Social Behavior, Dominance, and Neuromolecular Responses Differ in Male Eastern Mosquitofish (Gambusia holbrooki) Color Morphs,

Authors

Tanja Christine Zerulla, Florida International UniversityFollow

Document Type

Dissertation

Degree

Candidate in Philosophy

Major/Program

Biology

First Advisor's Name

Philip Stoddard

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Lidia Kos

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Joel Trexler

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Robert Lickliter

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Matthew DeGennaro

Fifth Advisor's Committee Title

Committee Member

Keywords

color polymorphism, melanism, phenotypic correlation, poeciliid, alternative phenotypes, coloration, social behavior, dominance, aggression, neurotranscriptome

Date of Defense

6-16-2023

Abstract

Across taxa, morphological and behavioral traits can correlate within individuals. Eastern Mosquitofish (Gambusia holbrooki) exhibit a discrete color polymorphism. Males are either the common silver morph or the uncommon mottled morph, unpigmented with black blotches. I first reviewed and synthesized literature about the biology and correlated phenotypes of this color pattern in Poeciliidae. This review revealed conflicting results about the social behavior of mosquitofish morphs. I subsequently studied how behavior was affected by the focal male’s morph and by indirect genetic effects, specifically the phenotypes of interacting individuals. I investigated how social behavior differed across three social contexts: with a group of females, in a male-male dyad, and in a mix-sex group. Mottled males are more assertive towards female groups than silver males, but not in mix-sex contexts. In dyads and mix-sex groups, mottled males dominate silver males, which results from silver males altering their behavior based on the opponent male’s morph. In silver mosquitofish, size usually predicts social dominance, but its effect on the dominance of mottled males was unknown. Arranging social dyads of every color morph-combination across a range of size differences, I found that larger relative body size predicts dominance in within-morph conflicts, but morph is more important in between-morph conflicts. Mottled males dominate silver males, regardless of size differences. Finally, to determine potential genetic mechanisms for phenotypic correlations within mosquitofish morphs, I used whole-brain transcriptomics of mottled and silver males following interactions with a silver male. Morphs show distinct differences in their neuromolecular responses. I identify three differentially expressed transcripts that correlate with social behavior, including GIPC1 (GIPC PDZ domain containing family, member 1), which was previously determined to have a Y-chromosome linked allele associated with the mottled pattern. In conclusion, social behavior depends both on the male’s morph and on the phenotypes of conspecific interacting individuals, but mottled males dominate silver males across size differences and social contexts. Future studies should examine whether and how the differentially expressed transcripts identified here affect the expression of color pattern and social dominance in male mosquitofish.

Identifier

FIDC011167

ORCID

0000-0003-1341-4213

Previously Published In

Chapter 2 was previously published as: Zerulla, T. C., & Stoddard, P. K. (2021). The biology of polymorphic melanic side-spotting patterns in Poeciliid fishes. Frontiers in Ecology and Evolution, 8, 608289. DOI: https://doi.org/10.3389/fevo.2020.608289

Recommended Citation

Zerulla, Tanja Christine, "Social Behavior, Dominance, and Neuromolecular Responses Differ in Male Eastern Mosquitofish (Gambusia holbrooki) Color Morphs," (2023). FIU Electronic Theses and Dissertations. 5402.
https://digitalcommons.fiu.edu/etd/5402