Fish Physiology: Euryhaline Fishes, Volume 32

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Thus, “Oligochaeta” constitutes a paraphyletic taxon. The relative density and rigidity of the test determine which process occurs. They do not fertilize their own eggs, but they exchange sperm with other sponges. ORDER DACTYLOCHIROTIDA: Body often U- shaped and enclosed in flexible test of skeletal plates; tentacles unbranched; most are deep-water PHYLUM ECHINODERMATA 5 1. since 2009: associate professor (University of Lodz; Department of Invertebrate Zoology & Hydrobiology) Subject: A revision of the family Typhlotanaidae Sieg, 1984 (Crustacea: Tanaidacea) with the remarks on the Nototanaidae Sieg, 1976.
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Reef Invertebrates: An Essential Guide to Selection, Care

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Sea cucumbers are in the class Holothuroidea and are soft, sluglike organisms with leathery outer skin. The earliest fossil Hymenoptera date from the Trias- sic (207–220 mya). In homopterans the forewings are entirely membranous, though often colored (and about the same size as the hindwings), whereas in all other hemipterans the forewings are hardened basally and membranous only distally (and the forewings are small- er than the hindwings). The milleporid exoskeleton, termed a coenosteum, is perfo- rated by pores of two sizes that accommodate two kinds of polyps (Figure 8.18).
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Phylogeny and Evolution of the Mollusca

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In these millipedes, males mold soil into a small cup into which they ejaculate sperm. Thus, at this particular locality, beaver engineering reduced the number of pest mosquitos. However, the ecdysteroids are a large and complex group of ancient compounds that occur throughout the Eukaryota, and hundreds of different chemical forms are known (Lafont and Wilson 1996, Sadikov, et al. 2001, Lafont 1997). Cteno- phores can regenerate virtually any lost part, includ- ing the apical sense organ.
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Worms (Looking at Minibeasts)

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Linnaeus distinguished and named over 4,400 species of animals, including Homo sapiens. The genome of an orthonectid, a group of highly modified parasitic invertebrates, is drastically reduced and compact, yet it shows the bilaterian gene toolkit. UNCORRECTED PAGE PROOFS 16 CHAPTER TWENTY Figure 20.12 The anatomy of Octopus. (A) General external anato- my. (B) Right-side view of the internal anatomy. (C) Arm and sucker (cross section). (D) Tip of the hectocotylus arm. (E) The diminutive Eastern Pacific Octopus digueti well camouflaged on a sand bottom. (F) The tropical Pacific Octopus chierchiae. (G) The remarkable Indo-West Pacific Octopus horridus. (F) (G) (E) UNCORRECTED PAGE PROOFS ing 20 m in overall length.
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An Inordinate Fondness for Beetles

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The most complex developmental sequences are seen among the dendrobranchiate shrimps, which hatch as a typical nauplius larva that eventually under- goes a metamorphic molt to become a protozoea larva, with sessile compound eyes and a full complement of head appendages. Fine structure and functions of haemerythrocytes and leucocytes of Sipunculus nudus. ZooKeys 40:1-239.(used for almost all classification above and most at or below genus level). They used their siphons to move by jet propulsion.
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SHARKS IN QUESTION (Smithsonian Answer Books)

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They help the nemerteans avoid bright light and potential exposure to predators or environmental stresses. AccessScience provides the most accurate and trustworthy scientific information available. Both of these factors may have contributed to the sudden die-off, which has taken place in the last two decades. “It’s just an association. Minot separated the nemerteans from the flatworms in 1876, but it was not until the mid- twentieth century (see Coe 1943 and Hyman 1951) that the unique combination of characters displayed by the ribbon worms was fully accepted.
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Animals of Sandy Shores (Naturalists' Handbooks)

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They probably function both in excretion and osmoregulation. In all these cases, iron oxide crystals in the form of magnetite have been shown to underlie the primary detection devices. Malpighian tubules accomplish the same process, but they must rely on assistance from the gut. In some ectoprocts, such as Cauloramphus spiniferum, large parti- cles are actually passed from zooid to zooid and then dumped into an excurrent chimney (Figure 21.12D).
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Respiration in the Invertebrates (Macmillan studies in

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In some insects it appears that air is taken into the body through the tho- racic spiracles and released through the abdominal spir- acles, thus creating a “flow-through system.” Each spiracle is usually recessed in an atrium, whose walls are lined with setae or spines (trichomes) that pre- vent dust, debris, and parasites from entering the tra- cheal tubes. Although the Univ offers no specific herp courses, herps are covered in the Animal Biology (BIOL3840), Animal Biology Lab (BIOL3850), and Zoo Biology (BIOL4104) courses offered through the Department of Biology.
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North-west European Thecate Hydroids and Their Medusae: Pt.

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In resting insects most of the spiracles are generally closed. Now, as the Bug Room Assistant, she assists with the care and maintenance of all live creatures at the museum. View at Publisher · View at Google Scholar A. Also, at some point before day 90, you need to perform an experiment. The ring canal gives off the usual five radial canals and also branches to a wreath of buccal tube feet around the mouth.
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The Carabidae (Coleoptera) of Fennoscandia and Denmark,

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ANIMAL ARCHITECTURE AND THE BAUPLAN CONCEPT 87UNCORRECTED PAGE PROOFS Figure 3.36 Schematic and generalized male and female reproductive systems. Invertebrates don't have an internal skeleton made of bone. Along these lines, we offer the following sampling of ideas. During early cleavage, the first four blastomeres arise by the usual two meridional cleavages, which mark the adult planes of symmetry. Sea urchin sperm can be obtained in large quantities, because sea urchins, like many marine invertebrates, engage in broadcast spawning, i.e., they release large quantities of gametes into the sea water.
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