A bar, somewhere in the ocean. A whale shark sits quietly sipping a Krillians.
Whale shark (quietly): <sip> Ahh, that’s some good Euphausia right there. <sip>
A baleen whale explodes through the door with a couple of his buddies, making an awful ruckus, breaching and slapping pectoral fins
Whale shark: <sip>
Whale: AAAAAHHH! Barkeep! Krill. KRILL dammit, and lots of it!
The whale notices his spotty fellow bar patron, and nods his enormous head towards the whale shark:
Whale shark: <sip> Good evening <sip>
Whale: Good evening? Good EVENING? What kind of crap is that? Hey Gary, check out Professor Snooty-pants over here, with his hoity toity Good evenings and such!
Whale shark (ignoring them): <sip>
The whale turns back to the bar
Whale: Keeerist! Whose vestigial pelvic girdle do you have to hump to get some krill around here? I could eat a whole swarm. Hey Gary, remember that time at Stellwagen when…aaaahhh, barkeep, bout freakin’ time, krill me, stat!
Whale shark: <sip>
The barkeep returns with several buckets of krill and sets them down in front of the whale and his mates.
Whale shark: <sip>
Whale: Barkeep, what the fudge is this? I asked for krill, LOTS OF krill. Engrish mofo, you speekit?
Whale shark: <sip> That IS lots of krill <sip>
Whale: Who asked you?
Whale shark (shrugging his pectoral fins): <sip>
The whale and his mates open their capacious mouths and lunge forward, the throat grooves on their necks ballooning as they engulf half the bar. They inhale the krill, knocking over several ashtrays and a decorative lanternfish in the process.
Whale shark: <sip> Woah! Easy there bud… <sip>
Whale (with his mouth full): Exqueeze me?
Whale shark: <sip> Look, I know you rorquals hang out together because you’re insecure, but just because your neck looks like a field hockey skirt doesn’t mean you can just go around knocking stuff over, taking it out on the rest of us. Some of us just came for a quiet bit of active surface suction feeding, meeting our scant poikilothermic energy needs with a bit of plankton here or some fish eggs there, and then you guys come in thinking you’re all boss and such, trying to inhale everything in sight and generally making a mess of the joint. I just think maybe you ought to tone it down a bit <sip>
Whale (shocked): Come again?
Whale shark: <sip> Filter feeding is really pretty easy. You don’t have to try to impress people by chugging it all at once, that’s all <sip>
Whale (calming down slightly): Well … how the hell else you gonna do it?
Whale shark: <sip> You don’t pay much attention do you. *sigh* OK. Watch me. I open my mouth, and I swim gently forwards. The 20 filter pads in my throat act as cross-flow filters, effectively directing water out through the gills, separating the krill with a minimum of clogging and even less fuss. The krill accumulate at the back of my throat and I just swallow now and then when there’s enough to make it worth doing so. Do that 8 or so hours a day and Bob’s your uncle <sip>
Whale (growing curious): Filter pads?
Whale shark: <sip> Ohhhhh! That’s right, I forgot, you don’t have filter pads. Yikes! Aw-kward… <sip> So how do YOU do it then?
Whale (growing excited): Oh yeah, check this out, it’s bitchin’! It’s the only way for a hot-blooded whale to get his, knowm sayin’? You just open your mouth as wide as you can and just sort of lunge forwards and snag the whole swarm.
The whale lunges again, this time poking the barkeep in the eye and nearly falling off his stool.
Whale shark: <sip> All right, settle down there sport <sip> So now you’ve got a mouth full of food, what are you supposed to do then?
Whale: mmm mmrph mmph mm
Whale shark: <sip> Swallow first, then talk <sip>
Whale (swallowing): Oh yeah, well my tongue is, like huge, so I just use it to squeeze all the water back out of my mouth.
Whale shark: <sip> How do you separate the food?
Whale (grinning): Scope my grill! Baleen bitches, it works! I squeeze the water through these bad boys, they trap the plankton and then I just sort of lick it all off.
Whale shark (grimacing): Sheesh! Put that away! Wait, so you mean to tell me you can only filter one mouthful at a time? And the water comes back out the same way it went in? And you have to squeeze it out with your tongue? And the baleen clogs every time? And you have to have a neck like Rob Ford to make it work?
Whale: Well when you say it like that…
Whale shark: <sip> Doesn’t that cost you a bunch of energy? All that lunging and such?
Whale: Oh yeah, totally, 50 times base metabolic rate. Sometimes I even go anaerobic. It’s a killer workout. Check out my pecs…
Whale shark: <sip> No thank you <sip>
Whale: Suit yourself. You know, you sure do sip a lot…
Whale shark: <sip> That’s just how I roll <sip> At least I can breathe and feed at the same time…
Whale: Wait, what now?
Whale shark: <sip> The same water that carries food into my mouth carries oxygen across my gills. Unidirectional system. It’s a symphony of precision and efficiency. If I understand you correctly, when your mouth is full of water, you can’t even breathe.
Whale: Well no, but we never breathe through our mouths anyway, only ever through the blowhole. Checkit!
The whale blows a towering plume, knocking several autographed pictures of dubious celebrities off the wall and coating the pendant lights with mucus
Whale shark: Dood!
Whale: Sorry man, I get a bit carried away sometimes. It’s actually pretty cool. Because our blowholes mainline to our lungs and our mouths go directly to the stomach, anatomically, we can’t choke. We don’t even have, like, a gag reflex!
Whale shark: <sip> … There are so many things I could say right now… <sip>
Whale: You know what, man, you’re OK. For a shark I mean. Kinda dull, but OK. Maybe we’ll hang out. I gotta show you this thing me and the boys do with bubbles sometimes.
Whale shark: Que sera, sera
The whale shark quickly finishes his drink and heads off in search of favourable currents.
Whale: Hey thanks man! Mi casa to you too!
Motta PJ, Maslanka M, Hueter RE, Davis RL, de la Parra R, Mulvany SL, Habegger ML, Strother JA, Mara KR, Gardiner JM, Tyminski J, Zeigler LD. Feeding anatomy, filter-feeding rate, and diet of whale sharks Rhincodon typus during surface ram filter feeding off the Yucatan Peninsula, Mexico. Zoology (Jena). 2010 Aug;113(4):199-212. doi: 10.1016/j.zool.2009.12.001.
Potvin J, Goldbogen JA, Shadwick RE (2012) Metabolic Expenditures of Lunge Feeding Rorquals Across Scale: Implications for the Evolution of Filter Feeding and the Limits to Maximum Body Size. PLoS ONE 7(9): e44854. doi:10.1371/journal.pone.0044854