Related Experiment Video
Updated: Mar 1, 2026

Individual Culturing of Tigriopus Copepods and Quantitative Analysis of Their Mate-guarding Behavior
Published on: September 26, 2018
ASEXUAL REPRODUCTION IN CESTODES (CYCLOPHYLLIDEA: TAENIIDAE): ECOLOGICAL AND PHYLOGENETIC INFLUENCES
Janice Moore1, Daniel R Brooks2
1Department of Zoology, Colorado State University, Fort Collins, CO, 80523.
Abstract:
Asexual reproduction, a rare trait among cestodes in general, occurs in the "larval" (metacestode) stage of species of the family Taeniidae. The distribution of this trait among taeniid species is not consistent with an ecological hypothesis of current environmental predictability. We therefore chose a subset of the family and studied their phylogenetic relationships by Wagner parsimony analysis as a test of historical influences on asexual reproduction. We produced a consensus tree based on four 50-step trees with consistency indices of 0.38. Given these hypothetical relationships, we found that asexual reproduction either arose or was lost multiple times. Moreover, this consensus tree is incongruent with both definitive and intermediate host phylogenies, and asexual reproduction does not correlate with host transfers inferred from these phylogenies. Developmental and phylogenetic constraints on asexual reproduction therefore appear to have been minimal. Given current information, neither historical constraint nor explanations invoking adaptation based on environmental predictability can account for life-history variation in these cestodes.
Related Concept Videos
Asexual Reproduction
Diversity of Protists I
Diversity of Protists IV
Bacterial Phylum Chlamydiae
Diversity of Protists II
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...

