The University of Texas Rio Grande Valley

Department of Biology College of Sciences

Saydur Rahman, Ph.D.

Saydur Rahman, Ph.D.Assistant Professor
School of Earth, Environmental, and Marine Science
Joint appointment: Department of Biology

BLHSB 2.812
(956) 882-5041


  • General Biology - I
  • Research Problems in Biology


  • 2001 Ph.D. Marine and Environmental Sciences, University of the Ryukyus, Japan
  • 2008 M.Sc. Marine Sciences, University of the Ryukyus, Japan
  • 1992 M.Sc. Fisheries Biology and Limnology, Bangladesh Agricultural University
  • 1989 B.Sc. Fisheries (Honors), Faculty of Fisheries, Bangladesh Agricultural University

Areas of Interest

Molecular endocrinology, stress physiology, epigenetics, ecophysiology and environmental toxicology of marine organisms.


One of the most significant impacts of global climate changes due to human activities over the past decades has been increased worldwide in the incidence of coastal hypoxia (dissolved oxygen <2.0 mg/L) and environmental contaminants. The coastal region of the northern Gulf of Mexico (nGoM) is one of the largest petroleum producing regions in the United States and the second largest hypoxic ‘dead’ zone in the world, affecting an average area 16,700 km2 during the summer months. However, the long-term impacts of the extensive hypoxia on nGOM ecosystems and fisheries cannot be accurately predicted at present due to an incomplete understanding of the effects of hypoxia on individual-level processes that can affect population abundance such as reproduction, growth and development. Moreover, the interactive effects of hypoxia/temperature (due to climate change), hypoxia/salinity (due to large fresh water diversions), hypoxia/crude oil, and hypoxia/ocean acidification, and migration on these critical functions are unknown. The exposure of motile animals such as fish and shellfish to these hypoxic waters and the long-term effects of multiple environmental stressors on molecular, physiological and epigenomic responses are largely unknown. An understanding of the interactive effects of these environmental stressors on coastal fish and shellfish will be required in order to make accurate predictions of the ecosystem impacts.
Research topics from last 10 years:

  •     Effects of environmental hypoxia on growth, reproduction and neuroendocrine functions in marine fishes
  •     Effects of environmental pollutants on neuroendocrine functions in teleost fishes
  •     Molecular and physiological responses of brown shrimp exposed to environmental hypoxia
  •     Hypoxia-induced global DNA methylation in marine fish and shellfish

Recent Publications

  • Rahman, M.S. and P. Thomas. 2015. Molecular characterization and hypoxia-induced upregulation of neuronal nitric oxide synthase in Atlantic croaker: reversal by antioxidant and estrogen treatments. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 185:91-106.
  • Thomas, P., M.S. Rahman, M.E. Picha, W. Tan. 2015. Impaired gamete production and viability in Atlantic croaker collected throughout the 20,000 km2 hypoxic region in the northern Gulf of Mexico. Marine Pollution Bulletin 101:182-192.
  • Rahman, M.S. and P. Thomas. 2014. Restoration of tryptophan hydroxylase functions and serotonin content in the Atlantic croaker hypothalamus by antioxidant treatment during hypoxic stress. Frontiers in Neuroscience 8 (130):1-13.
  • Berg, H.A., C.D. Rice, M.S. Rahman, J. Dong, P. Thomas. 2014. Identification and characterization of membrane androgen receptors in the ZIP9 zinc transporter subfamily: I. Discovery in female Atlantic croaker and evidence ZIP9 mediates testosterone-induced apoptosis of ovarian follicle cells. Endocrinology 155:4237-4249.
  • Mohan, J., M.S. Rahman, P. Thomas and B. Walter. 2014. Influence of constant and periodic experimental hypoxic stress on Atlantic croaker otolith chemistry. Aquatic Biology 20:1-11.
  • Rahman, M.S. and P. Thomas. 2013. Interactive effects of hypoxia with estradiol-17β on tryptophan hydroxylase activity and serotonin levels in the Atlantic croaker hypothalamus. General and Comparative Endocrinology 192:71-76.
  • Rahman, M.S. and P. Thomas. 2012. Effects of hypoxia exposure on cytochrome P4501A (CYP1A) expression in Atlantic croaker: molecular mechanisms of CYP1A down-regulation. PLoS ONE 7:e40825.
  • Thomas, P. and M.S. Rahman. 2012. Extensive reproductive disruption, gonadal masculinization, and aromatase suppression in Atlantic croaker collected from an extensive area in the northern Gulf of Mexico hypoxic zone. Proceedings of the Royal Society B 279:28-38.
  • Kodama, K., M.S. Rahman, T. Horiguchi and P. Thomas. 2012. Assessment of hypoxia-inducible factor-1α mRNA expression in mantis shrimp as a biomarker of environmental hypoxia exposure. Biology Letters 8:278-281.
  • Rahman, M.S. and P. Thomas. 2011. Characterization of three IGFBPs in Atlantic croaker and their regulation during hypoxic stress: potential mechanisms of their upregulation by hypoxia. American Journal of Physiology- Endocrinology and Metabolism 301:E637-E648.
  • Rahman, M.S., I.A. Khan, and P. Thomas. 2011. Tryptophan hydroxylase: a target for   neuroendocrine disruptions. Journal of Toxicology and Environmental Health B 14:473-494.

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