Chrosomus Saylori
   HOME

TheInfoList



OR:

The laurel dace (''Chrosomus saylori'') 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 ...
belonging to 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 ...
Leuciscidae Leuciscidae is a family of freshwater ray-finned fishes, formerly classified as a subfamily of the Cyprinidae, which contains the true minnows. Members of the Old World (OW) clade of minnows within this subfamily are known as European minnow ...
, which includes the
dace A dace is a small fish that can be one of many different species. The unmodified name is usually a reference to the common dace (''Leuciscus leuciscus''). This, like most fish called "daces", belongs to the family Leuciscidae, mostly in subfami ...
s,
chub Chub is a common fish name. It pertains to any one of a number of ray-finned fish in several families and general. In the UK, the term ''chub'' usually refers to the species '' Squalius cephalus''. In addition, see sea chub. In family Cyprinid ...
s and related fishes. This species is restricted to the U.S. state of
Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...
. It was first discovered in 1976. A very rare species, it has only been found in localized populations in six small streams on the Walden Ridge portion of the Cumberland Plateau in Tennessee. It is found in six streams: the Soddy, Horn, Cupp, Young's, Moccasin, and Bumbee Creeks, all of which drain into larger rivers that eventually feed the Tennessee River. It is believed to be
extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...
from Laurel Creek, the only other stream where it was known to occur. It is commonly considered a nest associate and uses its large mouth and short intestinal tract to support an animal-based diet. Displaying sexual dimorphism, an average adult ''C. saylori'' measures approximately at the age of reproduction. Similar to other ''Chrosomus'' species, two dark parallel lines run the length of the body, and a red coloration appears during the breeding season. Spawning is believed to take place in small, cool streams, lined with small pebbles. As of August 9, 2011, this species was placed on the endangered species list, as a result of agriculture, mining, and timbering in the Walden Creek area. This fish is threatened by increased
sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...
in its habitat, which occurs because surrounding hillsides have been logged, leading to
erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...
. This accumulation of
silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...
makes the fish's spawning areas unsuitable. Such activities can cause erosion, which increases
siltation Siltation is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary o ...
, impeding spawning efforts. Eggs can be suffocated by sediment settling into the rocky streambeds. The fish is named for
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 ...
Charles F. Saylor, who was one of the first to collect it. Its common name refers to mountain laurel (''Kalmia'' spp.), which is a common plant next to the streams where it lives.


Description

This
minnow Minnow is the common name for a number of species of small freshwater fish, belonging to several genus, genera of the family Cyprinidae and in particular the subfamily Leuciscinae. They are also known in Ireland as wikt:pinkeen, pinkeens. While ...
is long on average. It is olive green to tan in color with a silvery white underside. It has two black stripes on each side. During the breeding season the fish changes color, developing bright red coloration on the lower parts. Part of the
dorsal fin 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 ...
becomes red, as do the lips. The stripes become a deeper black and there are more black areas on the head and breast. The cheeks and the area between the black stripes become gold. Most of the fins turn yellow. Females and males both change colors, but the male's colors are more intense. Otherwise, female and male can be told apart by the shape of the
pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...
s.


Ecology

Because ''C. saylori'' is a relatively recent discovery, a detailed life study has not been performed. However, it is known to take shelter in the
riparian zone A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a ripari ...
s of creeks, where vegetation provides shelter. Because of this, it is extremely susceptible to changes, or the absence of such stream-side plants. They are generally found in cool, slow moving water, or pools containing small rocks, boulders, and rubble. This type of streambed is easily influenced by an increase in
siltation Siltation is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary o ...
. ''C. saylori'' are also susceptible to warmer water temperatures, above . The localized populations may be the result of pockets of the preferred, cooler water surrounded by warmer water. After analyzing the stomach contents, it was found that the diet of ''C. saylori'' is mostly animal material. It was mostly benthic insect larvae, as well as plant material and sand grains. Similar to other fish species with animal-based diets, they have large mouths, short intestines, a reduced number of pharyngeal teeth, and a primitively shaped basiocciptial bone. ''C. saylori'' are often found feeding in loosely grouped schools.


Life history

This species is characterized by two horizontal, uninterrupted black lines that run the length of the body which distinguish it from other similar species. Nuptial males have black pigment covering the breast and underside of head. Their intestines are loosely coiled in an S-configuration, and have a winged basioccipital pharyngeal pad, as opposed to rounded. Very little is known about the reproductive strategies of ''C. saylori'' because so little is known about the species in general. The species has been observed spending time around gravel beds with small pebbles, as well as spending time around gravel-bed nests made by other species. Yet, it is still unclear as to what actually happens, apart from spawning in gravel beds. This trait alone, however, may be its downfall. Redds, or gravel-pebble spawning beds, are hugely impacted by any increase in siltation in the water. When the sediments sink and settle into these rocky areas, they can easily smother the eggs and ruin an entire breeding season. Therefore, this species is at a serious risk.


Management

Because this species is so rare, only to be found in six streams, it has been listed as an endangered species. As of 2007, the species was listed as a candidate. As of September 8, 2011, this species was officially protected as an endangered species under the
Endangered Species Act of 1973 The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...
. ''C. saylori'' is most threatened by an increase in siltation that can cause serious damage to spawning grounds. Such an increase can be caused by a variety of events, including the removal of riparian vegetation and timber removal progress in the nearby area surrounding these particular streams in which ''C. saylori'' can be found. In 1883, the Walden Ridge railroad moved into the area allowing for the transport of timber, which cause a boom in timber output. However, trees that stand near streams are responsible for holding the rich soil in place, preventing it from being washed away and eroded by the stream. The removal of such trees through mining often results in stream bank erosion, causing an increase in siltation. In addition, nearby mining practices are known to have bad stream side management zones and problems with roadside construction. Two current projects are of greatest concern for this species including the installation of a water line crossing through a populated creek, and building an impoundment on a tributary to an occupied stream. These activities result in great danger for the ''C. saylori'' species. However, some efforts are being made to protect this fish. In 1992, an organization dedicated to aquatic conservation called Conservation Fisheries Inc. was established. It is responsible for monitoring and restoring at-risk populations such a ''C. saylori''. They work throughout the southeast, using a variety of methods of management. Because the danger to this species is not yet dire, as they are still quite abundant in these areas, this organization is not currently taking action with ''C. saylori''. They are able to raise them in hatcheries and are monitoring the populations, waiting for any indication of trouble. Due to a
drought A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D.  Jiang, A.  Khan, W.  Pokam Mba, D.  Rosenfeld, J. Tierney, ...
affecting southeastern Tennessee, 105 laurel dace were removed from their habitat in Walden Ridge in July 2024 and relocated to the Tennessee Aquarium Conservation Institute in Chattanooga, Tennessee. One fish did not survive relocation, and the 104 remaining dace are planned to be repatriated once normal stream flows resume. Since 2012, the laurel dace has been extirpated from three streams in the region due to
habitat degradation Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
.


References

{{Taxonbar, from=Q28599126 Chrosomus Endemic fauna of Tennessee Fish described in 2001 Freshwater fish of North America