SUPPLEMENTARY MATERIAL Journal of Zoology

Recluse spiders produce flattened silk rapidly using a highly modified, self-sufficient spinning apparatus Ivan L. F. Magalhaes, Alexandra M. Ravelo, Cristina L. Scioscia, Alfredo V. Peretti, Peter Michalik & Martín J. Ramírez

Movie S1. Movie of an adult female Loxosceles laeta spinning its web while allowed to move freely in a Petri dish (24 frames per second). Movie S2. Close-up movie of the spinnerets of an adult female Loxosceles laeta while spinning its silk at normal speed (60 frames per second); the specimen was being held in a glass tube so only the abdomen was free to move. Movie S3. Close-up movie of the spinnerets of Loxosceles laeta while spinning its silk with speed reduced to 20% (this is modified from Movie S2; originally filmed at 60 frames per second, reduced to 12 frames per second). Movie S4. Close-up movie of the spinnerets of an adult female Loxosceles laeta who had the modified setae from the posterior spinnerets experimentally removed with fine forceps; the specimen was being held in a glass tube so only the abdomen was free to move. Movie S5. 3D reconstruction of a micro-CT scan of the muscles associated to the spinnerets of an adult male Loxosceles laeta. Colours correspond to those in Fig. 4. Movie S6. 3D reconstruction of a micro-CT scan of the muscles associated to the spinnerets of an adult female Scytodes globula. Colours correspond to those in Fig. 4.

Figure S1. Dissections on fresh specimens (except B, fixed in 80% ethanol) showing muscles associated to spinnerets in dorsal view. A. Segestria floretina (Segestriidae), adult male. B. Pholcus phalangioides (Pholcidae), adult female. C. Sicarius levii (Sicariidae), adult female. D. Loxosceles laeta, immature. See text for abbreviations.

Figure S2. Scanning electron microscopy images of the internal apodemes associated to the spinnerets of an adult male Loxosceles laeta (A–B) and an adult female Scytodes globula (C–D). Arrow to sclerotized region of the diastema, where the lms probably attach to.

Figure S3. Scanning electron microscopy of silk strands spun by a female Loxosceles simillima from Ndumo Game Reserve, Kwazulu-Natal, South Africa.