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Pollicipes Polymerus
''Pollicipes polymerus'', commonly known as the gooseneck barnacle or leaf barnacle, is a species of stalked barnacle. It is found, often in great numbers, on rocky shores on the Pacific coasts of North America. Classification Barnacles are classified with shrimps, crabs, isopods and amphipods in the subphylum Crustacea. They are included in the class Maxillopoda, though this class does not appear to be a monophyletic grouping. They are included in the infraclass Cirripedia, the barnacles, members of which are sessile suspension feeders with two active swimming larval stages, the nauplius and the cyprid. The order Pedunculata includes barnacles attached to the substrate by stalks, the goose barnacles. The attachment is made by the cementing of the antennules of the cyprid larvae to the substrate and the elongation of that region into a stalk. Pedunculata is not itself a single monophyletic group but forms a transitional series of lineages moving towards the sessile acorn barnac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Brettingham Sowerby III
George Brettingham Sowerby III (16 September 1843 – 31 January 1921) was a British conchologist, publisher, and illustrator. He, too, worked (like his father George Brettingham Sowerby II and his grandfather George Brettingham Sowerby I) on the ''Thesaurus Conchyliorium'', a comprehensive, beautifully illustrated work on molluscs. He was colour blind, and thus his daughter did most of the colouring of his engravings. External links Petit, R. E. (2009). ''George Brettingham Sowerby, I, II & III: their conchological publications and molluscan taxa''. Zootaxa. 2189: 1–218 See also *Sowerby family The Sowerby family () was a British family of several generations of naturalists, illustrators, botanists, and zoologists active from the late 18th century to the mid twentieth century. *James Sowerby (1757–1822) **James De Carle Sowerby (178 ... Conchologists 1843 births 1921 deaths {{Zoologist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sessilia
Sessilia is an unranked clade of barnacles, comprising the barnacles without stalks, or acorn barnacles. They form a monophyletic group and are probably derived from stalked or goose barnacles. Sessilia is divided into two orders. The Verrucomorpha contain two families, Verrucidae and Neoverrucidae Neoverrucidae is a family of crustaceans belonging to the order Scalpellomorpha Scalpellomorpha is an order of acorn barnacles in the class Thecostraca Thecostraca is a Class (biology), class of marine invertebrates containing over 2,200 des ..., and the remaining 14 families are in the order Balanomorpha. References External links * Barnacles Crustacean orders {{maxillopoda-stub da:Rur de:Seepocken pl:Pąkle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Biological Bulletin
''The Biological Bulletin'' is a peer-reviewed scientific journal covering the field of biology. The journal was established in 1897 as the ''Zoological Bulletin'' by Charles Otis Whitman and William Morton Wheeler. In 1899 the title was changed to ''The Biological Bulletin'', and production was transferred to the Marine Biological Laboratory at Woods Hole, Massachusetts. The current editor-in-chief is Kenneth M. Halanych. ''The Biological Bulletin'' is indexed by several bibliographic services, including Index Medicus, MEDLINE, Chemical Abstracts, Current Contents, BIOBASE, and Geo Abstracts. Six issues are published per year and all content is made freely available one year after publication. According to the ''Journal Citation Reports ''Journal Citation Reports'' (''JCR'') is an annual publicationby Clarivate Analytics (previously the intellectual property of Thomson Reuters). It has been integrated with the Web of Science and is accessed from the Web of Science-Core Collec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-fertilisation
Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a reproductive mechanism employed by many flowering plants. However, species of protists have also been observed using autogamy as a means of reproduction. Flowering plants engage in autogamy regularly, while the protists that engage in autogamy only do so in stressful environments. Occurrence Protists ''Paramecium aurelia'' ''Paramecium aurelia'' is the most commonly studied protozoan for autogamy. Similar to other unicellular organisms, ''Paramecium aurelia'' typically reproduce asexually via binary fission or sexually via cross-fertilization. However, studies have shown that when put under nutritional stress, ''Paramecium aurelia'' will undergo meiosis and subsequent fusion of gametic-like nuclei. This process, defined as hemixis, a chromosomal rearrangement process, takes place in a number of steps. First, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilisation
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Processes such as insemination or pollination which happen before the fusion of gametes are also sometimes informally called fertilisation. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg (biology)
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was in size. Whale shark eggs typically hatch within the mother. At and up to , the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. For example, the great majority of tunicata, tunicates, pulmonate molluscs, opisthobranch, earthworms, and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites. Animal species having different sexes, male and female, are called Gonochorism, gonochoric, which is the opposite of hermaphrodite. There are also species where hermaphrodites exist alongside males (called androdioecy) or alongside females (called gynodioecy), or all three exist in the same species ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walla Walla University
Walla Walla University is a private Adventist university in College Place, Washington. The university has five campuses throughout the Pacific Northwest. It was founded in 1892 and is affiliated with the Seventh-day Adventist Church. The university has an annual enrollment of around 1,700 students. It is accredited by the Northwest Commission on Colleges and Universities and is also denominationally accredited. Walla Walla University offers more than 100 areas of study including preprofessional degrees and four graduate programs. History In 1887, W.W. Prescott became the first education secretary of the General Conference of Seventh-day Adventists. He noticed that Seventh-day Adventist schools were opening all over the place without a plan for long-term success, and decided to encourage these new Adventist schools to consolidate into larger, regional institutions that would stand a better chance of survival. In 1890, Prescott visited the Pacific Northwest and asked the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertidal Zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species of life, such as seastars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the ''littoral zone'' or '' seashore'', although those can be defined as a wider region. The well-known area also includes steep rocky cliffs, sandy beaches, bogs or wetlands (e.g., vast mudflats). The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. The peritidal zone is similar but somewhat wider, extending from above the highest tide level to below the lowest. Organisms in the intertidal zone are adapted to an environment of harsh extremes, living in water pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baja California
Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of Baja California (). It has an area of (3.57% of the land mass of Mexico) and comprises the northern half of the Baja California Peninsula, north of the 28th parallel, plus oceanic Guadalupe Island. The mainland portion of the state is bordered on the west by the Pacific Ocean; on the east by Sonora, the U.S. state of Arizona, and the Gulf of California; on the north by the U.S. state of California; and on the south by Baja California Sur. The state has an estimated population of 3,769,020 as of 2020, significantly higher than the sparsely populated Baja California Sur to the south, and similar to San Diego County, California, to its north. Over 75% of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states (Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th parallel, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about 32% of its total surface area, larger than Earth's entire land area combined .Pacific Ocean . '' Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the |
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