Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
A genus of STARFISH in the family Asterinidae. They externally hold developing embryos (EMBRYO, NON-MAMMALIAN) among the spines below the oral surface.
A genus of STARFISH in the family Asteriidae. One species, Asterias rubens, is the most common in the north-east Atlantic region.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
A mature haploid female germ cell extruded from the OVARY at OVULATION.
A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
Hormones produced by invertebrates, usually insects, mollusks, annelids, and helminths.
Protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by CYCLINS; MPF directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of MPF is PROTEIN P34CDC2.
Prepared food that is ready to eat or partially prepared food that has a final preparation time of a few minutes or less.
Affection; in psychiatry commonly refers to pleasure, particularly as it applies to gratifying experiences between individuals.
Large marine mammals of the order CETACEA. In the past, they were commercially valued for whale oil, for their flesh as human food and in ANIMAL FEED and FERTILIZERS, and for baleen. Today, there is a moratorium on most commercial whaling, as all species are either listed as endangered or threatened.
Occasions to commemorate an event or occasions designated for a specific purpose.
Clothing designed to protect the individual against possible exposure to known hazards.
A plant genus of the family ASCLEPIADACEAE. Members contain the alkaloids quindoline, CSA-3, cryptolepine, and neocryptolepine.
A plant family of the order Bromeliales, subclass Zingiberidae, class Liliopsida (monocotyledons).
Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.
A superorder of marine CRUSTACEA, free swimming in the larval state, but permanently fixed as adults. There are some 800 described species, grouped in several genera, and comprising of two major orders of barnacles: stalked (Pedunculata) and sessile (Sessilia).
Environment un-modified by human activity. Areas in which natural processes operate without human interference.
A weapon designed to explode when deployed. It frequently refers to a hollow case filled with EXPLOSIVE AGENTS.
Skills and knowledge required for assessment and treatment of traumatic, environmental, and medical emergencies in remote geographic or wilderness environments.
A prosthetic restoration that reproduces the entire surface anatomy of the visible natural crown of a tooth. It may be partial (covering three or more surfaces of a tooth) or complete (covering all surfaces). It is made of gold or other metal, porcelain, or resin.
Marine ridges composed of living CORALS, coral skeletons, calcareous algae, and other organisms, mixed with minerals and organic matter. They are found most commonly in tropical waters and support other animal and plant life.
A class in the phylum CNIDARIA, comprised mostly of corals and anemones. All members occur only as polyps; the medusa stage is completely absent.
Places for cultivation and harvesting of fish, particularly in sea waters. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The protection, preservation, restoration, and rational use of all resources in the total environment.
Inorganic salts of thiosulfuric acid possessing the general formula R2S2O3.