scholarly journals Spectral Sensitivities of Wolf Spider Eyes

1969 ◽  
Vol 54 (1) ◽  
pp. 1-32 ◽  
Author(s):  
Robert D. DeVoe ◽  
Ralph J. W. Small ◽  
Janis E. Zvargulis
Keyword(s):  
Energy Transfer ◽  
Visual Pigment ◽  
Scattered Light ◽  
Wolf Spider ◽  
Relative Sensitivity ◽  
Wolf Spiders ◽  
Absolute Sensitivity ◽  
Radiationless Energy Transfer ◽  
Accessory Pigment

ERG's to spectral lights were recorded from all eyes of intact wolf spiders. Secondary eyes have maximum relative sensitivities at 505–510 nm which are unchanged by chromatic adaptations. Principal eyes have ultraviolet sensitivities which are 10 to 100 times greater at 380 nm than at 505 nm. However, two animals' eyes initially had greater blue-green sensitivities, then in 7 to 10 wk dropped 4 to 6 log units in absolute sensitivity in the visible, less in the ultraviolet. Chromatic adaptations of both types of principal eyes hardly changed relative spectral sensitivities. Small decreases in relative sensitivity in the visible with orange adaptations were possibly retinomotor in origin. Second peaks in ERG waveforms were elicited from ultraviolet-adapted principal eyes by wavelengths 400 nm and longer, and from blue-, yellow-, and orange-adapted secondary eyes by wavelengths 580 nm and longer. The second peaks in waveforms were most likely responses of unilluminated eyes to scattered light. It is concluded that both principal and secondary eyes contain cells with a visual pigment absorbing maximally at 505–510 nm. The variable absolute and ultraviolet sensitivities of principal eyes may be due to a second pigment in the same cells or to an ultraviolet-absorbing accessory pigment which excites the 505 nm absorbing visual pigment by radiationless energy transfer.

Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada

2012 ◽  
Vol 90 (6) ◽  
pp. 714-721 ◽  
Author(s):  
J.J. Bowden ◽  
C.M. Buddle
Keyword(s):  
Reproductive Effort ◽  
Abiotic Factors ◽  
Wolf Spider ◽  
Local Variation ◽  
Yukon Territory ◽  
The Arctic ◽  
Wolf Spiders ◽  
Female Body Size ◽  
Trade Offs ◽  
History Of

We studied populations of three tundra-dwelling wolf spider (Lycosidae) species to determine reproductive trait relationships and developmental timing in the Arctic. We collected 451 Pardosa lapponica (Thorell, 1872), 176 Pardosa sodalis Holm, 1970, and 117 Pardosa moesta Banks, 1892 during summer 2008. We used log-likelihood ratio tests and multiple linear regressions to determine the best predictors of fecundity and relative reproductive effort. Female body size best explained the variation in fecundity and body condition was the best predictor for relative reproductive effort. We tested for a trade-off between the allocation of resources to individual eggs and the number of eggs produced (fecundity) within each species using linear regression. There was variation in detectable egg size and number trade-offs among sites and these may be related to local variation in resource allocation linked to density-related biotic or abiotic factors. These findings contribute to knowledge about the fitness of arctic wolf spiders in the region of study and are particularly relevant in light of the effects that climate changes are predicted to have on the arctic fauna.

Reproductive isolation and sex-role reversal in two sympatric sand-dwelling wolf spiders of the genus Allocosa

2008 ◽  
Vol 86 (7) ◽  
pp. 648-658 ◽  
Author(s):  
A. Aisenberg ◽  
F. G. Costa
Keyword(s):  
Reproductive Isolation ◽  
Sexual Size Dimorphism ◽  
Sex Role ◽  
Wolf Spider ◽  
Coastal Dunes ◽  
Pitfall Trap ◽  
Role Reversal ◽  
Adult Size ◽  
Wolf Spiders ◽  
Size Dimorphism

Allocosa brasiliensis (Petrunkevitch, 1910) is a nocturnal wolf spider inhabitant of coastal dunes. Pitfall-trap data suggested the occurrence of two sympatric and synchronic morphs, with differences in adult size and abdominal design (minor and major morphs). Previous studies performed with the major morph of A. brasiliensis, postulated courtship-role and sexual size dimorphism reversal for this spider. In the present study, we compare data on development and morphology and test reproductive isolation between morphs of A. brasiliensis, with the hypotheses that the two morphs are reproductively isolated and both show courtship-role reversal. As had been reported for the major morph of A. brasiliensis, the minor-morph females approached the burrows of minor-morph males, entered, initiated courtship, and after copulation, males closed their burrows with female cooperation from the inside. Females did not court or copulate with males belonging to the other morph and, in two cases, major-morph females cannibalised minor-morph males. Morphometrical and developmental data showed differences between morphs. The occurrence of copulation only between individuals of the same morph confirm reproductive isolation, supporting the occurrence of two species. Morphological and behavioural data are consistent with courtship-role-reversal hypotheses for the minor morph, constituting the second report in spiders of this atypical behaviour.

Locomotion in Burrowing and Vagrant Wolf Spiders (Lycosidae)

1981 ◽  
Vol 92 (1) ◽  
pp. 305-321 ◽  
Author(s):  
T. M. WARD ◽  
W. F. HUMPHREYS
Keyword(s):  
Wolf Spider ◽  
The Body ◽  
Power Stroke ◽  
Phase Lag ◽  
Running Speed ◽  
Wolf Spiders ◽  
High Speeds ◽  
Phase Lags ◽  
The Relationship

Locomotion in the vagrant wolf spider Trochosa ruricola is compared to that in the burrow dwelling wolf spider Lycosa tarentula (Araneae: Lycosidae). L. tarentula takes relatively shorter steps than T. ruricola. At high speeds T. ruricola approximates an alternating tetrapod gait but this does not occur in L. tarentula. Phase lag differs between species and varies marginally with speed except for ipsilateral phase lags in L. tarentula which are erratic if they include leg 1. In both species the protraction/retraction ratio is directly related to both running speed and stepping frequency, but the relationship is more marked in L. tarentula. The protraction/retraction ratio is more variable in leg 1 and varies between legs along the body but by a greater amount in L. tarentula. In these spiders, in contrast to the situation in many insects, both the duration of protraction and retraction show marked inverse relationships to stepping frequency. The power stroke (retraction) occupies a variable proportion of the stepping cycle, which is not the case in other spiders, and this proportion is lower than for other spiders. It is suggested that the first pair of legs is used more for sensory than for locomotory purpose and that this is more marked in the burrow dwelling species, L. tarentula.

scholarly journals Spiders by Night: An Outdoor Investigation Integrating Next Generation Science Standards

2019 ◽  
Vol 81 (8) ◽  
pp. 561-567
Author(s):  
Kathryn S. Craven ◽  
Alex Collier ◽  
Jay Y. S. Hodgson
Keyword(s):  
Wolf Spider ◽  
Field Investigation ◽  
Next Generation Science Standards ◽  
Laboratory Instruction ◽  
Next Generation ◽  
Science Standards ◽  
Natural Habitats ◽  
Wolf Spiders ◽  
Field Investigations ◽  
History Of

Field investigations represent an excellent opportunity to integrate the Next Generation Science Standards to complement and enhance both classroom and laboratory instruction. This inquiry-based exercise is designed to introduce students to the basic anatomy, ecology, and natural history of a common backyard denizen, the wolf spider (Lycosidae). Students are charged with developing one or more testable hypotheses regarding wolf spiders in their own backyards. Wolf spiders are an ideal subject for field investigation because their secondary eyes possess a highly reflective layer called the tapetum lucidum. At night, this layer produces an unmistakable “eyeshine” when viewed with the beam of a flashlight. Playing the role of students, we tested the hypothesis that wolf spiders should occur at higher density in an undeveloped field than in a typical backyard. To test this, we utilized random quadrat sampling in both habitats using flashlights to detect nocturnal eyeshine. Students obtaining similar results would likely have concluded that wolf spiders were more abundant in natural habitats.

scholarly journals Proteotranscriptomic Insights into the Venom Composition of the Wolf Spider Lycosa tarantula

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 501
Author(s):  
Dominique Koua ◽  
Rosanna Mary ◽  
Anicet Ebou ◽  
Celia Barrachina ◽  
Khadija El Koulali ◽  
...  
Keyword(s):  
Prey Capture ◽  
Wolf Spider ◽  
Secretory Proteins ◽  
Crude Venom ◽  
Wolf Spiders ◽  
Original Source ◽  
Venom Composition ◽  
Venom Glands ◽  
Ambush Predators ◽  
Venom Proteins

Spider venoms represent an original source of novel compounds with therapeutic and agrochemical potential. Whereas most of the research efforts have focused on large mygalomorph spiders, araneomorph spiders are equally promising but require more sensitive and sophisticated approaches given their limited size and reduced venom yield. Belonging to the latter group, the genus Lycosa (“wolf spiders”) contains many species widely distributed throughout the world. These spiders are ambush predators that do not build webs but instead rely strongly on their venom for prey capture. Lycosa tarantula is one of the largest species of wolf spider, but its venom composition is unknown. Using a combination of RNA sequencing of the venom glands and venom proteomics, we provide the first overview of the peptides and proteins produced by this iconic Mediterranean spider. Beside the typical small disulfide rich neurotoxins, several families of proteins were also identified, including cysteine-rich secretory proteins (CRISP) and Hyaluronidases. Proteomic analysis of the electrically stimulated venom validated 30 of these transcriptomic sequences, including nine putative neurotoxins and eight venom proteins. Interestingly, LC-MS venom profiles of manual versus electric stimulation, as well as female versus male, showed some marked differences in mass distribution. Finally, we also present some preliminary data on the biological activity of L. tarantula crude venom.

Elektronenanregungsenergieiibergang zwischen ungleichartigen Molekiilen in Losung / Electronic Excitation Energy Transition among unlike Molecules in Solution

1977 ◽  
Vol 32 (2) ◽  
pp. 140-143 ◽  
Author(s):  
J. Kamiński ◽  
A. Kawski
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Excitation Energy Transfer ◽  
Energy Transition ◽  
Mutual Orientation ◽  
Resonance Excitation ◽  
Electronic Excitation Energy ◽  
Radiationless Energy Transfer ◽  
Donor And Acceptor ◽  
Acceptor Molecules

In studying the radiationless energy transfer between unlike molecules (heterotransfer) in fluid and rigid solutions the fluctuations of the concentration of the acceptor molecules, as well as the dependence of the probability of resonance excitation energy transfer on the mutual orientation of the transition moments of the interacting donor and acceptor molecules have been taken into account. With these and the assumptions of the shell model of a luminescent centre (A. Kawski and J. Kaminski, Z. Naturforsch. 29 a, 452 [1974]) one obtains the Förster expression for the quantum yield of the donor fluorescence quenched by foreign absorbing substances

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