''Azygocypridina lowryi'', colloquially known as the baked bean, is a species of

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typic ...

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 ...

or "seed shrimp" in the family

Cypridinidae Cypridinidae is a family of ostracods, containing the following genera: *'' Amphisiphonostra'' Poulsen, 1962 *'' Azygocypridina'' Sylvester-Bradley, 1950 *'' Bathyvargula'' Kornicker, 1968 *'' Codonocera'' Brady, 1902 *'' Cypridina'' Milne-Edwa ...

. It is found in deep waters off the east coast of Australia.

Description

''Azygocypridina lowryi'' grows to a length of about . It has a shrimp-like body enclosed between a pair of translucent valves that are hinged at the top and are superficially similar to those of a bivalve mollusc. The animal inside is a bright orange colour and can be seen through the valves which has led to local fishermen naming it the "baked bean". There are two pairs of long antennae which project from the shell and which are used in swimming. The first pair bear long

iridescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...

hairs. These act as a

diffraction grating In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structura ...

and cause iridescence by the diffraction of light in a manner similar to that which happens in a

hologram Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other Holography#Applications, applic ...

. Another unusual feature of this ostracod is the possession of a lateral eye which takes the form of a hairy flap of skin containing flecks of

photosensitive Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicity. ...

pigment. This eye is unable to form a proper

image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...

but is able to detect differences in the intensity of light.

Distribution

''Azygocypridina lowryi'' is found on the sandy seabed at depths between off the east coast of Australia. Its range extends from Cape York in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

in the south. It comes from an ancient lineage:

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of other members of the genus ''Azygocypridina'' have been found in rocks from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period dating back about 150 million years.

Biology

Little is known of the behaviour of this ostracod but when kept in an aquarium it tended to bury itself in the sediment when exposed to light. It is a

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

and feeds on dead fish and other organic material that finds its way to the seabed. It can swim rather clumsily in a jerky fashion using its second pair of antennae as oars. The

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

are

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic and go through six moults before settling on the seabed as juveniles.

References

{{Taxonbar, from=Q4833143 Myodocopida Crustaceans described in 1985