Acarology: 6th, v. 1: International Congress Proceedings

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The hemal system is a complex array of canals and spaces, mostly enclosed within coelomic channels called perihemal sinuses. The particle is passed to an excurrent chimney. By monitoring the movement of the fluorescent material, Schmidt determined that 30 min- utes elapsed from the onset of feeding until the bacteria had been captured by choanocytes and moved to the base of the cells. Sever- al insects that are prey to bats have the ability to hear the high frequencies of bat echolocation devices, and they have evolved flight behaviors to avoid these flying mammals.

Australian Weevils (Coleoptera Curculionoidea): Brentidae,

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Cilia drive the food to the mouth, where it is ingested. The advancing portion of en- doplasm pushes forward and then becomes semirigid ectoplasm at the tip of the advancing pseudopodium. Guest Posts · Insects & Spiders · Mammals & Birds · Marine Environment. How organisms use flow-induced pressures. However, the transfer of genetic elements from one species to another is suspected to be by way of 16 CHAPTER ONE UNCORRECTED PAGE PROOFS viruses, bacteria, arthropod parasites, or other vectors.

Freshwater Macroinvertebrates of Northeastern North America

Barbara Peckarsky

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After attachment, there is a remarkable reorganization of tissue positions accompanied by histolysis of various larval structures. The nucleus from each gamete enters the tube where they fuse. This ganglion is located under its stomach. It has been said that at least half the planet’s species are symbionts and that all species have symbiotic partnerships—concepts suggesting that every individual is an ecosystem. In fact, it seems likely that a significant portion of Earth’s biodiversity, at the level of both genes and species, resides in the “invisible” prokaryotic world.

Classes Annelida

Cuvier Baron

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The cell rosettes may also transport wastes to the gut. Includes all antimicrobial studies except testing of commercial antimicrobials. Visual motion detection circuits in flies: Parallel direction- and non-direction-sensitive pathways be- tween the medulla and lobula plate. Hypotheses (branches of the tree) that consistently resist refutation are said to be highly corroborated. The first trait is based on evidence suggesting that somatic growth—as during regeneration—is provided by totipotent, undifferentiated “stem” cells rather than by proliferation of previously differentiated ones.

Candoninae (Ostracoda) from the Pilbara Region in Western

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This class of segmented worms includes the earthworms and a variety of aquatic species. Once a larva becomes competent, it generally begins to respond to certain environmental cues that induce set- tling behavior. The first few, very small, whorls at the apex are the remnant of the larval shell, or protoconch, which usually differ in sculpturing and color from the rest of the shell. Sessile forms, such as most cirripedes, have lost the heart altogether, although it is replaced by a vessel “pump” in the thoracicans.

Advances in Insect Chemical Ecology

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The 24 credit hours must include at least 12 credit hours of 600- or higher-level course work. In such cases the corona usu- ally bears spines or setae arranged as a funnel-shaped trap (Figure 12.1D). At this point, however, we can view the situation in a general way and examine the strategies of parasitism in terms of parasite life cycles, at the same time introduc- ing some basic terminology. Use this page to try and identify at least two different types of wings.

The American Horseshoe Crab

Carl N. Shuster, H. Jane Brockmann

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Particularly promising invertebrate groups include sponges, tunicates, ascidians, bryozoans, octocorals, and some molluscs … have anticancer properties. The choanoderm also can be simple and continuous, or folded and subdivided in various ways. In others a calcified partition, called the cryptocyst, lies beneath the frontal membrane, separating it from the soft parts within. Invertebrates, Second Edition.— Richard C.

Pratylenchus, (Nematoda, Pratylenchidae): Diagnosis,

Pablo Castillo

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The heartbeat is by peristaltic action, and the direction of this motion is periodically reversed, flushing the blood first one way through the heart and then the other. Fifteen genera are known, and many genera are found worldwide. Furthermore, they are hermaphroditic, and most possess relatively complicated reproductive sys- tems. Thus, if you come out of the surf with a jellyfish tentacle on you, douse it with urine (acidic) or baking soda (al- kaline) to reduce the impact.

The Earwig's Tail: A Modern Bestiary of Multi-legged Legends

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In addition, males produce sounds by stridulation and substratum thumping that are thought to attract potential mates. Can the Cambrian ex- plosion be inferred through molecular phylogeny? In this way, Didinium can en- gulf its relatively gigantic prey, Paramecium (Figure 5.17A). I probably should have discussed this in one of the more general sea cucumber articles in the past couple of columns, but because I did not, I’ll mention it here.

Sasol First Field Guide to Spiders & Scorpions of Southern

Tracey Hawthorne

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Raup is still an evolutionist, but he’s beginning to argue for “survival of the luckiest,” instead of “survival of the fittest.” Condemning with faint praise, he says, “Natural selection as a process is okay. Autozooids bear tentacles and function in feeding; siphonozooids are small, have reduced tentacles, and serve to create water currents through the colony. These inpock- etings are called pseudotrachea, but are probably not homologous to the trachea or the book lungs of insects and spiders.