The granular pugolovka (''Benthophilus granulosus'') is a

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 ...

of gobiid fish widespread in the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

. It is a small fish, with a length up to TL. It was listed as

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

in 2008: there are no known major threats. Granular pugolovkas are very abundant in their habitat due to their size and lack of natural predators. The common name 'pugolovka' is a Ukrainian word for

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

Description

''Benthophilus granulosus'' has a flat head with a flat barbel on the chin that is often described as being leathery. The body colors depend on the habitat in which the fish lives. ''Benthophilus granulosus'' can be distinguished from its relatives by their body being covered in thorny granules which are closely compacted, containing three dark blotches on their midline. ''Benthophilus granulosus'' also has black dots on the head and back Granular pugolovka starts its life cycle off as a tadpole, this tadpole stage of life is identified by the body of this fish and the absence of scales. The body of the tadpole stage also is covered with variable sized bony portions protruding out of the body, which will eventually disappear in only the males who have reached sexual maturity.

Habitat

''Benthophilus granulosus'' lives in both brackish and fresh waters; low-salinity zones seem to be preferred. It prefers river deltas and estuaries as well as shallow coastal waters () in the summer, and moves deeper (down to ) in the winter. Granular pugolovka is abundant along northern and eastern coasts around Ural and Volga rivers.

Life cycle

''Benthophilus granulosus'' has a life span of about a year, and reaches maturity at about 6–7 months. It spawns during April through July in shallow waters. ''Benthophilus granulosus'' starts life as a "tadpole" and matures into a goby fish. The granular pugolovka life cycle is about a year, which is normally how long it takes for their spawning season to start after their birth. The granular pugolovka all die shortly after spawning with the females dying before the males due to the more costly act of laying eggs as opposed to the males role of releasing sperm.

Diet

''Benthophilus granulosus'' is a bottom dweller and has a fairly limited diet or zoobenthos. They eat

mysid Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in thi ...

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s, and other

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...

References

Fish of the Caspian Sea Fish of Central Asia Fish of Western Asia Fish of Russia Benthophilus Endemic fauna of the Caspian Sea Fish described in 1877 {{Gobiidae-stub