Pionites leucogaster -Zoologico de Sao Paulo -Brazil-6a

A crop (sometimes also called a croup or a craw, ingluvies, or sublingual pouch) is a thin-walled expanded portion of the

alimentary tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

used for the storage of food prior to

digestion Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intest ...

. This anatomical structure is found in a wide variety of animals. It has been found in

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, and in invertebrate animals including

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

s (snails and slugs),

earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. T ...

leech Leeches are segmented parasitism, parasitic or Predation, predatory worms that comprise the Class (biology), subclass Hirudinea within the phylum Annelida. They are closely related to the Oligochaeta, oligochaetes, which include the earthwor ...

es, and

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

Insects

Cropping is used by

bees Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfam ...

to temporarily store nectar of flowers. When bees "suck" nectar, it is stored in their crops. Other

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typic ...

also use crops to store liquid food. The crop in eusocial insects, such as

ants Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...

, has specialized to be distensible, and this specialization enables important communication between colonial insects through trophallaxis. The crop can be found in the

foregut The foregut is the anterior part of the alimentary canal, from the mouth to the duodenum at the entrance of the bile duct. Beyond the stomach, the foregut is attached to the abdominal walls by mesentery. The foregut arises from the endoderm, devel ...

of insects.

Birds

In a

's digestive system, the crop is an expanded, muscular pouch near the gullet or throat. It is a part of the digestive tract, essentially an enlarged part of the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

. As with most other organisms that have a crop, it is used to temporarily store food. Not all bird species have one. In adult doves and pigeons, it can produce

crop milk Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds. It is found among all pigeons and doves where it is referred to as pigeon milk. An analog to crop milk is also secreted from the esopha ...

to feed newly hatched birds. Scavenging birds, such as

vulture A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture (including Condors). Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and ...

s, will gorge themselves when prey is abundant, causing their crop to bulge. They subsequently sit, sleepy or half torpid, to digest their food. Most raptors, including

hawk Hawks are birds of prey of the family Accipitridae. They are widely distributed and are found on all continents except Antarctica. * The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks and others. This subfa ...

eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...

s and

s (as stated above), have a crop; however, owls do not. Similarly, all true quail ( Old World quail and New World quail) have a crop, but buttonquail do not.

Chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...

turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

s, ducks and geese possess a crop, as do

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

s. Some extinct birds like

Enantiornithes The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cla ...

did not have crops.

Literary references

In the

Sherlock Holmes Sherlock Holmes () is a fictional detective created by British author Arthur Conan Doyle. Referring to himself as a " consulting detective" in the stories, Holmes is known for his proficiency with observation, deduction, forensic science and ...

story " The Adventure of the Blue Carbuncle" (1892), author

Arthur Conan Doyle Sir Arthur Ignatius Conan Doyle (22 May 1859 – 7 July 1930) was a British writer and physician. He created the character Sherlock Holmes in 1887 for ''A Study in Scarlet'', the first of four novels and fifty-six short stories about Ho ...

hid a valuable gem inside a goose's crop. "Craw" is an obsolete term for "crop", and this is still seen in the saying "it sticks in my craw" meaning "I can't etaphoricallyswallow it", that is, that a situation or other entity is unacceptable, or at any rate annoying.

References

External links

The Alimentary Canal in Birds
{{Gastropod anatomy Annelid anatomy Bird anatomy Gastropod anatomy Insect anatomy Dinosaur anatomy

Insects

Birds

Literary references

See also

References

External links