Niche Breadth and Life History Variation in a Hybrid Daphnia Complex
Laboratory life table experiments using multiple clones of Daphnia galeata, D. hyalina, and D. galeata x hyalina hybrids quantified differences in niche breadth among these taxa along a gradient of food carbon levels (0.2-2.0 mg/L). Two-way analysis of variance revealed significant main effects (i.e., species, food level) for all life history features examined, as well as significant species x food level interactions for several life history characters (e.g., age at first reproduction and intrinsic rate of increase, r). Nested analysis of variance revealed significant species level effects for all life history characters examined, as well as significant clone level effects for all characters except r. Overall, species level effects explained approximately twice the proportion of the total variance for individual traits when compared with clone level effects (means of 32.8 and 15.8%, respectively). Significant interspecific differences in breadth of response (i.e., niche breadth) were observed for estimates of r. D. galeata exhibited a significantly greater niche breadth across food treatments than D. hyalina; D. galeata x hyalina showed an intermediate response breadth, which was not significantly different from either parental species. The existence of considerable intraspecific (i.e., clonal) variation in several life history traits, implies that any interpretation of life history variation among members of hybrid species complexes may depend critically on the genetic (clonal) make-up of the populations examined. These results are discussed in reference to the coexistence of these taxa in nature.
원문보기 무료다운로드 유료다운로드
- 원문이 없습니다.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.