Date of Award

January 2015

Degree Type

Open Access Thesis

Document Type

Master Thesis

Degree Name

Master of Science (MS)

Department

Biological Sciences

First Advisor

Paul V. Cupp

Department Affiliation

Biological Sciences

Second Advisor

Robert B. Frederick

Department Affiliation

Biological Sciences

Third Advisor

Sherry L. Harrel

Department Affiliation

Biological Sciences

Abstract

Parents provide care for their young in several different ways. One of these is searching for and retrieving any young that may become displaced from their nest. In monogamous biparental species, parents may share care of their young, including retrieval efforts. Convict cichlids (Amatitlania siquia) are an example of a monogamous biparental fish that show shared parental care of young. In the wild, these cichlids defend nests and search for missing young in response to complete or catastrophic brood loss. This retrieval behavior is important for both parents because parents, especially the males, have been observed to abandon their mate and brood when it does not appear to be successful.

Because brood loss in a natural setting would most likely result in partial brood loss due to predation, instances of partial brood losses were manipulated in a laboratory setting by progressively removing young to see if the male and female convict cichlid parents would alter their behavior based on how many young were missing from the nest. The behaviors of the female and male parents were compared. The female was also retested as a single or “abandoned” parent to determine if her behaviors were altered by her pairing status. As the amount of brood loss increased, the parents spent an increasing amount of time searching the tank for their displaced young. The paired females and males searched the tank differently, making different numbers of trips and spending a differing amount of time in each area of the tank. However, paired and “abandoned” females did not differ in their offspring search behavior suggesting that that females could be maximally invested in their young (i.e., putting a maximum amount of effort into their broods) regardless of whether or not they have a male present to assist them. In addition, there was not a significant difference between the retrieval success of the paired parents and the “abandoned” females regardless of the amount of brood loss to which each was subjected. Although males perform a variety of parental duties necessary for successful care of the offspring, the offspring searching and retrieval data suggest that the male is not as helpful in retrieval of young; he might contribute different behaviors to the care of the young. Potentially, because females are maximally invested, males could be assessing the success of females in regard to an increase in the brood size before deciding whether abandonment is a higher fitness payoff option.

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