Anchovy sprat, ''Clupeonella engrauliformis'', is a

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), ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Clupeidae Clupeidae is a family of clupeiform ray-finned fishes, comprising, for instance, the herrings and sprats. Many members of the family have a body protected with shiny cycloid (very smooth and uniform) scales, a single dorsal fin, and a fusiform ...

. It is one of several species of '' Clupeonella'' found in the Central and Southern

Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...

. It lives

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

ally in the central and southern parts of this brackishwater lake. It is typically long, and up to maximum. It may be found down to a depth of . The achovy sprat was first described by

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

N. A. Borodin in 1904 under the name ''Clupea engrauliformis.'' The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

is 124 mm in length, was caught near Cape Buynak in the Caspian Sea and is stored in th
Zoological Institute of the Russian Academy of Sciences

Description

The maximum body length is 16.5 cm, with a mass up to 26 g. The body of the fish is elongated and low, with its height comprising 16-19% of the body length. The scales easily fall off. Its head is short and wide, with the interorbital distance being 16-18% of the body length and a small mouth. The abdomen of the achovy sprat is rounded with a keel, in which there are 23-31 keeled scales. There are 56-67 gill rakers. the dorsal fin has 13-21 soft rays with the first three being unbranched. the anal fin has 18-22 soft rays with the first three also unbranched. The tail fin is almost black and strongly notched. The edges of the pectoral fins are pointed. The back is dark with a greenish tint. Females are usually slightly larger than males.

Biology

The achovy sprat is a schooling pelagic fish that mainly inhabits open waters but occasionally approaches shores. In spring and autumn it rises to the surface, though most of the year is spent at depths up to 78 metres. It is found at water temperatures from 6 to 28 °С and salinity of 8-13%. It performs daily vertical and seasonal migrations. The difference between the mitochondrial genomes of anchovy and Black and Caspian Sea sprats concerns 449 bp (2.7%), including two insertions in the control region, unknown in other representatives of the genus ''Clupeonella''. The differentiation of tyulkas is probably related to the transgression and degradation of the Pontic Lake-Sea: it began in the Miocene, continued in the Pliocene, and was completed by the Pleistocene. The modern differences of tyulkas may be connected with different adaptations of their ancestors to specific conditions in different water bodies—remnants of the Pontic Mega-lake.

Diet

The basis of its diet consists of copepods, and it feeds on zooplankton during the daytime, especially ''Eurytemora grimmi''. To a lesser extent it consumes cladocerans, mysids and mollusk larvae. Its natural enemies are Brazhnikov's shad (''Alosa braschnikowi''), Caspian seal and sturgeons.

Reproduction

It spawns in the open sea at depths greater than 20 m in the upper layers of water. Spawning is partial, stretching from May to November. Fecundity is from 10 to 55 thousand eggs. Eggs have a fat drop, pelagic. The larval stage continues until the spring of the year following spawning.

Relationship with humans

Fishing

They are caught by light. Catches in the mid-1970s reached 350 thousand tons. It is used for the preparation of canned food, preserves and for spicy salting. Most of the raw material is used to make fish meal.

Gallery

File:Anchovy sprat head close up.jpg File:Anchovy sprat tail close up.jpg

References

Clupeonella Fish of the Caspian Sea Fish described in 1904 {{Clupeiformes-stub