The Rikuzen flounder, or Dexistes rikuzenius, is a marine bottom-dwelling fish with a strongly flattened body. Both eyes of the adult fish are on the right side of the head, which helps it see when lying on the bottom.
The Rikuzen flounder differs from other flounders in its unique head structure and preference for cold waters in the northwestern part of the Pacific Ocean. It plays an important role in the marine ecosystem as a predator eating small animals and serves as food for larger fish and marine mammals.
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
birth time
Pelagic Ocean
ambush
Taxons
carnivore
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
g
age
t
When your next jubilee falls in {name} life years
Predator remains still and concealed before launching a sudden attack.
Human
birth date
Palearctic realm
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?
mollusks
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
adult
Maturity
fish of small size
primary food sources
crabs
polychaetes
Coconut
live marine and freshwater shrimps
burrow
Temperate sea
Potential Habitat
About health
marine coastal
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
Repro interval
results
Mass
annelid polychaetes of marine habitats
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
Eyes count
Body size
Colors
Sex
{name} birthday
Upcoming jubilees
Gremllins
mo
Uses an excavated underground tunnel or chamber for refuge or nesting.
No results found
all seas and oceans
Trophic type
Filters
small fish
On the map
all life stages
Female ♀
Palearctic realm
Body color
Upcoming birthdays
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 (juvenile)
Age (from birth to death)
sq mm
yr
Age (embryo)
most of Europe and Asia, various forests, steppes and tundra
Wanderers
Age (larva)
How similar?
far from shore, deep water, large whales and sharks live here
Egg size
Jubilee = every 10th birthday
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
from birth to adulthood
Lifespan average
What do they eat?
water is almost always cold, there may be ice in winter, not hot in summer
Where do they live?
young after fast growth
Immature individual that has not yet reached reproductive maturity.
from birth to death
Marine world
Regeneration
Juvenile stage following larval metamorphosis but not yet adult.
early young
What do they look like?
Maturity
emergence (insects)
end of lifespan
Freshwater
How do they live?
fertilization / egg laying
How do they behave?
birth / hatching
metamorphosis / end of larval stage
end of acceleration
Share
live snails, mussels, oysters
Duration
Find a pet...
Mature, fully developed individual capable of reproduction.
Cold sea
saline marine habitat
Egg count
This is me
Lateral line count
most of Europe and Asia, various forests, steppes and tundra
water is cool or warm, cold in winter, comfortable to swim in summer
from 0.5 to 0.8 kilograms, 0.5 – 1 meter
Gamers
Pets
How are they built?
marine
shallow near the shore, water rises and falls, crabs live here
mm
Theoretical lifespan
ml
Stars
Link copied
coastal marine zone — shelf, neritic zone
My age?
wk
My size?
{name} jubilee
Asexual
swap
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?
celebrated their {n} birthday
When you would have been born if you lived as {name}
Littoral Zone
Litter size
live crabs, shrimps, lobsters
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
°C
Not specified
Hermaphrodite ⚥
Egg color
shrimp
Where are they found?
all seas and oceans
embryo
Dorsal fin size
all rivers and lakes
Length
kg
Observations
◉{N} more on tap