''Protosalanx'' is a small

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of icefishes that are native to

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 ...

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

and

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

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. Nelu ...

in China, where also introduced to some inland waters like Lake Dianchi. In addition to being eaten locally in Asia, they are exported to southern Europe as a replacement of the more expensive transparent goby, 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 fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

, 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 ...

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

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

, 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 also well document ...

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 thousa ...

, 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 environm ...

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 A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in this genus: * '' Protosalanx chinensis'' ( Basilewsky, 1855) * '' Protosalanx hyalocranius'' ( J. F. Abbott, 1901) (Clearhead icefish)

Genome and sex-determination

The ''Protosalanx''

genome 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 genes, other functional regions of the genome such as ...

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 '' Protosalanx hyalocranius'' were sequenced and GWAS 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 common sexes, males and females, and in ...

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