Selection by consumers has led to the evolution of a vast array of defenses in animals and plants. These defenses include physical structures, behaviors, and chemical signals that mediate interactions with predators. Some of the strangest defensive structures in nature are the globiferous pedicellariae of the echinoderms. These are small venomous appendages with jaws and teeth that cover the test of many sea urchins and sea stars. In this study, we report a unique use of these defensive structures by the collector sea urchin Tripneustes gratilla. In both the laboratory and the field, globiferous pedicellariae were unpalatable to fish consumers. When subject to simulated predator attack, sea urchins released a cloud of pedicellaria heads into the water column. Flume experiments established the presence of a waterborne cue associated with this release of pedicellariae that is deterrent to predatory fish. These novel results add to our understanding of how the ecosystem-shaping sea urchin T. gratilla is able to reach high densities in many reef habitats, with subsequent impacts on algal cover.
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http://dx.doi.org/10.1086/691437 | DOI Listing |
Sci Adv
January 2025
Department of Zoology, University of Cambridge, Cambridge, UK.
The evolutionary origin of the vertebrate brain remains a major subject of debate, as its development from a dorsal tubular neuroepithelium is unique to chordates. To shed light on the evolutionary emergence of the vertebrate brain, we compared anterior neuroectoderm development across deuterostome species, using available single-cell datasets from sea urchin, amphioxus, and zebrafish embryos. We identified a conserved gene co-expression module, comparable to the anterior gene regulatory network (aGRN) controlling apical organ development in ambulacrarians, and spatially mapped it by multiplexed in situ hybridization to the developing retina and hypothalamus of chordates.
View Article and Find Full Text PDFMar Drugs
January 2025
Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai 264117, China.
Echinoderms, a diverse group of marine invertebrates including starfish, sea urchins, and sea cucumbers, have been recognized as prolific sources of structurally diverse natural products. In the past five years, remarkable progress has been made in the isolation, structural elucidation, and pharmacological assessment of these bioactive compounds. These metabolites, including polysaccharides, triterpenoids, steroids, and peptides, demonstrate potent bioactivities such as anticancer, anti-inflammatory, antiviral, and antimicrobial effects, providing valuable insights and scaffolds for drug discovery.
View Article and Find Full Text PDFMar Drugs
December 2024
CESAM-Centre for Environmental and Marine Studies, Department of Environment and Planning, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal.
This review is focused on the research, innovation and technological breakthroughs on marine invertebrate collagens and their applications. The findings reveal that research dates back to the 1970s, and after a period of reduced activity, interest in collagens from several marine invertebrate groups was renewed around 2008, likely driven by the increased commercial interest in these biomolecules of marine origin. Research and development are predominantly reported from China and Japan, highlighting significant research interest in cnidarians (jellyfish), echinoderms (sea cucumbers, sea urchins and starfish), molluscs (squid and cuttlefish) and sponges.
View Article and Find Full Text PDFDokl Biol Sci
January 2025
Biological Faculty, Moscow State University, Moscow, Russia.
Expression of 11 genes of the Hox cluster (SiHox1, 2, 3, 5, 6, 7, 8, 9/10, 11/13a, 11/13b, and 11/13c) was assessed in the sea urchin Strongylocentrotus intermedius at early developmental stages, including the blastula (13 h post fertilization (hpf)), gastrula (35 hpf), prism (46 hpf), and pluteus (4 and 9 days post fertilization (dpf)) stages. Expression of SiHox7, 11/13b, and 11/13c was observed at the blastula stage; early activation of 11/13c was detected for the first time in regular sea urchins. The expression level was very low at the gastrula and prism stages.
View Article and Find Full Text PDFOpen Biol
January 2025
Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku , Tokyo 108-8477, Japan.
Sea urchins, integral to marine ecosystems and valued as a delicacy in Asia and Europe, contain physiologically important long-chain (>C) polyunsaturated fatty acids (PUFA) in their gonads, including arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) and unusual non-methylene-interrupted fatty acids (NMI-FA) such as 20:2. Although these fatty acids may partially be derived from their diet, such as macroalgae, the present study on has uncovered multiple genes encoding enzymes involved in long-chain PUFA biosynthesis. Specifically, 3 fatty acid desaturases (FadsA, FadsC1 and FadsC2) and 13 elongation of very-long-chain fatty acids proteins (Elovl-like, Elovl1/7-like, Elovl2/5-like, Elovl4-like, Elovl8-like and Elovl6-like A-H) were identified in their genome and transcriptomes.
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