Cycleptus elongatus 

blue sucker

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Type Locality

Ohio River (Lesueur 1817).

Etymology/Derivation of Scientific Name

Cycleptus: small circle, in reference to the small, round mouth elongatus: elongate or prolonged (Ross 2001).

Synonymy

Catostomus elongatus Lesueur 1817:103.

Cycleptus elongatus Hay 1883:72; Cook 1959:77; Hubbs et al. 1991:24.

Characters

Maximum size: 927 mm TL (Carlander 1969).

Coloration: Back and upper sides are blue-black to dark-gray, grading to white on undersides. Body coloration lighter in small fish, and the median and dorsal fins are uniformly dusky with white margins. Caudal fin bicolored, with the upper lobe immaculate and the lower lobe densely pigmented. Anal fin coloration is highly variable, with pigmentation becoming darker with increasing size (Ross 2001). Nuptial males intensely blue-black (Rupprecht and Jahn 1980; Ross 2001).

Teeth count: 40-45 teeth per bone; teeth relatively large, arranged in comblike fashion (Eastman 1977).

Counts: 50+ lateral line scales; 22-30 dorsal fin rays (Texas populations; Hubbs et al. 1991, 2008). Cross (1967) listed the following counts for Cycleptus elongatus: 53-56 lateral line scales; usually 7 anal rays; 10 or 11 pelvic fin rays; 16 or 17 pectoral fin rays.

Body shape: Terete; extremely muscular and heavy-bodied (Moss et al. 1983). Eye closer to back of head than to tip of snout; head abruptly more slender than body, in adults; dorsal fin base more than one-third of standard length (Hubbs et al. 2008).

Mouth position: Inferior mouth with large papillose lips (Miller and Robison 2004).

External morphology: Lip papillae short, only around mouth (Hubbs et al. 2008). Pelvic fins large; pectoral fins large and falcate; lateral line well developed; snout acute; eye small (Cross 1967). Caudal fin moderately forked; anal fin with nearly vertical profile when extended (Ross 2001). Breeding males and females with small tubercles covering body and fins; in breeding males, tubercles prominent and enlarged on snout, around eyes and on opercle (Moss et al. 1983).

Distribution (Native and Introduced)

U.S. distribution: Found in large rivers throughout the Mississippi Basin continuing southward into Texas (Hubbs et al. 2008).

Texas distribution: Occurs in limited numbers through the major streams of the state, except the Rio Grande (Hubbs et al. 2008). Warren et al. (2000) list the following drainage units for distribution of Cycleptus elongatus in the state: Red River (from the mouth upstream to and including the Kiamichi River), Sabine Lake (including minor coastal drainages west to Galveston Bay), Galveston Bay (including minor coastal drainages west to mouth of Brazos River), Brazos River, Colorado River, San Antonio Bay (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River), Nueces River.

Abundance/Conservation status (Federal, State, NGO)

State Threatened in Texas (Hubbs et al. 2008). Populations in the southern United States are vulnerable (Warren et al. 2000). Williams et al. (1989) listed status as Special Concern.

Habitat Associations

Macrohabitat: Throughout range, inhabits large, deep rivers, and deeper zones of lakes (reservoirs; Cross 1967). In the lower Mississippi River, species was abundant in main channel, reveted bank habitats; common in natural steep bank and lotic habitats; found regularly, but in low numbers in (Baker et al. 1991). Species rarely collected in the main body of Lake Texoma, Oklahoma and Texas, usually taken in the spring at all depths down to 15 feet; slightly more common in the tailwaters (Riggs and Bonn 1959).

Mesohabitat: Found over cobble and/or bedrock substrates; adults occupy deep riffles (typically 1-2 m depth) in areas of very swift flow, with current speeds from 100-260 cm/s; juveniles occupy shallower, less swift water (Moss et al. 1983); in laboratory stream channels, movement of juveniles was encumbered over irregular substrates in slower current. Cross (1967) collected fish from the Neosho River, Kansas, in strong currents over bottoms of exposed bedrock or rubble and gravel; juveniles found in broader less turbulent riffles. In areas of the Missouri River channelized by dikes, this species was most abundant in fast water at the tips of rock dikes and at low spots within a dike (Robinson 1977). In the Mississippi River, shallow, slack waters associated with islands (island borders and island sloughs) were important nursery areas for young fish (Adams et al. 2006).

Biology

Spawning season: Moss et al. (1983) reported spawning in May in the Neosho River, Kansas, at water temperatures of 20-23 degrees C. In Kansas, Cross (1967) reported collection of individuals in breeding condition in April, at water temperatures of 50-60 degrees F. In a study of a Mississippi River population, male characteristics indicated a late April-early May spawning season (Rupprecht and Jahn 1980). In the Mississippi River, spawning occurred over a 10-28 day period during the spring, and corresponded with rising water temperatures of 14-18 degrees C during mid-late April – early-mid May (Adams et al. 2006).

Spawning habitat: In deep riffles (1-2 m) with cobble and bedrock substrates; water velocities at spawning sites were 1.8 m/sec. (Moss et al. 1983).

Reproductive strategy:

Fecundity: Mean absolute fecundity of females was 150,704 (range 26,829-267,471) in the Wabash River, Indiana (Daugherty et al. 2008). Females age 6 (85 mm TL) produced 76,227 ova, and those of age 8 (680 mm TL) produced 149,520 ova indicating egg number is closely related to length of individual; largest eggs from non-breeding gravid females collected in August averaged about 1.0 mm in diameter (Rupprecht and Jahn 1980). Moss et al. (1983) reported that eggs are opaque, slightly yellow, adhesive and average 2.2 mm in diameter.

Age at maturation: Daugherty et al. (2008) estimated size-at maturity for specimens from Wabash River, Indiana, at 515 mm TL for males and 568 mm TL for females. Moss et al. (1983) collected a 507 mm TL, 1.02 kg, age III sexually mature specimen from the Neosho River, Kansas. According to Rupprecht and Jahn (1980), of those fish collected from Pool 20 of the Mississippi River, the males generally reached sexual maturity at age IV (youngest specimen measured 503 mm TL), and the females at age VI (youngest specimen measured 573 mm TL).

Migration: Adults probably winter in deep pools and move upstream in spring to spawn in riffles (Cross 1967). Males migrate into spawning area before females (Moss et al. 1983).

Longevity: 16 years of age reported from the Kansas River, Kansas (Eitzmann et al. 2007). 11 years of age reported from the upper Yazoo River basin, Mississippi (Hand and Jackson 2003). 10 years of age (possibly 13 years) reported form Pool 20, Mississippi River (Rupprecht and Jahn 1980).

Food habits: Fish collected from Pool 20 of the Mississippi River primarily consumed Tricoptera and Diptera larvae and pupae, and lesser numbers of Ephemeroptera larvae and amphipods (Rupprecht and Jahn 1980). Populations in the Neosho River, Kansas, reported to feed on hellgrammites (Corydalus), caddisflies (Hydropsyche and Cheumatopsyche), fingernail clams (Sphaerium), filamentous algae (mainly Cladophora) and leaf litter; young fish feed on smaller insect larvae (dipterans and caddisflies; Moss et al. 1983). In the Mississippi River, young fish used diverse feeding modes in the shoreline areas, consuming benthic (Chironomidae larvae), nektonic (Cyclopoida and Cladocera) and neustonic (Chironomidae adults, Bryozoa statoblasts and Thripidae) forms; young fish were observed picking at items floating on water surface, and skimming surfaces of floating logs and willow roots (Adams 2006). Fish inhabiting the tailwater habitat of Lewis and Clark Lake, Nebraska-South Dakota, consumed large amounts of algae from late-September to early-November when periphytic algae reached peak abundance; in spring months, primary diet items were chironomids and zooplankton (Walburg et al. 1971).

Growth and Population structure: Fish average 189-205 mm TL at the end of the first year, and are 296-346 mm, 397-461 mm, 471-512 mm, 533-569 mm, 578-611 mm, 589-641 mm, 643-680 mm, 711-732 mm, and 798 mm at ages 2-10, respectively (Walburg et al. 1971; Rupprecht and Jahn 1980; Moss et al. 1983). In Neosho River, Kansas, populations Moss et al. (1983) found that females were consistently larger than males at all ages; mature females reach greater maximum ages, weights and lengths (9 years, 4.1 kg, 763 mm TL) than males (7 years, 3.7 kg, 749 mm TL). Hand and Jackson (2003) reported calculated total length at annulus for fish collected in the upper Yazoo River basin, Mississippi: 159-203 mm TL at age 1, 231-395 mm TL at age 2, and 289-395 mm TL, 361-466 mm TL, 406-521 mm TL, 442-544 mm TL, 476-575 mm TL, 518-610 mm TL, 565-628 mm TL, 624-638 mm TL, and 661 mm TL for ages 3-11, respectively.

Phylogeny and morphologically similar fishes

Hubbs et al. (2008) refers to the Rio Grande, Texas, Cycleptus population as the Rio Grande blue sucker, Cycleptus sp. (formerly referred to as Cycleptus elongatus; Hubbs et al. 1991). Based on phylogenetic analyses, Bessert (2006) stated that Cycleptus in the Rio Grande basin is monophyletic and clearly divergent from C. elongatus. Buth and Mayden (2001) proposed that the Rio Grande drainage population to be recognized as a different species, noting that this population required further analysis of morphological and molecular variation and a formal description.

Differences between C. elongatus and Cycleptus sp. include the following: in C. elongatus the lip papillae is short, only around the mouth, while in Cycleptus sp. the lip papillae is long, extending forwards onto end of snout; also, Cycleptus elongatus does not occur in the Rio Grande basin, while Cycleptus sp. is found only in the Rio Grande basin (Hubbs et al. 2008).

Cycleptus elongatus is unlikely to be confused with other catostomids, as the species differs from all other suckers in the high lateral scale count (greater than 49) and long dorsal fin (Ross 2001).

Total myomere counts for larval Cycleptus elongatus ranged from 47-54; larval fish ≥12.5 mm TL are coal black to dark gray in life; yolk was absorbed by 13 mm TL (Hogue et al. 1981); protolarvae (fish up to about 12 mm TL) with more than 46 myomeres, and depth of head at posterior margin of orbit more than 11% of total length; mesolarvae (>12 mm TL to about 15 mm TL) with more than 46 myomeres, depth of body at vent (including anus) more than 8.7% of total length, and heavily pigmented; metalarvae (<20 mm TL) with more than 46 total myomeres, and having melanophores scattered on lateral surfaces with no apparent pattern; metalarvae (≥20 mm TL) with lips papillose, long dorsal fin, and heavy pigmentation.

Host Records

Rhabdochona cascadilla (Nematoda : Thelazioidea) detected in the intestine of Cyclepus elongatus, from Illinois (Dyer and Poly 2002). Myzotryma cyclepti (Monogenea) and Anonchohaptor olseni (Monogenea) reported from C. elongatus in the Missouri River, North Dakota (Leiby et al. 1973) ; M. cyclepti also reported from this species in the Mississippi River, Illinois (Robinson and Jahn 1980). A single leech, Helobdella sp. found on a specimen from Big Bend Reservoir, Missouri River, South Dakota (Alleman 1965).

Commercial or Environmental Importance

Abundance of Cycleptus elongatus has been decreased by impoundment, pollution, and reduced water flows in those systems in which it occurs (Edwards et al. 2004). Williams et al. (1989) listed threats to this species: present or threatened destruction, modification, or curtailment of its habitat or range; and other natural or manmade factors affecting its continued existence (hybridization, introduction of exotic or transplanted species, predation, competition). Spawning migration may be blocked and spawning areas inundated by dams, contributing in part to the decline of this species (Cross 1967). Walburg et al. (1971) reported collection of numerous Cycleptus elongatus in tailwaters below dams, but almost none were present in the reservoir above.

[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1957); Branson (1962); Nature Conservancy (2004).]  

References

Adams, S.R., M.B. Flinn, B.M. Burr, M.R. Whiles, and J.E. Garvey. 2006. Ecology of larval blue sucker (Cycleptus elongatus) in the Mississippi River. Ecology of Freshwater Fish 15:291-300.

Alleman, G.A. 1965. Parasites of fishes of Oahe and Big Bend Reservoir, South Dakota. Master’s Thesis, South Dakota State University. 46 pp.

Baker, J. A., K. J. Kilgore, and R. L. Kasu. 1991. Aquatic habitats and fish communities in the lower Mississippi River. Rev. Aqat. Sci. 3(4):313-356.

Bessert, M.L. 2006. Molecular systematics and population structure in the North American endemic fish genus Cycleptus (Teleostei: Catostomidae). Ph.D. dissertation, University of Nebraska, Lincoln. 219 pp.

Branson, B.A. 1962. Comparative cephalic and appendicular osteology of the fish family Catostomidae. Part I, Cycleptus elongatus (Lesueur). The Southwestern Naturalist 7(2):81-153.

Burr, B.M., and R.L. Mayden. 1999. A new species of Cycleptus (Cypriniformes: Catostomidae) from Gulf Slope drainages of Alabama, Mississippi, and Louisiana, with a review of the distribution, biology, and conservation status of the genus. Bulletin of the Alabama Museum of Natural History 20:19-57.

Buth, D.G., and Mayden, R.L. 2001. Allozymic and isozymic evidence for polytypy in the North American catostomid genus Cycleptus. Copeia 2001:899-906.

Carlander, K.D. 1969. Handbook of Freshwater Fishery Biology. Iowa State University Press, Ames. 752 pp.

Cook, F. A. 1959. Freshwater fishes in Mississippi. Mississippi Game and Fish Commission, Jackson. 239 pp.

Cross, F.B. 1967. Handbook of Fishes of Kansas. University of Kansas Museum of Natural History Misc. Publ. No. 45, Lawrence. 357 pp.

Daugherty, D.J., T.D. Bacula, and T.M. Sutton. 2008. Reproductive biology of blue sucker in a large Midwestern river. Journal of Applied Ichthyology 24(3):297-302.

Dyer, W.G., and W.J. Ploy. 2002. First record of Rhabdochona cascadilla Wigdor, 1918 (Nematoda: Thelazioidea) in the blue sucker, Cycleptus elongatus (Lesueur, 1817), from Illinois. Transactions of the Illinois Academy of Science 95(2):107-109.

Eastman, J.T. 1977. The pharyngeal bones and teeth of catostomid fishes. American Midland Naturalist 97(1):68-88.

Edwards, R.J., G.P. Garrett, and N.L. Allan. 2004. Aquifer-dependent fishes of the Edwards Plateau region. Chapter 13, pp. 253-268 in: Mace, R.E., E.S. Angle, and W.F. Mullican, III (eds.). Aquifers of the Edwards Plateau. Texas Water Development Board. 360 pp.

Eitzmann, J.L., A.S. Makinster, C.P. Paukert. 2007. Distribution and growth of blue sucker in a Great Plains river, USA. Fisheries Management and Ecology 14(4):255-262.

Hand, G.R., and D.C. Jackson. 2003. Blue sucker stock characteristics in the upper Yazoo River basin, Mississippi, USA. Fisheries Management and Ecology 10(3):147.

Hay, O. P. 1883. On a collection of fishes from lower Mississippi valley. Proc. Bull. U.S. Fish Comm. 2:57-75.

Hogue, J.J., Jr., J.V. Conner, and V.R. Kranz. 1981. Descriptions and methods for identifying larval blue sucker, Cycleptus elongatus (LeSueur). Rapp. P.-v. Reun. Cons. Int. Explor. Mer. 178:585-587.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. The Southwestern Naturalist 2(2/3):89-104.

Hubbs, C., R. J. Edwards, G. P. Garrett. 1991. An annotated checklist of the fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2^nd edition 43(4):1-87.

Leiby, P.D., D.C. Kritsky, and D.D. Bauman. 1973. Studies on helminthes of North Dakota. VII. Ancyrocephalinae (Monogenea) from the gills of the blue sucker, Cycleptus elongatus (LeSueur). Can. J. Zool. 51:777-779.

Lesueur, C. A. 1817. A new genus of fishes, of the order Abdominales, proposed, under the name of Catostomus; and the characters of this genus, with those of its species, indicated. J. Acad. Nat. Sci. Phil. 1(1):88-111.

Miller, R.J., and H.W. Robison. 2004. Fishes of Oklahoma. University of Oklahoma Press, Norman. 450 pp.

Morey, N.M., and C.R. Berry, Jr. 2003. Biological Characteristics of the blue sucker in the James River and the Big Sioux River, South Dakota. Journal of Freshwater Ecology 18(1):33-42.

Moss, R. E., J. W. Scanlan, and C. S. Anderson. 1983. Observations on the natural history of the blue sucker (Cycleptus elongatus Le Sueur) in the Neosho River. Amer. Midl. Nat. 109(1):15-22.

The Nature Conservancy. 2004. A biodiversity and conservation assessment of the Edwards Plateau ecoregion. Edwards Plateau Ecoregional Planning Team, The Nature Conservancy, San Antonio, Texas. 30 pp.

Riggs, C.D., and E.W. Bonn. 1959. An annotated list of the fishes of Lake Texoma, Oklahoma and Texas. The Southwestern Naturalist 4(4):157-168.

Robinson, G.L., and L.A. Jahn. 1980. Some observations of fish parasites in pool 20, Mississippi River. Trans. Am. Microsc. Soc. 99:206-212.

Robinson, J.W. 1977. The utilization of dikes by certain fishes in the Missouri River. Federal Aid Project No. 2-199-R, Missouri Department of Conservation, Jefferson City. 30 pp.

Ross, S. T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi, Jackson. 624 pp.

Rupprecht, R. J. and L. A. Jahn. 1980. Biological notes on blue suckers in the Mississippi River. Trans. Amer. Fish. Soc. 109(3):323-326.

Vokoun, J.C., T.L. Guerrant, and C.F. Rabeni. 2003. Demographics and chronology of a spawning aggregation of blue sucker (Cycleptus elongatus) in the Grand River, Missouri, USA. Journal of Freshwater Ecology 18(4):567-575.

Walburg, C. H., G. L. Kaiser, and P. L. Hudson. 1971. Lewis and Clark Lake tailwater biota and some relations of the tailwater and reservoir fish populations, pp. 449-467. In; Reservoir fisheries and limnology. G. E. Hall, ed. Spec. Publ., no. 8, American Fisheries Society, Washington, D.C.

Warren, L. W., Jr., B. M. Burr, S. J. Walsh, H. L. Bart, Jr., R. C. Cashner, D. A. Etnier, B. J. Freeman, B. R. Kuhajda, R. L. Mayden, H. W. Robison, S. T. Ross, and W. C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.

Williams, J.E., J.E. Johnson, D.A. Hendrickson, S. Contreras-Balderas, J.D. Williams, M. Navarro-Mendoza, D.E. McAllister, and J.E. Deacon. 1989. Fishes of North America Endangered, Threatened, or of Special Concern. Fisheries 14(6):2-20.