| Popis: |
genetic introgression after more than 20 years of contact between two pupfishes (Cyprinodon elegans and C. variegatus) in Lake Balmohrea, an artificial impoundment in west Texas. Cyprinodon elegans is native to spring-fed waters in the area, whereas C. variegatus was introduced into Lake Balmorhea in the 1960s. The two species contact one another near the mouth of a canal connecting spring flows with the lake. Within the canal, genotypes expected of C. elegans, C. variegatus, F, hybrids, and backcross progeny represented 7%, 85%, 5%, and 3%, respectively, of the pupfish collected. In lake areas outside the canal, all individuals were classified morphologically as C. variegatus, and genotypes typical of C. elegans were absent. There was only meager evidence of introgression in the lake population of C. variegatus outside the area of contact between the two species. |
