Systematics of the Subterranean Amphipod Genus <i>Stygobromus</i> (Crangonyctidae) in Western North America, With Emphasis on Species of the <i>Hubbsi</i> Group

<p>This dissertation presents a study of the systematics of the subterranean amphipod genus <em>Stygobromus</em> of family Crangonyctidae in western North America. A total of 53 species of <em>Stygobromus</em> from western North America (including one species from Wisconsin) are recognized, 28 of which are new to science. All species are described and illustrated using external morphological features. A key to the western North America species of <em>Stygobromus</em> is given, as well as a summary of habitats of the species.</p> <p>Cladistic analyses are conducted using 32 external morphological characters and two categories of outgroup choices: “all-zero” theoretical ancestor and three non-<em>Stygobromus</em> species. The consensus trees of unordered/unweighted and ordered/partially weighted are developed. The results of both categories support one monophyletic species cluster, which includes most species in California. Two loose constant congruent species clusters were also recognized in the two category runs: a California-Oregon-Washington species cluster includes <em>S. imperialis. S. rudolphi, S. gallawayae, S. latus, S. grahami, S wengerorum, S. harai, S. gradyi, S. elliorti, S. mysticus </em>, and <em>S. hubbsi</em>; a Colorado-Idaho-Montana species cluster includes <em>S. urospinatus, S. fontanalis, S. pennaki, S. coloradensis, S. canadensis</em>, and <em>S. idahoensis</em>. The number of species in each of the two loose constant clusters of the two categories is variable.</p> <p>The species diversity of <em>Stygobromus</em> decreases from east to west in North America, possibly resulting, from geologically more recent landforms in western North America. In addition, many habitats presently occupied by western species of <em>Stygobromus</em> may not be older than the Pleisiocene. Some lava tubes in Oregon and Washington are even more recent. This explanation may also account for close morphological similarity of <em>hubbsi</em> group species in western North America.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2001

Author dc:creator

• Wang, Daqing

Contributors dc:contributor

• John R. Holsinger
• James D. Thomas
• Kent E. Carpenter

• Crangonyctidae
• Stygobromus
• Subterranean amphipod
• Hubbsi
• Terrestrial and Aquatic Ecology

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9780493564609

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:biology_etds-1104