TN00360 CREEK CHUB SEMOTILUS A TROMACULATUS
Physical description: This is a medium to large chubby minnow with a preterminal barbel and a dark dorsal fin spot. The adults are usually from 100-200 mm TL. The body is somewhat elongate and stout with the dorsal fin origin distinctly posterior to the pelvic origin. The head and eye are moderate and the snout is round . The mouth is large and terminal with the frenum absent. The jaws have a firm and narrow plicate pad behind the lips. A terminal barbel is usually present. The tuberculate male usually has 3-7 large recurved tubercles per side, arranged in a curving line from the prenarial to the supraorbital areas. There are small tubercles on the opercle, subopercle and the margins of the body scales. On the body, they are best developed on the dorsal caudal peduncle. All fins may have tubercles with the best developed ones on the pectoral fin. They have 2,5-4,2 pharyngeal teeth and the lateral line is complete with (49)52-58(62) scales. There are (40)43-50(54) circumbody scales, and 20-23(24) circumpeduncle scales. There are 8 dorsal and anal rays, 19 principal caudal rays, (7)8(9) pelvic rays, (14)15-18(20) pectoral rays and 8-11 gill rakers. The juvenile and adult female are olive above. The side is pale olive with silver and some- times violet iridescence. The lateral stripe is leaden and the venter is white. The fins are pale or slightly olive except for the medium olive to black dorsal spot. In the young and small juveniles, the area of the incipient dorsal spot is pale reddish. The dorsum of the breeding male is olive and the side is brassy olive with a diffuse olive midlateral stripe overcast with violet iridescence. There is a rosy cast on the lower body, cheek and opercle. The dorsal fin spot is black-olive, with a submedial red wash bordering the medial interradial black streaking. The caudal fin is dusky olive and the lower fins have a rosy wash *4205*. Reproduction: This species is mature at ages 3 or 4 for males and 2 or 3 for females. The males grow faster than the females and by age 3 are usually 97-198 mm TL. The maximum longevity is age 7. Spawning begins in April or May and lasts until June in the northern areas. Water temperatures at the onset of reproduction range from 12-18 degrees C, and active spawning occurs in water from 15-17 degrees C but subsides in high turbidity and when the tmperature drops below 11 degrees C. Spawning was observed on several occasions in Virginia from April to May in water 13.6-16.7 degrees C *4205*. Spawning occurs in gravel nests constructed by the male in shallow areas just above and below riffles *4205,3055*. The nest is usually at the lower end of a pool where the current begins to quicken *1187,3041, 3044*. The nests observed in the middle of long riffles are usually aband- oned *3045*. Nests range from 10-36 inches in length *3045*. In Missouri, a gravel ridge about 1' wide rises above the general level of the stream bottom with the pit about 2-3 inches deep *1187*. In Manitoba, the typical nest is ridge of gravel 0.5-2, long, about 25 meters wide and 5 cm high. At the downstream end of ridge there is a spawning pit 20-25 cm in diameter and 8-20 cm deep *6252,3048*. Nesting sites often occur 0.5 meters apart *3041, 3044*, although this is not a communal spawner *4205*. The fry emerge from the nests 20-30 days after spawning and locate themselves along the edges of pools where the velocities are generally less than 10 cm/sec *3055*. Incubation takes 6 days after fertilization, at 18.3 degrees C *2278*. Fecundity is from 1115 to 7539 *4205*. They are repeat spawners *3045,3041, 3042*. In Michigan, females mature in the 3rd year, and males in the 4th year *842*. Some nests have just 1 nesting male at the nest site *3044,3041*, but often numerous males congregated at 1 nest site *3044,5849*. Many individuals show upstream spawning migration in the spring, and the males move into shallow gravel channels, runs, and riffles to build nest by making a depression by removing sand and gravel with his mouth. Gravel is moved to the upstream edge, and nest building increases during active spawning periods. The males are aggressive toward conspecific males but are not egg predators, and aggression involves long chases, parallel swims, and facing displays. Rarely does fighting occur. Spawning rates are inversely proportional to the amount of aggressive activity, and more aggression is required by the smaller males to defend the nest. The tubercles and head size of males provide visual stimuli for establishing rank. Females enter the nests singly in one of two ways. They approach from upstream, wherein the male shows initial aggressive behavior, then swim around the nest entering in a prespawning position. Or more commonly a female swims directly into the nest while the male is occupied with nest building or defending the nest from other males. The female must be in prespawning position or the male will chase her away *3031,3045,3040,3044,3041,3042,1477,1462,1478*. Behavior: This species has a breeding and nesting territory. Feeding occurs at all levels of the water column *6252*. They take crayfish, mollusks and rarely frogs with terrestrial insects taken in the summer and fall *4205*. Their dispersion is non-random, and the occur in loosely aggregated schools *1187,1114,1117,1462,1477,842,1127*. The newly hatched larvae are 6-6.2 mm TL and the postlarval stage begins at 9.2 mm TL *2278*. The male covers the eggs with gravel for protection after spawning and guards the nest *3044, 4205,3040*. The immatures move upstream throughout spring, and there is some evidence that young-of-year move downstream *3045*. Origin: This species is native *4205*. Limiting factors: The amount of gravel in small streams or ditches for spawn may limit this species *1187*. Egg predators include stonerollers, bluntnose minnow, hogsucker, and darters *3044*. Water birds and mink prey on adults *6252*. Parasites include nematodes *3049*. Population parameters: Production of this species is 14.06 g/square m/year. There is no growth during the winter, and the standing crop is greatest in autumn. The growth equation is as follows: LogW=-3.972 + 2.98LogTL, (W=weight in grams, TL=total length in mm) *3045,3049*. From Canada, W=-3.609 + 2.925 LogL, (W=weight in g, L=standard length in cm) *3039*. The turnover rate is 1.47 *3045*. The presence of a beaver pond increase the standing crop *3031*. It is suggested that populations in southern regions may be less long lived *3039*. There are more non-nesting males than nesting males *3042*. In Ohio, 224,000 fry were produced and by October 48,000 fry remained, and 15,000 survived until the following spring. Egg loss appears to be about 10% *3045*. Data as a prey species is covered in source *1622*. The adult sex ratios is 1.5 females/1 male *6252*. The occurance of Xanthic is documented *3033*. TN00360REPRODUCTION: NESTS ARE USUALLY WIDELY SEPARATED STONES TOO LARGE TO CARRY IN THE MOUTH ARE PUSHED ALONG THE BOTTOM DURING NEST CONSTRUCTION EGGS SETTLE TO THE BOTTOM OF THE NEST AND ARE COVERED BY GRAVEL WHEN THE MALE RESUMES NEST BUILDING THE FEMALE WILL RETURN TO THE FIRST NEST OR ANOTHER REPEATEDLY UNTIL ALL HER EGGS ARE DEPOSITED NO PARENTAL CARE OF YOUNG *TN5071* DURING SPAWNING, THE MALE CLASPS THE FEMALE BETWEEN HER PECTORAL FIN AND BODY THE FEMALE IS IN AN UPRIGHT POSITION AT THIS TIME AND AFTER THE CLASP, WHICH LASTS LESS THAN A SECOND, RELEASE OF THE EGGS, AND FERTILIZATION, THE FEMALE FLOATS UPWARD FOR A FEW SECONDS, APPARENTLY STUNNED, THEN SWIMMS AWAY PROBABLY NOT MORE THAN 25-50 EGGS ARE RELEASED AT ONE TIME FEMALE MAY ALSO ENTER NEST BY MOVING PASSIVLEY DOWNSTREAM INTO THE NEST, TAIL FIRST COMMUNAL NESTING SITES ARE ATTENDED BY SEVERAL MALES, BUT THE DOMINANT MALE CONTROLS THE NESTING TERRITORY, CHASING INTRUDERS AWAY AT SUCH TIMES, THE NEST- WATCHING MALE(S) WILL ENTER THE NEST AND INITIATE NEST BUILDING, BUT UPON RETURNING, THE DOMINANT MALE DRIVES THEM AWAY ALSO OCCASIONALLY APPROPRIATES SPAWNING PITS FROM STONEROLLER MINNOWS, WHICH ARE DRIVEN AWAY CREEK CHUBS ALSO MAY MOVE INTO A NEST CONTAINING ONE OR MORE COMMON SHINERS EGGS ARE ABOUT 1.5- 1.6 MM IN DIAMETER *TN5176* BEHAVIOR: AN ACTIVE FISH, THE CREEK CHUB WILL MOVE IMMEDIATELY TO INVESTIGATE ANY SMALL OBJECT FALLING INTO THE WATER *TN5071* LARVAE DRIFT DOWNSTREAM IN EARLY SUMMER *TN5176* CREEK CHUBS LARGER THAN 180 MM GENERALLY DO NOT SCHOOL, BUT OCCUPY SHELTERED SPOTS IN DEEP POOLS OR RUN AT THE EDGE OF THE CURRENT CREEK CHUBS WINTER IN DEEPER POOLS AND RUNS *TN5176* PHYSICAL DESCRIPTION: HEAD LENGTH CONTAINED ABOUT 3.8 TIMES, BODY DEPTH ABOUT 4 TIMES IN SL DORSAL FIN RAYS=8, ANAL FIN RAYS=8, LATERAL LINE SCALES=55-60 LENGTH COMMONLY=3-6 INCHES, RARELY 10, MAXIMUM=12 BODY STOUT, HEAVIEST FORWARD, DORSAL OUTLINE ARCHED WITH HIGHEST POINT IN FRONT OF DORSAL FIN AND TAPERING TO EITHER END HEAD LARGE, ROUNDED SNOUT THICK MOUTH LARGE, SLIGHTLY OBLIQUE LOWER JAW SLIGHTLY INCLUDED MAXILLARY BARBEL MORE OR LESS CONCEALED IN GROOVE SCALES SMALL, CROWDED ANTERIORLY LATERAL LINE SOMEWHAT DECURVED ANTERIORLY, GENERALLY COMPLETE FINS RELATIVELY SMALL BACK DUSKY-BLUE WITH A DARKER MEDIAN LINE SIDES HAVE A DUSKY BAND, DISTINCT IN YOUNG AND BECOMING OBSOLETE IN LARGE SPECIMENS SIDES ALSO HAVE A DARK HUMERAL BAR BELLY YELLOWISH-WHITE DORSAL FIN HAS DARK SPOT NEAR ANTERIOR BASE YOUNG HAVE BLACK SUBCAUDAL SPOT BREEDING MALES HAVE ROSY BELLY AND TUBERCLES ON HEAD *TN5058* POPULATION PARAMETERS: HAS BEEN OBSERVED THAT AT LEAST 30% OF THE MALES AND 15% OF THE FEMALES DIE EACH YEAR AFTER SPAWNING *TN5176*
| Life History |
References for Life History Codes
1114, 1115, 1117, 1462, 1477, 842, 1127, 835, 3055, 2278, 3048, 3039, 3041, 3042, 1478, 3031, 3045, 3040, 3044, 3034, 3052, 3049, 3033, 1622, 5849, 6252, 1187, 3045, 4205
Comments on Life History Codes