''Protosalanx'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of icefishes that are native to

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

and

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

where they primarily inhabit coastal waters and nearby fresh waters. They are commercially fished and used for

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

in China, where also introduced to some inland waters like

Lake Dianchi Dianchi Lake (), also known as Lake Dian and Kunming Lake (), is a large lake located on the Yunnan-Guizhou Plateau close to Kunming, Yunnan, China. Its nickname is the "Sparkling Pearl Embedded in a Highland" () and it was the model for the Ku ...

. In addition to being eaten locally in Asia, they are exported to southern Europe as a replacement of the more expensive

transparent goby ''Aphia minuta'', the transparent goby, is a species of the goby native to the northeastern Atlantic Ocean where it can be found from Trondheim, Norway to Morocco. It is also found in the Mediterranean Sea, Mediterranean, Black Sea and the Sea o ...

, a Mediterranean species used in the local cuisine. This replacement is often done openly, but sometimes it is done fraudulently. ''Protosalanx'' are up to in

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

, have a transparent body and largely lack

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

. They are open-water fish. Small ''Protosalanx'' mostly feed on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, but larger individuals also take small fish, including

cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, b ...

of young of their own species. They are naturally

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

, with adults migrating from their coastal sea habitat into

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

to spawn and the juveniles returning to the coastal sea. However, some of the introduced populations have been able to adapt their life cycle and always stay in fresh water. The scientific name is derived from proto (Greek proto = first) and the latinization of salamga, Filipino for a kind of swallow.

Species

There are currently two recognized

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in this genus: * ''

Protosalanx chinensis ''Protosalanx'' is a small genus of icefishes that are native to China, Korea and Vietnam where they primarily inhabit coastal waters and nearby fresh waters. They are commercially fished and used for aquaculture in China, where also introduced ...

'' ( Basilewsky, 1855) * ''

Protosalanx hyalocranius ''Protosalanx'' is a small genus of icefishes that are native to China, Korea and Vietnam where they primarily inhabit coastal waters and nearby fresh waters. They are commercially fished and used for aquaculture in China, where also introduced ...

'' ( J. F. Abbott, 1901) (Clearhead icefish)

Genome and sex-determination

The ''Protosalanx''

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

has an estimated size of 525Mb and encodes 19,884 protein-coding genes. Following this initial reference, whole genomes of 20 male and 20 female ''

'' were sequenced and

GWAS In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of genetic variants in different individuals to see if any varian ...

analyses were conducted to uncover its

sex determination system A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most organisms that create their offspring using sexual reproduction have two sexes. In some species there are hermaphr ...

and putative sex‐determining genes. Indicating a ZZ/ZW sex determination system, and that a “Z dosage” effect might play a vital role.

References

Salangidae Fish described in 1908 {{Osmeriformes-stub