Summary
Distinct species that look nearly identical and are separated only by molecular or behavioural evidence.
In depth
Often discovered by DNA barcoding or acoustic differences; they affect conservation estimates because a single apparently widespread species may be several rare ones.
Cryptic species diversity is large in many groups. Conservation status of a single species may hide extinction risk of its parts.
Key idea: look-alikes may be different species.
Cryptic species are two or more distinct species that were classified as one because they are nearly identical in appearance. They are revealed by DNA, calls, chemicals, mating tests or ecology, and are common in many groups, including insects, frogs, bats, corals and marine invertebrates.
They matter because underestimating species number misjudges the biodiversity and the vulnerability of each, since a widespread species may be several rare ones. They also affect disease control, as with the Anopheles gambiae complex of mosquitoes, which differ in their ability to carry malaria. Visual similarity can arise through stabilising selection or recent divergence.
Example: the brown long-eared bat was split into separate species by echolocation and DNA.
Remember: molecular tools are making cryptic species more common than rare.
Frequently asked questions
What is Cryptic Species?
Distinct species that look nearly identical and are separated only by molecular or behavioural evidence.
Which area of biology covers Cryptic Species, and how advanced is it?
Cryptic Species is one of the 52 topics in Taxonomy & Biodiversity. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Species Delimitation, Biodiversity and Ecosystem Function, Latitudinal Diversity Gradient.
Can you give an example of Cryptic Species?
Anopheles gambiae is a complex of species with different malaria transmission.
What should I learn before Cryptic Species?
Work through the Beginner topics in Taxonomy & Biodiversity first, such as Taxonomy, Binomial Nomenclature, Taxonomic Hierarchy, then return to Cryptic Species. Advanced topics assume the Intermediate vocabulary.
What topics are related to Cryptic Species?
The closest topics to Cryptic Species are Species Delimitation, Biodiversity and Ecosystem Function, Latitudinal Diversity Gradient, Conservation Genomics. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cryptic Species?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cryptic Species. To practise the whole of Taxonomy & Biodiversity, use the Taxonomy & Biodiversity quiz.
How is Cryptic Species different from Species Delimitation?
Cryptic Species: Distinct species that look nearly identical and are separated only by molecular or behavioural evidence. Species Delimitation: Methods integrating morphology, genetics and ecology to decide where species boundaries lie. Read both side by side and note what each one explains.
How should I study Cryptic Species step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Species Delimitation and explain the difference aloud. Finally, take the Taxonomy & Biodiversity quiz and come back to this page for any question you miss.