Tim writes: while walking on the Peak District moors this morning I came across some Star Jelly, which I have only seen once or twice before. I took this photograph on my phone but I thought it was too interesting to keep to myself. I hope you agree. So what is Star Jelly? Well it also goes by the names Astromyxin and Astral Jelly, and was once believed to be deposited on Earth during meteor showers. There is a Wikipedia entry for it and much of this information is from that source.
There have been reports of this mysterious substance for centuries. For example John of Gaddesden (1280-1361) mentions stella terrae (Latin for ‘star of the earth’ or ‘earth-star’) in his medical writings, describing it as “a certain mucilaginous substance lying upon the earth” and suggesting that it might be used to treat abscesses. A fourteenth-century Latin medical glossary has an entry for uligo, described as “a certain fatty substance emitted from the earth, that is commonly called ‘a star which has fallen'”. Similarly, an English-Latin dictionary from around 1440 has an entry for “sterre slyme” with the Latin equivalent given as assub (a rendering of Arabic ash-shuhub, also used in medieval Latin as a term for a “falling” or “shooting” star). The Oxford English Dictionary lists a large number of other names for the substance all associated with stars: star-fallen, star-falling, star-jelly, star-shot, star-slime, star-slough, star-slubber, and star-slutch. But not all of the early writers believed it came from the stars. For example, the great 18th century naturalist Thomas Pennant believed the material to be “something vomited up by birds or animals”.
Debate about its origins has raged until recent years. And it turns out that Thomas Pennant wasn’t far off the mark. In 1951 the New Naturalists’ volume on British Amphibians and Reptiles said “star jelly is most likely formed from the glands in the oviducts of frogs and toads. Birds and mammals will eat the animals but not the oviducts which, when they come into contact with moisture, swell and distort leaving a vast pile of jellylike substance sometimes also referred to as otter jelly”. Bizarrely an article in Nature in 2009 muddied the waters when an analysis failed to find any DNA. DNA forms the basis of all life on Earth so a jelly without a trace of DNA fuelled the idea of extra-terrestrial origins. But the mystery was finally laid to rest in the BBC programme Nature’s Weirdest Events, Series 4, episode 3, (14 January 2015) when Chris Packham showed a specimen of “star jelly” and had it sent to the Natural History Museum, London, for a DNA analysis by Dr. David Bass who confirmed it was from a frog. He also found some traces of magpie DNA on the jelly which may point to the predator of the frog. Though the Magpie could have poked around in the jelly later.
But November seems like an odd month to find this unfertilised spawn on the moors. Though my friend Nick Acheson (@themarshtit) tells me that star jelly can spend months in the guts of a heron before being vomited. Which might explain why this unfertilised spawn was on the moors in November. I cannot think which predator might have eaten a frog high on the Peak District Moors in November, though Fox and Buzzard are perhaps the most likely candidates.