Diamond darter
Encyclopedia
The diamond darter, Crystallaria cincotta, is a species
of freshwater
fish
of the darter
family
. It is named for the sparkling light it reflects during nighttime collections, the diamond darter was first described in 2008 and is only the second known member of its genus
, which also includes the crystal darter
, C. asprella.
s on their dorsal fin
s, and 11-15 soft rays. However, their anal fins do not have any spines at all, only 11-13 soft rays. Adults are estimated to be 3-5 inches long, with the largest specimen measuring 7.7cm, roughly 3.03 inches.
Diamond darters bear a strong resemblance to crystal darters, their relatives. Both fish are translucent, and have olive
-colored patterns on their bodies. Diamond darters differ in that they have a gape equal to or larger than the width of the base of their inter pelvic fins, which are shaped like sickles. They also have a blotch in front of the eye that is separate from the orbital rim. Diamond darters have fewer dorsal spines and anal rays than the crystal darter. They also have fewer rows of scale
s on the cheek
(2), and opercle (2).
The diamond darter was described from specimens collected from the drainages of the Cumberland
, Elk
, Green
, and Muskingum River
s, which are all part of the Ohio River
basin, from 1980 to 2005. Because of river alterations, and problems with water quality
, the diamond darter's range
has become greatly diminished. As of 2008, the fish is only known to still live in the Elk River, West Virginia
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of the darter
Darter (fish)
The fish popularly known as darters are small perch-like fish.They inhabit freshwater streams in North America. They are members of the family percidae and include members of the Ammocrypta, Crystallaria, Etheostoma and Percina genera....
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
. It is named for the sparkling light it reflects during nighttime collections, the diamond darter was first described in 2008 and is only the second known member of its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, which also includes the crystal darter
Crystal darter
The crystal darter, Crystallaria asprella, is a small North American fish found in small, moderate, and swift rivers in the drainage basins of the Mississippi and Ohio Rivers. It is now extirpated from a majority of its range along the Ohio River...
, C. asprella.
Description
Diamond darters have 11-13 spineSpine (zoology)
A spine is a hard, thorny or needle-like structure which occurs on various animals. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism. Spines are often formed of keratin...
s on their dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s, and 11-15 soft rays. However, their anal fins do not have any spines at all, only 11-13 soft rays. Adults are estimated to be 3-5 inches long, with the largest specimen measuring 7.7cm, roughly 3.03 inches.
Diamond darters bear a strong resemblance to crystal darters, their relatives. Both fish are translucent, and have olive
Olive
The olive , Olea europaea), is a species of a small tree in the family Oleaceae, native to the coastal areas of the eastern Mediterranean Basin as well as northern Iran at the south end of the Caspian Sea.Its fruit, also called the olive, is of major agricultural importance in the...
-colored patterns on their bodies. Diamond darters differ in that they have a gape equal to or larger than the width of the base of their inter pelvic fins, which are shaped like sickles. They also have a blotch in front of the eye that is separate from the orbital rim. Diamond darters have fewer dorsal spines and anal rays than the crystal darter. They also have fewer rows of scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
s on the cheek
Cheek
Cheeks constitute the area of the face below the eyes and between the nose and the left or right ear. They may also be referred to as jowls. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve...
(2), and opercle (2).
Distribution
Cumberland River
The Cumberland River is a waterway in the Southern United States. It is long. It starts in Harlan County in far southeastern Kentucky between Pine and Cumberland mountains, flows through southern Kentucky, crosses into northern Tennessee, and then curves back up into western Kentucky before...
, Elk
Elk River (West Virginia)
The Elk River is a tributary of the Kanawha River, long, in central West Virginia in the United States. Via the Kanawha and Ohio Rivers, it is part of the watershed of the Mississippi River.-Course:...
, Green
Green River (Kentucky)
The Green River is a tributary of the Ohio River that rises in Lincoln County in south-central Kentucky. Tributaries of the Green River include the Barren River, the Nolin River, the Pond River and the Rough River...
, and Muskingum River
Muskingum River
The Muskingum River is a tributary of the Ohio River, approximately 111 miles long, in southeastern Ohio in the United States. An important commercial route in the 19th century, it flows generally southward through the eastern hill country of Ohio...
s, which are all part of the Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...
basin, from 1980 to 2005. Because of river alterations, and problems with water quality
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
, the diamond darter's range
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
has become greatly diminished. As of 2008, the fish is only known to still live in the Elk River, West Virginia
West Virginia
West Virginia is a state in the Appalachian and Southeastern regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the northeast and Maryland to the east...
.