A Functional Biology of Free-Living Protozoa (Functional

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These are the so-called naked amebas (Figure 5.32A–D). These asexual processes depend largely on the or- ganism’s “reproductive exploitation” of its ability to re- generate (regrow lost parts). Sur les affinities des Cycliophora Funch et Kristensen, 1995, un novel embranchement d’invertébrés marins, ectoparasites ou commensal des Crustacés Décapodes. Densely packed gland cells of the proboscis epithelium secrete mucus, to which organic detrital par- ticles adhere. The tube develops inwardly from the mantle wall and con- nects with the genital duct.

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The Evolution of Mating Systems in Insects and Arachnids

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It has been proved now that these coelomocytes are mesodermal in origin generating from blast cells that also give rise to mesoderm. Best Regards Simo Dr Lorenzon Simonetta Dep. of Biology Via Giorgieri 9 University of Trieste 34100 Trieste Italy =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= To (un)subscribe to CRUST-L: Send (UN)SUBSCRIBE CRUST-L as the message body to MAJORDOMO@VIMS.

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An Ecological and Societal Approach to Biological Control

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The pedal lobes supply nerves to the funnel, and anterior divisions of the pedal ganglia, called brachial lobes, send nerves to each of the arms and ten- PHYLUM MOLLUSCA 49 Figure 20.39 Primitive molluscan nervous systems. (A) Aplacophoran (Proneomenia). (B) Polyplacophoran (Acanthochitona). For a long time stories of enormous squid were though to be just sea tales with no more truth than those of mermaids. Each ctene con- sists of a transverse band of hundreds of very long, part- ly fused cilia (to 3.5 mm in length) that beat together as a unit.

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Evolutionary Developmental Biology of Invertebrates

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Con- sequently, they do not have problems of osmotic and ionic regulation. The clypeus projects off the front of the head and extends down over the mandibles, much as our upper lip covers our teeth. It sur- rounds the mouth but not the anus. In these animals a narrow tract of shorter cilia—the inter- plate ciliated groove—runs between successive ctenes and is responsible for coordinating their activity.

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Entomopathogenic Nematology (Cabi)

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In hyper- mastigotes, sexual reproduction varies, occurs by either gametogamy, gamontogamy, or autogamy 8. Phylogenetic study of cirripedes and selected relatives (Thecostraca) based on 18S rDNA sequence analysis. Subsequent work supports a view of these animals as maxillopo- dans, although the presence of six or seven abdominal segments in juveniles of some species is inconsistent with this view. Each can act like a suction disk that is controlled by hydraulic and muscular action.

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Sea Snails: A natural history

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Forms the gut and its derivatives: in vertebrates, these include the liver, trachea, and lungs. epidermis -- The outermost layer of cells or skin. These compounds are energetically expensive to produce, but they often require relatively little or no dilution by water, and they can be stored within the body prior to excretion. This behavior appears to be related to the light and nutrient requirements of its symbiotic zooxanthel- lae. In sea stars, for example, these radial nerves appear as a distinct V-shaped thickening in the epidermis of each ambulacral groove (Figure 22.5B).

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Atlas of Invertebrate Reproduction and Development

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The oldest terrestrial animals on Earth are millipedes, dating to more than 425 mya (Silurian). Keep in mind that in such polychaetes the intersegmental septa are functionally complete, and thus the coelomic spaces in each segment can be effectively isolated hydraulically from each other. Chesapeake Street on OU’s South Campus), Room 144; phone: 325-7071; e-mail lbergey@ou.edu Credit: 1-2 hours. Nema- todes are known from virtually every habitat in the seas, fresh water, and on land.

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The Millipedes (Diplopoda) of the Asian Part of Russia

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The tentacles trail passively or are “fished” by various swirling movements of the body. Are Aschelminthes pseudocoelomate or acoelomate? These master regulatory genes modulate other sets of developmental genes and, in doing so, “select” the developmental pathways that are followed by di- viding cells. These crabs possess membranous discs on their legs or sternites that were once thought to be auditory organs (tympana), but are now thought to function as gas exchange surfaces (see Maitland 1986).

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Halacarid Mites (Arachnida: Acari): Keys and Notes for the

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It then became generally understood that classifications ought to reflect the phylogeny of organisms, by grouping each taxon so as to include the common ancestor of the group's members (and thus to avoid polyphyly). About a dozen species of sea anemones participate in this interesting rela- tionship. Hermaphroditism and sperm diver- sity among freshwater Gastrotricha. There can be thousands of ommatidia in a single insect eye. Examples of the major molluscan taxa appear in Figure 20.1.

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Metal Catalysed Reactions in Ionic Liquids (Catalysis by

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By the middle Paleozoic (the Devonian), life on land had begun to pro- liferate. These ac- tivities are further enhanced by the absence of linings and partitions within the body cavity, so the exchanges occur directly between the organ tissues and the body fluid. Byssal threads are secreted as a liquid by the byssus gland in the foot. Yazawa, “Neural control of the cardio-arterial valves in an isopod crustacean, Bathynomus doederleini: excitatory and inhibitory junctional potentials,” Journal of Comparative Physiology A, vol. 157, no. 4, pp. 529–536, 1985.

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