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The larvae of the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae), are highly efficient visually guided predators. Their visual system consists of a cluster of six stemmata and one eye patch on each side of the head capsule. Histological investigations show that the organization of individual stemmata differs strongly from any eye(More)
Adults and nymphs of the Peruvian stick insect Oreophoetes peruana (order Phasmatodea) have a pair of thoracic glands from which they discharge a malodorous fluid when disturbed. The secretion contains a single volatile component, quinoline. Quinoline has not been reported previously from an animal source. The compound proved repellent or topically irritant(More)
The binding of [(3)H]?-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) to synaptic membranes of rat brain was characterized in the absence of detergents and chaotropes. Optimal conditions for binding were a centrifugation assay employing a well washed, frozen-thawed synaptic membrane preparation and a 40 min incubation at 4 degrees C in 50 mM(More)
Nearly nothing is known about the transition that visual brain regions undergo during metamorphosis, except for Drosophila in which larval eyes and the underlying neural structure are strongly reduced. We have studied the larvae of the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae), which are sophisticated visually oriented(More)
Larvae of the predaceous diving beetle Thermonectus marmoratus bear six stemmata on each side of their head, two of which form relatively long tubes with linear retinas at their proximal ends. The physical organization of these eyes results in extremely narrow visual fields that extend only laterally in the horizontal body plane. There are other examples of(More)
Almost all animal eyes follow a few, relatively well-understood functional plans. Only rarely do researchers discover an eye that diverges fundamentally from known types. The principal eye E2 of sunburst diving beetle (Thermonectus marmoratus) larvae clearly falls into the rarer category. On the basis of two different tests, we here report that it has truly(More)
A number of invertebrates are known to be sensitive to the polarization of light and use this trait in orientation, communication, or prey detection. In these animals polarization sensitivity tends to originate in rhabdomeric photoreceptors that are more or less uniformly straight and parallel. Typically, polarization sensitivity is based on paired sets of(More)
Hexachlorobenzene (HCB) has been measured in the water, soil, air or biota at several uncontrolled hazardous waste sites. At one of these sites in Louisiana, 9,500,000 ppb have been measured in the oily fraction of an oil-water mixture taken from a monitoring well, and in water of nearby wells at concentrations up to 28 ppb. HCB has been detected in solid(More)
The sunburst diving beetle, Thermonectus marmoratus, ejects a milky fluid from its prothoracic defensive glands when disturbed. Two major volatile components of this secretion are steroids; cybisterone (structure 7) constitutes about 20% of the volatiles, and a new steroid, mirasorvone, about 50%. Mirasorvone is assigned an 18-oxygenated pregnane structure(More)
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