As the title says, this guide aims to be your one stop shop for all the details you could ever need on your adorable little fishes if (like myself) you want to get into the nitty-gritty details of animal care. Most of this information has been pulled from in-game and the wiki, and personally I'm not a fan of how the game organizes your animals, even after the additional filters that have been added. As such, I aim to make this guide, and finding the information within it, as simple and intuitive as possible.

This guide starts off with several sections on the icons that you will find in the animal information boxes and an alphabetized list of all the animals in the game. The bulk of this guide sorts every single animal in the game by Rank and gives all of their data for your convenience. I have also included my personal recommendations for which animals should be paired up with who, mainly judged by shared food type and skill levels. Feel free to ignore these, as they are completely subjective.

All data has been taken from Normal difficulty. This guide covers the Deep Freeze expansion. For the original Megaquarium, Freshwater Frenzy or Architect's Collection animals, check out my other guides at The Ultimate Animal Guide (Original), The Ultimate Animal Guide (Freshwater Frenzy) and The Ultimate Animal Guide (Architect's Collection).

Incidentally if you wish to access the wiki, here is the link: https://megaquarium.fandom.com/wiki/Megaquarium_Wiki
Credit goes to user FeelTheDango for the AcidicNeutral, Communal, Explorer and OpenSpace icons which I borrowed and edited for this guide.

This section will explain about all the icons shown on the animal information screens. Though most of these are self-explanatory, there can be some nuance to the details between different species, especially when it comes to breeding. The icons are organized in the same general order they show up in on the animal information screens, from left to right and up to down.

Prestige: Whenever a guest looks at an animal, there is a % chance that a certain amount of Prestige will be generated. The number on the star shows the amount generated, while this guide will show the % chance that this will occur for 1 animal, and the # of animals needed to make that 100%. As an animal grows bigger, the % chance per individual will increase, and sometimes the base Prestige amount can increase as well.

When this icon is a superscript to another icon (e.g.), it means that the animal's base Prestige will be increased by fulfilling optional tank requirements, like having a certain number of individuals more than the needed amount, or adding more species when not strictly required.

Ecology and Science: Similar to Prestige, these show the # of Ecology or Science points generated whenever a guest looks at this animal. Unlike Prestige however, this is always 100%. Also like Prestige, these amounts change as an animal grows.

Size and Warning Type: On the animal information screen, this shows the base and max size of an animal, designated as # - #. If an animal does not grow, it only shows one number. Also, if an animal has more than two stages of development, you will have to hover the mouse cursor over the Clock icon to see the middle stages (or consult this guide). When hovering over the Warning icon, this designates all animals that do NOT otherwise belong to a special group, such as Crustaceans (so, most of the animals in the game).

Temperature: The temperature of the water this animal requires to survive. The amount of heat or cold generated by your equipment must always be ≥ the size of the tank, or for super chilled, to be at least double. Some animals require the temperature to be over the threshold by a certain % to initiate breeding.

Air Conditioning: This animal requires the tank to be Air Conditioned. The amount of Air Conditioning generated by your equipment must always be ≥ the of the tank, or for ice to form, at least double.

Filter Power: Identical to filter power provided by your equipment, these animals will increase the water quality of the tank. The amount is very small, so don't count on these to make a difference in anything larger than the smallest tank sizes.

Land and Perch: The amount of Land or Perch capacity each individual of this species requires. Each beach tank and polar dome has a fixed Land and Perch capacity, regardless of how small or large you make it. Animals requiring Land or Perch have their size stat halved when calculating the water tank capacity (ex. an animal with 40 only takes up 20 in the tank).

Water Quality: The base quality of the water in the animal's tank for it to remain healthy, determined by equipment, decorations and the bioload of all resident animals. The formula for calculating the quality has not been made public and is apparently fiendishly complicated, so this guide does not provide details on the animals' bioload unless specifically noted in-game. Note that water quality above the base threshold can improve the % of an animal's offspring.

(and others) Food: The type of food this animal eats. Hovering over the icon will show the time interval between feedings, while the individual animal's information box will show the amount needed per feeding. This value increases as the animal grows. Note that the offspring of an animal sometimes has a different diet.

Supplement: This animal will require a supplement every three days. It is always one supplement, and always three days, even after it grows.

Clipboard: This animal requires "observation" after the number of days shown on the icon, repeating for its entire lifespan. The observation task requires a staff member with the Feeding skill to use the clipboard tool.

Kreisel, Rounded and Abyssal: This animal must reside in a tank of this type to stay healthy. Animals without a tank requirement can live in either Kreisel or Rounded, though only Abyssal animals can live in Abyssal tanks.

Scavenger: This animal is automatically fed when any other animal in the tank is fed and does not affect the water quality of the tank. Animals with this trait will still require food every day, so do not pair them with animals that can go a day or more between feedings.

Lights: How many lights the animal requires its tank to have. Some species require lights on their tank to initiate breeding.

Terrain Features: Many animals will need a certain amount of terrain features to feel healthy and at home (or dislikes the feature). From left to right are: Plant, Cave, Rock, Bogwood, Flat Surface, Floating Cover, Fluffy Foliage, Vertical Surface, Grass, Pebble and Den. Some animals will also require these for breeding purposes, as the offspring will live in these objects. Note that all Bogwood decorations will also provide acidity, some of the Floating Cover decorations have a depth requirement, and Grass, Pebble and Den decorations can only be placed on land.

Explorer: This animal will require a certain number of different decorations to stay healthy. These are simple to combine with the animal's innate terrain requirements.

Open Space: The tank this animal resides in must have a continuous unobstructed square area. There must be absolutely no decorations of any kind inside this area.

Tank Depth: The depth of this animal's tank must be at least the number shown.

Animal Type: Any animal with one of these icons does not belong to the default "Animal" group. From left to right these are: Crustaceans, Starfish, Soft Coral, Stony Coral, Anemone, Clams and Gorgonians.

No Conspecifics: Only one member of this species is recommended per tank, as any more will reduce the health of all members.

Wingman: This species must be paired with another animal with a size of the number shown or greater.

Shoaler: This species needs at least this many individuals (of its own species) per tank to be healthy.

Flying Bird: This animal can only be hurt by other animals that can attack Flying Birds.

Active Flyer: This animal will need its tank to be a minimum air volume to stay healthy.

Greedy: Consumes 33% more food and has a 33% increased bioload on the tank.

No Food Competitors: Cannot be housed with another species that eats the same food. Members of the same species are fine.

Wimp and Bully: A species with one of these traits cannot be housed with a species with the other trait.

Communal: This animal needs at least this number of additional species in the same tank.

Congeners: Can only be housed with species of the same group, or cannot be housed with species of the same group.

Active Swimmer: This animal will need its tank to be a minimum size to stay healthy.

Armored and Heavily Armored: This animal will have a higher effective size when determining whether it can be eaten. Hover over the icon to see the #. Heavily Armored animals cannot be eaten and are immune to Biters.

Acidity: All freshwater species will require a certain level of acidity to survive. This icon will indicate either neutral (green) or acidic (red). Some species can live in both.

Biter: This species will decrease the health of any animal not of the same species and at least 3 Size.

Plant Destroyer: This animal has a % chance to damage the plants in the tank. The more Plant Destroyers you have and/or the fewer plants you have will increase the % chance. With enough plants this can always be reduced to 0. Some species will count an individual as multiple Plant Destroyers.

Territorial: The combined size of the individuals of this species in the same tank must not exceed the percentage number shown of the tank's capacity (ex: a species of size 2 with 5 individuals has a combined size of 10. Therefore if the territorial percentage is 10%, the tank they inhabit must be at least 100 size).

Skill: When this icon is a superscript to another icon (e.g.), that task will take a longer time to complete. Staff members will need a correspondingly higher skill in that task to compensate.

Pairs Only: Members of this species must be kept in multiples of 2, or the single one will lose health.

Nibbler and Nibbleable: Similar to Wimp and Bully, A species with one of these traits cannot be housed with a species with the other trait. Multiple Nibblers will stack the health loss to the Nibbleable.

Warning: Hover over the triangle to see a list of other species that this animal may damage and/or eat. The victims are typically defined by type and a size range.

Hybrid: The offspring of this species have a chance to be a different color and/or pattern. This guide will not cover the process of hybridization, as it is purely aesthetic and not clearly defined.

Heart: Hover over this icon to see the breeding process for this species. This covers the initial requirements to initiate breeding and the offspring's diet and habitation needs.

Mucus: This offspring will require at least one parent to be present to feed.

Needs Parent: This offspring must share the tank with at least one parent. While they are growing, neither the offspring nor the parent can be sold or removed from the tank.

Predator: These offspring will lose one % chance for each animal that is size 5 or lower. Sometimes the parents will protect the offspring with an additional base % and sometimes they are Predators as well.

Days until growth: Shows how many days until this individual reaches its next growth stage as long as all of its basic care requirements are satisfied. Hover over the icon to see all of the growth stages and their timeframes.

Freshwater and Saltwater: The water type that this species will need in its tank. Some species can live in both.

Ice: At least this much Ice must be in the tank for the animal to stay healthy. Ice forms when Air Conditioning is at least double the tank's .

Enrichment: A certain amount of Enrichment decorations are required for this animal to stay healthy. Note that Enrichment decorations decrease in value beyond the first.

Survival: The base survival rate of this offspring. High water quality and parent protection can increase this, while predators and poor basic care will decrease this.

Eggs: The number of eggs or fry of this offspring. Every day this # will be reduced to the % (ex. 10 eggs and 70% means that the next day there will be 7 eggs).

Adélie Penguin (Rank 9)
Antarctic Feather Star (Rank 7)
Antarctic Scallop (Rank 5)
Antarctic Sea Pig (Rank 6)
Antarctic Sea Whip (Rank 6)
Antarctic Silverfish (Rank 5)
Arctic Char (Rank 4)
Arctic Skate (Rank 8)
Atlantic Halibut (Rank 11)
Atlantic Puffin (Rank 7)

Barreleye (Rank 11)
Black Seadevil Anglerfish (Rank 9)
Blackfin Icefish (Rank 6)
Bubblegum Coral (Rank 10)

Crabeater Seal (Rank 11)

Dumbo Octopus (Rank 7)

Emperor Penguin (Rank 10)

Giant Isopod (Rank 5)
Giant Phantom Jelly (Rank 13)
Goblin Shark (Rank 12)

Long-Nosed Chimaera (Rank 10)
Long-Tailed Duck (Rank 6)

Northern Sea Otter (Rank 8)

Pacific Viperfish (Rank 8)
Pacific Walrus (Rank 12)
Peacock Squid (Rank 9)
Polar Bear (Rank 13)

Shorthorn Sculpin (Rank 4)
Snow Petrel (Rank 9)

Zigzag Coral (Rank 8)

Arctic Char (Schooling Finfish)
Recommended Tank Mates: Antarctic Silverfish, Atlantic Cod, Fish-Eating Anemone

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Shorthorn Sculpin (Lionfish and Scorpionfish)
Recommended Tank Mates: Antarctic Scallop, Pie-Crust Crab, Turbot

Antarctic Scallop (Bivalves)
Recommended Tank Mates: Antarctic Silverfish, Blue Whiting, Fish-Eating Anemone, Shorthorn Sculpin

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Antarctic Silverfish (Schooling Finfish)
Recommended Tank Mates: Antarctic Scallop, Arctic Char, Atlantic Cod

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Giant Isopod (Crustaceans)
Recommended Tank Mates: Antarctic Sea Pig

Antarctic Sea Pig (Echinoderms)
Recommended Tank Mates: Any Abyssal animal

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Antarctic Sea Whip (Soft Coral)
Recommended Tank Mates: Bubblegum Coral, Peacock Squid, Zigzag Coral

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Blackfin Icefish (Oddballs)
Recommended Tank Mates: Emperor Penguin

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Long-Tailed Duck (Birds)
Recommended Tank Mates: Atlantic Mackerel, Pacific Walrus

Antarctic Feather Star (Echinoderms)
Recommended Tank Mates: Antarctic Sea Pig, Giant Phantom Jelly, Zigzag Coral

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Atlantic Puffin (Birds)
Recommended Tank Mates: Adélie Penguin, Crabeater Seal, Emperor Penguin, Snow Petrel












**Since the Polar Dome tanks max out at 13 Perch capacity, only 13 of these can exist in a tank at a time, though keep in mind you will need at least 1 open Perch capacity for breeding.

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Dumbo Octopus (Cephalopod)
Recommended Tank Mates: Barreleye, Black Seadevil Anglerfish

Arctic Skate (Rays)
Recommended Tank Mates: Northern Sea Otter

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Northern Sea Otter (Mammals)
Recommended Tank Mates: Arctic Skate, Crabeater Seal, Pacific Walrus

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Pacific Viperfish (Bioluminescent Fish)
Recommended Tank Mates: Black Seadevil Anglerfish, Peacock Squid

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Zigzag Coral (Stony Coral)
Recommended Tank Mates: Antarctic Sea Whip, Antarctic Feather Star, Giant Phantom Jelly

Adélie Penguin (Birds)
Recommended Tank Mates: Atlantic Puffin, Snow Petrel

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Black Seadevil Anglerfish (Bioluminescent Fish)
Recommended Tank Mates: Dumbo Octopus, Pacific Viperfish, Peacock Squid

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Peacock Squid (Cephalopod)
Recommended Tank Mates: Antarctic Sea Whip, Black Seadevil Anglerfish, Pacific Viperfish

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Snow Petrel (Birds)
Recommended Tank Mates: Adélie Penguin, Antarctic Silverfish, Atlantic Puffin, Crabeater Seal











**Since the Polar Dome tanks max out at 13 Perch capacity, only 13 of these can exist in a tank at a time, though keep in mind you will need at least 1 open Perch capacity for breeding.

Bubblegum Coral (Soft Coral)
Recommended Tank Mates: Antarctic Sea Whip, Barreleye

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Emperor Penguin (Birds)
Recommended Tank Mates: Atlantic Puffin, Blackfin Icefish














**Since the Polar Dome tanks max out at 43 Land capacity, only 13 of these can exist in a tank at a time and still have 3 Land capacity left over for breeding.

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Long-Nosed Chimaera (Oddballs)
Recommended Tank Mates: Antarctic Sea Pig

Atlantic Halibut (Oddballs)
Recommended Tank Mates: None

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Barreleye (Bioluminescent Fish)
Recommended Tank Mates: Bubblegum Coral, Dumbo Octopus

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Crabeater Seal (Mammals)
Recommended Tank Mates: Atlantic Puffin, Northern Sea Otter, Snow Petrel










**Due to this animal's Land and Ice Requirements, only 4 of these can exist in a tank at a time.

Goblin Shark (Sharks)
Recommended Tank Mates: Antarctic Sea Pig

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Pacific Walrus (Mammals)
Recommended Tank Mates: Long-Tailed Duck, Northern Sea Otter










**Since the Polar Dome tanks max out at 43 Land capacity, only 5 of these can exist in a tank at a time (4 for breeding purposes).

Giant Phantom Jelly (Jellyfish)
Recommended Tank Mates: Antarctic Feather Star, Zigzag Coral

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Polar Bear (Mammals)
Recommended Tank Mates: None












**Since the Polar Dome tanks max out at 43 Land capacity, only 3 of these can exist in a tank at a time (2 for breeding purposes).