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Chadwick J Johnson - One of the best experts on this subject based on the ideXlab platform.
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precopulatory sexual cannibalism in fishing spiders Dolomedes triton a role for behavioral syndromes
Behavioral Ecology and Sociobiology, 2005Co-Authors: Chadwick J Johnson, Andrew SihAbstract:Precopulatory sexual cannibalism (predation of a potential mate prior to copulation) offers an extreme example of intersexual conflict, a current focus in behavioral ecology. The ‘aggressive-spillover’ hypothesis, posits that precopulatory sexual cannibalism may be a nonadaptive by-product of a general syndrome of voracity (aggression towards prey) that is expressed in multiple behavioral contexts. In this view, selection favoring high levels of voracity throughout ontogeny spills over to cause sexual cannibalism in adult females even when it is not necessarily beneficial. Using the North American fishing spider, Dolomedes triton, we present the first in depth test of this hypothesis. We found support for three aspects of the spillover hypothesis. First, voracity towards hetero-specific prey results in high feeding rates, large adult size, and increased fecundity. Second, juvenile and adult voracity are positively correlated (i.e., voracity is a consistent trait over ontogeny). Third, voracity towards hetero-specific prey is indeed positively correlated with precopulatory sexual cannibalism. Assays of antipredator behavior further revealed positive correlations between boldness towards predators, voracity and precopulatory sexual cannibalism. Overall, our results support the notion that precopulatory sexual cannibalism in D. triton is part of a behavioral syndrome spanning at least three major contexts: foraging, predator avoidance, and mating.
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Precopulatory sexual cannibalism in fishing spiders (Dolomedes triton): a role for behavioral syndromes
2005Co-Authors: Chadwick J JohnsonAbstract:Pre-copulatory sexual cannibalism (pre-SC), or predation of a potential mate before sperm transfer, provides an ideal model system for behavioral ecology’s current focus on inter-sexual conflict. Studying the North American fishing spider (Dolomedes triton), I tested three female-benefit hypotheses for pre-SC: indirect benefits, direct benefits, and aggressive spillover. First, pre-SC may reflect a mating bias providing females with ‘good-genes ’ benefits. By manipulating each female’s options with regard to the most cited phenotypic advantage in male spiders, body size, I show that while females exhibit no bias in their attack tendency on males of different body sizes, large males mate significantly more often than small males. Second, pre-SC may be explained by direct benefits if females use it as an adaptive foraging/mating trade-off. My work provides mixed support for this idea: (i) females vary attacks according to the availability of mates, (ii) females do not vary attacks according to the availability of food, and (iii) females derive discrete fecundity benefits from consuming a male. Finally, I tested the aggressive-spillover hypothesis, which posits that pre-SC is a by-product of selection for high levels of aggression towards prey in traditional foraging contexts. Path analysis indicated intra-individual, positive correlations between aggression in foraging contexts and the mating context
Robert B. Suter - One of the best experts on this subject based on the ideXlab platform.
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Journal of Insect
2016Co-Authors: Robert B. SuterAbstract:insectscience.org Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attack
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WATER SURFACE LOCOMOTION BY SPIDERS: DISTINCT GAITS IN DIVERSE FAMILIES
Journal of Arachnology, 2003Co-Authors: Robert B. Suter, Gail E. Stratton, Patricia R. MillerAbstract:Abstract Pisaurids such as Dolomedes triton (Walckenaer 1837) are well known as inhabitants of ponds and streams and are adept at locomotion on the water surface. In a broad survey of water surface locomotion in spiders, we have found that most taxa do not use specialized gaits under these circumstances. However, some tetragnathids, araneids, and salticids (three families that are outside of the superfamily Lycosoidea to which the pisaurids belong) resemble D. triton to the extent that they do use specialized gaits when on the water surface. Of these, the tetragnathids are particularly accomplished at water surface locomotion, achieving velocities that exceed those of D. triton when it rows, but not when it gallops.
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Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks
Journal of Insect Science, 2003Co-Authors: Robert B. SuterAbstract:Abstract Fishing spiders (Pisauridae) frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana) and green frogs (R. clamitans) on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances), rearing the legs nearest the attacking frog (N=15, 29.4%), or showing no visible response (N=7, 13.7%). Spiders that jumped always did so away (in the ...
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SPIDER SIZE AND LOCOMOTION ON THE WATER SURFACE (ARANEAE, PISAURIDAE)
Journal of Arachnology, 2000Co-Authors: Robert B. Suter, Jessica GruenwaldAbstract:Abstract Newly emerged fishing spiders, Dolomedes triton (Walckenaer 1837), can achieve rowing velocities as high as those of adults despite an approximately 600-fold difference in mass (1.7 mg vs. 1.1 g). In contrast, when velocity is measured in relative terms (body lengths/sec), small spiders move much more rapidly than adults, with Vrel ∝ mass−0.31. This surprising performance of very small spiders can be attributed both to their very high stride frequency (fs ∝ mass−0.43) and to the high angular velocity of their propulsive legs (ω ∝ mass−0.33). Calculations of leg tip velocities, based on measurements of both angular velocities and leg lengths, reveal that maximum leg tip velocities are achieved by spiders of about 33 mg, nineteen times more massive than the smallest spiders we tested. Some very small spiders perform conspicuously and consistently less well than do others of the same size. A detailed dissection of the motion of these underachievers reveals that a disproportionate amount of their row...
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PREDATOR AVOIDANCE ON THE WATER SURFACE? KINEMATICS AND EFFICACY OF VERTICAL JUMPING BY Dolomedes (ARANEAE, PISAURIDAE)
Journal of Arachnology, 2000Co-Authors: Robert B. Suter, Jessica GruenwaldAbstract:Abstract Vertical jumps of fishing spiders (Dolomedes sp.) from the water surface have been presumed to be evasive behaviors directed against predatory fish. We used high-speed videography to analyze the jumps of fishing spiders and then constructed a numerical model to assess the effectiveness of these jumps in evading predatory strikes by trout. Jump height (mean = 3.7 cm) and duration (mean = 0.17 sec) were similar across spider masses (0.05–0.66 g) but latency to jump increased significantly with mass. To accomplish jumps of similar height, more massive spiders had to generate more force during the propulsive phase of the jump than did smaller spiders; and the contribution of fluid drag to the total force used in jumping was substantially greater for large spiders than for smaller ones. Our model juxtaposing the jumps of spiders and the attacks of trout revealed that jump heights and durations were inadequate: only the most lethargic strikes by trout could be successfully evaded by jumping vertically ...
Eugene V. Grishin - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive analysis of the venom gland transcriptome of the spider Dolomedes fimbriatus
Scientific Data, 2014Co-Authors: Sergey A. Kozlov, Vassili N. Lazarev, Elena S. Kostryukova, Oksana V. Selezneva, Elena A. Ospanova, Dmitry G. Alexeev, Vadim M. Govorun, Eugene V. GrishinAbstract:A comprehensive transcriptome analysis of an expressed sequence tag (EST) database of the spider Dolomedes fimbriatus venom glands using single-residue distribution analysis (SRDA) identified 7,169 unique sequences. Mature chains of 163 different toxin-like polypeptides were predicted on the basis of well-established methodology. The number of protein precursors of these polypeptides was appreciably numerous than the number of mature polypeptides. A total of 451 different polypeptide precursors, translated from 795 unique nucleotide sequences, were deduced. A homology search divided the 163 mature polypeptide sequences into 16 superfamilies and 19 singletons. The number of mature toxins in a superfamily ranged from 2 to 49, whereas the diversity of the original nucleotide sequences was greater (2–261 variants). We observed a predominance of inhibitor cysteine knot toxin-like polypeptides among the cysteine-containing structures in the analyzed transcriptome bank. Uncommon spatial folds were also found. Design Type(s) Nucleic Acid Sequencing Measurement Type(s) transcription profiling assay Technology Type(s) Expressed Sequence Tag Factor Type(s) Sample Characteristic(s) Dolomedes fimbriatus • venom gland Machine-accessible metadata file describing the reported data (ISA-Tab format)
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Comprehensive analysis of the venom gland transcriptome of the spider Dolomedes fimbriatus.
Scientific data, 2014Co-Authors: Sergey A. Kozlov, Vassili N. Lazarev, Elena S. Kostryukova, Oksana V. Selezneva, Elena A. Ospanova, Dmitry G. Alexeev, Vadim M. Govorun, Eugene V. GrishinAbstract:A comprehensive transcriptome analysis of an expressed sequence tag (EST) database of the spider Dolomedes fimbriatus venom glands using single-residue distribution analysis (SRDA) identified 7,169 unique sequences. Mature chains of 163 different toxin-like polypeptides were predicted on the basis of well-established methodology. The number of protein precursors of these polypeptides was appreciably numerous than the number of mature polypeptides. A total of 451 different polypeptide precursors, translated from 795 unique nucleotide sequences, were deduced. A homology search divided the 163 mature polypeptide sequences into 16 superfamilies and 19 singletons. The number of mature toxins in a superfamily ranged from 2 to 49, whereas the diversity of the original nucleotide sequences was greater (2–261 variants). We observed a predominance of inhibitor cysteine knot toxin-like polypeptides among the cysteine-containing structures in the analyzed transcriptome bank. Uncommon spatial folds were also found.
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» Data processing
2014Co-Authors: Sergey A. Kozlov, Vassili N. Lazarev, Elena S. Kostryukova, Oksana V. Selezneva, Elena A. Ospanova, Dmitry G. Alexeev, Vadim M. Govorun, Eugene V. GrishinAbstract:A comprehensive transcriptome analysis of an expressed sequence tag (EST) database of the spider Dolomedes fimbriatus venom glands using single-residue distribution analysis (SRDA) identified 7,169 unique sequences. Mature chains of 163 different toxin-like polypeptides were predicted on the basis of well-established methodology. The number of protein precursors of these polypeptides was appreciably numerous than the number of mature polypeptides. A total of 451 different polypeptide precursors, translated from 795 unique nucleotide sequences, were deduced. A homology search divided the 163 mature polypeptide sequences into 16 superfamilies and 19 singletons. The number of mature toxins in a superfamily ranged from 2 to 49, whereas the diversity of the original nucleotide sequences was greater (2–261 variants). We observed a predominance of inhibitor cysteine knot toxin-like polypeptides among the cysteine-containing structures in the analyzed transcriptome bank. Uncommon spatial folds were also found
John R. Spence - One of the best experts on this subject based on the ideXlab platform.
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Abiotic conditions rather than resource availability cues determine aerial dispersal behaviour in spiderlings of Dolomedes triton (Araneae: Pisauridae)
Canadian Entomologist, 2013Co-Authors: Carol M. Frost, Alice K. Graham, John R. SpenceAbstract:Many species respond to risks and benefits of dispersal that vary over the short term through condition-dependent dispersal. We used wind tunnels to investigate how abiotic factors, spiderling age, and indicators of environmental quality affect aerial dispersal behaviour of spiderlings in Dolomedes triton (Walckenaer) (Araneae: Pisauridae), a denizen of temporary habitats. More than half of all spiderlings exhibited preballooning, ballooning, or spanning behaviours. Warm temperatures (>22.5 °C) and low wind speeds ( D. triton adopt a fixed strategy of high dispersal rate under optimal abiotic conditions, rather than reducing dispersal in response to cues about local food availability or conspecific density.
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HABITAT AFFINITIES OF SPIDERS LIVING NEAR A FRESHWATER POND
Journal of Arachnology, 2003Co-Authors: Alice K. Graham, Christopher M. Buddle, John R. SpenceAbstract:Habitat ranges of ground-dwelling spiders were studied by pitfall trapping in and around a freshwater pond during the spring and summer of 1998 in central Alberta, Canada. Sixty species from 14 families were collected, and catches of several species suggested distinct habitat affinities along tran- sects between the pond and adjacent terrestrial habitats. Variation in the catches of Pirata piraticus (Clerck 1757), Pardosa moesta Banks 1892, Pardosa fuscula (Thorell 1875), and immature Pirata species were partially explained by soil moisture at trap locations extending from the shore. We devised a ''floating'' pitfall trap that captured several species, including mature and immature Dolomedes triton (Walckenaer 1837), Pirata piraticus, and other immature Lycosidae, directly on the water surface. A DCA ordination revealed distinct spider assemblages were associated with three habitat types: 1) the water surface; 2) the moist habitats closely associated with the water's edge; and 3) the drier, terrestrial grassland habitats located .2 m from the shore. A new, more inclusive definition of semi-aquatic spiders was developed, based on knowledge about both male and female activity near the shore, and affinities towards soil moisture. Thus, Pirata piraticus, Dolomedes triton, and Pardosa fuscula were defined as semi-aquatic spiders.
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Phenology and life-cycle regulation of the fishing spider Dolomedes triton Walckenaer (Araneae, Pisauridae) in central Alberta
Canadian Journal of Zoology, 1998Co-Authors: Manfred Zimmermann, John R. SpenceAbstract:Dolomedes triton Walckenaer, a widespread and common fishing spider in North America, has a semivoltine life cycle in central Alberta, Canada. Juvenile spiders hibernate twice. According to evidence from laboratory rearings and patterns in field collections, the main overwintering stages are instars 3-5 and 9-11. After the second overwintering period, large juveniles moult once or twice to reach the reproductive adult stage. Juveniles grow rapidly between May and August but during overwintering between September and April, virtually no growth (measured as maximum carapace width of individuals) was observed in field populations. Dolomedes triton has a variable number of juvenile stages, ranging from 10 to 15 in males and from 9 to 15 in females. Both overwintering phases are facultative even though most individuals overwinter twice in central Alberta: at high temperatures (24-25°C) and under long-day conditions (either 18 h light : 6 h dark or 19 h light : 5 h dark) juveniles can develop directly to adults...
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Effects of food limitation and sexual cannibalism on reproductive output of the nuseryweb spider Dolomedes triton (Araneae : Pisauridae)
Oikos, 1996Co-Authors: John R. Spence, Manfred Zimmermann, Jack P. WojcickiAbstract:Reproductive output of free-ranging females of Dolomedes triton was not constrained by natural food limits in relation to that of sated spiders held in field cages. A two-year study revealed both seasonal and annual variation in egg number and egg-sac development time that was driven by factors other than food availability. There was a strong, positive correlation between egg numbers in first and second egg-sacs; some females produced three egg sacs under field conditions. In an experiment using field cages, reproductive output was affected by food availability to adults, female body size measured as carapace width, and by interaction between these two variables. Under both ambient field conditions and experimentally maintained satiation, fecundity increased linearly with carapace width. However, larger females failed to achieve their full, reproductive potential when food was scarce, although reproductive output of smaller females was unaffected. Females of D. triton allowed to feed on their mates did not show increased reproductive output or rate and thus do not receive any special nutrient supplements through sexual cannibalism.
Zhonghua Liu - One of the best experts on this subject based on the ideXlab platform.
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A Comparative Analysis of the Venom Gland Transcriptomes of the Fishing Spiders Dolomedes mizhoanus and Dolomedes sulfurous.
PloS one, 2015Co-Authors: Hengyun Wang, Fang Zhang, Songping Liang, Zhonghua LiuAbstract:Dolomedes sulfurous and Dolomedes mizhoanus are predaceous arthropods catching and feeding on small fish. They live in the same area and have similar habits. Their venoms exhibit some similarities and differences in biochemical and electrophysiological properties. In the present work, we first performed a transcriptomic analysis by constructing the venom gland cDNA library of D. sulfurous and 127 novel putative toxin sequences were consequently identified, which were classified into eight families. This venom gland transcriptome was then compared with that of D. mizhoanus, which revealed that the putative toxins from both spider venoms might have originated from the same gene ancestors although novel toxins were evolved independently in the two spiders. The putative toxins from both spiders contain 6–12 cysteine residues forming seven cysteine patterns. As revealed by blast search, the two venoms are rich in neurotoxins targeting ion channels with pharmacological and therapeutic significance. This study provides insight into the venoms of two closely related species of spider, which will be of use for future investigations into the structure and function of their toxins.
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A comparative study of the molecular composition and electrophysiological activity of the venoms from two fishing spiders Dolomedes mizhoanus and Dolomedes sulfurous.
Toxicon : official journal of the International Society on Toxinology, 2014Co-Authors: Fan Zhang, Hengyun Wang, Zhonghua Liu, Songping LiangAbstract:Abstract Dolomedes mizhoanus and Dolomedes sulfurous are two venomous spiders found in the same area in southern China and are characterized by living in water plants and feeding on fish. In this study, the chemical compositions and activities of these venoms were compared. Both venoms contain hundreds of peptides as shown by off-line RP-HPLC/MALDI-TOF-MS analysis, but have a different peptide distribution, with D. mizhoanus venom containing fewer high molecular mass (7000–9000 Da) peptides (3%) than D. sulfurous venom (25.6%). Patch-clamp analyses showed that both venoms inhibited voltage-activated Na+, K+ and Ca2+ channels in rat DRG neurons, however, differences in their inhibitory effects were observed. In general, D. mizhoanus venom had lower inhibitory activity than D. sulfurous venom and both venoms had a different inhibitory spectrum against these ion channels, showing that both venoms are useful for identifying antagonists to them. In addition, intrathoracic injection of both venoms caused severe neurotoxic effects in zebrafish and death at higher concentrations, respectively. Considering that both spiders belong to the same genus, live in the same area and have similar habits, elucidation of the differences between the peptide toxins from both venoms would provide new molecular insights into the evolution of spider peptides.