Drouin and Moniz de Sa, 1995; Barzotti et al., 2000). They were also f...

The construction of supertrees from smaller, character−based cladograms permits simultaneous inclusion of a large num− ber of taxa in a single analysis, summarizes patterns of relationships from many independent data sources, and highlights areas of conflict to be targeted by character matrix studies. The method is applied for the first time to stylophoran echinoderms (cornutes and mitrates). P...