Douglas F. Markle

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Over 100 years ago, a work with a similar title, " The fishes of North and Middle America " , was a " descriptive catalogue " with keys and a focus on identifying fishes (Jordan and Evermann 1896). Identification and alpha taxonomy are still important as witnessed by the value of guides such as Page and Burr (2011). Although identification of freshwater(More)
Parasites may be an important component of early life mortality in fishes, but assigning part of total mortality to parasites is difficult. The Chapman-Robson mortality estimator is a robust and potentially valuable way to quantify the added mortality of parasites when age data are available. We used daily age data and the Chapman-Robson catch-curve(More)
Hybridization has been identified as a significant factor in the evolution of plants as groups of interbreeding species retain their phenotypic integrity despite gene exchange among forms. Recent studies have identified similar interactions in animals; however, the role of hybridization in the evolution of animals has been contested. Here we examine(More)
We examined 120 vexillifer larvae of Echiodon dawsoni and 40 of Carapus bermudensis collected from the continental shelf and slope of the Gulf of Mexico and the western North Atlantic to Nova Scotia. Age was estimated for a subset of vexillifers, from which otoliths (sagittae) were excised and growth increments were recognizable, and a linear, estimated age(More)
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