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  • Spider  (6)
  • Life and Medical Sciences  (4)
  • Central nervous system  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 171 (1992), S. 231-243 
    ISSN: 1432-1351
    Keywords: Vibratory communication ; Signal coding ; Mechanoreception ; Pattern recognition ; Spider
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Both amplitude and frequency contents of male courtship vibrations of Cupiennius salei change with signal propagation through a bromeliad (Fig. 3). Temporal pattern and carrier frequency of the opisthosomal signal (Fig. 1a) remain largely unchanged, however, and therefore satisfy the requirements to carry species specific information. Pedipalpal signals cover a broad range of frequencies (Fig. 3a, c); both their dispersive transmission and the frequency-dependent attenuation by the plants may provide the female with information about her distance from the male. 2. Parallel processing of different signal components already begins in the female's metatarsal lyriform vibration receptor. Opisthosomal signals: They mainly elicit responses from long distal slits; signal amplitude is of only minor influence (Fig. 7). Carrier frequency is represented by interspike frequencies of individual slits (Fig. 8b, d). Pedipalpal signals: They elicit responses from all slits (Figs. 6, 7a). Responses of individual slits differ and can be assigned to specific frequency components contained in a pedipalpal signal (Figs. 6, 8a, 9b). 3. The repetition of opisthosomal signals within the male courtship vibration improves the signal to noise ratio in the female's receptor response (Fig. 10). 4. For unknown reasons the intensity of the receptor response follows changes in acceleration amplitude in the case of heterospecific but not in the case of conspecific courtship vibrations (Fig. 11).
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  • 2
    ISSN: 1432-1939
    Keywords: Spider ; Cupiennius ; Ctenidae ; Range distribution ; Habitat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cupiennius is a genus of hunting spiders with seven established species. One of these (C. salei) has been used in laboratory research for many years. Here we report on the geographic distribution of the genus and some characteristics of its habitat. (1) The genus is Central American. Its range is from the state of Veracruz in Mexico in the north to Panama in the south. Five of the seven species are known to occur in the Canal Area, Panama. Sympatry is best documented for C. getazi and C. coccineus and is likely to occur in other species. (2) All known species of Cupiennius are closely associated with particular plants on which they hide during the day and prey, court, and moult at night. The most typical dwelling plant such as a bromeliad or a banana plant is a monocotyledon with mechanically strong and unbranched leaves that provide retreats at their bases. On plants not providing “ready-made” shelters, such as ginger or members of the Araceae, several species of Cupiennius have been observed to build retreats. (3) Average monthly rainfall and temperature data are given for six locations where we have recently observed C. coccineus, C. getazi, C. panamensis, and C. salei. According to measurements taken in the field the microclimate within a typical retreat differs considerably from the external environment: during the day the retreat space shows lower aver-age water evaporation rates and higher relative air humidity.
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  • 3
    ISSN: 1432-1939
    Keywords: Sensory ecology ; Spider ; Cupiennius ; Vibratory environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cupiennius salei (Ctenidae) is a tropical wandering spider which lives in close association with a particular type of plant (see companion paper). These plants are the channels through which the spiders receive and emit various types of vibrations. We measured the vibrations the spiders are typically exposed to when they sit on their dwelling plants (banana plant, bromeliad) in their natural biotope in Central America. In addition a laboratory analysis was carried out to get an approximate idea of the complex vibration-propagating properties of the dwelling plants, taking a banana plant as an example. (1) Types of vibrations (Figs. 1–4). Despite variability in detail there are characteristic differences in spectral composition between the vibrations of various abiotic and biotic origins: (a) Vibrations due to wind are very low frequency phenomena. Their frequency spectra are conspicuously narrow with prominent peaks close to or, more often, below 10 Hz. Vibrations due to raindrops show maximal acceleration values at ca. 1000 Hz. Their frequency band at-20 dB extends up to ca. 250 Hz where-as that of the vibrations due to wind extends to only ca. 50 Hz. (b) The frequency spectra of prey vibrations such as those generated by a running cockroach are typically broad-banded and contain high frequencies; they have largest peaks mostly between ca. 400 and 900 Hz. Their-20 dB frequency bands usually extend from a few Hz to ca. 900 Hz. Some potential prey animals such as grass-hoppers seem to be vibrocryptic; they walk by the spider as if unnoticed. Their “cautious” gait leads to only weak vibrations at very low frequencies resembling the background noise due to wind. Courtship signals are composed maily of low frequencies, intermediate between background noise and prey vibrations (male: prominent peaks at ca. 75 Hz and ca. 115 Hz; female: dominant frequencies between ca. 20 Hz and ca. 50 Hz). The male signal is composed of “syllables” and differs from all other vibrations studied here by being temporally highly ordered. A comparison with previous electrophysiological studies suggests that the high pass characteristics of the vibration receptors enhance the signal-to-(abiotic)-noise ratio and that the vibration-sensitive interneurons so far examined and found to have band pass characteristics are tuned to the frequencies found in the vibrations of biotic origin. (2) Signal propagation (Fig. 5). In terms of frequency-dependent attenuation of vibrations the banana plant is well suited for transmitting the above signals. Average attenuation values are ca. 0.35 dB/cm. Together with known data on vibration receptor sensitivity this explains the range of courtship signals of more than 1 m observed in behavioral studies. Attenuation in the plant is neither a monotonic function of frequency nor of distance from the signal source.
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  • 4
    ISSN: 1432-1351
    Keywords: Dispersal ; Spider ; Cupiennius getazi ; Drop and swing behavior ; Numerical model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary When exposed to certain air flows spiderlings of the wandering spider Cupiennius getazi (Ctenidae) drop from their dwelling plant and swing in the wind from a gradually lengthening dragline. If body contact is made with a nearby substrate the spiderling detaches. We refer to this form of aerial dispersal as the drop and swing dispersal behavior (DASDB). The dragline being only up to about 70 cm long and only rarely ruptured by the drag forces of the wind, this is a close range type of dispersal as opposed to the ‘ballooning’ known for many other species of spiders. DASDB is readily elicited in spiderlings at an age of ca. 9 days (outside egg sac). At this age their mass is 1.26 ±0.35 mg and their yolk usually depleted. They then start to catch prey and escape from the unfavorable conditions in the small space around the egg sac where hundreds of spiderlings compete. Air flow rates effectively eliciting DASDB in the laboratory are between 0.2 m/s and 1.5 m/s. The number of spiderlings showing DASDB increases considerably if the air flow is turbulent as opposed to laminar. A numerical model defining the window within which DASDB is supported mechanically was developed from theoretical considerations. Taking the effective wind speeds and the mechanical properties of the dragline, the model accounts very well for the fact that actual rupture of the dragline was observed only rarely in C. Getazi. Other features of the DASDB are also correctly predicted. The model is not only applicable to DASDB but also to the drop and swing preballooning behavior known to occur in several other species of spiders.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 258 (1989), S. 69-82 
    ISSN: 1432-0878
    Keywords: Neuroanatomy ; Central nervous system ; Sensory projections ; Lyriform slit sense organs ; Hair sensilla ; Spider, Cupiennius salei Keys. (Chelicerata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The basic organization of sensory projections in the suboesophageal central nervous system of a spider (Cupiennius salei Keys.) was analyzed with anterograde cobalt fills and a modified Golgi rapid method. The projections of three lyriform slit sense organs and of tactile hairs located proximally on the legs are described and related to central nerve tracts. There are five main longitudinal sensory tracts in the central region of the suboesophageal nervous mass arranged one above the other. Whereas the three dorsal ones contain fibers from the lyriform organs, the two ventral ones contain axons from the hair receptors. Axons from all three lyriform organs have typical shapes and widely arborizing ipsilateral intersegmental branches and a few contralateral ones. The terminal branches of the afferent projections from identical lyriform organs on each leg form characteristic longitudinal pathways, typical of each organ: U-shaped, O-shaped, or two parallel bundles. The terminations of the hair sensilla are ipsilateral and intersegmental. Two large bilaterally arranged “longitudinal sensory association tracts” receive inputs from all legs including the dense arborizations from tactile hairs, lyriform organs, and other sense organs. These tracts may serve as important integrating neuropils of the suboesophageal central nervous system.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 144 (1973), S. 409-433 
    ISSN: 1432-0878
    Keywords: Arthropod cuticle ; Spider ; Fiber reinforcement ; Composite material ; Electron microscopy, Light microscopy, Densitometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. According to its fine structure arthropod cuticle is a laminated composite material. The exoskeleton of a spider is surveyed in an electron microscopical study as to the characteristics of its fiber reinforcement. 2. Five types of fiber arrangement are distinguished, ranging from unidirectional to continuously rotating fiber orientation and with three types combining elements of both of these extreme cases. The unidirectional type is rare and its occurrence confined to the innermost part of the walking leg endocuticle and to parts of articular membranes. Quite contrary a continuous and regular rotation of fiber direction is common. In hard cuticle (exocuticle) this type of reinforcement is found exclusively. 3. Lamellar width, indicating a 180° rotation of the fiber direction, varies within wide limits. Variation is due to varying numbers of fiber layers and the amount of directional change between them (ca. 0.6–24°, type E). 4. The diameter of the chitin/protein microfiber amounts to ca. 35 Å. Its length measured up to 1,5 μm in the preparations. A periodicity of ca. 80 Å is noted. The precision of fiber alignment within the cuticle is high. 5. In the cuticle of the opisthosoma and the articular membranes endocuticular lamellae are taking a wavy course, which is interpreted to be in relation to the cuticle's softness. 6. The mechanical implications of both an increasing number of fiber directions in a composite material and of the different types of fiber reinforcement found in the spider cuticle are demonstrated by a calculation of the directional properties of the moduli of elasticity in tension and shear. The predictable strong influence of both the fiber content and the binder material's E-modulus on the mechanical properties of cuticle is illustrated. 7. Instead of a trajectorial design a continuous rotation of the fiber orientation is found in all exocuticles. Thus the spider does not make use of the special advantage (high strength/weight ratio) of unidirectional fiber arrangement in places where it seemed most likely.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 104 (1970), S. 87-106 
    ISSN: 1432-0878
    Keywords: Spider ; Cuticle ; Microfibers ; Pore Canals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Lamellen in der Cuticula des Tarsus der Spinne Cupiennius salei Keys. enthalten elektronenmikroskopisch darstellbare Mikrofasern. Die räumliche Anordnung dieser Mikrofasern wird analysiert; dabei werden zwei Wege beschritten: a) Beurteilung des elektronenmikroskopischen Bildes der Lamelle und dessen Abhängigkeit von der Schnittrichtung durch die Cuticula. b) Analyse der Porenkanalgestalt, von der aufgrund früherer Befunde eine enge Beziehung zur Mikrofaseranordnung zu fordern war. 2. Die Mikrofasern verlaufen sämtlich parallel zur Cuticulaoberfläche, haben jedoch in verschiedenen oberflächenparallelen Ebenen verschiedene Orientierung: Die Richtung ihres Verlaufs rotiert innerhalb einer Lamelle fortschreitend um insgesamt 180°. Sie verlaufen demnach nicht wie Bögen, die auf senkrecht zur Cuticulaoberfläche stehenden Ebenen in Reihen hintereinander liegen. 3. Die Porenkanäle haben die Gestalt von axial in sich verdrehten Bändern mit linsenförmigem Querschnitt, dessen Längsrichtung derjenigen der Mikrofasern folgt. Auf Schrägschnitten durch die Cuticulalamelle werden die Porenkanäle in verschiedener Höhe getroffen; deshalb lassen sich die Anschnitte verschiedener Kanäle auf gedachten Bogen anordnen, die denjenigen der Mikrofasern auf Schrägschnitten durch die Cuticula gleichen. Die Orientierung dieser Bogen ist in derselben Weise von der Schnittrichtung abhängig wie die der Mikrofaserbogen. In der Exocuticula lassen sich nicht alle Porenkanalanschnitte mit der Vorstellung des verdrillten Bandes und dessen Beziehung zur Mikrofaseranordnung vereinbaren. 4. Da die Lamellen des Tarsus Hohlzylinderform haben, sind die Mikrofasern, deren Verlaufsrichtung innerhalb einer Lamelle um 180° rotiert, auf koaxialen Helices variierender Ganghöhe angeordnet.
    Notes: Summary 1. The existence of microfibers in the cuticular lamellae of the spider leg (Cupiennius salei Keys.) is demonstrated. Two approaches were taken in the analysis of their architecture: a) An examination of the microfibers of the lamellae and the dependence of their course, as seen in electronmicrographs, on the angle of section through the cuticle, b) A study of the course and shape of the pore canals previously known to have some close relationship to microfiber arrangement. 2. All microfibers run roughly parallel to the cuticle surface; their orientation however gradually rotates through 180° within each lamella. Thus they do not form arches with constant orientation which would lie on planes perpendicular to the cuticle surface. 3. Pore canals form twisted bands. Throughout their length the longitudinal axis of their cross section remains parallel to the direction taken by the microfibers at any given level. In oblique sections through the lamellae the twisting pore canals are cut at different levels. Thus the band sections come to lie at intervals along imaginary arches, much the same as microfiber sections do when the cuticle is cut obliquely. The cutting angle has the same influence on the orientation of the arches formed by pore canal sections as it has on the arches from microfiber sections. In the exocuticle some sections of pore canals cannot be understood in terms of the twisted band concept. 4. Since the lamellae of the tarsus form a cylinder and because the orientation of the microfibers rotates, the microfibers are arranged in coaxial helices of continuously varying pitch.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 208 (1991), S. 91-98 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The results of volumetric measurements led Hanström ('28) to suggest that specialized neuropil in the brain, the so-called central body (CB), may be of particular importance in the nervous control of web building behavior in spiders. We compared the volumes of the various brain regions in four spider species clearly differing in lifestyle and web building behavior: an orb weaver (Nephila clavipes), a wandering spider (Cupiennius salei), a jumping spider (Phidippus regius), and a bird spider (Ephebopus sp.). Our results obtained in adult animals as well as our observations on the postembryonic development of the brain do not support Hanström's hypothesis. The relative share of the CB in the brain is very similar in all four species (ca. 3.1 to 5.1%). The differentiation of the CB into a clearly demarcated two-lobed structure does not coincide with the onset of web building behavior in Nephila. The CB of both Nephila and Cupiennius is already clearly recognizable in spiderlings which have not even left the egg sac.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 217 (1993), S. 129-136 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Central projections of lyriform organs and tactile hairs on the chelicerae of the wandering spider Cupiennius salei were traced using anterograde cobalt fills. Different fibers arising from both mechanoreceptor types arborize in the cheliceral ganglia, which are part of the tritocerebrum, and in sensory longitudinal tracts in the center of the suboesophageal nerve mass together with afferent fibers arising from mechanoreceptors on the walking legs and the pedipalps. This convergence of sensory projections in the sensory longitudinal tracts might provide the anatomical basis for the coordination of the movements of different extremities during prey capture and feeding. The findings also support the hypothesis that the tritocerebrum originally was a preoral ganglion in spiders. © 1993 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 209-227 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As in other arthropods the exoskeleton of arachnids is subjected to loads generated by external stimuli and behavioral activities. Far from being mere by-products of various activities such loads act as signals for mechanoreceptors capable of detecting minute displacements caused by them in the cuticle. In arachnids the slit sense organs serve in this capacity.Spiders have the most elaborate system of slit sense organs. Our previous studies clearly pointed to a functional significance of their specific location and orientation, as well as degree and type of aggregation (isolated, grouped, compound or lyriform) on respective body parts.The present study extends our work to the slit sense organs of scorpions. It gives a detailed account of the topography of the organs on the walking legs. In general slits are less orderly arranged on the legs of scorpions than on those of spiders. In the scorpion they never aggregate to form lyriform organs. Instead there are groups at comparable locations forming much more irregular, but still specific patterns. Isolated slits are more numerous on the scorpion leg, but are also less regularly distrubuted there. A common feature of the majority of slits on both the spider and the scorpion leg is their position on the lateral surfaces and their orientation roughly parallel to the long axis of the leg.
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