---
title: "What the sources say about the Siamese Fighting Fish | AnimalTracks.wiki"
description: "45 claims from the Siamese Fighting Fish profile, each beside the words of the source that backs it."
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---

# What the sources say about the Siamese Fighting Fish (*Betta splendens*)

> 45 claims from the Siamese Fighting Fish profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Siamese Fighting Fish](https://animaltracks.wiki/animals/siamese-fighting-fish/)

## Evolution, Culture, and Care for Betta splendens. UF/IFAS Extension, University of Florida.

https://edis.ifas.ufl.edu/publication/FA212

| The page says | The source says |
| :--- | :--- |
| breathes air through a labyrinth organ | Labyrinth fishes take their name from a specialized air-breathing structure called the labyrinth organ. (note: tagline and superpower) |
| whose males flare their gill covers at each other | Males will almost immediately display aggressive behaviors—spreading their fins and flaring out their gill covers—when they encounter another male. (note: tagline; 'almost' hedges the timing (almost immediately), which the tagline does not state) |
| Typically shallow ponds, rice paddy fields and puddles in Southeast Asia | In the wild, the betta is typically found in standing waters, including shallow ponds, rice paddy fields, and even puddles. (note: habitat; Southeast Asia from the same page: The betta, native to Southeast Asia) |
| Breathes air through a labyrinth organ above its gills | Labyrinth fishes have paired chambers located above the gills which are extensions of the first gill arch. These chambers contain complex, folded, bony structures covered with respiratory epithelium (the labyrinth organ), allowing them to breathe air. (note: superpower) |
| It belongs to the labyrinth fishes, named for the labyrinth organ | Labyrinth fishes take their name from a specialized air-breathing structure called the labyrinth organ. |
| folded, bony structures in paired chambers above the gills that let the fish take in air | Labyrinth fishes have paired chambers located above the gills which are extensions of the first gill arch. These chambers contain complex, folded, bony structures covered with respiratory epithelium (the labyrinth organ), allowing them to breathe air. |
| Life in hypoxic (low-oxygen) water appears to have driven the diversification of this group | Life in hypoxic environments appears to have been the driving force behind the evolutionary diversification of labyrinth fishes |
| The wild betta is typically found in standing water, from shallow ponds and rice paddy fields to puddles | In the wild, the betta is typically found in standing waters, including shallow ponds, rice paddy fields, and even puddles. |
| the water averaged 29.9°C and about 5.0 cm deep | temperature of 29.9°C (about 86°F on average; range from approximately 27.0 to approximately 31.5°C), and depth of about 5.0 cm (2 inches on average (note: Thailand betta population) |
| its dissolved oxygen averaged about 3.8 mg/L, swinging between 0.0 and about 7.4 mg/L | dissolved oxygen can be low (average about 3.8 mg/L), exhibiting extreme variation (dissolved oxygen ranges from 0.0 to about 7.4 mg/L) |
| When a male meets another male, he spreads his fins and flares out his gill covers almost immediately. | Males will almost immediately display aggressive behaviors—spreading their fins and flaring out their gill covers—when they encounter another male. |
| As the fight goes on, the fish bite each other, particularly on the fins and flanks. | As aggression proceeds, the fish will then bite each other, particularly on the fins and flanks. |
| Male bettas are among the most aggressive of the labyrinth fishes. | betta males are among the most aggressive |
| Fights between two males were popular in Thailand for gambling, and the first fish to retreat was deemed the loser. | Early on, males were selected for their aggression because fights between two males were popular in Thailand for gambling. |
| the first fish to retreat was deemed the loser | Males were placed into small containers together to fight, and the first fish to retreat was deemed the loser. |
| The modern aquarium betta is a product of almost 100 years of selective breeding, first for aggression and now for bright colors and elaborate fins. | The modern betta is a product of almost 100 years of selective breeding. Early on, males were selected for their aggression (note: bright colors and elaborate fins: next paragraph says 'selected for bright colors as well as elaborate fins') |
| now for bright colors and elaborate fins | Today's commercial bettas are much different than these early "fighting" fish, and have now been selected for bright colors as well as elaborate fins |
| The wild betta, by comparison, is dull brown or green. | Compared to the conspicuous color patterns observed in captivity, the wild betta is dull brown or green. |
| allows eggs to develop in water with elevated temperature, low pH and low dissolved oxygen, relatively free of predators | The bubble nest allows eggs to develop in environments with elevated temperature and low pH and dissolved oxygen, relatively free of predators. |
| Placing the eggs at the surface increases oxygen exchange, and the nest also keeps them from drying. | Placement of the eggs at the surface increases oxygen exchange, while the bubble nest also prevents the eggs from drying. |
| the male wraps his body around the female and fertilizes the eggs as she releases them | The male will wrap his body around the female and fertilize the eggs as she releases them, a few at a time. |
| Then he picks the eggs up in his mouth as they fall and places them in the bubble nest. | The male will then pick up the eggs in his mouth as they fall through the water and place them in the bubble nest |
| About 300 eggs are released per spawning event. | with about 300 eggs released per spawning event |
| The male adds bubbles to the nest when needed and keeps newly hatched larvae in it. | Males will tend to the fertilized eggs and add bubbles to the nest when needed. Additionally, males will tend to newly hatched larval bettas and make sure they stay in the nest. |
| The wild bettas the University of Florida describes in Thailand lived in shallow water that was hot, acidic and short of oxygen. | these habitats were characterized by heavy emergent vegetation, shallow water, low dissolved oxygen, high temperature, and an acidic pH (note: faq 2; 'these habitats' are the Thailand population's) |
| A floating nest of bubbles lets the eggs develop there with fewer predators around | The bubble nest allows eggs to develop in environments with elevated temperature and low pH and dissolved oxygen, relatively free of predators. (note: faq 2) |
| The University of Florida describes the wild betta as dull brown or green. | the wild betta is dull brown or green (note: faq 3) |
| The bold colors and long fins of pet bettas came from selective breeding in captivity. | beautiful, bold colors, and long fins developed by selective breeding in captivity (note: faq 3) |
| gives them better oxygen exchange at the surface and keeps them from drying out | Placement of the eggs at the surface increases oxygen exchange, while the bubble nest also prevents the eggs from drying. (note: faq 2) |
| the folded chambers above its gills that let it breathe air | Labyrinth fishes have paired chambers located above the gills which are extensions of the first gill arch. These chambers contain complex, folded, bony structures covered with respiratory epithelium (the labyrinth organ), allowing them to breathe air. (note: vibe.reason (#1238)) |

## Betta splendens, Siamese fighting fish. FishBase.

https://www.fishbase.se/summary/Betta-splendens.html

| The page says | The source says |
| :--- | :--- |
| A fish up to 6.5 cm long | Max length : 6.5 cm TL male/unsexed (note: tagline) |
| FishBase gives a maximum length of 6.5 cm | Max length : 6.5 cm TL male/unsexed |
| The maximum reported age is 2 years | max. reported age: 2.00 years |
| FishBase lists a maximum length of 6.5 cm for males or unsexed fish, and a maximum reported age of 2 years. | Max length : 6.5 cm TL male/unsexed; (Ref. 12693 ); max. reported age: 2.00 years (note: faq 1) |
| can breathe air | Facultative air-breathing (note: FishBase species-level: 'Facultative air-breathing' means it can, not must, breathe air; EDIS labyrinth-organ quote covers the mechanism) |
| dangerLevel: Low | Threat to humans
Harmless (note: stats.dangerLevel (#1165)) |

## AnAge entry for Betta splendens. AnAge: The Animal Ageing and Longevity Database.

https://genomics.senescence.info/species/entry.php?species=Betta_splendens

| The page says | The source says |
| :--- | :--- |
| AnAge also gives 2 years as the maximum longevity. | Maximum longevity 2 years (note: faq 1; quote joined across a line break) |

## Betta splendens Regan, 1910. USGS Nonindigenous Aquatic Species database.

https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=326

| The page says | The source says |
| :--- | :--- |
| the USGS lists the size as 6 cm | Size: 6 cm. |
| The species is native to Southeast Asia, including the northern Malay Peninsula, central and eastern Thailand, Cambodia and southern Vietnam | Native to Southeast Asia including the northern Malay Peninsula, central and eastern Thailand, Kampuchea, and southern Vietnam (note: Kampuchea is Cambodia) |

## Siamese Fighting Fish (Betta splendens) Ecological Risk Screening Summary. U.S. Fish and Wildlife Service.

https://www.fws.gov/sites/default/files/documents/Ecological-Risk-Screening-Summary-Siamese-Fighting-Fish.pdf

| The page says | The source says |
| :--- | :--- |
| Mosquito larvae and other water insects | Bettas are carnivorous fish with a diet consisting of mosquito larvae and other water insects (note: diet) |
| Bettas are carnivores that eat mosquito larvae and other water insects | Bettas are carnivorous fish with a diet consisting of mosquito larvae and other water insects |
| an adult male eats about ten to fifteen thousand larvae per year | It is estimated that adult male fish eat about ten to fifteen thousand larvae per year |
| also makes the air bubbles for the male's nest | The labyrinth organ is also responsible for the production of air bubbles for nest building. (note: vibe.reason (#1238); USFWS quoting its own sources; males build the nest per edis-fa212) |

## Vidthayanon (2011). Betta splendens. The IUCN Red List of Threatened Species 2011: e.T180889A7653828.

https://doi.org/10.2305/iucn.uk.2011-1.rlts.t180889a7653828.en

| The page says | The source says |
| :--- | :--- |
| The IUCN Red List rates the species Vulnerable, in an assessment published in 2011. | IUCN Red List category: Vulnerable (VU). (note: status; category read through GBIF's copy of the Red List (current); 2011 from the DOI's Crossref record, issued 2011-02-25) |

## Thongprajukaew et al. (2025). Recovery of Male Siamese Fighting Fish (Betta splendens) After Overland Shipping. Animals.

https://doi.org/10.3390/ani15142156

| The page says | The source says |
| :--- | :--- |
| weightKg: 0.0016 | One hundred and twenty fish were screened by size (1.56 ± 0.02 g body weight, 5.91 ± 0.04 cm total length) (note: #1229: 1.56 g = 0.0016 kg. The fish are 3.5-month-old males from a betta farm ("Solid-red, short-finned, 3.5-month-old male Siamese fighting fish"), at 5.9 cm against the page's 6.5 cm maximum) |