Life Sciences Commons^™

Compromised Weaponry Enhances Crayfish Tailflipping, Sandra Y. Espinoza, Zen Faulkes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

As a defense strategy, many crustaceans perform one of two well described stereotyped single fast tailflips (~6 ms in adult crayfish), which are triggered by a neural circuit that includes medial giant interneurons (MG) and lateral giant interneurons (LG). Tailflips can also occur without these giant interneurons firing, however; these non-giant tailflips are variable, repetitive, and significantly longer (~150 ms). Previous work showed that crayfish exposed to natural stimulus respond with a non-giant tailflip significantly faster than when presented with an artificial stimulus and that complete removal of claws lowered tailflipping threshold. We tested whether compromising weapons would influence tailflipping. …

Changes In Shell Morphology Of Elimia Comalensis (Gastropoda: Pleuroceridae) From The Edwards Plateau, Texas, Russell L. Minton, Scott A. Reese, Kim Swanger, Kathryn E. Perez, David M. Hayes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Species in the pleurocerid genus Elimia are important components of freshwater systems in the eastern United States, but little is known about their natural history. Using dual-simultaneous linear regression and principal components analyses, we show patterns of morphological change in two populations of E. comalensis from the Edwards Plateau, Texas. Both populations had similar rates of change for all shell measurements analyzed, and both showed similar decreases in growth as total length of shell increased. However, the size at which growth slowed was different between populations, and small shells tended to have a consistent shape, while larger shells were more …

Re-Occurrence Of The Tropical Green Macroalga, Penicillus Capitatus (Chlorophyta: Bryopsidales), In Lower Laguna Madre Of South Texas., Joseph L. Kowalski, Donald L. Hockaday, Gilbert H. Boza Jr., Hudson R. Deyoe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The siphonaceous green alga Penicillus capitatus Lamarck is a common macroalga of the Carribean and Gulf of Mexico (Littler & Littler 2000). This shaving brush-shaped macroalga was a common inhabitant of the Lower Laguna Madre Texas (LLM) until about 40 years ago when the population was decimated following a salinity decline in the fall of 1959, another salinity reduction due to Hurricane Carla in 1961, and finally a severe freeze in 1962 (Sorensen 1963). Since that time, there have been no reports of P. capitatus in the LLM. During a reconnaissance trip in July 2006, a small population was found …

The Riparian Bio-Regions Of The Lower Rio Grande…And The Threats They Face From The Proposed Border Wall, Martin Hagne

Border Wall / Border Security Documents

PDF of original PPT presentation created by Martin Hagne for the Valley Nature Center. The presentation includes regional maps, original photographs, and information on the diverse ecosystems of Starr, Hidalgo, and Cameron Counties, Texas.

Sensory Modulation Of Crustacean Non-Giant Tailflipping, Sandra Y. Espinoza, Zen Faulkes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

As a first step in re-examining the modulation of non-giant tailflipping, we further investigate how the presence of weapons affects non-giant tailflipping. Removing both claws significantly changes the threshold for tailflipping (Krasne and Wine, 1975; Lang et al., 1977). Claw removal affects several variables at once, however; e.g., the animal’s mass; visual stimuli associated with having claws; tactile and proprioceptive cues. For example, a crayfish with claws that are present but useless might “bluff,” and may not tailflip away from a stimuli more than an intact animal.

Effects Of Temperature And Illumination On Background Matching In Mediterranean Geckos (Hemidactylus Turcicus), Frederic Zaidan, Pamela L. Wiebusch

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The ability to change skin color is a relatively common phenomenon in lizards whose occurrence is often related to crypsis. Field observations suggest that Mediterranean geckos (an often ubiquitous introduced species in many metropolitan areas of the southern United States) have the ability to lighten and darken in response to their background. On light backgrounds, the geckos were typically light pink whereas on dark backgrounds they were typically much darker with a brownish hue to their skin. This study investigated the ability to background match in this species, the main effects of temperature (20, 25, and 30[degrees]C), illumination (total darkness …

Predicting Physical Activity Among Low-Income Mexican American Women: Application Of The Theory Of Planned Behavior, Bobby Guinn, Vern Vincent, Layne Jorgensen, Donna Dugas, Tom Semper

Health & Human Performance Faculty Publications

Objectives : To utilize the theory of planned behavior (TPB) in explaining the prediction of physical activity intention and determine if present activity behavior attenuates theory construct relationships in a sample of low-income Mexican women.

Methods : Data were gathered on 201 subjects through a self-report survey instrument and analyzed through structural equation modeling.

Results : Present activity behavior attenuated theory construct influence on intention, and perceived behavioral control was the strongest predictor of intent to engage in physical activity.

Conclusions : Interventions promoting voluntary physical activity for this population group should address factors perceived as barriers to participating in …

Trampling, Peeling And Nibbling Mussels: An Experimental Assessment Of Mechanical And Predatory Damage To Shells Of Mytilus Trossulus (Mollusca: Mytilidae), Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Shell damage, if properly recognized, can provide information about biotic interactions between molluscs and their predators. However, it can be difficult to distinguish predatory damage from mechanical breakage, thus making interpretation of damaged modern and fossil shells problematic. To establish a clear-cut distinction between antemortem predatory crab damage and ante- and postmortem mechanical damage in Mytilus trossulus shells, a combined field and experimental approach was used. Mussels were exposed to predation by crabs, tumbled-live, tumbled-dead, and trampled. After 100 h of tumbling, live-collected mussel shells were abraded and disarticulated but not otherwise damaged. Eight percent of the dead-collected shells were …

Seasonal Variation In Dune Vegetation At South Padre Island, Texas., Frank W. Judd, Robert I. Lonard, Kenneth R. Summy, Ruben A. Mazariegos

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Seasonal variation in vegetative cover, species richness, species composition and species importance were compared in the backshore and primary dunes topographic zones at a dune protection area and an unprotected site on South Padre Island, Texas, from May 2004 to April 2005. Cover was greatest in fall, but there was no significant variation among seasons in percent cover in the backshore or primary dunes at either site. Species richness was significantly greater at the dune protection site, but there was no significant seasonal variation in species richness in either topographic zone at either site. Species composition differed between topographic zones …

On The Use Of Modis Evi To Assess Gross Primary Productivity Of North American Ecosystems, Daniel A. Sims, Abdullah Rahman, Vicente D. Cordova, Bassil Z. El-Masri, Dennis D. Baldocchi, Lawrence B. Flanagan, Allen H. Goldstein, David Y. Hollinger, Laurent Misson, Russell K. Monson, Walter C. Oechel, Hans P. Schmid, Steven C. Wofsy, Liukang Xu

School of Earth, Environmental, & Marine Sciences Faculty Publications

[1] Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote‐sensing data, we examined direct relationships between the enhanced vegetation index (EVI) and gross primary productivity (GPP) measured at nine eddy covariance flux tower sites across North America. When data from the winter period of inactive photosynthesis were excluded, the overall relationship between EVI and tower GPP was better than that between …

Capraria Mexicana (Scrophulariaceae) In Cameron County, Texas: Rediscovered In The United States, Alfred Richardson, Ken King

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Two new sites are reported for Capraria mexicana (Scrophulariaceae) in the United States.

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Se reportan dos nuevos sitios para Capraria mexicana (Scrophulariaceae) en los Estados Unidos

Notes On Invasive Plants In The Rio Grande Delta Of Cameron County, Texas., Robert I. Lonard, Frank W. Judd

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

No abstract provided.

Searching Response Of A Wandering Spider To Potential Cues Associated With Lepidopteran Eggs, Rosa Isela Ruiz

Theses and Dissertations - UTB/UTPA

Cheiracanthium inclusum (Hentz), a wandering spider, has been frequently observed feeding on the eggs of Helicoverpa zea (Boddie), an important cotton pest. Wandering spiders are known to feed mainly on mobile prey, thus mechanisms used by these spiders to locate sessile prey remain understudied. Vibratory and visual are among the main cues used by spiders to identify prey. However, other sensory modalities such as chemoreception may be used but are poorly understood. This study investigated the types of cues utilized by C. inclusum to locate and identify H. zea eggs as prey. Results show that C. inclusum responds positively to …

Comparative Pollen Foraging Of Africanized And European Honeybees In A Non-Agricultural Environment, Ruben Ruiz

Theses and Dissertations - UTB/UTPA

With the advent of the Africanized honeybee, ways to differentiate it from the European honeybee have been greatly sought in attempts to better understand the role of Africanized bees in pollination. Pollen collecting strategies for both honeybee subspecies have been explored in attempts to exploit their pollinating capabilities. This project examined pollen collected by honeybees from feral and managed European and Africanized colonies in a relatively isolated site. Paired European and Africanized honeybee colonies were used to obtain pollen foragers. Through acetolysis (series acidified Acetic Anhydride washings); the collected pollen from the individual foragers was treated and observed with light …

Mercury Concentrations In South Texas Game Fishes, E. Anthony Reisinger

Theses and Dissertations - UTB/UTPA

Mercury (Hg) is one of the most ubiquitous and controversial metals in the world primarily due to the toxicity of the organic form of the metal, methylmercury (MeHg). MeHg is a neurotoxin at high levels, known to manifest its effects on humans primarily through consumption of certain fish and marine mammals, which tend to bioaccumulate MeHg in their tissues over time. Increased fish consumption and, thus, mercury intake in residents of coastal areas necessitates a better awareness of MeHg content in game fish species, thus the subject of this study.

Three hundred thirty-nine tissue samples were taken from 19 south …

Roles Of Intra-Fruit Oxygen And Carbon Dioxide In Controlling Pepper (Capsicum Annuum L.) Seed Development And Storage Reserve Deposition, J. Blasiak, Anxiu Kuang, Chakavak S. Farghangi, M. E. Musgrave

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Seeds developing within a locular space inside hollow fruit experience chronic exposure to a unique gaseous environment. Using two pepper cultivars, `Triton' (sweet) and `PI 140367' (hot), we investigated how the development of seeds is affected by the gases surrounding them. The atmospheric composition of the seed environment was characterized during development by analysis of samples withdrawn from the fruit locule with a gas-tight syringe. As seed weight plateaued during development, the seed environment reached its lowest O2 concentration (19%) and highest CO2 concentration (3%). We experimentally manipulated the seed environment by passing different humidified gas mixtures through the fruit …

Study Of Metals In Leached Soils Of A Municipal Dumpsite In Tampico, Tamaulipas, Mexico: Preliminary Results, P. F. Rodríguez-Espinosa, D. Chazaro Mendoza, J. A. Montes De Oca, G. Sánchez Torres E., Alejandro Fierro-Cabo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Zapote dumpsite measures 420000 m 2 and is 28 years old; an estimated 2.5 millions tons of waste have accumulated on the site (household waste, clinical waste, commercial waste). The thickness of the waste is 3 to 9 meters. Since operations began, no control regulations have existed on the residues received. The Zapote dumpsite is located within a salt-marsh between a system of channels and river lagoons of brackish water, located in a tropical sedimentary environment in the urban zone of Tampico, Tamaulipas, Mexico. Recently, the Zapote has been closed and work is presently underway in its rehabilitation since …

Loss Of Escape-Related Giant Neurons In A Spiny Lobster, Panulirus Argus, Sandra Y. Espinoza, Lana Breen, Nisha Varghese, Zen Faulkes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

When attacked, many decapod crustaceans perform tailflips, which are triggered by a neural circuit that includes lateral giant interneurons, medial giant interneurons, and fast flexor motor giant neurons (MoGs). Slipper lobsters (Scyllaridae) lack these giant neurons, and it has been hypothesized that behavioral (e.g., digging) and morphological (e.g., flattening and armor) specializations in this group caused the loss of escape-related giant neurons. To test this hypothesis, we examined a species of spiny lobster, Panulirus argus. Spiny lobsters belong to the sister taxon of the scyllarids, but they have a more crayfish-like morphology than scyllarids and were predicted to have escape-related …

Digging Mechanisms And Substrate Preferences Of Shovel Nosed Lobsters, Ibacus Peronii (Decapoda: Scyllaridae), Zen Faulkes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Digging is a distinct form of locomotion that poses different mechanical problems than other locomotor modes that are commonly used by crustaceans, e.g., walking, swimming. I examined the mechanisms of digging by shovel nosed lobsters (Ibacus peronii), which spend most of the day underneath sand. Ibacus peronii were videotaped while digging. Ibacus peronii use a “wedge” strategy to submerge into sand. An individual penetrates the sand with the walking legs, then extends the abdomen to push sand backwards, then flexes the abdomen while pushing backward with the legs, which slowly drives the body into the sand. This basic …

Detecting Submarine Groundwater Discharge With Synoptic Surveys Of Sediment Resistivity, Radium, And Salinity, John A. Breier, Crystaline F. Breier, Henrietta Edmonds

School of Earth, Environmental, & Marine Sciences Faculty Publications

A synoptic geophysical and geochemical survey was used to investigate the occurrence and spatial distribution of submarine discharges of water to upper Nueces Bay, Texas. The 17 km survey incorporated continuous resistivity profiling; measurements of surface water salinity, temperature, and dissolved oxygen; and point measurements of dissolved Ra isotopes. The survey revealed areas of interleaving, vertical fingers of high and low conductivity extending up through 7 m of bay bottom sediments into the surface water, located within 100 m of surface salinity and dissolved Ra maxima along with peaks in water temperature and lows in dissolved oxygen. These results indicate …

Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri

School of Earth, Environmental, & Marine Sciences Faculty Publications

We tested the potential of estimating per-pixel gross primary production (GPP) directly from the MODIS enhanced vegetation index (EVI) and respiration directly from MODIS surface temperature (MOD11). Carbon flux data were obtained from 10 eddy covariance tower sites representing a wide range of North American vegetations. The correlation between across-site tower GPP and EVI was comparable (r = 0.77) to that between tower GPP and MOD17-GPP (r = 0.73), suggesting that EVI could be used to provide reasonably accurate direct estimates of GPP on a truly per-pixel basis. There was also a strong relationship (r2 = 0.67) between respiration and …

Ascidians Of South Padre Island, Texas, With A Key To Species, Gretchen Lambert, Zen Faulkes, Charles C. Lambert, Virginia L. Scofield

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The ascidians of South Padre Island, Texas were surveyed in August 2004. Because the subtidal area is limited to soft sediments, the survey was restricted to marina floats and pilings, harbor buoys, boat hulls and other artificial substrates which offer suitable attachment surfaces for ascidians. Fifteen species were documented, with multiple species representing each of the three orders of ascidians. None of the species found in this survey are native, suggesting they were all introduced through boat traffic. About half the species were found in a reproductive state, however, indicating that they have established local breeding populations.

Effects Of Oxidative Stress On Ascidia Interrupta Embryogenesis, Anna Stwora, Virginia L. Scofield, Zen Faulkes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Discussion: Oxidative stress does not affect very early development, which is consistent with the "be prepared" hypothesis (Epel, 2003). Two possible hypotheses could explain this result. The"be prepared" hypothesis suggests that very early embryos have static but short-lived anti-oxidant defensive mechanism in place, such as enzymes that neutralize hydrogen peroxide...

Collection, Isolation And Evaluation Of Nitrogen Fixing Bacteria In The Rio Grande Valley Of Texas, Thomas M. Eubanks

Theses and Dissertations - UTB/UTPA

Isolation from local soil samples with Phaseolus vulgaris (L.) produced 20 samples from which pure cultures were obtained. A commercial strain of Rhizobium #132 was obtained from Becker Underwood and included as a standard in the experiment. The results demonstrated that a variety of infective and effective of strains of Rhizobium nodulating Phaseolus vulgaris (L.) exist in the native soils of the Rio Grande Valley of Texas. A cluster of effective bacteria was identified and can serve as a basis for recommendations to inoculant industry in the Valley. An isolate collection has been established to serve as a source of …

The Effects Physical Activity Has On The Menstrual Cycle Characteristics Between Two Groups Of High School Athletes And One Group Of High School Non-Athletes, Yolanda D. Robinson

Theses and Dissertations - UTB/UTPA

The purpose of this study was to assess and compare the menstrual cycle characteristics between two groups of high school athletes and one group of high school non-athletes. The study consisted of 30 high school females from Donna High School. The participants consisted of ten female basketball athletes from the Donna High School Basketball Team (14.5 ± 4.5 years), ten female volleyball athletes from the Donna High School Volleyball Team (14.5 ± 4.5 years) and ten females (14.5 ± 4.5 years) that were randomly picked out of the general female population of the Donna High School that do not participate …

Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul

School of Earth, Environmental, & Marine Sciences Faculty Publications

Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23 - 31° N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information.

Seed Storage Reserves And Glucosinolates In Brassica Rapa L. Grown On The International Space Station, M. E. Musgrave, Anxiu Kuang, L. K. Tuominen, L. H. Levine, R. C. Morrow

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Although plants are envisioned to play a central role in life support systems for future long-duration space travel, plant growth in space has been problematic due to horticultural problems of nutrient delivery and gas resupply posed by the weightless environment. Iterative improvement in hardware designed for growth of plants on orbital platforms now provides confidence that plants can perform well in microgravity, enabling investigation of their nutritional characteristics. Plants of B. rapa (cv. Astroplants) were grown in the Biomass Production System on the International Space Station. Flowers were hand-pollinated and seeds were produced prior to harvest at 39 days after …

Tracking The Sea-Level Signature Of The 8.2 Ka Cooling Event: New Constraints From The Mississippi Delta, Torbjörn E. Törnqvist, Scott J. Bick, Juan L. Gonzalez, Klaas Van Der Borg, Arie F. M. De Jong

School of Earth, Environmental, & Marine Sciences Faculty Publications

The ever increasing need for accurate predictions of global environmental change under greenhouse conditions has sparked immense interest in an abrupt, century‐scale cooling around 8200 years ago, with a focal point in the North Atlantic and with hemispheric teleconnections. Despite considerable progress in the unraveling of this striking feature, including a conceivable driving mechanism (rapid drainage of proglacial Lake Agassiz/Ojibway and a resulting reduced strength of North Atlantic thermohaline circulation), several key questions remain unanswered. One salient aspect concerns the total amount of freshwater released during this catastrophic event, likely echoed by a near‐instantaneous eustatic sea‐level rise. So far, no …

Use Of Pedometers To Promote Improvement In Selected Physiological Measurements In An Older Female Mexican American Population, Zasha Romero

Theses and Dissertations - UTB/UTPA

The problem of this study was to determine if pedometers promoted daily walking exercise reflected by changes on selected physiological measurements in older Mexican American females. Significance in the study was determined at the 95% level of confidence. The researcher offered the null hypothesis of no difference in results from the pretest to the posttest in both the control and treatment groups for the selected physiological measurements. The subjects of this study were 55 Mexican-American females ages 60 to 75. The subjects were randomly assigned to a treatment or control group. An analysis of covariance (ANCOVA) method was used to …

Response Of Brood-Parasitic Bronzed Cowbird To Playback Of The Song Of Audubon's Oriole, Steven G. Monk, Timothy Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

ABSTRACT—In the Lower Rio Grande Valley of South Texas, Audubon’s orioles (Icterus graduacauda) have declined substantially in the past 50 y, probably due to habitat loss, fragmentation, and brood parasitism by bronzed cowbirds (Molothrus aeneus). Tape playback of the song of Audubon’s oriole, originally intended to better survey the oriole, also attracted bronzed cowbirds. Bronzed cowbirds flew silently into the nearest tree in 14.1% of 234 playbacks, whereas Audubon’s orioles responded vocally or flew toward the recorder in 15.8% of playbacks. Bronzed cowbirds might use vocalizations of Audubon’s oriole as a cue to find breeding pairs or nests of this …