Date of Award


Degree Type


Degree Name

Honors Thesis



First Advisor

Shelley Etnier

Second Advisor

Carmen Salsbury


Fish represent the most diverse and oldest living class of vertebrates, making up approximately 48% of all known members of the subphylum Vertebrata (Bolis, et al. 2001). They are able to live in a wide variety of habitats, from salt water to fresh water and from cold polar seas to areas of intense pressure in the depths of the ocean (Moyle and Cech 1996). Because of this overwhelming diversity, the evolution and ecology of fishes has been a dynamic field of study (Moyle and Cech 1996). Researchers have generally divided fish into three distinct groups: jawless fishes (Class Agnatha), cartilaginous fishes (Class Chondrichthyes), and bony fishes (Class Osteichthyes), with the largest amount of diversity found in the last group, the bony fish, which represent 95% of all living fish species (Nelson 1994; Volff 2005). More than 99.8% of these bony fish are members of the teleosts, with more than 28 thousand described species (“Bony”; Pough, et al. 2005).

Morphologically, all teleosts share similar caudal and cranial structures, with a skeleton of bone, scales, paired fins, a single pair of gill openings, and paired nostrils (“Bony”). In addition to species diversity, this class of fish also displays more reproductive diversity than many other vertebrates. Teleost fish display many different kinds of sexual development, modes of reproduction and sexual morphology. There are several factors that can affect their reproductive events, they have several different methods for nest building, and commonly display differing degrees of parental care and energy investments in reproductive efforts (Pough, et al. 2005). This chapter will first focus on describing certain reproductive characteristics that are shared among teleosts. It will then discuss the various modes of sexual maturation displayed by teleosts and describe differing reproductive strategies observed (gonochorism, hermaphrodism, and unisexuality, specifically). Lastly, it will discuss general reproductive behaviors including spawning behavior and parental care among teleost fish.