Here's a list of all the fish available in Animal Crossing: New Leaf. Note that you'll find different fish at different times of the day and locations. Also, don't forget to visit the island, as it's amazing how many valued fish you'll find there versus back in your town, especially sharks. Once they're in your museum collection, sell them for crazy loads of cash (I come back from the island every night with 150,000-200,000 bells)!

The names of fish you see with an asterisk (*) are new additions to AC New Leaf, and hard-to-find fish are marked with the flag
icon.
Where you can you find fish in Animal Crossing: New Leaf?
Obviously, fish are always in the water, but be sure to fish in the river, the sea shore, and ponds. Different fish, different locations! Also, you'll find other creatures like frogs and turtles.
Animal Crossing: New Leaf - Ocean, Pond, and River Fish List
Picture | Fish Name | Location | Spawn. Chance | Months | Times | Re-Tail Price | Average Size | 
Angelfish

River2%May - Oct4pm - 9am3,0004.72 in
12 cm

Arapaima

River1%July - Sept4pm - 9am10,000118.11 in
300 cm

Arowana

River1%June - Sept 154pm - 9am10,00027.56 in
70 cm

Barbel SteedRiver16%All YearAll Day20019.69 in
50 cm

Barred Knifejaw

Ocean5%March - NovAll Day5,00023.62 in
60 cm

BitterlingRiver18%Dec - FebAll Day9003.15 in
8 cm

Black BassRiver16%All YearAll Day30019.69 in
50 cm

Blowfish*Ocean5%Nov - FebAll Day1259.84 in
25 cm

Blue Marlin

Ocean2%June - SeptAll Day10,00086.61 in
220 cm

BluegillRiver10%All Year9am - 4pm1209.84 in
25 cm

ButterflyfishOcean8%April - SeptAll Day1,0007.09 in
18 cm

CarpRiver15%All YearAll Day30023.62 in
60 cm

CatfishLarge Pond / River16%May - Oct4pm - 9am80023.62 in
60 cm

Char

Near Waterfalls8%March - June
Sept - Nov4am - 9am
4pm - 9pm
4am - 9pm3,80019.69 in
50 cm

Cherry SalmonRiver11%March - June
Sept - Nov4am - 9am
4pm - 9pm
4am - 9pm1,00013.78 in
35 cm

Mitten Crab*River5%Sept 15 - Nov4pm - 9am2,0003.15 in
8 cm

ClownfishOcean8%April - SeptAll Day6505.91 in
15 cm

CrawfishPond13%April - Sept 15All Day2004.72 in
12 cm

Coelacanth

Ocean (rain /snow)2%All Year4pm - 9am15,00059.06 in
150 cm

Crucian CarpRiver22%All YearAll Day1207.87 in
20 cm

DabOcean14%Oct - AprilAll Day30019.69 in
50 cm

DaceRiver16%All Year4pm - 9am20013.78 in
35 cm

Dorado

River2%June - Sept4am - 9pm15,00039.37 in
100 cm

EelRiver12%June - Sept 154pm - 9am2,00039.37 in
100 cm

Football Fish

Ocean8%Nov - March4pm - 9am2,50023.62 in
60 cm

Freshwater GobyRiver5%All Year4pm - 9am3005.91 in
15 cm

FrogPond10%May - AugAll Day1201.57 in
4 cm

Gar

Large Pond1%June - Sept4pm - 9am6,00074.80 in
190 cm

Giant Trevally*

Island Ocean2%All YearAll Day4,50070.87 in
180 cm

Giant Snakehead

River2%June - Aug9am - 4pm5,50033.46 in
85 cm

GoldfishRiver2%All YearAll Day1,3005.91 in
15 cm

GuppyRiver3%April - Nov9am - 4pm1,3001.57 in
4 cm

Hammerhead Shark

Ocean1%June - Sept4pm - 9am8,00098.43 in
250 cm

Horse MackerelOcean30%All YearAll Day15015.75 in
40 cm

KillifishPond5%April - AugAll Day3001.57 in
4 cm

King Salmon

Near River Mouth6%SeptAll Day1,80055.12 in
140 cm

Koi

River2%All Year4pm - 9am4,00023.62 in
60 cm

LoachRiver21%March - MayAll Day3007.87 in
20 cm

Moray Eel

(rare in your town's ocean)Ocean/Island Ocean2%Aug - Oct (Town)
All Year (Island)All Day2,00031.50 in
80 cm

Napoleonfish

Island Ocean1%June - Aug4am - 9pm10,00070.87 in
180 cm

Neon TetraRiver3%April - Nov9am - 4pm5000.79 in
2 cm

Nibble Fish*

River2%May - September9am - 4pm1,5003.54 in
9 cm

Oarfish*

Ocean1%Dec - MayAll Day9,000228.35 in
580 cm

Olive FlounderOcean8%All YearAll Day80031.50 in
80 cm

Ocean Sunfish

Ocean2%June - Sept4am - 9pm4,000118.11 in
300 cm

Pale ChubRiver10%All Year9am - 4pm2005.91 in
15 cm

Pike

River1%Sept - Dec4am - 9pm1,80047.24 in
120 cm

PiranhaRiver3%June - Sept 159am - 4pm
9pm - 4am2,50011.81 in
30 cm

Pond SmeltRiver39%Dec - FebAll Day3005.91 in
15 cm

Popeyed Goldfish

River2%All Year9am - 4pm1,3005.91 in
15 cm

Puffer FishOcean/ Island Ocean12%Aug - SeptAll Day24013.78 in
35 cm

Rainbow TroutRiver11%March - June
Sept - Nov4am - 9am
4pm - 9pm
4am - 9pm80023.62 in
60 cm

Ray

Island Ocean1%June - Nov4am - 9pm3,00047.24 in
120 cm

Ribbon Eel*Island Ocean5%All YearAll Day60047.24 in
120 cm

Red SnapperOcean8%All YearAll Day3,00035.43 in
90 cm

Saddled Bichir*

River1%June - Sept9pm - 4am4,00023.62 in
60 cm

Salmon

Near River Mouth40%SeptAll Day70035.43 in
90 cm

Saw Shark*

Ocean1%June - Sept4pm - 9am12,00059.06 in
150 cm

Sea BassOcean25%All YearAll Day20039.37 in
100 cm

Sea ButterflyOcean12%Dec - FebAll Day1,0001.18 in
3 cm

Shark

Ocean3%June - Sept4pm - 9am15,000212.60 in
540 cm

SeahorseOcean9%April - NovAll Day1,1003.15 in
8 cm

Soft Shelled Turtle*River5%Aug - Sept4pm - 9am3,75011.81 in
30 cm

SquidOcean14%Dec - JulyAll Day40013.78 in
35 cm

Stringfish

River1%Dec - Feb4pm - 9am15,00055.12 in
140 cm

SurgeonfishOcean
Island2%April - SeptAll Day1,00012.20 in
31 cm

SweetfishRiver16%July - Sept 15All Day9009.84 in
25 cm

Tadpole*Pond5%March - JulyAll Day1001.57 in
4 cm

Tuna

Ocean4%Nov - MarchAll Day7,00090.55 in
230 cm

Whale Shark*

Island Ocean1%All YearAll Day13,000236.22 in
600 cm

Yellow PerchRiver8%Oct - MarchAll Day24013.78 in
35 cm

Zebra TurkeyfishOcean12%April - NovAll Day40011.81 in
30 cm