A cordial introduction to fishes How to Cold- Read a Fish

What is a fish, anyway? Vertebrates Backbone CNS with brain Bilateral symmetry Sexual reproduction Fishes have: Jaws Gills Paired fins Scales (usually) Cold-blood (almost always) Fish vs. Fishes

Let’s classify fish! Kingdom: Animalia Multicellular heterotrophs Phylum: Chordata Notochord, dorsal hollow nerve chord, gills, tail Bottom Line Fish are aquatic vertebrates with gills, jaws, and paired fins. All other rules are up for the breaking.

Fish, in a class by themselves Well, not really… Class: Chondricthyes – sharks and rays Class: Osteichthyes – bony fishes Other classes include: Placodermi, Acanthodii

Most fish are bony Subdivision: Teleostii Just about everything you know as a fish Still over 24,000 spp. in 38 orders

How to memorize 25,000 fish… Don’t memorize…read them Take clues from: Body shape Fins Mouth Senses Color/patterns Habitat

Fins on the football Fusiform Paired fins Pectoral fins Pelvic fins Unpaired fins Dorsal Anal Caudal Modified fins

Fish sense Eyes Size Position Nostrils/nares Position Shape Other Barbels Lateral line

Fish mouths Mouth position Point up – surface food and oxygen Point down – prey on or near the bottom Point forward – AKA terminal, chase food Size and shape Inside Teeth – all over Rakers – filtering

Staying out of trouble Armor Spines Skin color Countershading Disruptive coloration Cryptic coloration Silver and red Imitation Schooling

Eco-shapes Rover predators Fusiform, terminal mouth, forked tail, evenly placed fins Lie-in-wait predators Fins far back Surface-oriented Upturned mouth, large eyes, dorsal back

Eco-shapes Bottom fish – flat, camouflaged Rovers – goatfish Clingers – sculpins, clingfishes Flatfishes Rattails Deep-bodied Smooshed, pecs, small mouth, large eyes, spines Eel-like - eely

Habitat is context Individual adaptations may only make sense in the context of a fish’s habitat Specific challenges

How to cold-read a fish  Body shape  Fusiform  Flattened  Eel-like  Deep-bodied  Fins  Tail shape  Pectoral fins  Dorsal/anal fins  Modified fins  Spines?  Senses  Eyes  Nostrils/nares  Barbels  Mouth  Position  Size and shape  Skin color  Silvery/counter-shaded  Cryptic/disruptive  Eyespots, etc.

Tell me about this fish

What about me?

Me?

What about me?

And us?

Curveballs

Phantasmagoric Fish Stories It’s all about resource partitioning Extreme specialization leads to… Freaks!

Freaky feeders Archer fish Arawana Dusky damsel Angler fishes Gulper eels Electric fishes Cichlids Vege piranhas

Bizarre sex stories The mile-high club Splash tetra Lonely and loving it Functional hermaphrodites Lancets, tripods Transvestites and transsexuals Sneaker males Changing with age, population composition Omega males Deep sea anglers Amazon Molly

We could go on World’s smallest vertebrate Ice-fishes Anti-freeze in blood Rivulines Eggs to adults in 4 weeks, dead in a year Elephant fishes Huge brains (3%) Tarpon can drown Walking catfish Swimmer’s surprise Swamp eels Can live out of water for up to 6 months Telescope/tripod Flying fish 30 sec, 1m high, 200m Four-eyed fish Pearlfish