Just 30 meters underneath the waves of the Northwest coast of Spain, the recently discovered “accordion worm” was found to contract itself, like the instrument, to one-fifth of its size. Scientists have now ‘described’ the species – a formal process where scientists detail the characteristics of a new organism – but the worm and its unique ability were first noticed in 2021. Local diver, Jacinto Pérez Dieste, accidentally disturbed five of these worms under a clam shell and they rapidly curled in on themselves from alarm. It’s a good thing he didn’t get any closer because scientists have now discovered, through genetic analysis, that these worms belong to the carnivorous Ribbon worm (Nemertea) family that use venom to defend themselves.
These worms, spanning up to an impressive quarter of a metre in length, could be described as terrifying, interesting, and perhaps even cool, but could they be described as romantic? The lead scientist seems to think so, as he named the worm Pararosa vigarae which translates to For Rosa Vigara, his wife, as a gift for their golden (50th) wedding anniversary.
Blind cavefish, local to North America, don’t just dislike socialising but actively avoid each other – especially when hungry. Around 200,000 years ago, a portion of the social Astyanax mexicanus migrated from the surface of freshwaters to pitch-black caves where, over time, they lost their sight. Despite this, they remain capable of detecting and responding to others and, when social hormones were administered by scientists, they partially restored their schooling behaviour.
This would suggest that their anti-social lifestyle is not from a lack of ability, but rather from a lack of motivation. The scientists speculate that this is a response to their predator-free, food-scarce environment, which would explain why they actively avoid each other more when hungry. This last part is something I’m sure we can all relate to.
Flower mantises – those that have evolved to mimic flowers – have developed a new trick to defend themselves against larger mantises: they parry. By stretching their forelegs like fencing masters, they either redirect oncoming attacks onto their less vulnerable body parts or they confuse them, hopefully giving them a chance to escape.
Researchers placed a species of flower mantis – colloquially known as the boxing mantis – in a 20 cm x 20 cm “arena” with the larger Rhombodera longa mantis after starving them both for two days. According to Chinese regulations, this work, somehow, did not require ethical approval. 26 flower mantises were tested in total, 8 of which had their forelegs “slightly injured with a pointed tweezer” so they could not parry. As you can imagine, the 8 “slightly injured” mantises did less well.
The forelegs of the flower mantises were originally only used to catch prey, meaning that co-option – where existing traits acquire novel adaptive functions – may be more common in nature than previously thought. I wonder if human limbs will ever be co-opted for weird and interesting functions. I hope no-one ever puts me in an arena to find out.