AnimalTracks.wiki

What the sources say

OlmProteus anguinus

Every figure, record and mechanism on the Olm profile was written from a source, and this is the working table behind it: 47 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.

Profile updated

Source
01

Animal Diversity Web, University of Michigan

Proteus anguinus (olm). Animal Diversity Web, University of Michigan.

The page saysUnderground lakes and streams of limestone caves
The source saysProteus anguinus is found in the subterranean, freshwater lakes and streams of limestone caves in the Dinaric Alps.Note: covers stats.habitat and the body's opening sentence ('the underground lakes and streams of limestone caves').
The page saysAmphipods, isopods, small snails, and insect larvae
The source saysThey prey on arthropods and small invertebrates such as Oniscus asellus as well as organsims of the genera Belgrandiella and Niphargus. They also feed on a wide variety of insect larvaeNote: covers stats.diet; Niphargus = amphipod genus, Oniscus asellus = isopod, Belgrandiella = small freshwater snail genus.
The page sayslives a salamander with greatly reduced eyes
The source saysIts eyes still retain some light sensitivity, but they are greatly reduced.
The page saysA young olm (*Proteus anguinus*) has better developed eyes than an adult
The source saysJuveniles may be distinguished from adults by the faint yellow or red blotches on their skin, and their better developed eyes.
The page sayswhose eyes are very small and do not even breach the skin
The source saysIts eyes are very small and do not even breach the skin.
The page saysit has skin on its underside translucent enough to reveal the contours of its internal organs
The source saysOn the ventral side of the body the skin is translucent and reveals the contours of internal organs.
The page saysAn olm's skin is usually creamy white to pale pink
The source saysThe skin is usually creamy white, but may have a pinkish hue.
The page saysexposed to light it turns dark violet to black, and the darkening reverses once it is back in the dark
The source saysWhen exposed to light, the skin turns dark violet to black. Darkening of the skin is reversed when it is returned to the darkness.
The page saysBehind its head sit three feathery pink gills on each side
The source saysDirectly behind the head on each side are three large, feathery, bright pink gills.
The page saysthe olm is neotenic
The source saysDevelopment - Life Cycle neotenic/paedomorphic
The page saysHatchlings skip a distinct period of metamorphosis and develop directly into adults, retaining some larval features such as their gills and finned tail
The source saysolm larvae do not go through a distinct period of metamorphosis. Instead, the hatchling juveniles have developed directly into adults, retaining some of their larval characters such as gills and tail fins.
The page saysIt hunts amphipods, isopods, small snails and insect larvae
The source saysThey prey on arthropods and small invertebrates such as Oniscus asellus as well as organsims of the genera Belgrandiella and Niphargus. They also feed on a wide variety of insect larvaeNote: Niphargus = amphipod genus, Oniscus asellus = isopod, Belgrandiella = small freshwater snail genus; common names used in place of the Latin names ADW gives.
The page saysin water generally more than 300 metres below the surface
The source saysThey are generally found over 300 meters below surface.
The page saysIts eyes keep some light sensitivity, but the olm leans on non-visual senses
The source saysProteus anguinus has developed non-visual sensory systems to better suit an aphotic lifestyle. Its eyes still retain some light sensitivity, but they are greatly reduced.
The page saysare suspected to help it locate prey by detecting electric fields
The source saysAll members of the genus Proteus contain an ampullary electroreceptor which is used to detect electric fields. The main function of their ampullary electroreceptor is not known, but it is suspected top be used for locating prey.
The page says20 to 30 centimetres long
The source saysRange length 20 to 30 cm
The page saystops out around 30 centimetres long
The source saysRange length 20 to 30 cmNote: upper end of ADW's 20-30 cm range.
The page sayseyes buried under its skin
The source saysIts eyes are very small and do not even breach the skin.
The page saysBehavioural studies suggest olms can also detect and orient to magnetic fields
The source saysBehavioral studies suggest that Proteus anguinus is also able to detect and orient itself to magnetic fields.
The page saysTo find prey they combine chemoreceptors, electroreceptors and mechanoreceptors
The source saysTo locate and capture their prey, olms use a combination of chemoreceptors, electroreceptors, and mechanoreceptors.
The page saysIts eyes do not even breach the skin
The source saysIts eyes are very small and do not even breach the skin.Note: vibe.reason (settle #880)

Source
02

Miaud et al. 2024

Miaud et al. (2024). Proteus anguinus. The IUCN Red List of Threatened Species 2024: e.T18377A227229041.

The page saysThe IUCN lists the species as Vulnerable
The source saysIUCN Red List category: Vulnerable (VU). Proteus anguinus Laurenti, 1768Note: Category read through GBIF's copy of the Red List, per docs/fact-check.md (iucnredlist.org refuses scripts).

Source
03

Voituron et al. 2010

Voituron et al. (2010). Extreme lifespan of the human fish (Proteus anguinus): a challenge for ageing mechanisms. Biology Letters.

The page saysKnown as the "human fish"
The source sayswe show that the 'human fish' (olm, Proteus anguinus)
The page says15 to 20 grams
The source saysa small cave salamander (weighing 15-20 g)
The page saysa predicted maximum lifespan of over 100 years
The source saysa predicted maximum lifespan of over 100 years
The page saysThe same study put the average adult lifespan at 68.5 years
The source saysan adult average lifespan of 68.5 years
The page sayson average a female lays 35 eggs every 12.5 years
The source sayslays, on average, 35 eggs every 12.5 years
The page sayssexual maturity arrives at about 15.6 years old
The source saysan age at sexual maturity of 15.6 years
The page saysa predicted lifespan past 100 years
The source saysa predicted maximum lifespan of over 100 years
The page saysPredicted 100-year-plus lifespan
The source saysa predicted maximum lifespan of over 100 years
The page saysA 2010 study predicted a maximum lifespan of over 100 years
The source saysa predicted maximum lifespan of over 100 yearsNote: 2010 is the paper's publication year (Biology Letters, published online 2010).
The page sayswhich makes the 15 to 20 gram olm an outlier among amphibians for its size
The source saysa small cave salamander (weighing 15-20 g) ... this animal sits as an outlier in the amphibian size/longevity relationship
The page saysweightKg: 0.018
The source saysa small cave salamander (weighing 15-20 g)Note: battleStats (settle #880)

Source
04

Bizjak Mali, Sepčić & Bulog 2013

Bizjak Mali, Sepčić & Bulog (2013). Long-term starvation in cave salamander effects on liver ultrastructure and energy reserve mobilization. Journal of Morphology.

The page saysDeprived of food, an olm's liver uses up its glycogen first and turns to lipids and proteins later
The source saysGlycogen is rapidly utilized at the beginning of the starvation period, whereas lipids and proteins are utilized subsequently, during prolonged food deprivation.
The page saysone study kept olms without food for 18 months, the length of its longest treatment rather than a measured limit
The source saysafter food deprivation periods of one and 18 months were investigatedNote: 18 months is the longer of the study's two treatments; the paper reports no survival limit.
The page saysan experimental fast of a year and a half
The source saysafter food deprivation periods of one and 18 months were investigatedNote: 18 months is a year and a half; the length of a treatment, not a survival limit.
The page saysan 18-month experimental fast
The source saysafter food deprivation periods of one and 18 months were investigated
The page saysAt least 18 months: that was the longer of the two fasts in one study, not a measured limit
The source saysafter food deprivation periods of one and 18 months were investigated
The page saysBy then their liver cells had shrunk and held fewer fat droplets, yet the liver's integrity was apparently maintained
The source saysAfter 18 months of food deprivation hepatocytes were reduced in size, lipid droplets were less numerous ... The liver integrity was apparently maintained

Source
05

Sket 1997

Sket (1997). Distribution of Proteus (Amphibia: Urodela: Proteidae) and its possible explanation. Journal of Biogeography.

The page saysspread across Italy, Slovenia, Croatia, and Bosnia and Herzegovina
The source saysit ranges from the Isonzo‐Soća River in southeastern Venezia Giulia, Italy, through the southern half of Slovenia, southern Croatia, and parts of Bosnia and Hercegovina, to the Trebišnica River in eastern Hercegovina
The page saysDinaric Karst of Italy, Slovenia, Croatia, and Bosnia and Herzegovina
The source saysThe species is limited to the Dinaric Karst; it ranges from the Isonzo‐Soća River in southeastern Venezia Giulia, Italy, through the southern half of Slovenia, southern Croatia, and parts of Bosnia and HercegovinaNote: covers stats.habitat, worded to match the field's own text.
The page saysBy 1997, pollution and human-made changes to water flow had wiped out or endangered populations in some regions
The source saysIn some regions, populations have been extinguished or endangered by pollution or human‐induced hydrographical changes.Note: 1997 is the publication year of Sket's survey, which dates the statement.

Source
06

Dumas & Chris 1998

Dumas & Chris (1998). The olfaction in Proteus anguinus: a behavioural and cytological study. Behavioural Processes.

The page saysin experiments, an olm's sense of smell reached its detection threshold at about 1 gram of prey, in a water current of 250 cubic centimetres a minute
The source saysProteus shows a well-developed olfactive sense: the sensitivity threshold occurs around 1 g of prey (in a 250 cm(3)/min water current).

Source
07

Istenič & Bulog 1984

Istenič & Bulog (1984). Some evidence for the ampullary organs in the European cave salamander Proteus anguinus (Urodela, Amphibia). Cell and Tissue Research.

The page saysIts ampullary organs, small pits in the skin
The source saysTheir fundamental structure consists of single ampullae with sensory and accessory cells with apical parts that extend into the pit of the ampulla, and of a short jelly-filled canal connecting the ampulla pit with the surface of the skin.
The page saysare built like electroreceptors
The source sayssupport the view that the morphologically-identified ampullary organs are electroreceptive
The page sayselectroreceptive ampullary organs
The source saysthe morphologically-identified ampullary organs are electroreceptive
The page sayssmall pits in its skin built like electroreceptors
The source sayssupport the view that the morphologically-identified ampullary organs are electroreceptiveNote: vibe.reason (settle #880)

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.