(DRAFT) - Taxonomy
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
TAXONOMY
NAME - CHUB, SLENDER
OTHER COMMON NAMES - CHUB and SLENDER
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - OSTEICHTHYES,
ORDER AND SUBORDER - CYPRINIFORMES,
FAMILY AND SUBFAMILY - CYPRINIDAE,
GENUS AND SUBGENUS - HYBOPSIS,
SPECIES AND SSP - CAHNI,
SCIENTIFIC NAME - HYBOPSIS CAHNI
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Slender Chub
Hybopsis cahni Hubbs and Crowe, 1956
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Cypriniformes FAMILY: Cyprinidae
Hybopsis cahni was described by Hubbs and Crowe in 1956 (01). It
is a small, slender minnow, the largest known being 94 mm total
length, with a long, somewhat pointed snout; inferior mouth; one small
barbel at each end of the lips; well-developed, rugose taste buds on
the underside of the head; dark lateral stripe on the body, often
slightly interrupted at intervals the size of lateral line scales;
small caudal spot present; caudal base pattern of increased pigment
intensity at the upper and lower base of the fin, with a pale area
between each of these marks and the caudal spot. In life the fish is
brown and/or olive above, green and violet reflections on the side,
belly white. Scale size is moderate, 40-49 scales in the lateral
line; pharyngeal teeth 4-4; anal rays 7 (01,02,03).
Since described, the slender chub has been classified in the
subgenus Erimystax of the genus Hybopsis. However, Erimystax (with
three other species) may warrant elevation to generic status, or be
Taxonomy - 1 (DRAFT) - Taxonomy
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
allocated to a generic group other than Hybopsis (04).
Type specimens are at the University of Michigan Museum of
Zoology and U.S. National Museum of Natural History (01). Voucher
specimens are also at: Roanoke College, Southern Illinois University,
Tulane University, University of Alabama, and the University of
Tennessee, Knoxville. Published photographs are in references 05, 06,
07, 08, and 12.
Taxonomy - 2 (DRAFT) - Status
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
STATUS
Coded Status
Tennessee; State Listed
Virginia; State Recognized
T: Federal Threatened
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The slender chub (Hybopsis cahni) has been designated a
Threatened species pursuant to the Endangered Species Act of 1973
(50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540),
as amended. The species has this status wherever found including the
States of Tennessee and Virginia. Critical Habitat has been
designated in Claiborne and Hancock Counties, TN and Lee and Scott
Counties, VA (50 CFR 17.95(e)).
Special rules concerning "take" of this species can be found in
50 CFR 17.44(c).
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
Status - 1 (DRAFT) - Status
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
STATE: Tennessee
DESIGNATED STATUS: Threatened
ADMINISTRATIVE AGENCY: Wildlife Resources Agency
STATE STATUTE: TN Annotated Code, Chapter 9, Sec. 51-901 through
51-912, and Proclamation 75-15, 76-4 and
amendments.
STATE: Virginia
DESIGNATED STATUS: Recognized Threatened
ADMINISTRATIVE AGENCY: Commission of Game and Inland Fisheries
STATE STATUTE: VA State Code 29.230 - 29.237.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The slender chub is listed as Vulnerable in the IUCN Red Data
Book, Vol. 4, 1977.
ECONOMIC STATUSES:
The species does not have any cultural or commercial value. It
is sensitive to changes in water quality and, therefore, would be an
indicator of environmental quality.
77/01/12:42 FR 02507/ - Proposed rule
77/09/09:42 FR 45527/ - Final rule, listed as Threatened with CH
82/09/27:47 FR 42387/ - Five year review
87/07/07:52 FR 25523/25528 - Notice of review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Cropland and Pasture
Confined Feeding Operations
Deciduous Forest Land
Streams and Canals
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, upper perennial UB2
Riverine, upper perennial UB1
Riverine, upper perennial SB2
Riverine, upper perennial SB1
Riverine, upper perennial RS2
Riverine, upper perennial RS1
Riverine, upper perennial RB2
Riverine, upper perennial RB1
Riverine, upper perennial FL2
Riverine, upper perennial FL1
Riverine, upper perennial BB1
COMMENTS ON HABITAT ASSOCIATIONS -
Three primary factors appear to dictate the natural distribution
of the slender chub (02,07,09,10,11).
(1) Large stream size, ca 30-400 m width. This species has been
found only in main-river channels of the extreme upper Tennessee
drainage. Suitable substrate and current occur in some of the small-
and medium-sized tributaries, but the chub apparently does not occupy
these.
(2) Clean, pea- to medium-sized gravel. The chub is found only
at sites with a large area of this substrate, areas of about 25 square
meters and larger. At known chub sites that have larger stones, sand
and silt, the fish is still found in areas of small- to medium-size
gravel.
(3) Moderate to swift current. The exact needs of the chub
regarding current speed are unknown. However, moderate to swift
currents render its preferred substrate virtually free of silt.
Overall, the range of habitat conditions of the chub comprise
warm, well-oxygenated, moderate gradient, Ridge and Valley province
streams that tend to have more frequent (longer) pools than riffles
and swift shoals. These are alkaline waters, pH normally ca 7.5-8.0
(02,09,11). They become considerably turbid from heavy rains, but
the Clinch and Powell Rivers are more frequently clear than turbid.
The river valley floors are narrow; slopes are forested. Streams
populated by this species also run through cropland and pasture land.
The chub sometimes occurs along beds of the emergent water willow,
Justicia, but is not associated with this plant.
Habitat Associations - 1 (DRAFT) - Food Habits
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
LIFESTAGE FOOD FOOD PART
General Arthropods
General Molluscs
Food Habits - 1 (DRAFT) - Environment Associations
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Inland wetlands: swamp
G Aquatic Features: Pool areas
G
Environment Associations - 1 (DRAFT) - Life History
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
Based on 14 young to adult slender chubs collected during June to
October, this species feeds largely on immature benthic insects
(chiefly mayflies, caddisflies and trueflies) and small snails. Two
fish took tiny individuals of the introduced Asiatic clam, Corbicula.
One had eaten unidentified eggs (probably fish) (02).
HOME RANGE/TERRITORY:
The slender chub is not known to exhibit territoriality.
Apparently they are localized over the gravel riffle area (02,03).
PERIODICITY:
Periodicity is unknown. Fish activity is probably reduced during
winter.
MIGRATION PATTERNS:
Migration is unknown in this species. It is most likely
non-migratory (02).
COVER/SHELTER REQUIREMENTS:
Cover requirements of the slender chub are unknown. This species
frequently is taken in water as shallow as 0.2 m, usually 0.3-0.8 m
depth, and maximally (with small seines) to 1.2 m. The chub was
always found, during spring through fall, in open, shallow areas that
lack larger substrate that could provide cover. When chubs are
disturbed, the adults have been seen to simply swim away to other
shallow areas, apparently not seeking gravel interstices (02,03,09).
REPRODUCTIVE SITE REQUIREMENTS:
The reproductive site is unknown, but very likely it is the
moderate to fast current areas with gravel that are occupied by adults
in spring (02).
REPRODUCTIVE CHARACTERISTICS:
Reproductive characteristics of this species are largely unknown.
It matures before the second spring following the year of hatching
(12). Based on chronology of female gonadal development, nuptial male
tuberculation, and first capture of young (late June), spawning
probably occurs once a year in mid-Spring, at least during May,
possibly also late April. Only two- and three-year-old chubs were
reproductively mature. Based on its low level of sexual dimorphism
and apparent lack of dichromatism, this species probably is not a
nest-builder or egg-guarder (02).
PARENTAL CARE:
Parental care is unknown, and unlikely to occur. The
developmental period is unknown. Young-of-the-year have been captured
in the juvenile-adult habitat within about two months after the
probable spawning season (03).
POPULATION BIOLOGY:
Life History - 1 (DRAFT) - Life History
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
The sex ratio of 55 slender chubs is 36 males:19 females.
Maximum known longevity is three years and about four months. Fish
may possibly survive to four years (02).
Population density (quantitatively) and exact limiting factors
are unknown. Seining the open, shallow gravel runs provides an index
of abundance from year to year. The populations at the most
frequently sampled sites - Frost Ford and Brooks Island areas - of the
Clinch River have fluctuated somewhat: low in 1971, moderate in the
mid-1970's, strong in early and mid-1980's. Since the mid-1970's
the Clinch River had several major floods. Populations elsewhere in
the Clinch have generally always been low since 1968; i.e., a one-hour
seining usually yielded fewer than 10 slender chubs. Larger samples
taken at Kyles Ford in 1980 were from more intensive efforts. The
type locality population, at the lowermost Powell River site, has
generally been low, but was strong in 1976. Elsewhere in the Powell,
it was always found in low numbers (02,03,09,10).
SPECIES INTERRELATIONSHIPS:
Although there obviously is a relationship between the slender
chub and its invertebrate food, no concept of food specificity and
critical food population levels are known.
OTHER LIFE HISTORY DESCRIPTORS:
None are known.
Life History - 2 (DRAFT) - Management Practices
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Developing/maintaining stream structures
Beneficial Maintaining/Controlling Water Flow
Beneficial Controlling/Restricting Mining
Beneficial Controlling/Restricting Road Maintainance Actions
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Creating Artificial Habitat/Nesting Structure
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting wild animals
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Surface Mines
Existing Surface Mines
Adverse Siltation
Existing Siltation
Adverse Water Temperature Alteration
Existing Water Temperature Alteration
Adverse Reservoirs
Existing Reservoirs
Adverse Migration barriers
Existing Migration barriers
Adverse Dredging
Existing Dredging
Adverse Developing/maintaining stream bank vegetation
Existing Developing/maintaining stream bank vegetation
Adverse Shoreline modification/development
Existing Shoreline modification/development
Adverse Environmental Contamination/Pollution
Existing Environmental Contamination/Pollution
Adverse Erosion
Existing Erosion
Adverse
Existing
Adverse Harvesting
Existing Harvesting
COMMENTS ON MANAGEMENT PRACTICES -
The slender chub is strictly associated with shoals and riffles
of moderate to swift current in two major rivers, the Powell and
Clinch, of the upper Tennessee River drainage. Moreover, at these
sites it is closely tied to clean substrate of pea- to medium-sized
gravel. Hence, it is highly localized within the river reaches
occupied (02,07,09,10,11).
Impoundments caused extirpations of populations by inundation
and/or cool/cold water release in the lower Powell and Clinch Rivers
Management Practices - 1 (DRAFT) - Management Practices
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
(Norris Reservoir, TN, shortly after filling in 1936) and of the only
known population in the Holston River (Cherokee Reservoir, TN after
1941) (02,07,09,10). The population in the Powell River above Norris
Reservoir possibly has been depressed by sedimentation from
strip-mining and coal-washing operations in Virginia and by gravel
removal in Tennessee (07,09,10).
The population in the Clinch River, TN was most likely affected
by the disastrous alkaline waste spill in June 1967 (09,10,11). This
event would have extirpated a possible Virginia population. The
spill, primarily composed of calcium hydroxide, was released into the
Clinch River when the dyke of a fly ash settling pond broke sending
490,000 cubic meters of liquid fly ash slurry with a pH of 12.0 to
12.7 into the river. During the next 4 1/2 days following the spill
the alkaline slug traveled downstream killing essentially all fish for
106 km (or to approximately the Tenn./Va. state line).
The Holston population, hypothetically above Cherokee Reservoir,
probably was extirpated by pollution from Kingsport, TN and/or
Saltville, VA (09,10).
Because this species was described after the period of extensive
forest clearing, it is not known how great an impact this development
had on the chub. However, early deforestation and recent poor
agricultural and grazing land practices have contributed to river
sedimentation; the chub avoids silted areas. General siltation
probably has had an adverse impact on the chub.
Future perceived threats are sedimentation in general and the
possibility of a chemical slug from the Appalachian Power Co.
steam-electric generating plant at Carbo, Russel Co., VA.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1983. Slender Chub Recovery Plan.
U.S. Fish and Wildlife Service, Atlanta, GA. 34 pp.
Actions for the recovery of the slender chub include:
1. Continue to utilize existing legal mechanisms to protect the
species and its habitat.
2. Conduct continued population and habitat surveys to determine the
status and range of the species.
3. Determine the present and forseeable threats to the species and
strive to minimize and/or eliminate them where necessary. Impacts of
coal related pollution must be determined; it is likely that recovery
of this species in the Powell River is not possible without control of
this problem. Other impacts may include toxic spills, pesticides,
herbicides, siltation from road construction/maintenance and/or
agricultural practices, and potential decreased water flow from a coal
slurry pipeline.
4. Determine the best methods for reintroducing the fish back into
its historic range and reintroduce where feasible (e.g., introducing
adults and/or juveniles, wild or captive bred stock, etc.).
Management Practices - 2 (DRAFT) - Management Practices
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
Introduction of the species back into its former range (Holston River)
may be feasible; however, the protection of established populations
and their essential habitat is the key to the survival of the species.
5. Due to previous human related, detrimental modifications to the
streams inhabited by this species, habitat rehabilitation may be
necessary to meet specific habitat requirements before expansion or
reintroduction of populations will be effective.
Except for utilizing existing legal mechanisms, there are no
ongoing recovery efforts for this species.
Management Practices - 3 (DRAFT) - References
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCUR *****
01 Hubbs, C.L. and W.R. Crowe. 1956. Preliminary analysis of the
American cyprinid fishes, seven new, referred to the genus
Hybopsis, subgenus Erimystax. Occ. Pap. Mus. Zool., Univ. Mich.
No.578. 8 pp.
02 Jenkins, R.E. 1975. Hybopsis cahni Hubbs and Crowe 1956, slender
chub. Status report to Office of Endangered Species, U.S. Fish and
Wildlife Service. 12 pp. + 1 map.
03 Jenkins, R.E. and N.M. Burkhead. 1985. From a collection at Frost
Ford, Clinch River, in June 1985.
04 Cavender, T.M. and M.M. Coburn. 1985. Interrelationships of North
American Cyprinidae, Part II. Abst. 65th Annu. Meet., Amer. Soc.
Ichthyol. Herpetol.:49.
05 Davis, B.J. and H.W. Reno. 1966. Rediscovery of the slender chub,
Hybopsis cahni Hubbs and Crowe (Cyprinidae) at the type locality in
Claiborne County, Tennessee. Southwest. Nat. 11(2):307.
06 Parker, W. and L. Dixon. 1980. Endangered and threatened wildlife
of Kentucky, North Carolina, South Carolina and Tennessee. N.C.
Agric. Ext. Serv., N.C. State Univ., Raleigh, NC. 122pp.
07 Starnes, W.C. and D.A. Etnier. 1980. Fishes, pages B-1 to B-134.
IN: D.C. Eager and R.M. Hatcher (eds.). Tennessee's Rare
Wildlife. Vol.1: The vertebrates. Tenn. Wildl. Resour. Agency,
Nashville.
08 Deacon, J.E., G. Kobetich, J.D. Williams, S. Contreras, et al.
1979. Fishes of North America endangered, threatened, or of
special concern: 1979. Fisheries 4(2):29-44.
09 Burkhead, N.M. and R.E. Jenkins. 1982. Five-year status review of
the slender chub, Hybopsis cahni, a threatened cyprinid fish of the
upper Tennessee drainage. Rep. Off. Endang. Spec., U.S. Fish and
Wildlife Service. 27 pp. + 1 map.
10 U.S. Fish and Wildlife Service. 1983. Slender Chub Recovery Plan.
U.S. Fish and Wildlife Service, Atlanta, GA. 34 pp.
11 Masnik, M.T. 1974. Composition, longitudinal distribution, and
zoogeography of the fish fauna of the upper Clinch system in
Tennessee and Virginia. Ph.D. Diss., Va. Polytech. Inst. & St.
Univ., Blacksburg, VA. 399 pp.
12 Jenkins, R.E. and N.M. Burkhead. 1980. Hybopsis cahni Hubbs and
Crowe, slender chub, page 182. IN: D.S. Lee, et al., Atlas of
North American Freshwater Fishes. N.C. State Mus. Nat. Hist.,
Raleigh, NC.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Hubbs, C.L. and W.R. Crowe. 1956. Preliminary analysis of the
American cyprinid fishes, seven new, referred to the genus
Hybopsis, subgenus Erimystax. Occ. Pap. Mus. Zool., Univ. Mich.
No.578. 8 pp.
02 Davis, B.J. and H.W. Reno. 1966. Rediscovery of the slender chub,
Hybopsis cahni Hubbs and Crowe (Cyprinidae) at the type locality in
References - 1 (DRAFT) - References
Species CHUB, SLENDER
Species Id ESIS254007
Date 13 MAR 96
Claiborne County, Tennessee. Southwest. Nat. 11(2):307.
03 Jenkins, R.E. 1975. Hybopsis cahni Hubbs and Crowe 1956, slender
chub. Status report to Office of Endangered Species, U.S. Fish and
Wildlife Service. 12 pp. + 1 map.
04 Starnes, W.C. and D.A. Etnier. 1980. Fishes, pages B-1 to B-134.
IN: D.C. Eager and R.M. Hatcher (eds.). Tennessee's Rare
Wildlife. Vol.1: The vertebrates. Tenn. Wildl. Resour. Agency,
Nashville.
05 Burkhead, N.M. and R.E. Jenkins. 1982. Five-year status review of
the slender chub, Hybopsis cahni, a threatened cyprinid fish of the
upper Tennessee drainage. Rep. Off. Endang. Spec., U.S. Fish and
Wildlife Service. 27 pp. + 1 map.
06 Feeman, J.C. 1976-1982. Personal communications. Tennessee
Valley Authority, Norris, TN.
07 Masnik, M.T. 1974. Composition, longitudinal distribution, and
zoogeography of the fish fauna of the upper Clinch system in
Tennessee and Virginia. Ph.D. Diss., Va. Polytech. Inst. & St.
Univ., Blacksburg, VA. 399 pp.
08 U.S. Fish and Wildlife Service. 1983. Slender Chub Recovery Plan.
U.S. Fish and Wildlife Service, Atlanta, GA. 34 pp.
09 Jenkins, R.E. and N.M. Burkhead. 1980. Hybopsis cahni Hubbs and
Crowe, slender chub, page 182. IN: D.S. Lee, et al., Atlas of
North American Freshwater Fishes. N.C. State Mus. Nat. Hist.,
Raleigh, NC.
References - 2