Joy Garcia

Date of Award


Document Type


Degree Name

Master of Science (MS)


Biological Sciences

Committee Chair

Bruce Stallsmith

Committee Member

Paul Wolf

Committee Member

Luis R. Cruz-Vera


Darters (Fishes)--Paint Rock River (Tenn. and Ala.)--Reproduction., Etheostoma--Paint Rock River (Tenn. and Ala.)--Reproduction., Darters (Fishes)--Parasites--Paint Rock River (Tenn. and Ala.)., Etheostoma--Parasites--Paint Rock River (Tenn. and Ala.)., Host-parasite relationships.


The aim of this experiment was to determine what effect gill parasites have on reproduction in stripetail darters. Nearly 450 stripetail darters were collected from Estill Fork stream in Jackson County, Alabama. Their gonads were excised and the oocytes were photographed, counted, and then classified into one of four developmental stages. Their gill parasites, flatworms belonging to genus Aethycteron, were also removed and counted. Sexual dimorphism in size was discovered in the stripetails, as well as a high gonadosomatic index and large (2.0 mm) size of clutch oocytes. Reproductive maturity was observed in females as small as 19.3 mm in length. The number of males found at the 25> mm length range far outnumbered females. Prevalence and intensity of parasitic infection were both high, with prevalence nearing or reaching 100% in breeding males and females. Two hypotheses were advanced to explain these phenomena: fecundity compensation in females is likely causing the early reproductive maturity in stripetail females, and the lack of older females may be the result of a high cost of reproduction being paid at the expense of long-term survivability. The combination of both of these factors may ultimately be forcing a shift in life history in stripetail females that favors semelparity.



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