Crocodylus niloticus
Laurenti, 1768 · speciesAt a glance
Sources13 archives
Databases and archives Crocodylus niloticus's data was compiled from.
WikipediaWikimedia Foundation20 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility6 306 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI80 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics86 specimens↗
NPASSNat. Product Activity & Species Sourcecompounds↗
Open Tree of LifeOpenTreephylogeny backbone↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
NCBIUS National Library of Medicinegenome & karyotype↗
Tree of SexTree of Sex Consortiumgenome & karyotype↗
Paleobiology DatabasePBDB consortiumfossil record↗
WikidataWikimedia Foundationstructured facts↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
The Nile crocodile (Crocodylus niloticus) is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed throughout sub-Saharan Africa, occurring mostly in the central, eastern, and southern regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, swamps, and marshlands. In West Africa, it occurs along with two other crocodilians. Although capable of living in saline environments, this species is rarely found in saltwater, but occasionally inhabits deltas and brackish lakes. The range of this species once stretched northward throughout the Nile, as far north as the Nile Delta. On average, the adult male Nile crocodile is between in length and weighs including stomach stones. However, specimens exceeding in length and weighing up to have been recorded. It is the largest freshwater predator in Africa, and may be considered the second-largest extant reptile in the world, after the saltwater crocodile (Crocodylus porosus).Wood, G. (1983). The Guinness Book of Animal Facts and Feats. Sterling Pub Co Inc. Size is sexually dimorphic, with females usually about 30% smaller than males. The crocodile has thick, scaly, heavily armoured skin. Nile crocodiles are opportunistic apex predators; a very aggressive crocodile, they are capable of taking almost any animal within their range. They are generalists, taking a variety of prey. Their diet consists mostly of different species of fish, reptiles, birds, and mammals. They are ambush predators that can wait for hours, days, and even weeks for the suitable moment to attack. They are agile predators and wait for the opportunity for a prey item to come well within attack range. Even swift prey are not immune to attack. Like other crocodiles, Nile crocodiles have a powerful bite that is unique among all animals, and sharp, conical teeth that sink into flesh, allowing a grip that is almost impossible to loosen. They can apply high force for extended periods of time, a great advantage for holding down large prey underwater to drown. Nile crocodiles are relatively social.Huchzermeyer, F. (2003). Crocodiles: Biology, Husbandry, Diseases. CABI International Publishing. UK and Massachusetts. They share basking spots and large food sources, such as schools of fish and big carcasses. Their strict hierarchy is determined by size. Large, old males are at the top of this hierarchy and have first access to food and the best basking spots. Crocodiles tend to respect this order; when it is infringed, the results are often violent and sometimes fatal. Like most other reptiles, Nile crocodiles lay eggs; these are guarded by the females. The hatchlings are also protected for a period of time, but hunt by themselves and are not fed by the parents. The Nile crocodile is one of the most dangerous species of crocodile and is responsible for hundreds of human deaths every year. It is common and is not endangered, despite some regional declines or extirpations.
No narrative description available for this taxon yet.
Size & morphology2
Life cycle & reproduction7
Habitat & environment2
Compounds documented for Crocodylus niloticus across natural-product and food-composition databases — not just the ~150 nutrients on a classic label ("nutritional dark matter").
Compound class profile4 classes
Documented compounds17 total
| Compound | Class | Amount | Source |
|---|---|---|---|
| (8-Methyl-2-oxochromen-7-yl) acetate | present | NPASS | |
| 3-Hydroxylup-20(29)-En-28-Amide | present | NPASS | |
| 7-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]oxy-8-methoxychromen-2-one | present | NPASS | |
| 7-hydroxy-8-[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-2-one | present | NPASS | |
| 7-hydroxy-8-[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-2-one | present | NPASS | |
| 8-hydroxy-5-[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-2-one | present | NPASS | |
| 8-hydroxy-7-[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-2-one | present | NPASS | |
| 8-methoxy-7-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-2-one | present | NPASS | |
| [2-methoxy-5-[4-oxo-5-[(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxychromen-2-yl]phenyl] acetate | present | NPASS | |
| Bergapten | present | NPASS |
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Crocodylus niloticus has left across the world's sequence archives.
At a glance
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
The complete instruction manual Crocodylus niloticus carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Genome sizehow big the whole instruction manual is
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
2n 325×GoaT · Animal Chromosome Counts Database · GoaT · Tree of Sex Database · GoaT · Animal Genome Size Database +1
Sequencing statusassembly quality — how far to trust these numbers
Assembly level tells you how finished the sequence is — from fragmented contigs, through scaffolds, up to a full chromosome-level assembly. BUSCO % estimates completeness: the share of genes expected to be present that were actually found. These describe the data quality, not the organism.
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The solid bar is the fossil range: the span between the oldest and the youngest fossil that palaeontologists have assigned to Crocodylus niloticus. Above itBeside it, the bars count how many dated finds fall in each slice of time; the tallest bar is labelled, and heights use a square-root scale so that thin slices stay visible next to rich ones. Read this as how well each stretch of time is preserved and studied — thick bars mean plenty of the right kind of rock and plenty of collectors, which is related to, but not the same as, how common it actually was. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
The two clocks disagree here. The fossil record reaches back to 23 Ma, but the molecular clock dates the lineage to only 6.82 Ma — about 16.2 Myr younger. A fossil cannot be older than the lineage it belongs to, so one of the two is off: either the fossil is assigned to the wrong species, or the clock is running fast.
How it livedPBDB
Record type6 352 records
Origin
Range
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Holding institutions12 of 22 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
| Institution | Specimens |
|---|---|
| Teylers Museumlocation not on record | 22 |
| Washington, US | 12 |
| 11 | |
| New Haven, US | 9 |
| Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record | 7 |
| MUHNAClocation not on record | 5 |
| Brussels, BE | 4 |
| Seattle, US | 3 |
| RBINS-Scientific Heritagelocation not on record | 3 |
| Muzeum Górnośląskie w Bytomiulocation not on record | 3 |
| Ann Arbor, US | 3 |
| GBClocation not on record | 3 |
| CASlocation not on record | 2 |
| KwaZulu-Natal Museumlocation not on record | 2 |
| Los Angeles, US | 2 |
| Bonn, DE | 2 |
| Natural History Museum, Aarhus Denmarklocation not on record | 1 |
| Kuopio, FI | 1 |
| Museo civico La Terra e l'Uomo di Crocetta del Montellolocation not on record | 1 |
| Berkeley, US | 1 |
| Saint John, CA | 1 |
| Auckland, NZ | 1 |
Where the DNA of Crocodylus niloticus was picked up in samples of water, soil or air — nobody saw the organism, only its DNA left behind. A trace is a clue that the species was near, not a confirmed sighting.
Signal
Where its DNA was found
How strong is each trace?
Modelled climatemodelled
How to read this: each dot is one detection of this species' DNA in an environmental sample. The confidence meter weighs how many independent studies and places back up the signal — one detection in one study is a hint; many across several studies is solid. Records dated before 2008 (when eDNA methods began) are treated as likely mislabeled and left off the map.