Spectral sensitivity in jumping spiders (Araneae, Salticidae)

SUMMARYUltraviolet (UV) vision plays an important role in interspecific and intraspecific communication in many animals. However, UV vision and its adaptive significance have been investigated in only approximately 1% of more than 5000 species of jumping spiders (Araneae: Salticidae), renowned for their unique, complex eyes that support exceptional spatial acuity and visually based behaviour. To appreciate the adaptive significance of UV vision, it is important to establish whether salticids can perceive UV and whether the perception of UV varies with ecological factors such as light environment. In this study, we measured the UVtransmission properties of the principal-eye corneas of 128 salticid species. We found that the corneas of all measured species were able to transmit UV light, making the perception of UV possible. Three classes of corneal spectral transmission curves were identified; the majority of species had a Class II curve with a less-steep slope and a gradual onset of the transmission cut-off; all the remaining species had a Class I curve with a very steep slope and a sharp cut-off except for one species that had a Class III curve with an intermediate step, which appeared as a shoulder on the descending part of the transmission curve. The T 50 cut-off transmission values (the wavelength at which 50% of the maximum transmission is reached) in salticid corneas vary with species and light habitat. The corneas of species inhabiting open bush had a higher relative transmission at short wavelengths in the UV than forest species. This is the first investigation of corneal transmission in spiders and suggests that UV perception is widespread in salticids.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spectral transmission of the principal-eye corneas of jumping spiders: implications for ultraviolet vision

et al. 2012

“…Up to four different types of photoreceptors were found in salticids (Land, 1969;De Voe, 1975;Yamashita and Tateda, 1976;Blest et al, 1981), leading to a broad spectral sensitivity from 330nm up to 700nm (Peaslee and Wilson, 1989). Colour vision abilities were investigated in simple behavioural experiments where coloured stripes could be discriminated (Kästner, 1950), and in a more elaborate heat-avoidance learning test the animals could discriminate the colours blue, green, yellow and red (Nakamura and Yamashita, 2000).…”

Section: Introductionmentioning

confidence: 99%

Colour blindness of the movement-detecting system of the spider Cupiennius salei

Orlando

Schmid

2011

SUMMARYThe nocturnal wandering spider Cupiennius salei has one pair of principal eyes and three pairs of secondary eyes located on the prosoma, which differ in both morphology and function. Their spectral sensitivity, measured with intracellular recordings, is due to three different types of photoreceptors with absorbance maxima in the mid-range of the spectrum, at 480nm and 520nm and in the UV at 360nm. Based on these physiological data colour vision might be possible. In the present study, the ability to discriminate coloured moving stimuli from grey backgrounds was tested. The perception of moving coloured stripes in front of backgrounds with 29 different grey levels was measured by using extracellular recordings from the anterior median eye muscles as a monitoring system. Each of these eyes has two muscles, which increase their activity when moving stimuli are presented in front of a secondary eye. This variation in eye muscle activity can be recorded extracellulary in a living spider using a single channel telemetry device. If colour perception exists, the animal should be able to detect a moving coloured stripe in front of any grey level. Blue, green and red stripes were used as moving stimuli, in front of all 29 grey backgrounds. The results indicate that C. salei is not able to discriminate the coloured stimuli from distinct shades of grey. It is therefore evident that the movementdetecting system in this spider appears to be colour blind.

“…Their anterior median eyes are adapted for both high spatial resolution (Eakin and Brandenburger, 1971) and for color vision (DeVoe, 1975;Land, 1969a;Land, 1969b;Land, 1985;Peaslee and Wilson, 1989). These eyes, in combination with three pairs of motion-detecting eyes, result in the most highly developed visual system in spiders (Land, 1985).…”

Section: Introductionmentioning

confidence: 99%

Cross-modal effects on learning: a seismic stimulus improves color discrimination learning in a jumping spider

VanderSal

Hebets

2007

SUMMARY The production of multimodal signals during animal displays is extremely common, and the function of such complex signaling has received much attention. Currently, the most frequently explored hypotheses regarding the evolution and function of complex signaling focus on the signal and/or signaler, or the signaling environment, while much less attention has been placed on the receivers. However, recent studies using vertebrates suggest that receiver psychology (e.g. learning and memory) may play a large role in the evolution of complex signaling. To date, the influence of multimodal cues on receiver learning and/or memory has not been studied in invertebrates. Here, we test the hypothesis that the presence of a seismic (vibratory)stimulus improves color discrimination learning in the jumping spider Habronattus dossenus. Using a heat-aversion learning experiment, we found evidence for a cross-modal effect on color learning. Over a series of training trials, individuals exposed to a seismic stimulus jumped onto the heated color less frequently and remained there for less time than did individuals not exposed to a seismic stimulus. In addition, in a final no-heat test trial, individuals from the seismic-present treatment were more likely to avoid the previously heated color than were individuals from the seismic-absent treatment. This is the first study to demonstrate a cross-modal influence on learning in an invertebrate.