''Thryssa mystax'', the moustached thryssa or Gangetic anchovy, is a species of

oceanodromous 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 ...

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

in the family

Engraulidae An anchovy is a small, common forage fish of the family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water. More than 140 species are placed in 1 ...

. It is found in the tropical western

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region from India, Sri Lanka to Myanmar and south to

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

, and Indonesia. Engraulis mystax Achilles 157

It is a small

schooling A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of fo ...

fish found in depths up to . Maximum length does not exceed . The fish has 11 to 12 dorsal soft rays and only present 29 to 37 anal soft rays. There are 24 to 32 keeled

scutes A scute () or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterio ...

from isthmus to anus on belly region. Lower

gill raker Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of th ...

s are serrated. Body is silver, darker dorsally. There is a distinctive dark blotch behind upper part of gill opening, which can easily identify the species from other ''

Thryssa ''Thryssa'' is a genus of anchovies in the family Engraulidae. Some authorities include the species from the genus '' Thrissina'' here. It contains the following species: Species * '' Thryssa adelae'' ( Rutter, 1897) (Swatow thryssa) * '' Thr ...

'' species. Caudal fin is yellowish. It feeds on

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

fish larvae Ichthyoplankton (from Greek: wikt:ἰχθύς, ἰχθύς, , "fish"; and πλαγκτός, , "drifter") are the Fish eggs, eggs and larvae of fish. They are mostly found in the sunlit zone of the water column, less than 200 metres deep, which ...

, and small

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s like shrimp larvae.

References

Notes

the fleshy throat region of a fish which extends forward from the ventral part of the chest and narrows anteriorly {{Taxonbar, from=Q2313843 Fish of Thailand Taxa named by Marcus Elieser Bloch Taxa named by Johann Gottlob Theaenus Schneider Fish described in 1801 mystax