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What the sources say

Water FleaDaphnia pulex

Every figure, record and mechanism on the Water Flea profile was written from a source, and this is the working table behind it: 48 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Animal Diversity Web, University of Michigan

Daphnia pulex. Animal Diversity Web, University of Michigan.

The page saysA mostly see-through
The source saysmost of its outer covering is clear, showing most of the internal organs at workNote: tagline; the account's sentence on D. pulex anatomy
The page sayspond crustacean
The source saysthe highest concentrations of Daphnia populations are found in the vegetation in most lakes and pondsNote: tagline
The page saysAlmost every permanent, nutrient-rich water body, mostly fresh water
The source sayscan be found in almost every permanent, eutrophic (nutrient-rich) water bodyNote: stats.habitat; ADW also says Daphnia are generally freshwater organisms
The page saysPhytoplankton and fine detritus filtered from the water
The source saysmost species of Daphnia, including D. pulex, are herbivorous or detritivorous (feeding on phytoplankton)Note: stats.diet; genus scope in ADW's food-habits paragraph, which also gives the detritus and filtering
The page saysNot Evaluated
The source saysIUCN Red List [Link] Not EvaluatedNote: conservationStatus; ADW lists the IUCN Red List status as Not Evaluated, and GBIF's copy of the Red List has no category for this name (prefetch 2026-10-11). Nothing quoted from an API.
The page saysWater fleas as a group are generally 0.2 to 3.0 mm long
The source saysThey are, in reality, a type of small crustacean and are generally 0.2-3.0 mm longNote: scope: water fleas as a group, as the account words it
The page saysMost of its outer covering is clear, showing most of the internal organs at work, including the heart.
The source saysmost of its outer covering is clear, showing most of the internal organs at work, including the heart
The page saysThey got their name from their general appearance and their jerky swimming, which resemble a land flea's.
The source saysTheir common name was given because of their general appearance and jerky swimming motions which resembles that of the land flea
The page saysthe most common water flea, a group found in almost every permanent, nutrient-rich water body
The source saysDaphnia pulex is the most common species of the water flea, an organism which can be found in almost every permanent, eutrophic (nutrient-rich) water body
The page sayslists it as native to the Nearctic, Palearctic, Oriental, Ethiopian, Neotropical and Australian regions, biologists' names for land from North America to Australia
The source saysnearctic nearctic native native palearctic palearctic native native oriental oriental native native ethiopian ethiopian native native neotropical neotropical native native australian australian native nativeNote: range list as extracted from the ADW map table; the gloss is geography
The page saysDaphnia are filter feeders that do not usually seek out food: their legs keep water moving through the shell, and bristles called setae filter out food particles.
The source saysThey are filter feeders meaning they do not usually actively seek food; they merely create a constant movement of water using their thoraic legs through their carapace where they are able to filter out any food particles with the setaeNote: genus scope
The page saysLike most Daphnia, it eats phytoplankton, tiny drifting algae, and detritus, bits of decaying matter.
The source saysmost species of Daphnia, including D. pulex, are herbivorous or detritivorous (feeding on phytoplankton)
The page saysAnimal Diversity Web puts water fleas at generally 0.2 to 3.0 mm long.
The source saysgenerally 0.2-3.0 mm longNote: FAQ

Source
02

Colbourne et al. 2011

Colbourne et al. (2011). The Ecoresponsive Genome of Daphnia pulex. Science.

The page says200-megabase genome holds at least 30,907 genes
The source sayswhich is only 200 megabases and contains at least 30,907 genesNote: tagline
The page saysSome clones grow neckteeth in response to chemical cues from the predator Chaoborus
The source saysThis clone was shown to respond to chemical cues from Chaoborus by producing distinct neckteethNote: stats.superpower; one D. pulex clone (R9)
The page saysis a microcrustacean, a tiny kind of crustacean
The source saysthe microcrustacean Daphnia pulex
The page saysis only 200 megabases
The source sayswhich is only 200 megabases
The page saysYet it holds at least 30,907 genes.
The source sayscontains at least 30,907 genes
The page saysthe animal has an elevated rate of gene duplication, which makes tandem gene clusters
The source saysThe high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters
The page saysMore than a third of its genes have no detectable match in any other available proteome
The source saysMore than a third of Daphnia's genes have no detectable homologs in any other available proteome
The page saysThe animal that was sequenced was a natural isolate within the D. pulex species complex.
The source saysA natural isolate within the D. pulex species complex was picked for sequencing
The page saysDaphnia-specific genes, including many loci in stretches otherwise devoid of annotations, were the most responsive genes to ecological challenges.
The source saysDaphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challengesNote: blockquote; the unannotated-loci clause restored
The page saysclone from arctic Canada, called R9
The source saysDaphnia pulex clone R9 (isolated from arctic Canada by Dr. Larry Weider)
The page sayswas shown to respond to chemical cues from the predator Chaoborus by producing distinct neckteeth
The source saysThis clone was shown to respond to chemical cues from Chaoborus by producing distinct neckteeth
The page saysAll juveniles in the induction treatment carried neckteeth.
The source saysAll juveniles in the induction treatment carried neckteeth.

Source
03

Schurko, Logsdon & Eads 2009

Schurko, Logsdon & Eads (2009). Meiosis genes in Daphnia pulex and the role of parthenogenesis in genome evolution. BMC Evolutionary Biology.

The page saysreproduces by cyclical parthenogenesis, which alternates bouts of clonal and sexual reproduction
The source saysThe microcrustacean Daphnia pulex reproduces by cyclical parthenogenesis
The page sayscyclical parthenogenesis, which alternates bouts of clonal and sexual reproduction
The source sayscyclical parthenogenesis, which alternates bouts of clonal and sexual reproductionNote: definition, from the paper's intro on animals generally
The page saysfemales make summer eggs that develop right away in the mother's brood chamber, with no fertilization
The source saysDirect-developing eggs (also called subitaneous or summer eggs) are produced parthenogenetically and immediately develop in the female's brood chamber prior to hatchingNote: 'with no fertilization' glosses parthenogenetically
The page saysFemales make direct-developing eggs that grow in the brood chamber and hatch without fertilization.
The source saysDirect-developing eggs (also called subitaneous or summer eggs) are produced parthenogenetically and immediately develop in the female's brood chamber prior to hatchingNote: FAQ
The page saysThe resting eggs made in the sexual cycle do need fertilization, plus a long spell of dormancy.
The source sayshaploid resting eggs (also called ephippial, diapause, or winter eggs) are produced by meiosis and require fertilization and a period of extended dormancy for development to completeNote: FAQ
The page saysSome lineages reproduce by obligate parthenogenesis
The source saysgenetic and phenotypic evidence has revealed D. pulex lineages that reproduce by obligate parthenogenesis
The page saysthey have lost the requirement for meiosis and fertilization to produce viable resting eggs
The source saysobligate parthenogens have lost the requirement for meiosis and fertilization to produce viable resting eggs
The page saysIn its clonal phase a female makes summer eggs with no fertilization
The source saysDirect-developing eggs (also called subitaneous or summer eggs) are produced parthenogenetically and immediately develop in the female's brood chamber prior to hatchingNote: vibe.reason, same quote as the body

Source
04

Eads et al. 2007

Eads et al. (2007). Profiling sex-biased gene expression during parthenogenetic reproduction in Daphnia pulex. BMC Genomics.

The page saysCrowding, lower temperatures or a food shortage can switch the program.
The source sayssuch as crowding, lowered temperature or food scarcity can induce either male production
The page saysThey can bring on males, which are genetic copies of their mothers
The source saysmales are genetically identical to their mothers
The page sayshaploid eggs that are fertilized and overwinter in a dormant state called diapause
The source sayshaploid gametes that are fertilized and overwinter in a state of diapause
The page sayscrowding, cold or a food shortage switches the program
The source sayssuch as crowding, lowered temperature or food scarcity can induce either male productionNote: vibe.reason, same quote as the body

Source
05

Tucker et al. 2013

Tucker et al. (2013). Population-genomic insights into the evolutionary origin and fate of obligately asexual Daphnia pulex. Proceedings of the National Academy of Sciences.

The page saysA genome study of 11 sexual and 11 asexual genotypes indicates that today's asexual lineages are very young.
The source saysWhole-genome analysis of 11 sexual and 11 asexual genotypes of Daphnia pulex indicates that current asexual lineages are in fact very young
The page saysGenes passed in from a sister species, Daphnia pulicaria, underlie the origin of their asexuality
The source saysintrogression from a sister species, Daphnia pulicaria, underlies the origin of the asexual phenotypeNote: introgression glossed as genes passed in
The page saysThe spread of asexuality is as recent as 1,250 years
The source saysindicates that the spread of asexuality is as recent as 1,250 y
The page saysalthough the genetic element that suppresses meiosis could be substantially older
The source saysalthough the origin of the meiosis-suppressing element or elements could be substantially olderNote: the source's own qualifier on the 1,250-year figure

Source
06

Leoni & Garibaldi 2009

Leoni & Garibaldi (2009). Population dynamics of Chaoborus flavicans and Daphnia spp.: effects on a zooplankton community in a volcanic eutrophic lake with naturally high metal concentrations (L. Monticchio Grande, Southern Italy). Journal of Limnology.

The page saysCues from invertebrate predators are known to induce longer tail spines, bigger helmet crests or neck teeth in Daphnia, a defence that makes the prey harder to handle or better at escaping.
The source sayskairomones of invertebrate predators are known to induce elongation of tail spines, enlarged helmet crests or the development of neck teeth in Daphnia spp. (Parejko 1991; Spitze 1992; Black 1993; Repka et al. 1995) as a defence mechanism that makes the handling of prey more difficult (Caramujo & Boavida 2000) and/or increases the prey's escape abilityNote: genus scope, stated as such on the page

Source
07

Ukhueduan et al. 2022

Ukhueduan et al. (2022). Relationship between oxidative stress and lifespan in Daphnia pulex. Scientific Reports.

The page saysIn a lab study of 11 clones kept under identical conditions, the median lifespan ran from about 15 to about 85 days.
The source saysThe median lifespans in 11 clones of D. pulex were determined by life tables under identical conditions. As seen in Fig. 1 A, the median lifespans differ greatly (~ 15 to 85 days) among the clones.
The page saysWhen one lab raised 11 D. pulex clones under identical conditions, the clones' median lifespans differed greatly, from roughly 15 days to roughly 85.
The source saysThe median lifespans in 11 clones of D. pulex were determined by life tables under identical conditions. As seen in Fig. 1 A, the median lifespans differ greatly (~ 15 to 85 days) among the clones.Note: FAQ
The page saysLifespan varies by clone.
The source saysthe median lifespans differ greatly (~ 15 to 85 days) among the clones
The page saysIt depends on the clone.
The source saysthe median lifespans differ greatly (~ 15 to 85 days) among the clonesNote: FAQ

Source
08

Liu et al. 2019

Liu et al. (2019). Polystyrene nanoplastic exposure induces immobilization, reproduction, and stress defense in the freshwater cladoceran Daphnia pulex. Chemosphere.

The page saysIn a lab study, after exposure to polystyrene nanoplastic, the digestive organs glowed with the particles
The source saysthe digestive organs of D. pulex were strongly fluorescent after exposure to the nanoplastic particles
The page saysevery treatment group produced fewer offspring per female
The source saystotal offspring per female and number of clutches were decreased in all the treatment groups

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.