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

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s, molluscs

Mollusca

The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...

 and fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

. It provides the functions which in mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s are provided separately by the liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 and pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

, including the production of digestive enzymes, and absorption of digested food.

Arthropods

Arthropods, especially detritivore

Detritivore

Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...

s in the Order Isopoda

Isopoda

Isopods are an order of peracarid crustaceans, including familiar animals such as woodlice and pill bugs. The name Isopoda derives from the Greek roots and...

, Suborder Oniscidea (woodlice

Woodlouse

A woodlouse is a crustacean with a rigid, segmented, long exoskeleton and fourteen jointed limbs...

), have been shown to be able to store heavy metals in their hepatopancreas. This could lead to bioaccumulation

Bioaccumulation

Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...

 through the food chain

Food chain

A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

 and implications for food web destruction, if the accumulation get high enough in these polluted areas; for example, high metal concentrations are seen in spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s of the genus Dysdera

Dysdera

Dysdera is a genus of spiders from the family Dysderidae, with more than 200 species. They occur mostly in Eurasia from Central Asia to Spain, extending into northern Africa . However, at least two species occur in South America Dysdera is a genus of spiders from the family Dysderidae, with more...

which feed on woodlice

Woodlouse

A woodlouse is a crustacean with a rigid, segmented, long exoskeleton and fourteen jointed limbs...

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

Molluscs

Hepatopancreas is a centre of lipid metabolism

Lipid metabolism

Lipid metabolism refers to the processes that involve the intercourse and degradation of lipids.The types of lipids involved include:* Bile salts* Cholesterols* Eicosanoids* Glycolipids* Ketone bodies* Fatty acids - see also fatty acid metabolism...

 and storage of lipids in gastropods.

Some species in the genus Phyllodesmium

Phyllodesmium

Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod mollusks in the family Facelinidae. These nudibranchs occur in the tropical Indo-Pacific Oceans....

contains active zooxanthellae of the genus Symbiodinium in the hepatopancreas.