On Friday I gave you these objects to identify:

I expected you to work out what these came from pretty easily – and you proved me right. In fact, I think this was probably the easiest mystery object so far, given that everyone managed to get a correct identification of Stingray barbs.

Now, I’m not sure which species of Stingray these came from, because there are over a hundred species of Stingray and as the barbs fulfil the same functional role for each species they’re not particularly diagnostic. They tend to have a series of hooked serrations and it’s interesting to note the two grooves on the underside of the barb (you can see these on the one on the left). These are the areas where the venom glands are situated.

The barbs are used for defence against predators – they’re situated part way down the tail, which is flicked up when the Stingray feels threatened. Unfortunately for Steve Irwin. Fatalities due to Stingrays are very rare and usually human injuries from these animals are limited to stings on the legs, when people tread on the animals as they lie hidden on the sea or river bed.

I thought it might be worth mentioning that quite a lot of the answers suggested made reference to the excellent 1960’s marionette TV show Stingray, which had the following intro. Enjoy!