''Ligidium duospinatum'' is a species of terrestrial

isopod Isopoda is an Order (biology), order of crustaceans. Members of this group are called isopods and include both Aquatic animal, aquatic species and Terrestrial animal, terrestrial species such as woodlice. All have rigid, segmented exoskeletons ...

in the family

Ligiidae Ligiidae is a family of woodlice, the only family in the infraorder Diplocheta. Its members are common on rocky shores, in similar habitats to those inhabited by species of the bristletail '' Petrobius'' and the crab '' Cyclograpsus''. The famil ...

, found in

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It is only known from a single location near Dongbacai Village in the

Tibet Autonomous Region The Tibet Autonomous Region (TAR), often shortened to Tibet in English or Xizang in Pinyin, Hanyu Pinyin, is an Autonomous regions of China, autonomous region of the China, People's Republic of China. It was established in 1965 to replace the ...

. The species name ''duospinatum'' refers to the diagnostic two spines on the apex of the male second

pleopod The anatomy of a decapod consists of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment – often called a somite – may possess one pair of appendages, although in various groups these m ...

endopodite The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ...

, which distinguishes it from closely related species. The only known specimens were collected from beside a stream at above sea level. ''Ligidium duospinatum'' is dark grey with white markings and yellowish green spots. Males range in size from in length and females range from in length. It is very similar to '' Ligidium inerme'' in overall appearance but can be separated by the

flagellum A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

having seven segments, and the presence of the namesake two spines on the male second pleopod endopodite.

References

Isopoda Endemic fauna of Tibet Crustaceans of China Crustaceans described in 2022 {{Isopod-stub