A HOLDING DEVICE FOR LIVE SPIDERS

Short communication

A HOLDING DEVICE FOR LIVE SPIDERS

E. N. RAMIRES

1 School of Biological Sciences, Tuiutí University of Paraná, State of Paraná, Brasil.

ABSTRACT. This paper describes a new restraining device for live spiders. This device is recommended for reducing or eliminating contact between the handler and potentially dangerous spiders, as well as to avoid serious injury to the specimens.

KEY WORDS: Loxosceles; Phoneutria; venom extraction; Scytodes; spiders; venomous spiders.

INTRODUCTION

Descriptions of several different types of apparatus for restraining live spiders, with or without anesthesia, are available in literature. These were designed for the examination and measurement of spiders (3,4,6), and for venom milking (1,2) and surgical procedures (5).

While studying the behavior and ecology of brown spiders (Loxosceles spp.), the author designed and built a simple low cost device for live spiders that can be used for all the above mentioned procedures.

The device (Figure 1) was built by modifying a simple plastic pippetor (cutting its bottom cover) and attaching some other components to it. Two parallel pins were inserted at the end of the piston of the pipettor. A piece of soft rubber with a trapezoidal cross section, against which the pins press, was attached to the body of the pipettor, and rubber bands attached to the piston and body of the pipettor (Figure 1b).

FIGURE 1.
Diagram of the holding device for spiders: a) side view with the restrained spider; b) main components.

To use this device the piston of the pipettor should be pressed, keeping the pins at a distance of 1 cm or more from the soft rubber. The two pins must be carefully placed in line with the spider's body, one at each side of the carapace, below the basal segments of the legs, avoiding contact with the specimen. It is better to begin the location of the pins from the abdomen end to minimize the possibility of spider movements. After placing the pins as described above, the piston should be released. Then, the rubber bands cause an upward movement of the piston, pressing the pins against the soft rubber and holding the spider by the legs, exposing the ventral side (externum) (Figure 1a).

Pairs of pins and rubber of several dimensions can be made to examine spiders of different sizes. The distance between the pins should be a little wider than the carapace width of the restrained spider. The pressure exerted by the pins against the soft rubber should be only that necessary for the restrain of the spider, avoiding injury to the specimen.

Spitting spiders (Scytodes globula Nicolet) were easily restrained without anesthesia after some practice. In nearly all cases with L. intermedia, Mello-Leitão, and sometimes with Loxoceles gaucho, Gertsch, low temperatures or CO2 had to be used to reduce the specimen's activity prior to restraint. The spiders in this condition can be held in a reverse position as well, exposing their dorsal side (carapace).

To avoid anesthesia the spiders can be induced to walk over a surface covered with adhesive tape. Their legs become attached to the adhesive tape, facilitating in the capture with the device. Some specimens, however, can autotomize their legs.

Four females of each of the three above species were restrained for five hours, without any apparent damage to the specimens, even several days after release.

This device permits the examination of spiders under a stereomicroscope, which can be useful to carefully examine the venom milking by electric shock, avoiding possible contamination by other body fluids. Direct bites can easily be induced and closely observed. It is also useful in restraining very aggressive and/or large spiders, such as Phoneutria nigriventer Keyserling, or other large ctenids after anesthesia (CO2, low temperatures), avoiding the risk of accidents due to recovery from anesthesia during venom milking and/or examination.

ACKNOWLEDGEMENTS

I am grateful to Antonio D. Brescovit (Butantan Institute) for the identification of Scytodes globula, and Manuel Machado da Cunha Neto for the drawings of the device.

REFERENCES

01 SELIGY VL. A method for studying spiders at various stages of development. Can. J. Zool., 1970, 48, 406-7.

02 RANDALL JB. An apparatus for the observation of living immature and small adult spiders. Florida Entomol., 1978, 6, 192.

03 OXFORD GS. An easily constructed holding device for the examination of live spiders. Bull. Br. Arachnol. Soc., 1981, 5, 278-9.

04 GROTHAUS RH., HOWELL DE. A new technique for the recovery of spider venom. J. Kansas Entomol. Soc., 1967, 40, 37-41.

05 BASCUR L. YEVENES I., ADRIAN H. An electric method to obtain Loxosceles spider venom. Toxicon, 1980, 18, 224.

06 RANDALL JB. Surgical restraint apparatus for living spiders. J. Arachnol., 1982, 10, 91.

Received 22 July 1998

Accepted 07 January 1999

CORRESPONDENCE TO:

E. N. RAMIRES, UTP, Faculdade de Ciências Biológicas, Rua Marcelino Champagnat, nº 500, 80710-250, Curitiba, PR, Brasil.

Publication Dates

• Publication in this collection
  17 Sept 1999
• Date of issue
  1999

History

• Received
  22 July 1998
• Accepted
  07 Jan 1999