Variation in Reproductive Life History Traits between Two Populations of Blackbanded Darters (Percina nigrofasciata)
We examined the life history of Blackbanded Darters (Percina nigrofasciata) from two streams in the Choctawhatchee River drainage, Florida, over a three-year study period. Blackbanded Darters from Turkey Creek were longer than fish from Ten Mile Creek; however, size-adjusted clutch and egg sizes were similar between populations. Larger females produced larger clutches, whereas egg size did not vary with female body size. Seasonally, clutch sizes were greater in May than in August. When contrasted with previous studies of Blackbanded Darters in Alabama and Louisiana, the reproductive season of Blackbanded Darters in Florida was unusually long, ceasing for only a few months in late fall. The reproductive season was longer in Turkey Creek than in Ten Mile Creek. Differences in thermal regime among streams may explain differences in life history traits among local and distant populations of Blackbanded Darters. This research, alone and in combination with previous studies of this species, emphasizes two main points. First, it reaffirms that life history studies based on a single locality or conducted at a single point in time may fail to capture the full range of variation in life history traits. Second, it highlights the extensive phenotypic variation found in species with broad geographic ranges. Such species lend themselves to comparative and experimental research on patterns and causes of life history variation.
Seasonal variation in standard length of Blackbanded Darters collected in northwestern Florida (n = 1073 individuals). (A) Males from Ten Mile Creek. (B) Females from Ten Mile Creek. (C) Males from Turkey Creek. (D) Females from Turkey Creek. Open circles represent individuals and closed circles indicate collection means.
Relationship between sex ratio and standard length in Blackbanded Darters. Closed circles above the line indicate individual males and open circles below the line indicate individual females of a given size.
Seasonal variation in mean (± 1 SE) gonad weight of (A) male and (B) female Blackbanded Darters collected from Ten Mile Creek (closed circles) and Turkey Creek (open circles) in northwestern Florida. Only data for fish larger than the minimum size of reproductive maturity are included (n = 990 individuals).
(A) Relationship between standard length and clutch size in female Blackbanded Darters. Symbols indicate female maturation stage: mature (MA: open gray circle), mature-ripening (MR: filled gray triangle), and ripe (RE: black squares). We show all three maturation stages although only clutches from mature and mature-ripening females were included in analyses of clutch size. (B) Seasonal variation in mean (± 1 SE) clutch size of Blackbanded Darters collected from two creeks (Ten Mile Creek: closed circles, Turkey Creek: open circles) in northwestern Florida.
(A) Relationship between standard length and egg mass in female Blackbanded Darters. Symbols indicate female maturation stage: mature (MA: open gray circle), mature-ripening (MR: filled gray triangle), and ripe (RE: black squares). We show all three maturation stages although only clutches from mature-ripening and ripe females were included in analyses. (B) Seasonal variation in mean (± 1 SE) egg mass of Blackbanded Darters collected from two creeks (Ten Mile Creek: closed circles, Turkey Creek: open circles) in northwestern Florida.
Relationship between clutch size and egg mass in female Blackbanded Darters collected from two creeks in northwestern Florida. Symbols indicate female maturation stage: mature (MA: open gray circle), mature-ripening (MR: filled gray triangle), and ripe (RE: black squares).
Contributor Notes
Associate Editor: D. Buth.