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You searched for +publisher:"Florida International University" +contributor:("Matthew Grober"). One record found.

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Florida International University

1. Goldina, Anna. Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish.

Degree: PhD, Biology, 2011, Florida International University

Communication signals are shaped by the opposing selection pressures imposed by predators and mates. A dynamic signal might serve as an adaptive compromise between an inconspicuous signal that evades predators and an extravagant signal preferred by females. Such a signal has been described in the gymnotiform electric fish, Brachyhypopomus gauderio, which produces a sexually dimorphic electric organ discharge (EOD). The EOD varies on a circadian rhythm and in response to social cues. This signal plasticity is mediated by the slow action of androgens and rapid action of melanocortins. My dissertation research tested the hypotheses that (1) signal plasticity is related to sociality levels in gymnotiform species, and (2) differences in signal plasticity are regulated by differential sensitivity to androgen and melanocortin hormones. To assess the breadth of dynamic signaling within the order Gymnotiformes, I sampled 13 species from the five gymnotiform families. I recorded EODs to observe spontaneous signal oscillations after which I injected melanocortin hormones, saline control, or presented the fish with a conspecific. I showed that through the co-option of the ancient melanocortin pathway, gymnotiforms dynamically regulate EOD amplitude, spectral frequency, both, or neither. To investigate whether observed EOD plasticities are related to species-specific sociality I tested four species; two territorial, highly aggressive species, Gymnotus carapo and Apteronotus leptorhynchus, a highly gregarious species, Eigenmannia cf. virescens, and an intermediate short-lived species with a fluid social system, Brachyhypopomus gauderio. I examined the relationship between the androgens testosterone and 11-ketotestosterone, the melanocortin a-MSH, and their roles in regulating EOD waveform. I implanted all fish with androgen and blank silicone implants, and injected with a-MSH before and at the peak of implant effect. I found that waveforms of the most territorial and aggressive species were insensitive to hormone treatments; maintaining a static, stereotyped signal that preserves encoding of individual identity. Species with a fluid social system were most responsive to hormone treatments, exhibiting signals that reflect immediate condition and reproductive state. In conclusion, variation in gymnotiform signal plasticity is hormonally regulated and seems to reflect species-specific sociality. Advisors/Committee Members: Philip Stoddard, Maureen Donnelly, Matthew Grober, Lidia Kos, Robert Lickliter.

Subjects/Keywords: Gymnotiformes; Adrenocorticotropic hormone (ACTH); alpha-melanocyte stimulating hormone (alpha-MSH); 11-Ketotestosterone (11-KT); Testosterone (T); electric communication signals; plasticity; EOD; sociality

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Goldina, A. (2011). Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish. (Doctoral Dissertation). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/521 ; 10.25148/etd.FI11120803 ; FI11120803

Chicago Manual of Style (16th Edition):

Goldina, Anna. “Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish.” 2011. Doctoral Dissertation, Florida International University. Accessed May 08, 2021. https://digitalcommons.fiu.edu/etd/521 ; 10.25148/etd.FI11120803 ; FI11120803.

MLA Handbook (7th Edition):

Goldina, Anna. “Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish.” 2011. Web. 08 May 2021.

Vancouver:

Goldina A. Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish. [Internet] [Doctoral dissertation]. Florida International University; 2011. [cited 2021 May 08]. Available from: https://digitalcommons.fiu.edu/etd/521 ; 10.25148/etd.FI11120803 ; FI11120803.

Council of Science Editors:

Goldina A. Endocrine Regulation of Dynamic Communication Signals in Gymnotiform Fish. [Doctoral Dissertation]. Florida International University; 2011. Available from: https://digitalcommons.fiu.edu/etd/521 ; 10.25148/etd.FI11120803 ; FI11120803

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