If You Suffer From Arachnophobia,

I would skip this post,

but if like many you like or even keep tarantulas, you may find this interesting, above a cobalt blue tarantula, (Haplopelma lividum), image credit: Bastian Rast/ EurekAlert, it has always been thought that these spiders were color blind, but if so why do they come in so many colors? Researchers from Yale-NUS College and Carnegie Mellon University (CMU) have investigated, and they found out that the tarantulas might be using these colors to communicate with other tarantulas that could be potential mates. If this is the case, then it also suggests that these spiders are not color-blind, the study was published last week,

the research was jointly led by Dr Saoirse Foley from CMU, and Dr Vinod Kumar Saranathan, in collaboration with Dr William Piel, both from the Division of Science at Yale-NUS College. To understand the evolutionary basis of tarantula colouration, they surveyed the bodily expression of various opsins (light-sensitive proteins usually found in animal eyes) in tarantulas. They found, contrary to current assumptions, that most tarantulas have nearly an entire complement of opsins that are normally expressed in day-active spiders with good colour vision, such as the Peacock Spider.

these findings suggest that tarantulas, long thought to be colour-blind, can perceive the bright blue colours of other tarantulas. Using comparative phylogenetic analyses, the team reconstructed the colours of 110 million-year-old tarantula ancestors and found that they were most likely blue. They further found that blue colouration does not correlate with the ability to urticate or stridulate - both common defence mechanisms -- suggesting that it did not evolve as a means of deterring predators, but might instead be a means of attracting potential mates, I had never thought that spiders were colour blind, and now it seems they are not.