Thread by @PKurnath

NEXT UP: No. 2 seed Midgardia Seastar (Midgardia xandaros) vs No. 15 seed Hydra (Hydra vulgaris). This battle is a team effort from myself & @je_light #2021MMM

@je_light Midgardia Seastar is a relatively new species, described only 50 years ago! M. Seastar is an echinoderm (star fish, sea urchins & sea cucumbers) with lots of arms - in fact, it has the longest arms of any other known starfish (Downey 1972)! tinyurl.com/m9y6m3fa #2021MMM

@je_light Midgardia Seastars can have 12 long arms, each up to 600 mm in length (that's 1.76 stoats!) & can reach over 130 cm long from arm tip to arm tip (3.8 stoats!) #StoatsAsMeasurement #2021MMM

@je_light Midgardia has roots in Norse mythology, specifically referring to the sea serpent of middle earth (Midgard) who encircles the land & also goes by Jormungand. Midgard serpent eats its own tail, representing the eternal & renewal cycle of life #2021MMM

@je_light Hydra vulgaris is a small freshwater cnidarian (silent "c"), which is closely related to jellyfish, corals & anemones. Described 200 years before M. Seastar, Hydra vulgaris are plant-like in appearance but pack a punch... #2021MMM

@je_light Hydra, like most cnidarians, are carnivores & use stinging cells in their tentacles called cnidocytes (also silent "c") to subdue their often larger-bodied prey #CARNAGE #2021MMM tinyurl.com/vsrbrp8z

@je_light This sea beastie gets its name from Greek mythology: the Lernaean Hydra was a water serpent with multiple heads who famously battled Hercules (Hydra also roughly translates as "water snake" in Greek) #2021MMM

@je_light The location for tonight's battle is in the deep depths of the southern Gulf of Mexico. Our bright red Midgardia Seastar on stretched out on the ocean floor, waiting... #2021MMM

@je_light Hydra is anchored by its foot right next to Midgaria Seastar. It bends its 2 cm body, reaching & stretching its tentacles out to grab & sting potential prey #GetInMyBelly #2021MMM

@je_light Tap tap tap tap tap....Hydra's tentacles make contact with Midgardia Seastar & stings! Hydra opens its mouth by stretching cells apart eurekalert.org/pub_releases/2… (Carter et al. 2016 tinyurl.com/4c52xmdx) #SayAhh #2021MMM

@je_light But instead of a nourishing meal, Hydra's body cavity fills with salty sea water! #SoWhat #2021MMM

@je_light Hydra is a freshwater organism! With only two cell layers! Hydra is completely enveloped in a hypertonic solution! #Oh #2021MMM

@je_light Even though Hydra have amazing regenerative capabilities (they can renew & replace their entire body once a month! Check out #ActualLivingScientist @Juliano_Lab), water molecules are rapidly leeching out of Hydra's cells.... #2021MMM

@je_light @Juliano_Lab ...while the toxins from Hydra's tentacles are ineffective against Midgardia Seastar. The large echinoderm continues to wait as the ocean current washes a small amount of cnidarian detritus away #2021MMM

@je_light @Juliano_Lab MIDGARDIA SEASTAR OUTLASTS HYDRA VULGARIS!!! #2021MMM