SREL Reprint #1804

 

 

 

 

Life History of the Savannah Darter, Etheostoma fricksium, in the Savannah River Drainage, South Carolina

STEVEN R. LAYMAN

Etheostoma fricksium is endemic to the Savannah, Broad, Combahee, and Edisto river drainages on the Coastal Plain in South Carolina and Georgia. In Tinker Creek, South Carolina, a third-order blackwater stream, E. fricksium was most common in medium to moderately fast current over sandy substrates in association with woody debris, undercut banks, or eel grass. Males and females matured at 1 yr. Nuptial males had bright red-orange and green lateral bars and small tubercles on anal fin rays. Mean clutch size was 26, and there was indirect evidence of multiple clutch production. Spawning was from Feb.-May at water temperatures of 11-23 C. Aquarium-held spawning adults buried eggs in sand and fine gravel. Eggs (mean diameter = 1.7 mm) hatched in 6-11 days at 22 C. Larvae had large melanophores on top of the head and two rows of melanophores on the dorsum; modal myomere counts were 16 preanal, 22 postanal, and 38 total. Early growth was rapid, and males grew faster than females. The largest male and female were 55 and 50 mm SL, respectively. Females outlived males, attaining a maximum age of 49 mo and outnumbered males 1.5:1. Chironomid larvae numerically dominated the diet of all size classes but were replaced by heptageniid (Stenonema) nymphs as the volumetrically dominant food item in larger darters. Life histories were compared between E. fricksium and other species of Belophlox to identify variable traits that may help to resolve their phylogenetic relationships.

SREL Reprint #1804

Layman, S.R. 1993. Life history of the Savannah darter, Etheostoma fricksium, in the Savannah River drainage, South Carolina. Copeia 1993:959-968.

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