Jumping Spider

Although Jumping spiders look peaceful, they are active hunters that stalk and pursue prey until close enough to attack (Enders, 1975)[1]. They select prey on the basis of experience and seemingly they have a preference for slow moving prey (Gardner, 1964)[2]. Jumping spiders are poly-phagous meaning that they consume almost anything. Due to their complex eight eyes arranged in three rows, they possess an excellent vision, and where many spiders are nocturnal, Jumping spiders are diurnal.

Large Jumping Spiders such as Phidippus spp, which are found in North America, reach lengths of 8-15 mm. Jumpings spiders sometimes hunt in pairs, male and a female together, and during daytime. That relationship is sympatric meaning that it is mutually beneficial.

Their vision is important for catching the prey they pursue. According to several sources (Land 1969ab & Blest et al. 1990)[3,4] the spatial accuracy of Jumping spider's eyes is approaching that of large mammals.


Notice the prey in the back

Jumping kinematics

High-resolution video reveals the mechanism behind their jumps. In a study by Weihmann et al. (2010)[6] two distinctive types of jumps were discovered: prepared jumps and unprepared jumps. In the study they reduced the five joints (See drawing) to three joints.

The leg of a jumping spider - hand drawing

The conclusion was that a specific sequence of movements precluded prepared jumps. A part of the preparation was that the spiders placed their legs in a characteristic pattern where after they would lean back in a certain way, followed by a special acceleration phase [ibid].

Unprepared jumps occurred after disturbances. The jumps had no prelude and all jumps were away from the disturbance. These were unprepared and sometimes ended up in summersaults [ibid].

Apparently Jumping Spiders are capable of having a dragline ready even for unprepared jumps.

Jumping distances

In the above study, Jumping spiders could accomplish to traverse distances of approximate 35 cm (14 inch), or 43 times their own length during the jump. No other animal can jump that far compared to its own size.

Some jumping spiders display a "fly-catching" tactics – they just jump to clench onto something flying by.

Note In the video it says that they can jump 50 times their own length; studies show only 43 times.

Before they jump they tether a dragline in case something goes wrong during the jump.

Bimodal breathing system

Jumping spiders also breathe air in a special way, as they have a bimodal breathing system, where they depend on both a tracheal system and traditional book lungs. The tracheal system consist of four primary thick tracheae that branches into smaller secondary tracheae (Schmitz & Perry, 2001)[5].

Book lungs are responsible for the oxygen uptake in many spiders, whereas the tracheal system is mostly undeveloped in many species. However, the tracheal system functions fine in Jumping spiders. The advantage is that while both systems are necessary for the oxygen uptake in all parts of the spiders, the tracheal system offers extra accessible oxygen to areas strategically important – such as muscle with a high oxygen demand and the nervous system.

Preferred diet

Jumping spiders eats prey significantly smaller than itself. Average size's of prey is one fourth of the spider's own size, although it depends on the defensive capabilities of the prey. Soft and relative defenseless invertebrates such as flies are usually larger, and can be attacked without the same risk as more protected invertebrates.

Besides being poly-phageous they are cannibalistic. In a study (Nelson & 2009) it was shown that they prefer spiders over insects. In that study, Jumping spiders were the second most preferred spider species and that Jumping spiders are very selective in their choice of prey.

References

1. Gardner, B. T. 1964. Hunger and sequential responses in hunting behavior of salticid species. J. Comp. Physiol. Psychol. 58:164-173 (1964).
2. Enders, F., The Influence of Hunting Manner on Prey Size, Particularly in Spiders with Long Attack Distances (Araneidae, Linyphiidae, and Salticidae) The American Naturalist, Vol. 109 (970) pp. 737-763 (1975)
3a. Land, M.F. Structure of the retinae of the principal eyes of jumping spiders (Salticidae: Dendryphantinae) in relation to visual optics. J. Exp. Biol. 51, 443-470 (1969)
3b. Land, M. Movements of the retinae of jumping spiders (Salticidae: Dendryphantinae) in relation to visual optics. J. Exp. Biol. 51, 471-493. (1969)
4. Blest, A.D., O’Carroll, D.C. & Carter, M. Comparative ultrastructure of layer I receptor mosaics in the principal eyes of jumping spiders: the evolution of regular arrays of light guides. Cell Tissue Res. 262, 445-460 (1990)
5. Schmitz, A., Perry, S.F. Bimodal breathing in jumping spiders: morphometric partitioning of the lungs and tracheae in Salticus scenicus (Arachnida, Araneae, Salticidae) The Journal of Experimental Biology 204, 4321-4334 (2001)
6. WeihmannTom Weihmann, T., Karner, M., Full, R.J., Blickhan, R. Jumping kinematics in the wandering spider Cupiennius salei Journal of Comp Physiology A 196 pp. 421-438 (2010)

Jumping spider links

Jumping S. (The Piedpiper)
Salticidae
Jumping S. (USA/Canada)
French Jumping Spiders
J.S. link collection
Jumpings Spiders Canada