Tarantulas in the Classroom Charles B. Buckel HammondCentral School Hammond,New York13646 Large, hairy spiders, such as the Tarantulas can be long-lived; into the seminal 'receptacles of the Huntsmen, Wolf, and Trapdoor females have a maximum life span of female. The particularly large pedi- spiders, have always captured the twenty years. Males can be distin- palps make it appear that the taran- attention of arachnid enthusiasts guished from females by the chit- tula has ten walking legs rather than and others as well; but none is as inous extensions of the pedipalps the conventional eight. celebrated -as the tarantula. Most of (feeding legs) used to insert semen Tarantulasare excellent specimens the tarantulas native to the arid to use in the study of arachnid be- American Southwest belong to the havior in the classroom. A small Downloaded from http://online.ucpress.edu/abt/article-pdf/43/3/161/38947/4447192.pdf by guest on 27 September 2021 genera, Avicularia, Dugesiella, or terrariumwith 3 to 5 cm of fine sand Aphonopelma; this group includes is an ideal tarantula habitat (fig. 1). about thirty species. 'Tarantula," A piece of light driftwood under however, refers specifically to spiders which the spider can burrow pro- of the genus, Lycosa, such as Lycosa vides a necessary 'alcove 'to this tarantula, (the European Wolf nocturnal animal. A screened open- Spider). The suspicion and fear ing allows water to evaporate and surrounding these animals has been keeps the humidity low. We modi- reinforced by Hollywood and folk- fied a terrarium using transparent lore. Their bite, popularly believed tape and a small (5-by-5 cm) piece to cause everything from agonizing of aluminum screening (fig. 2).,A lid death to 'tarantism" (the irresistable for the terrariumis essential and must desire to dance) is actually no more ........ be repositioned following each open- harmful than a wasp sting to most ing for feeding or observation be- humans. As with any animal bites, . ..... _... -- ---- cause tarantu,las have no difficulty however, infection, hypeprallergy,and walking up the glass walls, other side effects are possible. Simi- A small dish filled with 1 cm of larly, the jumping abilities of the water will provide adequate mois- tarantula are often highly exagger- ture. Water should be changed ated, though some can pounce on FIGURE 1. Terrariumadapted to the needs of periodically to remove sand, debris, nearby prey. the tarantula. and excrement. Tarantulas do well ... .... .... g ~ ~ i~. .1 ~~~~~~~~~~.0. .. ....... FIGURE 2. A small -piece of window screen helps to dehumidify the FIGURE3: Tarantulaand discardedcuticle aftermoltihg. environment. TEACfHER-TO.TEACHER 161 on a diet of live insects such as crick- 9nl s-i are fed. Unless food is dropped near- ets; a more economical alternative by, it will not be eaten until it is found is to provide mealworms (Tenebrio). later as the spider wanders about A culture of Tenebrio can be easily the habitat. Tarantulas, like most maintained in the classroom (Best arachnids, use body hairs to detect 1978). Tarantulas will accept either vibrations and air currents. They larval or adult forms. One insect a soon become conditioned to "feed- day is ordinarily sufficient, but stu- ing time" activities and assume a dents soon learn that the spider's more aggressive posture at that time. hunger is related to its activity level. Like most arthropods, tarantulas Like most poikilotherms,feeding and molt their exoskeletons to accom - activity decrease dramatically as modate growth. Prior to molting temperatures drop. (Weekend drops (which seems to occur somewhat in buildingtemperatures do not seem less than annually depending on the to affect them adversely, however). rate of growth relative to that speci- Though not usually considered ...................... men), the condition of the existing Downloaded from http://online.ucpress.edu/abt/article-pdf/43/3/161/38947/4447192.pdf by guest on 27 September 2021 web spinners, tarantulas may pro- exoskeleton will deteriorate signifi- duce trap or drag lines along the cantly until the spider seems to be in surface of the sand (the spinneretts poor health. This state is character- for this purpose can be seen pro- ized by the loss of most abdominal FIGURE 4. Tarantula climbing the glass walls truding from the posterior portion of the terrarium. hairs and a dramatic lightening of of the abdomen) that help some color. At this time, and for as long as tarantula species detect intruders or two months later, the spider will prey; some species use the spin- This toxin, however, should be dis- accept no food and its activity level nerets to construct egg cases as well. tinguished from the highly neuro- decreases. The animal becomes Our experience has been that trap- toxic poisons of spiders such as the markedly more timid, partially due lines collect moisture and debris BlackWidow (Latrodectusmactans), to loss of vision as the new cuticle is that tend to foul the habitat. They which are known to be fatal to forming. When molting actually should, therefore, be removed every humans. Food is predigested in the begins, a circular split in the dorsal two to three weeks with forceps. mouth region, and the liquified carapace occurs, and the spider Though most spiders are car- tissue is sucked in through the withdraws. Its legs are the last body nivorous, their method of ingesting pharynx. Spiders can endure long parts to emerge from the discarded food varies. Tarantulas use the fang- periods of food deprivation, especi- cuticle. Students can readily observe like extensions of their jaws (chilicera) ally at lower temperatures. that the discarded cuticle is a dupli- to inject digestive juices into or onto Most spiders have four pairs of cate of the spider and includes the their prey. The toxin, which is largely eyes. The largest of these are clearly formidable mouth parts (fig. 3). hemolytic, may cause some inflam- visible on the dorsal surface. The Observing the emergence of a vel- matory response and tissue damage absence of good visual acuity be- vety. black spider is a rewarding in the immediate area of the bite. comes apparent when these animals experience for students. Molting ...............................1 ................... ...... ;:....: FIGURE 5 Note the enlarged feeding legs (pedipalps) and closely FIGURE 6. Handling is not recommended. but the spiders have little spaced pairs of simple eyes. reason for biting. 162 THE AMERICAN BIOLOGY TEACHER, VOLUME43, NO. 3, MARCH 1981 requires from two to five hours and soon thereafter, normal behavior is Why Leaves Turn Color: resumed. At maturity, molting ceases in the males of the species. A Laboratory Model for Because of their cannibalistic and territorialnature, tarantulas must be Hypothesis Formation housed in separate containers. They are also difficult to breed and rear; thus, I do not advise that teachers attempt to do so. Stephen D. Klein There are some inherent dangers ShenendohawaHigh School in working with tarantulas, but stu- CliftonPark, New York12065 dents do learn to respect and appre- ciate spiders in this carefully control- led classroom experience. If this Many tenth grade students enter 1. "The other colors weren't there helps dispell the unwarranted fears our college preparatory biology before";or Downloaded from http://online.ucpress.edu/abt/article-pdf/43/3/161/38947/4447192.pdf by guest on 27 September 2021 and misconceptions surrounding course (N.Y.S. Regents Syllabus) 2. 'The other colors were hidden these creatures and similar forms of lacking the ability to formulate by the green." animal life, then it is well worth the hypotheses necessary for designing I write the two types of student re- effort. and conducting controlled experi- sponses on the chalkboard in the ments. Students do, however, show form of hypotheses as follows: great curiosity about natural occur- l. Leaves turn color in *the fall rences. For several years, I have used because new substance (s) [pigments] their curiosity in a controlled labora- are produced at this time of year. tory activity on aging of leaves that 2. Leaves turn color in the fall gives the students an opportunity to because chlorophyll breaks down, observe, question, and formulate thus revealing substance(s)* [pig- hypotheses. ments] that were hidden prior to this time. Forming Hypotheses I then ask if anybody has a third idea (hypothesis). Usually., one Early autumn is not only the start student per class realizes that the two of the school year; it is also the alternatives already listed are mutu- season for beautiful natural foliage in ally exclusive.. If nobody speaks up. deciduous forests that surround I ask if both hypotheses could be many areas. Several weeks into the true. Most students soon see that school term, I gaze out the window because several colors may be in- and comment on the color display. I volved, a composite hypothesis is then pose a question to my students: possible. I list this hypothesis as "What causes leaves to turn color follows: and drop this time of year?" This FIGURE7 This spidertipped the scales at a 3. Leaves turn color in the fall littleover 12 usually inspires a flurry of answers g* because: (a) one or more new sub- with typical responses centering stances are produced; and (b) one or around a drop in temperature or the more new substances are revealed shortening in the length of the days. at this time of year. References and Resources I then pose a second question: "Why don't we see colors other than green BEST, R.L. 1978. Living a*thropods in earlier in the year?" Students hesitate Experime-ntalDesign the classroom. Burlington, North in answering because this question The next step is to ask whichof the Carolina: Carolina Biological Supply three hypotheses is most correct. Company Culture Leaflet. demands responses that approach DODGE; N.N.