Predation can cause morphological divergence among populations, while ontogeny and sex often determine much of morphological diversity among individuals. We used geometric morphometrics to characterize body shape in the livebearing fish Brachyrhaphis rhabdophora to test for interactions between these three major shape-determining factors. We assessed shape variation between juveniles and adults of both sexes, and among adults for populations from high- and low-predation areas. Shape differed significantly between predation regimes for all juveniles regardless of sex. As males grew and matured into adults, ontogenetic shape trajectories were parallel, thus maintaining shape differences in adult males between predation environments. However, shape of adult females between predation environments followed a different pattern. As females grew and matured, ontogenetic shape trajectories converged so that shape differences were less pronounced between mature females in predator and nonpredator environments. Convergence in female body shape may indicate a trade-off between optimal shape for predator evasion versus shape required for the livebearing mode of reproduction.
Recovery plans for many endangered fishes include production of large numbers of individuals in hatcheries to augment wild populations. However, effects of hatchery culture on phenotypic development are poorly documented for most species. June sucker (Chasmistes liorus) is an endangered lake sucker endemic to Utah Lake (Utah, USA), and recovery plans include raising thousands of juveniles to stock in the lake. To determine effects of hatchery culture on morphology of young June sucker, we raised individuals from four different families in both lake and hatchery environments and compared shape variation among families and between environments. We compared shape from three perspectives: lateral body, ventral mouth, and lateral head views. Mean shape varied between hatchery-reared and lake-reared individuals in each of the three views. In addition, hatchery-reared individuals exhibited higher variance in shape both within and among families compared with shape variance in lake-reared individuals. Hatchery-reared individuals exhibited divergent phenotypes compared with lake-reared individuals. These results suggest that exposure to the native environment during early life stages may be important for phenotypic development suitable to native habitats. Hatcheries should incorporate designs and practices to minimize divergent phenotypic development of individuals.
A questionnaire was completed by 178 patients and relatives with dermatologic conditions as the first phase of a two-part study of the interrelationships between understanding and treatment compliance. Substantial numbers of those surveyed had ideas about cause, treatment, and prognosis that might adversely affect therapy. Diet, dirt, soap and water, topically applied acne gels, and realistic expectations for cures seem to be the most important subjects to emphasize in the written or oral "teaching" of patients with acne.
Decades of persistent natural and anthropogenic threats coupled with competing water needs have compromised numerous species of freshwater fishes, many of which are now artificially propagated in hatcheries. Low survival upon release is common, particularly in systems with substantial nonnative predator populations. Extensive sampling for Shortnose (Chasmistes brevirostris) and Lost River Suckers (Deltistes luxatus) in the Klamath River Basin on the California-Oregon border have failed to detect any new adult recruitment for at least two decades, prompting an investigation into artificial propagation as an extinction prevention measure. A comprehensive assessment of strategies and successes associated with propagation for conservation restocking has not been performed for any Catostomid. Here, we review available literature for all western lake sucker species to inform propagation and recovery efforts for Klamath suckers and summarize the relevance of these considerations to other endangered fishes.
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