[1] Immature (3 mm, 3rd instar)  Phidippus audax apparently feeding on solid, crystalline exudate on the surface of a leaf.  This exudate may have been the result of leaf damage by insects, although some salticids (Pelegrina galathea) are known to bite into leaves directly.  Crouching was accompanied by pumping action of the opisthosoma, and this spider appeared to feed at multiple sites.  [D. E. Hill,  posted 28 AUG 2008]

[2] Large adult female Phidippus clarus (Salticidae) feeding on an adult female Acasesia hamata (Araneidae) in Greenville Co., SC, USA.  A. hamata is highly variable in color, and rests on leaves near the top of herbaceous plants during the day, usually facing toward the stem of the plant with legs held together tightly.  The P. clarus circled around to the rear of this A. hamata and then jumped it.  You can see the extended left fang of the clarus as it macerated the soft opisthosoma of its prey.   [D. E. Hill,  posted 05 SEP 2008]

[3] Two sequential views of an adult female Phidippus clarus (Salticidae) feeding on a brachyceran fly.  Left:  Inflated opisthosoma.  Right:  Deflated opisthosoma several seconds later, after regurgitation of digestive fluid into (and onto) the prey.  Note the maximal contraction at points of attachment of dorsal opisthosomal muscles (paired, dark spots bare of scales on dorsal opisthosoma).  There have been few studies of the spider feeding process.  In Phidippus,  regurgitation takes only a few seconds, and is followed by a much longer cycle of pumping and ingestion that inflates the opisthosoma.  This is one more example of hydrostatic opposition (opisthosomal inflation through rhythmic pumping action of prosomal sucking stomach) to muscular contraction (deflation through contraction of opisthosomal muscles) in spiders.  This also illustrates why, apart from its well-known role as a silk-spinning organ, the flexible volume of the opisthosoma also plays a critical role in the feeding process.  [D. E. Hill,  posted 12 SEP 2008]

[4] Four sequential views of an adult male Pelegrina galathea weaving a shelter between two leaves.  Note the tactile contact of the agile spinnerets with either framework silk lines or one of the leaf surfaces.  Salticid spinning is no less sophisticated than that of web spiders, and salticids use different silks for attachment, framework, and layered surface fabrics.  [D. E. Hill,  posted 16 SEP 2008]

[5] Four sequential views of an adult male Thiodina puerpera from Greenville County, SC, USA, preparing to jump.  After legs III and IV were positioned, the spider formed and attachment disk (1), then raised the opisthosoma and pulled out a short dragline (2).  This was followed by elevation of legs I and II (3 and 4).  View (4) shows the spider right before the jump.  [D. E. Hill,  posted 23 SEP 2008]

[6]  Adult female Thiodina sylvana from Greenville County, SC, USA, feeding on a thomisid spider.  T. sylvana will macerate the soft opisthosoma of spiders that it preys upon, but will also use a single leg, as shown here, like a soda straw, to suck out the remaining fluids in the prosoma and legs.  In this case the legs of the prey were semi-transparent, and it was possible to see fluid moving in both directions through the leg, into and out of the prosoma of the prey,  as this spider fed.   [D. E. Hill,  posted 24 SEP 2008]

[7]  Sequential positions during a series of alignment (ρ) turns by an adult female Thiodina sylvana from Greenville County, SC, USA, looking at an immobile thomisid spider.   Alignment is thought to facilitate depth perception in other animals, but may also be related to the effective use of the AME.  [D. E. Hill,  posted 28 SEP 2008]

[8]  Thiodina sylvana feeding on the thomisid spider sighted in [7].  This Thiodina used a nearby stem to slowly climb to the level of the thomisid.  The thomisid saw this approach and turned to flee.  At this point the Thiodina ran toward it and bit it in the rear of the carapace as shown here.  When viewed from the front, the AME of Thiodina change from black to deep red as the long pigmented tubes of the AME are moved within the prosoma,  [D. E. Hill,  posted 28 SEP 2008]

[9]  Adult female Thiodina sylvana, spinning and slowly turning as it surveyed its surroundings (Greenville County, SC, USA).  Note the silk ball spun by this spider (arrow), connected to a thick, woven silk fiber.  Most of the adult female T. sylvana that I have observed occasionally produced chains of these connected balls when walking slowly on a leaf or other surface.  They appear to consist of woven dragline silk, and their function is not known.  Is this advertisement, to males?  There are many other mysteries related to Thiodina, including the function of two pairs of bulbous setae on the underside of each leg I tibia (ventral and proximal with respect to two pairs of spines or macrosetae), in both sexes [D. E. Hill,  posted 03 OCT 2008]

[10]  Rearing adult male Phidippus princeps (Greenville County, SC, USA).  Rearing (sequence from left to right) involves the sudden (less than 0.05 s) extension of all legs (in place), presumably (in this case) to improve the field of view of the spider.  Rearing may also be observed in courting spiders, most likely either to increase the visibility of their display, or to give them a better view of the situation.  Crouching is the reverse of rearing, and a crouching salticid may also pull its legs in, close to the body, reducing its apparent size.  A single facing turn may include components of rearing, lateral (α) turns of the prosoma, dorso-ventral elevation (β) turns of the prosoma, alignment (ρ) by rotation of the mid-sagittal plane of the prosoma, and walking in any direction.  The components involved in a given facing turn depend greatly on the orientation of a salticid and the surface on which it rests, with respect to the subject.  Facing in a horizontal plane on a perfectly horizontal surface (most studied in the laboratory, but encountered less frequently in nature) involves primarily a lateral (α) component, with or without stepping depending on the angle subtended.  Facing in a horizontal plane on the side of a vertical stem consists primarily of walking and elevation (β) components, as the spider moves around the stem for a better view.   [D. E. Hill,  posted 03 OCT 2008]

[11]  Adult female Phidippus princeps (Greenville County, SC, USA) before (left) and after (right) completion of a turn in place, on a horizontal surface..  This turn included both lateral (α) and dorso-ventral (β) components.  As shown by this example, many of the smaller facing turns by salticids are completed by pivoting in place, without any stepping movements.  [D. E. Hill,  posted 09 OCT 2008]

[12]  Adult female Phidippus princeps (Greenville County, SC, USA) feeding on a nymph of the common assassin bug Zelus luridus (Heteroptera: Reduviidae: Harpactorinae).  If prey is not chemically defended, it is more likely that a Phidippus will hold it securely with legs I and II.  When prey is chemically defended or distasteful, a Phidippus may limit its direct contact, as shown here, and it may also drag that prey against a surface.  Most reduviid nymphs have dorsal abdominal glands, and Z. luridus nymphs and adults also secrete an adhesive from sticky glands on their legs to assist in the capture of their prey.  They can also deliver painful "bites" with their long beaks (visible here to the right of center).  This dangerous prey was captured and eaten from the rear, and its sticky legs were discarded.   [D. E. Hill,  posted 13 OCT 2008]

[13]  Six views of an adult female Pelegrina galathea (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA)  on blackberry (Rubus).  1,2:  Feeding from the surface of leaves in areas with no visible exudate.  The spider appeared to bite directly into the leaves, and liquid was visible pumping into and out of the spider's mouth.  3:  Here the spider appeared to be feeding on exudate on the surface of a leaf, possibly the result of recent feeding by aphids.  4:  The spider bit into the soft apical meristem of the plant with its chelicerae, and appeared to feed.  Note the presence of aphids that also exploit these soft plant tissues.  5,6:   The spider stalked (5) and then fed upon (6) one of the numerous aphids on this plant.  Some aphids have potent chemical defenses, and P. galathea generally minimized contact (legs I outstretched) when feeding on these.  [D. E. Hill,  posted 24 OCT 2008]

[14]  Adult male Zygoballus sexpunctatus (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA) resting within a specialized trichose leaflet near the stem of an unidentified herbaceous plant (note small yellow flowers).  Although small salticids frequently use rolled leaves for shelters, in this case the plant itself provided protective trichae around the leaf margins, within a folded leaf cup.  [D. E. Hill,  posted 24 OCT 2008]

[15]  Adult male Zygoballus sp. (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  These pictures illustrate how the appearance of iridescent (mixed violet, orange, and green in this case) opisthosomal scales varies with the angle of view and the direction of illumination (shiny at left, dark at right).  Zygoballus frequently wave legs I up and down as shown here, possibly in an effort to signal nearby conspecifics.  This may represent a form of Z. rufipes (bettini), but the few published descriptions of the physical appearance of this species are not consistent.  Note the small white scale patch on the posterior-lateral opisthosoma.  There was only a small patch of iridescent scales at the posterior midline of the carapace, otherwise the carapace and chelicerae were dark, without any scales.  [D. E. Hill,  posted 24 OCT 2008]

[16]  Four sequential frames of a male Zygoballus sexpunctatus, as it displayed to a nearby male of the same species (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  This spider alternately raised and lowered legs I as it pivoted from side to side.  Positions of legs II-IV on the leaf did not change during this sequence.  Note the extreme extension of pedipalps and chelicerae, and the depressed position of the vibrating opisthosoma.  [D. E. Hill,  posted 25 OCT 2008]

[17]  Adult female Zygoballus sexpunctatus, in a secure resting position near the stem of an herbaceous plant, facing an approaching heteropteran nymph.  Moments later, the spider fled as this potentially dangerous insect approached.  Resting positions like this allow a salticid to watch approaching insects and spiders, with no risk of an attack from the rear.  (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  [D. E. Hill,  posted 27 OCT 2008]

[18]  Four sequential frames (left to right) of an adult male Zygoballus sexpunctatus, crouching or pulling in its legs to reduce its visible profile in a resting position.  This sequence is reminiscent of the folding or retraction operation of a popular transformer toy.  (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  [D. E. Hill,  posted 27 OCT 2008]

[19]  Four sequential frames (1-4) of an adult female Zygoballus sexpunctatus at a vantage point near the top of an herbaceous plant.  One of the most interesting aspects of salticid behavior lies in their ability to multitask.  This alert salticid was waving legs I up and down in a visual display, at the same time that it successively groomed a leg with its mouthparts (1), cleaned its fangs with the pedipalps (2), cleaned the anterior surface of its chelicerae with its pedipalps (3), and groomed its right pedipalp with its chelicerae (4) (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  Distinctive, light blue facial scales are found on both males and females of this species.  The dark femora of legs I may impact the apparent size of these small spiders when viewed from the front  [D. E. Hill,  posted 27 OCT 2008]

[20]  Display of adult male to a mostly-concealed female female Zygoballus sexpunctatus  (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA).  This male spider began a protracted display (including movement of legs I and vibration of the opisthosoma) as soon as the yellow legs of the female appeared, as shown here.  There have been a number of studies of the reaction of salticids to frontal images of other salticids, but a limited view of movement or body parts, perhaps in association with vibration of the host plant, can also elicit courtship.  Contact with silk, or a previous sighting may have influenced this male's behavior, but display behavior was definitely elicited by the movement and limited appearance of the female in this case.   [D. E. Hill,  posted 27 OCT 2008]

[21]  Four sequential frames (1-4) of an adult female Zygoballus sexpunctatus (Araneae: Salticidae: Dendryphantinae, Greenville County, SC, USA), feeding on a mosquito (Diptera: Nematocera: Culicidae).  Many salticids routinely use the pedipalps and/or legs I or legs I-II to manipulate larger prey when feeding, but all legs can be used for this purpose.  Here the spider  first manipulates it prey with with 3 legs (1), then with 5 legs (2, note the repositioning of leg RIV), 6 legs (3), and finally with 7 legs (4).  Note the successive repositioning of the opisthosoma  to a vertical orientation to support the spider, in effect serving as an additional leg.   Coordinated use of multiple appendages by spiders is less stereotyped and much more versatile than many studies would suggest.  This kind of behavior appears to be more objective driven.  [D. E. Hill,  posted 27 OCT 2008]

[22]  Two sequential frames (left to right) depicting the mating behavior of Anasaitis canosa in Greenville County, SC, USA.  The first frame (left) shows how an increase of hydrostatic pressure in the prosoma inflated the inserted left bulb as it extended many of the macrosetae of the male.  Similar extension of male macrosetae during mating has been observed in both Lyssomanes and Phidippus (the latter to a lesser extent).  Extension of spines and bulb (left) was also associated with retraction of the chelicerae into the prosoma.  The extremely bright reflective scales on the pedipalp of the male are metallic white with light blue iridescence.   [D. E. Hill,  posted 24 NOV 2008]

[23]  Three frames in a sequence (left to right) showing completion of a single, rapid α facing turn by an adult male Pelegrina galathea in Greenville County, SC, USA.  Elapsed time is given for each frame.  In a study of the related Phidippus, each turn near 180^o invariably took the direction (clockwise or counterclockwise) that subtended the smallest angle. Here the spider turned counter-clockwise ~165^o instead of clockwise ~195^o, in less than 1/3 of a second.  [D. E. Hill,  posted 16 FEB 2009]