Scientists Say: Parthenogenesis

Parthenogesis (noun, “PAR-then-oh-JEN-eh-sis”)

This is a form of reproduction where an animal produces offspring from an egg that has not been fertilized. It is a type of asexual reproduction. This means two animals do not have to combine eggs and sperm to produce young. Parthenogesis can occur in arthropods such as spiders. It also can happen in amphibians, birds, fish and reptiles.

In a sentence

A baby shark was born recently even though its mother hadn’t seen a male shark for almost four years. At first, scientists thought it might be parthenogenesis. They were wrong.

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Power Words

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arthropod  Any of numerous invertebrate animals of the phylum Arthropoda, including the insects, crustaceans, arachnids and myriapods, that are characterized by an exoskeleton made of a hard material called chitin and a segmented body to which jointed appendages are attached in pairs.

mammal  A warm-blooded animal distinguished by the possession of hair or fur, the secretion of milk by females for feeding the young, and (typically) the bearing of live young.

parthenogenesis   An unusual form of reproduction where animals sometimes produce healthy offspring from an unfertilized egg.

Edited February 20, 2015 at 12:36 PM ET to remove “crabs” as an example of partehnogenesis, as only two known species of decapod crustacean reproduce in this manner.