Freshwater Fishes of North America. Volume 1: Petromyzontidae to Catostomidae. Melvin L. Warren, Jr., and Brooks M. Burr (editors). Illustrated by Joseph R. Tomelleri. ISBN 978-1-4214-1201-6. Johns Hopkins University Press, 2715 North Charles Street, Baltimore, Maryland 21218 USA (www.press.jhu.edu). 644 pp. $US100.00 (hardcopy).

Myxobolus rhinichthidis Fantham, Porter and Richardson, 1939 (Myxosporea) is redescribed from longnose dace (Rhinichthys cataractae) in Maryland. Large round plasmodia occurred in the connective tissue of the skin covering the head and opercular regions. Fixed spores are oval in front view and measure 11.5–14.5 μm long, 9.0–10.5 μm wide, and 6.0–7.0 μm thick. The polar capsules are 5.5–7.0 μm long and 3.0–3.5 μm wide. Photomicrographs of formalin-fixed spores document variation in spore size and shape. The report is the first for M. rhinichthidis since the species was described from blacknose dace (Rhinichthys atratulus) in Quebec. An updated list of species of Myxobolus Bütschli, 1882 reported from freshwater fishes in North America is provided. Myxobolus jahnricei Landsberg and Lom, 1991 is considered a junior synonym of Myxobolus filamentus Grinham and Cone, 1990; and Myxobolus lii Desser, 1993 and Myxobolus gibbosus Li and Desser, 1985 are junior synonyms of Myxobolus uvuliferus Cone and Anderson, 1977.

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Postglacial dispersal of freshwater fishes into Ontario

Canadian Journal of Zoology ◽

10.1139/z92-302 ◽

1992 ◽

Vol 70 (11) ◽

pp. 2247-2259 ◽

Cited By ~ 128

Author(s):

Nicholas E. Mandrak ◽

E. J. Crossman

Keyword(s):

North America ◽

Freshwater Fishes ◽

Eastern North America ◽

Glacial Period ◽

Before Present ◽

Last Glacial Period ◽

Historical Processes ◽

Dispersal Routes ◽

Atlantic Coastal ◽

The Last Glacial

The present-day distributions of 117 native freshwater fishes in Ontario have been shaped by processes active following the Wisconsinan glacial period, 80 000–10 000 years before present. During this glacial period, these species survived in unglaciated réfugia. To understand the processes that resulted in the recolonization of Ontario by fishes following the last glacial period, the refugial areas occupied by each species were determined using a refugial index, and glacial water bodies used as dispersal routes were identified. The refugial origins of the Ontario populations of 91 species were resolved. Seventy-two species resided in the Mississippian refugium, 13 species in the Atlantic Coastal refugium, 4 species in dual Atlantic Coastal – Mississippian refugia, 1 species in a Missourian refugium, and 1 species in Atlantic Coastal, Mississippian, and Missourian refugia. These conclusions differed significantly from those of other studies. Five general patterns were identified from the distributions of 104 species. In addition, there are 13 species that do not fit any of the general patterns. Most species with similar distributions in Ontario shared the same refugia and dispersal routes in eastern North America, therefore it is hypothesized that historical processes were important in shaping the present-day distributions of Ontario freshwater fishes.

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