Biology Commons^™

Great Curassow And Crested Guan Near Ciudad Victoria, Tamaulipas, Mexico, Timothy Brush

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

Great Curassow (Crax rubra) and Crested Guan (Penelope purpurascens) were rediscovered in the Ciudad Victoria area of southwestern Tamaulipas, Mexico for the first time since 1909. Birds were found in low elevation canyons containing permanent running water, with riparian forest dominated by Montezuma bald-cypress (Taxodium mucronatum) and steep scrub-covered slopes. These records represent the northernmost known points of the ranges of both species. Additional field work will be needed to determine whether these small populations are isolated from the nearest known populations in the El Cielo/Gómez Farías area of southern Tamaulipas.

Production Of Marine Trematode Cercariae: A Potentially Overlooked Path Of Energy Flow In Benthic Systems, David W. Thieltges, Xavier De Montaudouin, Brian L. Fredensborg, K. Thomas Jensen, Janet Koprivnikar, Robert Poulin

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

Parasites, in particular trematodes, are unseen but ubiquitous components of marine intertidal ecosystems. Although parasites are known to affect population dynamics and food web structure, their potential function as an unrecognized path of energy flow in these ecosystems is yet to be quantified. We use published data on rates at which trematodes produce free-swimming infective larvae (cercariae) that are released from their gastropod intermediate hosts to investigate patterns in cercarial output as a function of different variables, and to calculate the annual production of cercariae in different marine benthic systems. Across 18 trematode species, cercarial output (no. cercariae shed snail–1 …

Undergraduate Research: A Bridge To Graduate Education In Agricultural Biotechnology For Hispanics, Eliezer S. Louzada, Hilda Sonia De Rio, Allison J. Abell, Gerson Peltz, Michael W. Persans

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

Hispanics lag behind all other U.S. ethnic groups in education, and are especially poorly represented in science careers. Undergraduate research is an efficient method to attract undergraduate students to science, and many universities are taking advantage of this; however, much still needs to be done to fully explore its potential. In 2000, Texas A&M University-Kingsville, in collaboration with the University of Texas at Brownsville and the University of Texas Pan-American, initiated a undergraduate research internship program in citrus biotechnology to channel Hispanic undergraduate students into graduate education. To date, 51 internships have been provided, and 20 students have been channeled …

Dune And Vegetation Stability At South Padre Island, Texas, United States Of America, Frank W. Judd, Kenneth R. Summy, Robert I. Lonard, Ruben A. Mazariegos

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

Padre Island is the longest of five barrier islands occurring along the Texas Gulf Coast. South Padre Island is separated from the northern two-thirds of the island by the Mansfield Channel. The composition and pattern of vegetation on South Padre Island are relatively well known, but data on the interrelationship of dune and vegetation stability are lacking. We hypothesized that (1) there should be an inverse relationship between elevation change and percent cover on transects across the nearshore dunes of South Padre Island; and (2) percent cover, species composition, and species importance should be most stable where elevation change was …

Complementary Dna Sequencing And Identification Of Mrnas From Venomous Gland Of Agkistrodon Piscivorus Leucostoma, Ying Jia, Bruno A. Cantu, Elda E. Sánchez, John C. Pérez

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

To advance our knowledge on the snake venom composition and transcripts expressed in venom gland at the molecular level, we constructed a cDNA library from venom gland of Agkistrodon piscivorus leucostoma for the generation of expressed sequence tags (ESTs) database. From the randomly sequenced 2,112 independent clones, we have obtained ESTs for 1,309 (62%) cDNAs which showed significant deduced amino acid sequence similarity (scores > 80) to previously characterized proteins in NCBI database. Ribosomal proteins make up 47 clones (2%) and the remaining 756 (36%) cDNAs represent either unknown identity or show BLASTX sequence identity scores of < 80 with known GenBank accessions. The most highly expressed gene encoding phospholipase A2 (PLA2) accounting for 35% of A. p. leucostoma venom …

Failure To Replicate Evidence Of Decapod Crustacean Nociception, Sakshi Puri, Zen Faulkes

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

Introduction Here, we attempt to replicate their experiments with two other species of decapod crustaceans that bracket P. elegans phylogenetically: white shrimp (Litopenaeus setiferus) and Louisiana red swamp crayfish (Procambarus clarkii). Litopenaeus setiferus have a similar ecology to prawns. Procambarus clarkii is widely used in the study of neurobiology, and would be an excellent candidate for further neurophysiological studies.

Discussion We found no behavioral evidence of nociception in either L. setiferus or P. clarkii. This outcome contrasts sharply with results that indicated P. elegans had nociception (Barr et al. 2007).

Using Color Infrared Imagery To Detect Sooty Mold And Fungal Pathogens Of Glasshouse-Propagated Plants, Kenneth R. Summy, Christopher R. Little

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

Fungi are major biotic constraints for optimum production and quality of glasshouse plants. When plants are infested with sooty mold (Capnodium spp.) or infected with pathogens, the reflected wavelengths of the electromagnetic spectrum are altered. Spectroradiometric measurements and color infrared (CIR) images of control, honeydew- coated, and sooty mold-infested saplings and individual leaves from trifoliate orange (Poncirus trifoliata), sour orange (Citrus aurantium), ‘Valencia’ orange (C. sinensis), and ‘Bo’ tree (Ficus religiosa) were obtained. Grapefruit saplings and individual leaves infected with Mycosphaerella citri (greasy spot) were imaged under glasshouse conditions. Similarly, muskmelon foliage showing low and high levels of powdery mildew …

Neptunia Plena (Fabaceae: Mimosoideae) Rediscovered In Texas, Alfred Richardson, Ken King

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

On October 17, 1938, Robert Runyon collected a specimen of Neptunia plena from a shallow pond south of Armstrong in Kenedy County, Texas. No subsequent collections from Texas have been reported . It was assumed that it was not a permanent member of our flora. On October 27, 2007, a population of N. plena was found near the same locality.

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El 17 de octubre de 1938, Robert Runyon recogió un espécimen de Neptunia plena de una charca somera de Armstrong en el condado de Kenedy, Tejas. No se ha encontrado ninguna colección posterior de Tejas. Fue asumido que no …

Additions To The Breeding Avifauna Of The Lower Rio Grande Valley Of Texas, Timothy Brush

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

The breeding avifauna of the Lower Rio Grande Valley (LRGV) of Texas has experienced many changes during the 20th century, primarily because of declines in native habitats due to land being converted to agriculture and urban habitats. This paper summarizes changes in breeding avifauna from 2003–2007 in the area. Breeding has been confi rmed for Cooper’s Hawk (Accipiter cooperii), Eurasian Collared-Dove (Streptopelia decaocto), and Mangrove Yellow Warbler (Dendroica petechia oraria) for the fi rst time, and for Gray-crowned Yellowthroat (Geothlypis poliocephala) and Ferruginous Pygmy-Owl (Glaucidium brasilianum) after periods of apparent absence. Short-tailed Hawk (Buteo brachyurus) is a possible breeder, based …

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 …

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 …

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 …

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.

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 …

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 …

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 …

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 …

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 …

Recovery Of Vegetation Following A Wildfire In A Barrier Island Grassland, Padre Island National Seashore, Texas, Robert I. Lonard, Frank W. Judd, Elizabeth H. Smith, Chenghai Yang

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

Vegetation recovery following a wildfire in vegetated flats and secondary dunes of Padre Island National Seashore, Texas, was studied from January 2000 to January 2002. Species richness, diversity, evenness, abundance, and importance were evaluated. Species richness, diversity, and evenness were restored quickly in vegetated flats (51 days) and secondary dunes (71 days). The burned secondary dune site had the same dominant species as its non-burned counterpart from the beginning to the end of the study, but it took 106 days for the dominant species to be restored in the burned vegetated flats. No exotic species established in burned sites. Two …

Community Ecology Of Freshwater, Brackish And Salt Marshes Of The Rio Grande Delta, Frank W. Judd, Robert I. Lonard

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

Species composition and importance, species diversity and evenness, species richness, and community similarity are compared among 6 freshwater, 9 brackish and 11 salt marshes in the Rio Grande Delta. Community similarity is generally low among marshes, but salt marshes have a greater mean coefficient of similarity than brackish marshes. Species richness per marsh ranges from 15 to 31 for freshwater marshes, 7 to 24 for brackish marshes and 7 to 26 for salt marshes. Each freshwater marsh has a different dominant species. The first six species in importance in all three kinds of marshes contribute from 72.6 to 99.8% of …

The Vascular Flora Of The Palo Alto National Battlefield Historic Site, Cameron County, Texas, Robert I. Lonard, Alfred T. Richardson, Norman L. Richard

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

A checklist is provided of the vascular plant taxa of the 1,376 ha Palo Alto Battlefield National Historic Site (PABNHS) in Cameron County of south Texas. PABNHS consists of four plant communities: resacas and tanks, salt flats, brush-grasslands and coastal marshes. Vascular plants of disturbed sites are noted. Two hundred forty-three taxa in 66 families are documented and their community affiliations are given. Three families, Poaceae, Asteraceae and Fabaceae contain 37.5% of the species richness at PABNHS.

Hooded Oriole Nest Failure Associated With A Novel Nest Site, Kevin Ellison, Timothy Brush

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

Ecological traps occur where species are attracted to use a resource that exposes them to greater than normal risk of mortality or reproductive failure. We observed complete failure of Hooded Oriole (Icterus cucullatus) nests in streetlights in a south Texas suburb where use of such nest sites was relatively common. This is of concern as streetlights functioned essentially as traps: orioles built their nests within them but all these nests failed, evidently because the eggs were exposed to lethal temperatures. Moreover, Hooded Oriole nesting success on all other substrates in this area was low (31%, n -- 69). Therefore, sufficient …