Phliantidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of isopod

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...

-like amphipod

Amphipoda

Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. The name amphipoda means "different-footed", and refers to the different forms of appendages, unlike isopods, where all the legs are alike. Of the 7,000 species, 5,500 are classified...

 crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s chiefly from the southern hemisphere.

Description

Members of the family Phliantidae are unusual among the order Amphipoda, because they have dorso-ventrally flattened bodies with a pronouned dorsal keel, rather than being flattened side-to-side. Because of this, and various other factors, including the square-ended form of the rostrum

Rostrum (anatomy)

The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....

, they resemble isopods

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...

.

Distribution and ecology

Most species are found in the Southern Hemisphere

Southern Hemisphere

The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

, where they live on algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 in the intertidal zone

Intertidal zone

The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...

.

Taxonomy

Phliantidae was originally proposed by Thomas Roscoe Rede Stebbing

Thomas Roscoe Rede Stebbing

The Reverend Thomas Roscoe Rede Stebbing F.R.S., F.L.S. was a British zoologist, who described himself as "a serf to natural history, principally employed about Crustacea". Educated in London and Oxford, he only took to natural history in his thirties, having worked as a teacher until then...

 in 1899 for a group that also contained the genera currently placed in the family Prophliantidae, while Temnophlias has also been moved from Phliantidae to its own monotypic families. It contains the following genera:

• Iphinotus Stebbing, 1899
• Palinnotus Stebbing, 1900
• Pariphinotus Kunkel, 1910
• Pereionotus Bate & Westwood, 1862
• Plioplateia Barnard, 1916