Sigh Again!!!!

The Oceanographer

Eastern Kingdoms/Kalimdor
Algaefin Rockfish - Twilight Highlands (15% Coastal Open Water)
Big-Mouth Clam - Swamp of Sorrows (6-12% Coastal Open Water) *Best catch rate 00:00-06:00.
Bloated Giant Sunfish - Isle of Quel'Danas (7% Coastal Open Water)
Bloated Salmon - Blasted Lands
Darkshore Grouper - Darkshore (30% Coastal/Inland Open Water)
Deepsea Sagefish - Uldum (30% Coastal Open Water)
Fathom Eel - Vashj'ir (30% Coastal Open Water)
Firefin Snapper - Wetlands (15% Coastal Open Water)
Giant Sunfish - Isle of Quel'Danas (78% Coastal Open Water)
Glossy Mightfish - Eastern Plaguelands (4-18% Coastal Open Water) *Highest catch rate 00:00-06:00 (18% of catches).
Jaggal Clam - Isle of Quel'Danas (15% Coastal Open Water)
Large Raw Mightfish - Swamp of Sorrows (5-10% Coastal Open Water) *Best catch rate may be 00:00-06:00 (15% of all catches - 5-10% at other times).
Murglesnout - Vashj'ir (50% Coastal Open Water)
Oily Blackmouth - Wetlands (25% Coastal Open Water)
Raw Rainbow Fin Albacore - Wetlands (60% Coastal Open Water)
Raw Redgill - Eastern Plaguelands (40% Coastal/Inland Open Water)
Raw Rockscale Cod - The Hinterlands (55% Coastal Open Water)
Raw Slitherskin Mackerel - Tirisfal Glades (98% Coastal Open Water)
Stonescale Eel - Swamp of Sorrows (80% Coastal Open Water) *Highest catch rate from open water 00:00-06:00.
Raw Spotted Yellowtail - Eastern Plaguelands (40% Coastal Open Water)
Raw Summer Bass - Swamp of Sorrows (10-30% Coastal Open Water) *Seasonal March 20 - Sept. 22. Highest catch rate 12:00-18:00. Cannot be caught 00:00-06:00, except in Blasted Lands and Swamp of Sorrows.
Raw Sunscale Salmon - Blasted Lands [Tainted Forest (0-35% Inland Open Water) *Highest catch rate 12:00-18:00. Cannot be caught 00:00-06:00.
Raw Whitescale Salmon - Blasted Lands [Tainted Forest (40% Inland Open Water)
Winter Squid - Swamp of Sorrows (10-30% Coastal Open Water) *Seasonal Sept. 22 - March 20. Highest catch rate 12:00-18:00. Cannot be caught 00:00-06:00, except in Blasted Lands and Swamp of Sorrows.

Northrend
Borean Man O' War - Borean Tundra (20% Coastal Open Water)
Darkwater Clam - Borean Tundra (10% Coastal Open Water)
Deep Sea Monsterbelly - The Frozen Sea (20% Coastal Open Water)
Imperial Manta Ray - Borean Tundra (20% Coastal Open Water)
Moonglow Cuttlefish - The Frozen Sea (20% Coastal Open Water)
Pygmy Suckerfish - Howling Fjord (10% Coastal/Inland Open Water) *Caught with other fish.
Rockfin Grouper - The Frozen Sea (60% Coastal Open Water)

Abyssal Clam - At the time of writing these cannot be gained by fishing. Abyssal Clam can be looted from Crate of Tasty Meat.

The Limnologist

Eastern Kingdoms/Kalimdor
Albino Cavefish - Deepholm (15% Open Water)
Blackbelly Mudfish - Uldum (15% Open Water)
Bloated Catfish - Redridge Mountains
Catfish - Deadwind Pass (20% Inland Open Water)
Brilliant Smallfish - Elwynn Forest (60% Coastal/Inland Open Water)
Bristle Whisker Catfish - Redridge Mountains [Lake Everstill (60% Inland Open Water)
Crescent-Tail Skullfish - Deadwind Pass (20% Inland Open Water)
Deviate Fish - Northern Barrens [Oasis (30% Inland Open Water)]
Greater Sagefish - Western Plaguelands (80% Inland Greater Sagefish School)
Highland Guppy - Twilight Highlands (15% Inland Open Water)
Lavascale Catfish - Deepholm (30% Inland Open Water)
Loch Frenzy - Loch Modan (30% Inland Open Water)
Longjaw Mudsnapper - Stormwind City (60% Coastal/Inland Open Water)
Mithril Head Trout - Western Plaguelands (60% Inland Open Water)
Mountain Trout - Mount Hyjal (15% Inland Open Water)
Plated Armorfish - Blasted Lands [Tainted Forest (5-35% Inland Open Water)] * Highest catch rate 00:00-06:00.
Sagefish - Loch Modan (80% Inland Sagefish School)
Sharptooth - Deepholm (50% Inland Open Water)
Sickly Looking Fish - Tirisfal Glades (15% Inland Open Water)
Striped Lurker - Mount Hyjal (30% Inland Open Water)

Outland
Barbed Gill Trout - Zangarmarsh (71% Inland Open Water))
Felblood Snapper - Shadowmoon Valley (100% Inland Open Water/Lava)
Figluster's Mudfish - Nagrand [Lakes (21% Inland Open Water)]
Furious Crawdad - Terokkar Forest (65% Inland Highland Mixed School)
Golden Darter - Terokkar Forest [Rivers (22% Inland Open Water)]
Goldenscale Vendorfish - Terokkar Forest (1% Inland Highland Mixed School)
Huge Spotted Feltail - Terokkar Forest (2% Inland Highland Mixed School)
Icefin Bluefish - Nagrand [Lakes (22% Inland Open Water)]
Nightfin Snapper - Blasted Lands [Tainted Forest (0-35% Inland Open Water)] * Highest catch rate 00:00-06:00.
Spotted Feltail - Zangarmarsh (15% Inland Open Water)
Zangarian Sporefish - Zangarmarsh (15% Inland Open Water)

Northrend
Barrelhead Goby - Sholazar Basin (70% Coastal/Inland Open Water)
Bonescale Snapper - Crystalsong Forest (70% Inland Open Water)
Dragonfin Angelfish - Dragonblight (90% Inland Dragonfin Angelfish School)
Fangtooth Herring - Howling Fjord (22% Brackish/Inland Open Water)
Fountain Goldfish - Dalaran [Eventide (41-67% Inland Open Water)]
Giant Darkwater Clam - Wintergrasp (4% Inland Open Water)
Glacial Salmon - Wintergrasp (32% Inland Open Water)
Glassfin Minnow - Crystalsong Forest (30% Inland Open Water)
Musselback Sculpin - Wintergrasp (32% Inland Open Water)
Nettlefish - Wintergrasp (32% Inland Open Water)
Sewer Carp - Dalaran [Underbelly (54% Inland Open Water)]
Shimmering Minnow - Dalaran [Violet Hold (58% Inland Open Water)]
Slippery Eel - Dalaran [Violet Hold (23% Inland Open Water)]

****credit to Feliciamarie from Wowhead.com

To All the Squirrels Who Cared for Me
Alpine Chipmunk Winterspring/Stonetalon Mountain/Mount Hyjal
Grotto Vole Mount Hyjal
Oasis Moth Uldum/Lost City of Tol'vir
Rattlesnake Twilight Highlands/Badlands/Tanaris
Rockchewer Whelk Shimmering Expanse
Sea Cucumber Abyssal Depths/Shimmering Expanse
Yellow-Bellied Marmot Twilight Highlands
Baradin Fox Kit Tol Barad
Mac Frog Uldum/Lost City of Tol'vir
Rock Viper Desolace
Sassy Cat
Wharf Rat Booty Bay
Highlands Turkey