, "spider"; and -λογία, -logia
) is the scientific
study of spiders
and related organisms such as scorpions
, collectively called arachnids
. However, the study of ticks
is sometimes not included in arachnology, but is called Acarology
. Those who study spiders are arachnologists
Arachnologists are primarily responsible for classifying arachnids, for this reason they are sometimes casually referred to as spider experts. This can be a difficult task due to the sheer number of arachnids in existence. Two species of arachnids may appear virtually identical while two others of the same species may boast very different traits. Often enough, it is only possible to discern two species by dissecting the specimen
under a microscope
Although about 40,000 spider species have been described since Carl Alexander Clerck
described the first spiders 250 years ago, estimates vary how many species are as yet undescribed, with some setting the number as high as 200,000. Not only do scientists find new species in the field, but lots of specimens stored in collections are waiting to be described and classified. There are museum collections of spiders already 200 years old, with specimens half macerated and discolored, still not identified.
Because it is much easier to study the morphology of dead spiders than to observe their behavior in the wild, with many species living in very inaccessible places, the study of spider behavior has been much neglected.
Around 1970 arachnids became popular pets (specifically tarantulas
). This prompted sellers and breeders
to appoint a second name to each type (known as a common name). Brachypelma smithi
for example has become known as the Mexican redknee tarantula
ever since it entered the pet trade.