two fish. In the wild, kittiwakes have to learn to look for particular colours and patterns in the ocean to find the best place to fish. The researchers tried to recreate this for the captive birds by making them search for their food among a chequerboard of different coloured bowls. Chicks on the unrestricted fatty diet quickly learned which bowls contained food, but chicks on lean rations wer...

The pentaradial organisation of echinoderms is postulated to have evolved as the result of the reorganisation of the internal U-shaped mesentery of the intestinal tract during inflation of the trunk of a pterobranchlike ancestor. Under this scenario, loops of the mesentery developed between five hydraulic bulges by three different mechanisms: (1) by the early formation of two additional loops r...

The present author has been studying the biochemical systematics of echinoids and asteroids of echinoderms by using some biochemical methods such as allozyme analysis, immunological assay, enzyme kinetic study, and comparison of amino acid composition (Matsuoka, 1980, 1986, 1987, 1992; Matsuoka et al., 1983; Matsuoka and Suzuki, 1989; Matsuoka and Hatanaka, 1991, etc.). Echinoderms are represen...

Echinoderms have long served as model organisms for a variety of biological research, especially in the field of developmental biology. Although the genome of the purple sea urchin Strongylocentrotus purpuratus has been sequenced, it is the only echinoderm whose whole genome sequence has been reported. Nevertheless, data is rapidly accumulating on the chromosomes and genomic sequences of all fi...

Echinoderms (sea urchins, sea stars, brittle stars, sea lilies and sea cucumbers) are a group of diverse organisms, second in number within deuterostome species to only the chordates. Echinoderms serve as excellent model systems for developmental biology due to their diverse developmental mechanisms, tractable laboratory use, and close phylogenetic distance to chordates. In addition, echinoderm...

Pleurocystitid rhombiferans are among the most unusual echinoderms whose mode of life has been long debated. These echinoderms are usually interpreted as vagile epibenthic echinoderms, moving over the sea bottom by means of a flexible stem. Although their life habits and posture are reasonably well understood, the mechanisms that control the movement of stem are highly controversial. Specifical...

Echinoderms are unique in being pentaradiate, having diverged from the ancestral bilaterian body plan more radically than any other animal phylum. This transformation arises during ontogeny, as echinoderm larvae are initially bilateral, then pass through an asymmetric phase, before giving rise to the pentaradiate adult. Many fossil echinoderms are radial and a few are asymmetric, but until now ...

Antimicrobial peptides (AMPs) are important immune effector molecules for invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system. Here we summarize the knowledge of such peptides in echinoderms. Strongylocins are a novel family of cysteine-rich AMPs, recently identified in the sea urchins, Strongylocentrotus droebachiensis and S. purpuratus. Although these mol...