The ayu is a small fish with an elongated body that lives in rivers and coastal waters of East Asia. It feeds on algae and usually lives for only one year.
Ayu differs from related fish by its comb-like teeth for feeding on algae and a short life cycle with a single spawning. This fish is important for rivers because it controls algae growth and serves as food for predators.
Legendary longevity: over 100 years. Galapagos tortoises, Greenland sharks, ocean quahogs celebrate with family once every 4 years
Immature form that undergoes metamorphosis before adulthood.
Offspring
Worker
Elders
Bro
scraping
birth time
lakes and ponds
freshwater marsh and wetlands
Taxons
if born as {name}
Dogs, dolphins, lynx hang out for 9-25 years and party on their birthday three times a year
m
Map
will celebrate their {n} birthday
shallow coastal zones of rivers and lakes
g
age
t
When your next jubilee falls in {name} life years
Human
birth date
no permanent shelter
Palearctic realm
freshwater coastal and creek
Close
was
days
Career from 7 to 15 months. Dwarf hamsters, voles, field crickets celebrate their birthday twice a month
Marine world
The basics
How old you would be if you lived as {name}
Theoretical maximum lifespan estimated from the Dynamic Energy Budget (DEB) mathematical model. This value reflects a biological potential derived from metabolic parameters, not from direct observation — real recorded lifespans are often significantly shorter.
My weight?
Rasping or abrading food surfaces with teeth or mouthparts.
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
adult
Maturity
Mouth size
primary food sources
Temperate sea
Fins count
Potential Habitat
About health
Searches for food on or among rocks and stony surfaces.
algae
When your next birthday would fall if you lived as {name}
d
In husbandry
On the go from 1.3 to 3.5 years. Forest mice, anoles, rainbow fish party on their birthday once a month
results
Mass
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
biofilm on stones and surfaces in water — algae, bacteria, protozoa (afvukhs)
Colors
Sex
{name} birthday
Upcoming jubilees
Gremllins
mo
No results found
all seas and oceans
Trophic type
Filters
On the map
all life stages
Female ♀
Palearctic realm
Body color
Upcoming birthdays
standing fresh waters — lakes, ponds, oxbow lakes
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
Potential habitat modelled from GBIF occurrence data. Map © Zveriki.com, licensed under CC BY 4.0.
Truly long lives: 40-100 years. Bowhead whales, albatrosses, giant tortoises recall their birthday at most once a year
Lifespan
birth year
Maturity
Age (from birth to death)
rock
sq mm
yr
phytoplanktophagy, plant plankton — microscopic algae
most of Europe and Asia, various forests, steppes and tundra
Wanderers
How similar?
algae
Jubilee = every 10th birthday
periphyton and biofilm
scraping algae from rocks
Male ♂
until the celebration
age as {name}
How do they breed?
On the go from 3.5 to 6 years. Hedgehogs, crows, lizards treat themselves to birthday snacks 6 times a year
What if eaten?
Neither
Earliest developmental stage inside an egg or womb.
Business sausages
Lifespan average
What do they eat?
Where do they live?
young after fast growth
Marine world
Regeneration
phyto-plankton
Juvenile stage following larval metamorphosis but not yet adult.
early young
What do they look like?
Maturity
water often floods the land, lots of grass
emergence (insects)
end of lifespan
Freshwater
How do they live?
fertilization / egg laying
How do they behave?
birth / hatching
metamorphosis / end of larval stage
Temperate mixed forest
end of acceleration
Share
swampy freshwater biotopes — peat bogs, marshes, river mangroves
Duration
Find a pet...
Mature, fully developed individual capable of reproduction.
Freshwater
Egg count
This is me
most of Europe and Asia, various forests, steppes and tundra
water is cool or warm, cold in winter, comfortable to swim in summer
freshwater
Gamers
aquatic plants and algae
65 to 130 grams, 25 – 60 centimeters
Pets
How are they built?
all rivers and lakes
shallow near the shore, water rises and falls, crabs live here
mm
Theoretical lifespan
ml
Stars
Link copied
My age?
wk
My size?
estuary
{name} jubilee
Asexual
swap
freshwater environment — rivers, lakes, ponds, swamps
cm
Old-timers
Find an animal or breed...
turns
Rabbits, falcons, red-eared turtles hang out for 6-9 years and party on their birthday four times a year
Rascals
Where do they take shelter?
Warm summer and lots of rain
Flooded grasslands
celebrated their {n} birthday
When you would have been born if you lived as {name}
Littoral Zone
Litter size
rocky riverbed
Daddies
Lifespan maximum
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
How to care for them?
Living from 25 to 40 years. Orangutans, bald eagles, African elephants celebrate their birthday twice a year
foraging
°C
Not specified
Hermaphrodite ⚥
Actively searching habitats to locate food items.
Egg color
Where are they found?
all seas and oceans
Species lacks any fixed or lasting shelter structure.
embryo
Carrot
all rivers and lakes
summer warm, many oaks, birches, maples
herbivore
Length
kg
lots of rain, warm and pleasant summer
Observations
◉{N} more on tap