''Percina phoxocephala'', the slenderhead darter, is a species of freshwater

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 ...

, a darter from the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Etheostomatinae Etheostomatinae is a species-rich subfamily of freshwater ray-finned fish, the members of which are commonly known as the darters. The subfamily is part of the family Percidae which also includes the perches, ruffes and pikeperches. The family ...

, part of 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 ...

Percidae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains nearly 250 ...

, which also contains the

perch Perch is a common name for freshwater fish from the genus ''Perca'', which belongs to the family Percidae of the large order Perciformes. The name comes from , meaning the type species of this genus, the European perch (''P. fluviatilis'') ...

es, ruffes and pikeperches. It is found in North America in the central

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

and

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

basins, to northeastern

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

and the

Lake Winnebago Lake Winnebago (, , ) is a shallow freshwater lake in the north central United States, located in east central Wisconsin. At , it is the largest lake entirely within the state, covering an area of about by with of shoreline, an average depth ...

system in

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

, and as far south as the Red River in eastern

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

and northeast

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, typically in small to medium size rivers. It is a colorful species, with an average length of . Males take on a deeper hue during the breeding season. It feeds on insect larvae and other small invertebrates, and spawns between April and June. It is a common fish with a very wide range and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has classified its conservation status as being of "

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

Description

Slenderhead darters are typically 6–9 centimeters long, and can reach 10 centimeters at times. They have a pointed snout and a long narrow body. Their mouths are subterminal with the snout projecting only slightly beyond the mouth. Teeth are present on the jaws but are minute. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

side of the body is light brown with 14–22 dark blotches down the center serving as camouflage to potential predators above the darter. The

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

side is cream colored which helps disguise the darter from potential predators below them. They have a row of 11–16 blotches down their sides that are taller than they are wide and connected by a thin lateral stripe. The

dorsal fins A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found i ...

are distinctly separate with the first dorsal fin containing a dark brown band near the base and an orange band near the outer edge. The second dorsal fin and tail have many small spots often forming rows. The pelvic fins are transparent and are located on the

thoracic The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main ...

position and have two spines and 9–10 fin rays. The

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

has a square shape and is slightly forked. On breeding males the orange band on the dorsal fin is more intensely colored and thicker. Males also can have a dark dusky coloration to their body which often hides many of the blotches on their back and sides. Slenderheads have small

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 ...

and a

lateral-line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

count ranging from 60–80. The female breast is naked except for the presence of one or two cternoid scales, the posterior half of the males breast is scaled with the

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

half being naked. Their conservation status is of least concern.

Distribution and habitat

The slenderhead darter is a medium-sized

darter The darters, anhingas, or snakebirds are mainly tropical waterbirds in the family Anhingidae, which contains a single genus, ''Anhinga''. There are four living species, three of which are very common and widespread while the fourth is rarer and c ...

and the most widely distributed of the four species assigned to the

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

Swainia. It is found in North America from the central

and

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

River basins, to northeastern South Dakota and the

system (in

Lake Michigan Lake Michigan ( ) is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume () and depth () after Lake Superior and the third-largest by surface area (), after Lake Superior and Lake Huron. To the ...

drainage) in Wisconsin, and as far south as the Red River in eastern Oklahoma and northeast Texas. www.bio.txstate.edu (Percina phoxocephala) Slenderhead darters are found in areas of relatively shallow water with

riffles A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indica ...

and a moderate current. They prefer areas over sand and gravel bottoms with little silt. They are bottom dwellers and found in the

Benthic zone The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

Reproduction

Slenderhead darters spawn between late April and early June. The darters exhibit

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

with the males

pigmentation A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go in ...

darkening in April and peaking during

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

. The first dorsal fin becomes orange and the dorsal rays become outlined in yellow. Older and larger males are darker and able to attract more females. Males are territorial and guard patches of swift flowing water 15–60 centimeters deep. The females will lay their

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

burying them in sand or gravel. The number of eggs laid ranges from 50 to 1000 with larger females producing more (one-year-olds on average lay 83 eggs and two-year-olds produce 270). Juveniles remain in the spawning habitat for 2–4 weeks after hatching. Slenderhead darters reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized ...

after one year.

Development

When Slenderhead darters hatch, they are around 19 millimeters in length. There is continual growth during the first year, with one year old individuals averaging 46 millimeters. There is little influence of sex on size. Individuals will become sexually mature after one year. After approximately one month in the spawning habitat, the darters move to deeper water.

Diet

Slenderhead darters are lie-in-wait predators that feed predominantly on insect

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

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

, and other

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...

. A study conducted in Illinois examined the contents of several darters' stomachs and found that 99 percent of the contents were

midge A midge is any small fly, including species in several family (biology), families of non-mosquito nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid ...

larvae, blackfly larvae,

caddisfly The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

larvae, and

mayfly Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the orde ...

naiads In Greek mythology, the naiads (; ), sometimes also hydriads, are a type of female spirit, or nymph, presiding over fountains, wells, springs, streams, brooks and other bodies of fresh water. They are distinct from river gods, who embodied ...

References

{{Taxonbar, from=Q3752150 phoxocephala Fish described in 1876