The Gnathiidae are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

isopod Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s. They occur in a wide range of depths, from the

littoral zone The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal are ...

to the deep sea. The adults are associated with

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...

s and may not feed. The juvenile form is known as a 'praniza', and it is a temporary parasite of marine fish. These forms are not larvae; ''Gnathiidae'' instead become parasitic during the manca stage. Mancae of the ''Gnathiidae'' closely resemble the adult form, however they lack the final pair of

pereiopod The decapod (crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

Hesse Mémoire sur les pranizes et les ancées Plate 3

Taxonomy in the family relies on male characters, such that females and juveniles cannot be reliably identified. The family contains 182 species, divided among the following genera: *'' Afrignathia'' Hadfield & Smit, 2008 *'' Bathygnathia'' Dollfus, 1901 *'' Bythognathia'' Camp, 1988 *'' Caecognathia'' Dollfus, 1901 *'' Elaphognathia'' Monod, 1926 *'' Euneognathia'' Stebbing, 1893 *'' Gibbagnathia'' Cohen & Poore, 1994 *''

Gnathia ''Gnathia'' is a genus of isopod crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amph ...

'' Leach, 1814 *'' Monodgnathia'' Cohen & Poore, 1994 *'' Paragnathia'' Omer-Cooper & Omer-Cooper, 1916 *'' Tenerognathia'' Tanaka, 2005 *'' Thaumastognathia'' Monod, 1926

References

External links

Gnathiidae
Australian Isopoda Cymothoida Taxa named by William Elford Leach Parasitic crustaceans Crustacean families {{parasitic animal-stub