7 research outputs found
Reproductive timing of the Scarlet Shiner (Lythrurus fasciolaris) in Northern Alabama
The Scarlet Shiner (Lythrurus fasciolaris) is a cyprinid species widely distributed in parts of the Ohio, Cumberland and Tennessee river drainages of the United States. The objective of this study was to determine the Scarlet Shiner’s reproductive schedule. Maturation of ovaries and oocytes was determined through the categorization of developmental stages from early maturing to ripe, along with the calculation of monthly gonadosomatic index (GSI) measurements over two reproductive seasons in 2012 and 2015. In both years reproductive competence began in April. Average monthly GSI for females peaked in May, followed by a slow decline through August. Average clutch size was largest both years in April and May, although individual females were found with late developmental stage oocytes as late as August. Compared to other studied sympatric cyprinid species, the Scarlet Shiner was found to be a relatively late spawner with an extended spawning tail well into the summer
A Comparison of Seasonal Reproductive Pattern in Two Sympatric Darters of the \u3ci\u3eSimoperca\u3c/i\u3e Clade, \u3ci\u3eEtheostoma duryi\u3c/i\u3e and \u3ci\u3eEtheostoma simoterum\u3c/i\u3e
We present results from an examination of the seasonal reproductive patterns of two closely related sympatric darter species of the Simoperca clade, Etheostoma duryi and Etheostoma simoterum. Most members of the genus Etheostoma exhibit striking sexual dimorphism, making reproductive strategy a logical point of study. Monthly collections of specimens over a one-year period were performed at a single site on the Flint River near Huntsville, Alabama. Standard length and gross somatic mass were measured for all individuals. Sex ratio was examined for possible skew. Measures of reproductive effort were monthly means of gonadosomatic index of both sexes, total oocyte count, oocyte size at different development stages, and clutch size. Reproductive season for both species was February through May. Etheostoma duryi was found to be slightly larger in SL and mass, and to produce more oocytes, larger clutch size, and smaller oocytes earlier in the breeding season. Both species displayed strong female skew, especially Etheostoma simoterum
Reproductive Schedule of the Silver Shiner (Notropis photogenis) in the Flint River of Alabama
Many river-dwelling species of fish are dependent upon and stimulated by fluctuations in river flow for successful reproduction. This is especially true of pelagophils, a reproductive guild whose eggs and larvae require free drifting on river currents for several days. Notropis photogenis (Silver Shiner) is a rheophilic species with a broad distribution from Ontario to the southeastern United States including northern tributaries to the Tennessee River in Alabama. Little is known of its reproductive biology. The purpose of this study was to describe aspects of reproductive biology such as timing and pattern of ovarian development and oocyte maturation of N. photogenis in the Flint River of Alabama. We investigated whether and how abiotic cues such as river discharge and temperatures were related to ovulation and spawning. Monthly fish collections were made from August, 2011, to July, 2013. From these collections monthly gonadosomatic index (GSI) was evaluated, along with the status of ovarian maturation, oocyte maturation and size, and oocyte counts to establish fecundity and clutch size. Median monthly river discharges in cubic feet per second for 1999–2015 were obtained from the U.S. Geological Survey database. Observations over two years showed associations between daily mean discharge and months of peak GSI (February–April). Mean GSI peaked in March of both 2012 and 2013 when median flow was approximately 600 cfs. Large synchronous spawning events appear to occur during times of steady substantial discharge increases but after peaks of discharge \u3e 3000 cfs
Reproductive Biology of Hybopsis amblops, the Bigeye Chub, in the Flint River of Alabama
Gonadal measurement
Reproductive Timing of \u3ci\u3eErimystax insignis\u3c/i\u3e (Blotched Chub) in the Flint River of North Alabama
Important details of the reproductive ecology of many freshwater fishes of the species-rich southeastern United States are still poorly known. One such species is Erimystax insignis (Blotched Chub), whose range includes the Tennessee River drainage in northern Alabama, USA. To determine timing and patterns of reproductive effort, collections were made monthly of as many as 30 individuals from August 2011 through July 2012 from a 14 km stretch of the Flint River in Madison County, Alabama. Female and male gonadosomatic index (GSI) and ovarian development data indicate that reproductive activity for the species peaks from March through May. Ripe and mature oocytes were found in females from March through June peaking in April but ripe ovaries were found only in March and April. The number of mature and ripe oocytes was larger than reported for a population in the Little River of Tennessee, and diameter of all stages of maturing oocytes was smaller than the Little River population