Faculty Profiles

Faculty Profiles

Turingan, Ralph

Professor, Ocean Engineering and Marine Sciences

Educational Background

B.S., University of the Philippines, Magna Cum Laude
M.S., University of Rhode Island
Ph.D., University of Puerto Rico

Post-Doctorate, Florida State University

Professional Experience

Program Chair, Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology (2018-Present)

Junda Lin Professor of Marine Biology, Florida Institute of Technology (2017-Present)

Program Chair of Marine Biology, Department of Biological Sciences, Florida Institute of Technology (2010-2018)

Fulbright Senior Faculty-Fellow, 2006 and 2013.

Professor of Biological Sciences, Florida Institute of Technology (2007-Present)

Associate Professor of Biological Sciences, Florida Institute of Technology (2001-2006)

Assistant Professor of Biological Sciences, Florida Institute of Technology (1995-2000)

Research Scientist, Department of Biological Science, Florida State University (1993-1995)

Additional Duties

Dr. Turingan is the Florida Sea Grant Prgram Coordinator and the Fulbright Program Advisor at Florida Institute of Technology.

Current Research

Our research laboratory is designed to address questions that advance our understanding of the biological and evolutionary mechanisms that underlie variation in phenotypes of fishes. There are three clusters of research that our fishlab currently pursues.

In the first cluster, we investigate the effects of fishing on fitness-relevant phenotypes including growth rate, size and age at sexual maturity in an attempt to assess the efficacy of Marine Protected Areas (MPAs) as a tool in fisheries-resource management. Human fishing effort is size-selective, preferentially removing the largest individuals from harvested stocks. Intensive, size-specific fishing mortality induces directional shifts in phenotypic frequencies towards the predominance of smaller and earlier-maturing individuals, which are among the primary causes of declining fish biomass. Fish that reproduce at smaller size and younger age produce fewer, smaller, and less viable larvae, severely reducing the reproductive capacity of harvested populations. Marine protected areas (MPAs) are extensively utilized in coral reefs for fisheries management, and are thought to mitigate the impacts of size-selective fishing mortality and supplement fished stocks through larval export. However, empirical evidence of disparities in fitness-relevant phenotypes between MPAs and adjacent fished reefs is necessary to validate this assertion. Results of our comparative analysis of key life-history traits between MPAs and fished reefs in the Philippines support previous hypotheses regarding the impacts of MPAs on phenotypic traits. Asymptotic length and growth rates differed between conspecifics in MPAs and fished reefs, with protected populations exhibiting phenotypes that are known to confer higher fecundity. Shifts toward advantageous phenotypes were most common in the oldest and largest MPAs, but occurred in all of the MPAs examined. These results suggest that MPAs may provide protection against the impacts of size-selective harvest on life-history traits in coral-reef fishes.

 In the second cluster, we investigate the stage-specific effects of prey-size and behavior on the feeding performance of fish larvae. Most marine fishes undergo a pelagic larval phase, the early life history stage that is often associated with a high rate of mortality due to starvation and predation. Using a digital high-speed video camera, we have recorded the swimming velocity of zooplankton prey and the feeding behavior of fish larvae. Our comparative analyses revealed that: (1) swimming velocity varied among zooplankton prey; and (2) all zooplankton prey, except rotifers and ciliates, increased their swimming velocity in the presence of a fish larva. The kinematics of prey capture also differed between two developmental stages of fish larvae. The hyoid-stage larvae (3-4 days old) fed on slow swimming zooplankton while hyoid-opercular stage larvae (15 days and older) ate fast moving prey. Hyoid-opercular stage red drum larvae had a larger gape, hyoid depression and lower jaw angle, and a longer gape cycle duration relative to their hyoid-stage conspecifics. Interestingly, the feeding repertoire within either developmental stage of fish was not affected by prey type. Knowledge of the direct relationship between fish larvae and their prey aids in our understanding of optimal foraging strategies and of the sources of mortality in marine fish larvae.

 In the third cluster, we investigate the effects of environmental stress (e.g., thermal stress) on the feeding behavior and transcriptome of fishes, particularly invasive species, in an attempt to elucidate the development of compensatory mechanisms that mitigate the environmental effects on organismal performance. As a consequence of global warming, tropical invasive species are expected to expand their range pole-ward, extending their negative impacts to previously undisturbed, high-latitude ecosystems. Investigating the physiological responses of invasive species to environmental temperature is important because the coupled effects of climate change and species invasion on ecosystems could be more alarming than the effects of each phenomenon independently. Especially in poikilotherms, the rate of motion in muscle-driven biomechanical systems is expected to double for every 10oC increase in temperature. In our comparative analyses of prey-capture kinematics in invasive fishes, we found that the feeding behavior, particularly the velocity of cranial movements during prey-capture remained consistent despite the change in environmental temperature. It is conceivable that the ability to maintain peak performance at different temperatures helps facilitate the spread of invasive fishes globally.

Selected Publications

Geng Qin, G., Johnson, C., Zhang, Y., Zhang, H., Yin, J, Miller, G., Turingan, R.G., Guisbert, E., Lin, Q. 2018. Temperature-induced physiological stress and reproductive characteristics of the migratory seahorse Hippocampus erectus during a thermal stress simulation. Biology…

Fidler, R.Y., Carroll, J., Rynerson, K.W., Matthews, D.F., Turingan, R.G. 2018. Coral reef fishes exhibit beneficial phenotypes inside marine protected areas. PLOSONE. https://doi.org/10.1371/journal.pone.0193426

Fidler, R.Y., Turingan, R.G., Alava, M.N.R., and White, A. T. 2017. Reef-wide beneficial shifts in fish population structure following establishment of marine protected areas (MPAs) in Philippine coral reefs. Marine Ecology Progress Series 570: 187–202. https://doi.org/10.3354/meps12067

Turingan, R.G. and Sloan, T.J. 2017. Thermal resilience of feeding kinematics may contribute to the spread of invasive fishes in light of climate change. Biology 5, 46; doi:10.3390/biology5040046

Fidler, R.Y., Maypa, A., Apistar, D., White, A. and Turingan, R.G. 2014. Body size shifts in Philippine reef fishes: Interfamilial variation in responses to protection. Biology 4 (3): 264-280. doi:10.3390/biology3020264

Harms, C.A. and Turingan, R.  2012.  Dietary flexibility despite functional stereotypy contributes to the successful invasion of the pike killifish, Belonesox belizanus, in Florida, USA. Aquatic Invasions 7 (4):547-553.

Kerfoot, J., Lorenz, J. and Turingan, R..  2011.  Environmental correlates of the abundance and distribution of Belonesox belizanus in a novel environment.  Environmental Biology of Fishes 92: 125-139.

Wittenrich. M. and Turingan, R..  2011.  Linking functional morphology and feeding performance in larvae of two coral-reef fishes.  Environmental Biology of Fishes 92: 295-312.

Anto, J. and Turingan, R.G. 2010.  Relating the ontogeny of functional morphology and prey selection with larval mortality in Amphiprion frenatus.  Journal of Morphology 271:682–696.

Maliao, R.J., White, A.T., Maypa, A.P. and Turingan, R.G. 2009.  Trajectories and magnitude of change in coral reef fish populations in Philippine marine reserves: a meta-analysis. Coral Reefs (2009) 28:809–822

Wittenrich, M.L., Nicole R. Rhody, N.R., Turingan, R.G. and Main, K.L. 2009. Coupling osteological development of the feeding apparatus with feeding performance in common snook, Centropomus undecimalis, larvae: Identifying morphological constraints to feeding. Aquaculture 294 (2009) 221–227.

Maliao, J.R., Turingan, R.G. and Lin, J.  2008.  Phase-shift in coral reef communities in the Florida Keys National Marine Sanctuaty (FKNMS), USA.  Marine Biology 154(5):841-853.

Beck, J.L. and Turingan, R.G. 2007  The effects of zooplankton swimming behavior on prey-capture kinematics of red drum larvae, Scieanops ocellatus. Marine Biology (2007) 151:1463-1470.

Carroll, A.M., Wainwright P.C., Huskey, S.H., Collar, D.C. and Turingan, R.G..  2004.  Morphology predicts suction feeding performance in centrarchid fishes.  Journal of Experimental Biology.  207:3873-3881.

Cutwa, M., Turingan, R.G.  2000.  Intralocality variation in food habit and feeding biomechanics in the sheepshead, Archosargus probatocephalus, with implications for the ecomorphology of fishes. Environmental Biology of Fishes 59:191-198.

Wainwright, P.C. and Turingan, R.G.  1997.  Evolution of pufferfish inflation behavior.  Evolution 5(2): 506-518.

Turingan, R.G., Wainwright, P.C., and Hensley, D.A..  1995.  Interpopulation variation in prey use and feeding biomechanics in triggerfishes.  Oecologia.  102:296-304.

Turingan, R.G..  1994.  Ecomorphological relationships among Caribbean tetraodontiform fishes.  J. Zool., London.  233:493-521.

Turingan, R.G. and Wainwright, P.C..  1993.  Morphological and functional bases of durophagy in the queen triggerfish, Balistes vetula (Pisces, Tetraodontiformes).  J. Morph.  215:101-118.