Specimen of the Week: Week 102
By Emma-Louise Nicholls, on 23 September 2013
As the weather has become decidedly wetter, my thoughts this week turned to creatures (very much unlike myself) who might appreciate such things. The obvious train of thought skipped all lesser creatures and went straight to sharks, but I’m not allowed to turn the blog into Sharks R Us, so I went for something else with teeth, attitude, and unashamedly resembling a retro computer game character. This week’s Specimen of the Week is…
**The horned frog**
1) This crazy looking frog (not to be confused with the crazy frog), gets its name from the horns above its eyes. You don’t get points for working that out by yourself. They grow up to 15 centimetres in length and weigh up to 480 g. That’s about eight tennis balls, to put it into perspective. They inhabit freshwater marshes and pools throughout the Amazon Basin from Columbia in the west over to Brazil in the East.
2) A would-be-NHS nightmare, the horned frog maintains its large (for a frog) proportions by indiscriminately eating whatever it comes across. They are primarily ambush predators, meaning they bury their body beneath the substrate or amongst the leaf litter, leaving only their head above the surface. When pretty much anything, that is smaller than they are, wanders passed the frog leaps from its position in the mud, dives on to the prey, and swallows it whole. The horned frog prevents its prey escaping with a fine set of sharp teeth.
3) The enormous mouth is responsible for the alternative common name ‘Pacman‘. The horned frog is so voracious, many individuals have been found in the wild with a prey item protruding from the mouth, having expired from trying to ingest something way too big for them. A case of their eyes are bigger than their… airway.
4) Normally, the female is larger than the male, though what the boys lack in size they make up for with colouration. They range from dark green to lime-colored and have a quite attractive mottled appearance, presumably for camouflage. In contrast, females are usually just tan-coloured. The horns provide a bit of a mystery, as scientists are still trying to unravel what what their purpose could be. The most popular theory at present is that they aid camouflage- possibly resembling leaf stems.
5) Is has been said that many Amazon villagers wear high leather boots called botas escuerzas because of these frogs. The horned frog is highly territorial and will ‘attack’ intruders, including Homo sapiens. In some areas of the Amazon Basin, the horned frog is thought to be venomous. Although not true, fear of these frogs has resulted in attempts to eradicate them.
Emma-Louise Nicholls is the Museum Assistant at the Grant Museum of Zoology.