Latitudinal Variation in Thermal Tolerance and Preference of <i>Fundulus notatus</i> and <i>F. olivaceus</i>: Implications for Temperature Mediated Reproductive Isolation

<p>Temperature is one of the most pervasive and influential abiotic factors affecting the life histories of fish, regulating a host of physiological processes and influencing behavioral thermoregulation. <em>Fundulus notatus</em>, the blackstripe topminnow, and <em>F</em>.<em> olivaceus</em>, the blackspotted topminnow, are widely distributed species located in drainages along the northern part of Gulf of Mexico (30°N latitude) and as far north as southern Illinois (39°N latitude). However, <em>F</em>.<em> notatus</em> has a much broader range reaching up into the Great Lakes (43°N latitude). Due to their broad geographical range, these populations inhabit a wide range of thermal regimes, thus having to locally adapt to their surrounding thermal environments. Variable temperature regimes along latitudinal gradients might be responsible for adaptive differences in thermal biologies among populations. I examined whether latitude reflects intra- and interspecific differences in thermal preference and tolerance across a gradient of temperatures. <em>Fundulus notatus</em> were collected at four latitudes (southern Mississippi – 30°N, northern Alabama – 34ºN, southern Illinois - 38°N, and northern Ohio - 41°N). <em>Fundulus olivaceus</em> were collected at three latitudes (southern Mississippi – 31°N, northern Alabama – 34°N and central Missouri – 37°N). These two species are known to hybridize throughout their sympatric distribution. Thus, I quantified hybridization under different thermal shifts in the Pearl and Sabine River drainages to examine the influence of temperature on hybridization between sympatric populations. Understanding the influence of temperature within and among species may allow us to gain further knowledge into the nature of variation of thermal adaptation.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2015

Author dc:creator

• Stewart, Laura Kristin

Contributors dc:contributor

• Jake Schaefer
• Brian Kreiser
• Carl Qualls

• Thermal preference
• thermal tolerance
• reproductive isolation
• Biology
• Other Ecology and Evolutionary Biology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/117

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1126