Phallostethus cuulong is a very small freshwater fish from the Mekong Delta in Vietnam. Males of the species have a special copulatory organ on the head that is used during reproduction.
Phallostethus cuulong differs from other fish by the placement of the male sexual organ on the head. The species is important for studying the evolution of reproduction in fish and for conserving the biodiversity of the Mekong Delta.
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
freshwater marsh and wetlands
Taxons
carnivore
freshwater pelagic
Priapium count
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
Human
birth date
no permanent shelter
Close
was
days
Career from 7 to 15 months. Dwarf hamsters, voles, field crickets celebrate their birthday twice a month
The basics
active search and capture of prey
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?
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
adult
Maturity
primary food sources
Fins count
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
Priapium color
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
Eyes count
Southeast Asia and islands, always hot and humid
Body size
Colors
Sex
{name} birthday
Upcoming jubilees
Gremllins
mo
No results found
Hot with heavy summer rains
all seas and oceans
Trophic type
Filters
On the map
lunge
small crustaceans
all life stages
Female ♀
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.
open water in the water column of a freshwater body, away from the bottom and shore
Truly long lives: 40-100 years. Bowhead whales, albatrosses, giant tortoises recall their birthday at most once a year
Lifespan
up to ~3 grams, up to 3 centimeters
birth year
Maturity
Age (juvenile)
Fins size
insect larvae and caterpillars
Age (from birth to death)
sq mm
yr
Age (embryo)
Wanderers
Age (larva)
How similar?
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
zoo-plankton
Priapium size
Lifespan average
What do they eat?
insect larvae
Where do they live?
young after fast growth
Immature individual that has not yet reached reproductive maturity.
Marine world
from birth to death
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
swampy freshwater biotopes — peat bogs, marshes, river mangroves
Duration
Find a pet...
Mature, fully developed individual capable of reproduction.
Freshwater
saline marine habitat
This is me
freshwater
Actively hunting and capturing live prey.
Gamers
hot, heavy rains in summer, little precipitation in winter
Pets
How are they built?
all rivers and lakes
Indomalayan realm
marine
shallow near the shore, water rises and falls, crabs live here
mm
Indomalayan realm
Theoretical lifespan
ml
Stars
Link copied
coastal marine zone — shelf, neritic zone
My age?
wk
My size?
{name} jubilee
Eyes size
Asexual
swap
freshwater environment — rivers, lakes, ponds, swamps
cm
zooplankton feeding, animal plankton — small crustaceans and larvae
Old-timers
Find an animal or breed...
Southeast Asia and islands, always hot and humid
active predation
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
delta
When you would have been born if you lived as {name}
Littoral Zone
Litter size
Daddies
small crabs, amphipods and other crustaceans
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
river
°C
Not specified
Sand grain
Hermaphrodite ⚥
Where are they found?
Species lacks any fixed or lasting shelter structure.
embryo
all rivers and lakes
Length
kg
Rapid forward strike to seize prey.
Observations
◉{N} more on tap