How to Cold-Read a Fish

What is a fish, anyway?

VertebratesBackboneCNS with brainBilateral

symmetrySexual

reproduction

Fishes have:JawsGillsPaired finsScales (usually) Cold-blood

(almost always)Fish vs. Fishes

How to memorize 25,000 fish…Don’t memorize…read

themTake clues from:

Body shapeFinsMouthSensesColor/patternsHabitat

Fins on the football

Fusiform

Paired finsPectoral finsPelvic fins

Unpaired finsDorsalAnalCaudal

Modified fins

Fish senseEyes

SizePosition

Nostrils/naresPositionShape

OtherBarbelsLateral 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 predatorsFusiform, terminal

mouth, forked tail, evenly placed fins

Lie-in-wait predatorsFins far back

Surface-orientedUpturned 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 StoriesIt’s all about resource partitioningExtreme specialization leads to…

Freaks!

Freaky feeders

Archer fishArawanaDusky damselAngler fishesGulper eelsElectric fishesCichlidsVege 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