Day 2 of #SlugsVsFishes is feeding and predation. As you know, fishes for that covered real good. If there’s something edible in the sea, fishes will find a way to eat it. Acanthurids, like this Zebrasoma, are herbivorous. They feed mostly on algae and other vegetal growth. 1/- 
Surgeonfishes have long guts with specialized bacteria that help ferment and digest plant matter. They are effective grazers and provide important ecosystem services by clearing filamentous algae in young reefs, allowing corals to colonize and grow. #SlugsVsFishes 2/-
Some other herbivorous fishes, like parrot fishes, take this a step further. Their teeth are fused into a sharp, powerful beak, which they use to rasp at rock and live coral. Not only do they eat surface algae, they also eat symbiotic algae growing within live coral tissue! 3/-
This heavy intake of rock and other calcium carbonate substrate gets ground up and passed out as very fine sand. Rock goes in, sand comes out. If you’ve ever went holidaying Hawai’i, chances are you’ve built sandcastles made of parrotfish poop. Neat! 4/-
But by far most fishes on coral reefs are either omnivores or carnivores. Some are specialist feeders, like this Ornate Butterflyfish. They feed only on live coral polyps, and only from select coral genera. VERY fussy. But, highly successful. That’s why they’re still here. 5/-
Other fishes are more generalist omnivores, like this saddleback butterflyfish. It will eat most anything, including worms, coral, anemones, jellyfishes.... yup. They are something else. And GORGEOUS too. I mean, GAWJUS. 6/-
What if you wanna pick at worms in holes? Grow a beak! 7/-
What if you wanna pick at worms in DEEPER holes? Grow an even LONGER beak! 8/-
What if you wanna pick at worms UNDER rocks? FLIP Em’! This is a rock mover wrasse. And it’s name is very apt because it moves rocks to find food. They are also known to smash their food against rocks to disable them. Fishes are NEAT. 9/-
The carnivorous fishes have evolved a whole magician’s hat of tricks too. Some like this scorpionfish pretend to be coralline algae, lying in wait for unsuspecting fish to swim by before lunging at them. 10/-
Why stop at algae when you can look like a sponge? Imagine you’re hungry and you want food, so you evolve to look like a sponge just so you can lie on a rock and never ever move. Wow. The ultimate mood. 11/-
And if you’re a greedy pig that will literally DIE for your food? Sure. Also covered. Chiasmodon, the black swallower, can fit fishes 10x it’s size in its highly expandable stomach. 12/-
I guess one other way of getting food to come to you is to dangle a glowy glowy goatee under your chin and then snapping it up with needle like teeth and a highly flexible jaw 13/-
Some fishes, like cleaner wrasses, make a living off cleaning other fishes, picking at parasites and dead tissue. They provide important ecosystem services and help maintain vital fish health on the reef. Like a doctor! But you eat the nasty stuff off your patients. 14/-
This strategy is so successful that a myriad of species have comvergently evolved upon this same niche. Others however are a bit more insidious. The fang blenny (above) mimics the cleaner wrasse (below), but instead of picking parasites, it takes a bite out of its client! 15/-
Ah yes - can’t talk about fish feeding without bringing out the big guns. The internet’s best photo of the sling jaw wrasse, Epibulus insidiator. Let’s have a mouth that can extend THIS MUCH so we can SUCK unsuspecting prey up like a vacuum. 16/-
Ok I think you get it. FISHES ARE WHACKED. They can eat almost ANYTHING, and with lots of crazy tricks up their fins to help them do it. I’ll let the rest of #TeamFish demonstrate some of these innovative morphological adaptations. I will do so too, tomorrow. #SlugsVsFishes
