The hepatopancreas, digestive gland or midgut gland is an organ of the

digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s and

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s. It provides the functions which in

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s are provided separately by the

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and

pancreas The pancreas (plural pancreases, or pancreata) is an Organ (anatomy), organ of the Digestion, digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a ...

, including the production of digestive

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s, and absorption of digested food.

Arthropods

Arthropods, especially

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

s in the Order

Isopoda Isopoda is an order of crustaceans. Members of this group are called isopods and include both aquatic species and terrestrial species such as woodlice. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed l ...

, Suborder Oniscidea (

woodlice Woodlice are terrestrial isopods in the suborder Oniscidea. Their name is derived from being often found in old wood, and from louse, a parasitic insect, although woodlice are neither parasitic nor insects. Woodlice evolved from marine isopods ...

), have been shown to be able to store

heavy metals upright=1.2, Crystals of lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals is a controversial and ambiguous term for metallic elements with relatively h ...

in their hepatopancreas. This could lead to

bioaccumulation Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. T ...

through the

food chain A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as ...

and implications for

food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Position in the food web, or trophic level, is used in ecology to broadly classify organisms as autotrophs or he ...

destruction, if the accumulation gets high enough in polluted areas; for example, high metal concentrations are seen in

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

s of the genus ''

Dysdera ''Dysdera'' is a genus of woodlouse hunting spiders that was first described by Pierre André Latreille in 1804. They originated from Central Asia to Central Europe. The family has gained many common names from their individual species, includi ...

'' which feed on

, including their hepatopancreas, the major metal storage organ of isopods in

polluted Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

sites.

Molluscs

The hepatopancreas is a centre for

lipid metabolism Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown and storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In ani ...

and for storage of lipids in

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

.Böer M., Graeve M. & Kattner G. (2006). "Exceptional long-term starvation ability and sites of lipid storage of the Arctic pteropod ''

Clione limacina ''Clione limacina'', known as the naked sea butterfly, sea angel, and common clione, is a sea angel (pelagic sea slug) found from the surface to greater than depth.Gofas, S. (2012). ''Clione limacina''. Accessed through: World Register of Marine ...

''". ''Polar Biology'' 30(5): 571-580. . Some species in the genus ''

Phyllodesmium ''Phyllodesmium'' is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Myrrhinidae.Bouchet, P. (2012). ''Phyllodesmium'' Ehrenberg, 1831. Accessed through: World Register of Marine Species at http://www. ...

'' contains active

zooxanthellae Zooxanthellae (; zooxanthella) is a colloquial term for single-celled photosynthetic organisms that are able to live in symbiosis with diverse marine invertebrates including corals, jellyfish, demosponges, and nudibranchs. Most known zooxanthell ...

of the genus ''

Symbiodinium ''Symbiodinium'' is a genus of dinoflagellates that encompasses the largest and most prevalent group of endosymbiotic dinoflagellates known and have photosymbiotic relationships with many species. These unicellular microalgae commonly reside in ...

'' in the hepatopancreas.

References

{{Gastropod anatomy Digestive system Mollusc anatomy Gastropod anatomy Arthropod anatomy Fish anatomy

Arthropods

Molluscs

See also

References