Turtle or half-melted processed cheddar? You might need to squint to get your answer when you’re presented with this, glossy vividly yellow slab:

As it happens, the pedigree’s definitely chelonian – that is, a turtle, the second such wacky-hued specimen stumbled across in the past several months in India. Specifically, this is an Indian flapshell turtle, a common South Asian softshell species named for the femoral flaps that help "seal off" the reptile when its limbs are pulled in – a nifty party trick that is not just an anti-predator adaptation, but also a survival mechanism for enduring drought.

This particular flapshell turtle, retrieved from a pond in Burdwan, West Bengal last month, prompted a flurry of media attention employing no shortage of culinary allusions to describe its colour: American-cheese yellow, egg-yolk yellow, butter-yellow, etc. Carly Cassella, writing about the find for ScienceAlert, remarked that the turtle “looks good enough to eat.” (As it happens, that’s not so far off: Indian flapshells are widely trapped and traded for food.)

Similar international coverage followed the discovery this past July of another mustard-toned (who’s getting hungry?) flapshell plucked from a field in the village of Sujanpur in Balasore, Odisha. Tweeting about that turtle, which ended up released back into the wild, Susanta Nanda of the Indian Forest Service wrote, “Most probably it was an albino. One such aberration was recorded by locals in Sindh [a] few years back.”

A typical Indian flapshell turtle comes suited up in brown or olive-green with a lighter-coloured plastron (or undershell); one subspecies, the spotted northern Indian flapshell, is known for yellow blotches on its head, neck, and carapace.

As Nanda suggested, however, 2020’s all-golden flapshells aren’t alone: They represent an uncommon but well-described colour variant. This Twitter thread from Freshwater Turtles & Tortoises of India – founded by herpetologists Sneha Dharwadkar and Anuja Mital – spells that out:

Similar flapshells have also apparently recently been observed in the Sundarbans, that great mangrove jungle along the mouths of the Ganges and Brahmaputra.

A species account published by the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group references an albino Indian flapshell documented from Gujarat in 1997 – sporting a “uniformly yellow carapace, head and limbs, the plastron light yellow with pink callosities [calluses, basically], and pink eyes” – and notes other albino individuals have been reported from Bangladesh and Myanmar.

This year, a report published in Herpetology Notes detailed a yellow spotted northern Indian flapshell with a whitish underside found in southeastern Nepal in 2018: the first such colour variant formally described in that country. The authors attribute the lemony hue not to albinism per se – a condition defined by the complete absence of pigments – but to a chromatic leucism in which a dearth of melanin in the skin allows yellow pteridine pigments to express.

The leucistic Nepal golden flapshell was, like its Odisha counterpart of this year, released after examination, but the authors of the Herpetology Notes article suggest such brightly coloured turtles may be more vulnerable to predation out there. Indian flapshells are preyed upon by a variety of other critters, including mugger crocodiles, the large fish called mahseers, and – the outrage! – their bigger relative the Ganges softshell turtle. They also wrote that “such aberrant individuals are highly valued in the pet trade.”

Having gazed upon the golden glory of these flapshell turtles, you’re surely now hopelessly hooked on the subject of unusual colour variants in the animal kingdom. Feed your newfound obsession in the Earth Touch archives: Stick with the chelonian theme and read about a tiny albino sea-turtle hatchling, then move on to “strawberry” leopards, pale tigers, Migaloo the white humpback, white kangaroos (aka “white hoppers”), ghostly albino civets, and the cute-but-not-so-cuddly white echidna.