Indirect predator-induced effects on growth, morphology and reproduction have been extensively studied in marine invertebrates but usually without consideration of size-specific effects and not at all in post-metamorphic echinoids. Urchins are an unusually good system, in which, to study size effects because individuals of various ages within one species span four orders of magnitude in weight ...

In echinoderms, major morphological transitions during early development are attributed to different genetic interactions and changes in global expression patterns that shape the regulatory program for the specification of embryonic territories. In order more thoroughly to understand these biological and molecular processes, we examined the transcriptome structure and expression profiles during...

The sea urchin Tripneustes gratilla (Toxopneustidae, Echinoids) is a source of protein for many islanders in the Indo-West Pacific. It was previously reported to occasionally cause ciguatera-like poisoning; however, the exact nature of the causative agent was not confirmed. In April and July 2015, ciguatera poisonings were reported following the consumption of T. gratilla in Anaho Bay (Nuku Hiv...

In contrast to biomineralization phenomena, that are among the most widely studied topics in modern material and earth science and biomedicine, much less is systematized on modern view of demineralization. Biomineralized structures and tissues are composites, containing a biologically produced organic matrix and nano- or microscale amorphous or crystalline minerals. Demineralization is the proc...

Sea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP). Diadema mexicanum and Eucidaris thouarsii are the most important sea urchins on the Ecuadorian coastal reefs. This study provided a trophic scenario for these two species of echinoids in the coral-rocky reef bottoms of the Ecuadorian coast, using stable isotopes. We evaluated the relative pro...

Understanding the relationship between egg size, development time, and juvenile size is critical to explaining patterns of life-history evolution in marine invertebrates. Currently there is conflicting information about the effects of changes in egg size on the life histories of echinoid echinoderms. We sought to resolve this conflict by manipulating egg size and food level during the developme...

Phylogenetic relationships, rates of evolution, and codon usage were investigated in a family of retrotransposons (SURL elements) found in echinoids. The phylogeny of SURL element reverse transcriptase sequences from 10 echinoid species clearly shows the phylogenetic signature of the host taxa as well as paralogous sequences that diverged prior to speciation events. Two subfamilies (1 and 5) of...

Enzyme polymorphism was studied in the populations of two tropical starfish species, Acanthaster planci of the family Acanthasteridae and Echinaster luzonicus of the Echinasteridae from Ryukyu Islands (Okinawa) in Japan by allozyme analysis of 11 different enzymes. In 35 genetic loci scored, the proportion of polymorphic loci(P)was 12.5% and 22.9%, the average heterozygosity per locus(H)was 6.1...

Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

In situ occurrences of the calcareous marine phylloid alga Calcipatera cottonwoodensis in the Permian Cottonwood Limestone Member (Beattie Limestone) occur in Greenwood County, Kansas, in association with platy algal packstones, which are the phylloid algal facies most commonly described in the literature. The in situ algal facies occurs in the upper 0.45 m of an exposure where it is overlain a...