John J. Hasse

Publication Date


Document Type


First Advisor

Greenfield, David W.||Sorensen, Paul D.||Zar, Jerrold H., 1941-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Fishes--Belize; Thorichthys


Four members of the Thortchthys group in the genus Cichlasoma, from British Honduras, were examined and compared inter- and intra-specifically. All species exhibited allometric growth for body depth, eye diameter, pelvic fin length, and soft dorsal and anal fin length. Constancy of fin length in proportion to body size may indicate importance in locomotion and balance while allometric growth may indicate importance in behavioral activities. C. aureum can be differentiated from C. affine and C. meeki by basic body colorations, a blunter head and fewer gill rakers. C. affine and C. meeki are separable on the basis of fin lengths. C. hyorhynchum is a junior synonym of C. meeki. C. affine is endemic to the Lake Peten, Guatemala drainage. This results in C. aureum and C. meeki being the only Thorichthys group Cichlasoma in British Honduras. The Thorichthys group probably originated in the Peten, Guatemala region. Their present distribution has probably been largely determined by competition from other fish, and flooding of much of Central America during the Miocene by the oceans.


Includes bibliographical references.||Includes illustrations.


viii, 117 pages




Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type