Ornithoctonus huwena is a large terrestrial burrowing tarantula from China. It can be very common in some areas of Southern China, where it is known as the earth tiger because of its tiger like coloration and temperament or the cow killer because of its reputation for killing cows. In the West, its common name has been changed to golden Chinese tarantula, apparently to make it more palatable for the pet trade and it is considered to be Haplopelma schmidti. It is also called Selenocosmia huwena in some of literature on the venom.

Toxicity

The venom appears to have significant mammalian toxicity (1.16 mg/kg mouse) and its reputation as a cow killer appears to be confirmed by toxicity tests and pharmacology. It appears to be a bit less toxic per unit than the infamous Atrax robustus but it has considerably more venom. We harvested approximately 50 microliters of venom from large females.

We have not been able to find published accounts of envenomation but Chinese literature describes a rapid death when cows are bitten in the region of the mouth and progressive paralysis following bites to the feet. The rapid death may be due to paralysis in the upper airways, resulting in suffocation. This appears to be consistent with discovery of sodium channel and N-type calcium channel inhibitors from the venom. There is also an unpublished account of the death of a child from a bite (Tan Yi, personal communication).

Venom

More than 400 proteins and peptides have been separated and detected by 2D electrophoresis, including 13 that have been studied fairly intensively (Liang (2004)). These include insect and mammalian toxins targeting sodium and calcium channels.