''Spilopsyllus cuniculi'', the rabbit flea, is a species of

flea Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Pulicidae. It is an external

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

s and

hare Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores and live Solitary animal, solitarily or in pairs. They nest in slight depressions called forms, and their young are precociality, able to fend for themselves ...

s and is occasionally found on cats and dogs and also certain seabirds that nest in burrows. It can act as a

vector Vector most often refers to: * Euclidean vector, a quantity with a magnitude and a direction * Disease vector, an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematics a ...

for the

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

that causes the rabbit disease myxomatosis.

Description

The rabbit flea is about long and a dark brown colour. It is laterally compressed, has three pairs of legs and no wings. Its head is held at an angle to its body and its mouthparts are adapted for piercing the skin of its host and sucking its blood. It has a pronotal comb or row of spines just behind the head and a genal comb of spines below the head and these help to distinguish it from other species of flea. It is a sedentary flea that stays feeds of a single location for a long period of time. ''S. cuniculi'' have adapted to feed on the ears of rabbits, which are in rich in blood supply.

Host species

''S. cuniculi'' originated in Europe with the definitive host being the European rabbit, as the rabbit was brought overseas the flea was inadvertently brought with it and is now found in most places where the European rabbit is found. It is usually as an external parasite found on rabbits and hares but occasionally also on cats and dogs. It can work its way through the animal's fur but is usually found in clusters around the bases of the host's ears. On some of the islands off the coasts of the United Kingdom it can be found on

Manx shearwater The Manx shearwater (''Puffinus puffinus'') is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is an ...

s and

Atlantic puffin The Atlantic puffin ('), also known as the common puffin, is a species of seabird in the auk family (biology), family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin being found ...

s, presumably because the birds nest in burrows and often take over holes previously occupied by rabbits.

Life cycle

Adult female rabbit fleas can detect the changing levels of certain

hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

s in a female rabbit's blood that show that she is near to

parturition Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

. This triggers sexual maturity in the fleas and they mate and start producing eggs. As soon as the young rabbits are born, the fleas move onto them and start feeding, mating and laying eggs. About twelve days later, they return to the mother rabbit. They complete this migration every time she produces a litter of young. Piper, Ross (2007), ''Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'',

Greenwood Press Greenwood Publishing Group, Inc. (GPG) was an educational and academic publisher (middle school through university level) which was part of ABC-Clio. Since 2021, ABC-Clio and its suite of imprints, including GPG, are collectively imprints of B ...

. The larvae are legless grubs, creamy-white with a brown head. After three larval stages they pupate. Fleas newly emerged from the pupa need to have a blood meal within a week, otherwise they will die. After that they can survive for many months without feeding. The optimum temperature for the flea's life cycle is .

Disease transmission

Myxomatosis is a virus disease of rabbits which can be fatal. The symptoms are swelling of the eyelids and lips, conjunctivitis and the formation of skin tumours on the face, ears and limbs. The rabbit flea acts as a vector for the disease and the virus has been shown to remain viable in the flea's mouthparts for at least one hundred days. The rabbit flea has also been implicated in the transmission of the '' Bartonella alsatica''

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

, an opportunistic

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

that causes disease in animals and man.

References

{{Taxonbar, from=Q10675774 Pulicidae Parasitic arthropods of mammals Rabbits