Big Thicket National Preserve Research Articles

The ABT BioMystery

This month's BioMystery, with its prominent flower, is certainly a member of the botanical community. However, this angiosperm is missing a central characteristic that most students likely believe all plants possess. What plant is this? What does it seem to be missing? Photo taken by W. F. McComas in the Big Thicket National Preserve, northeast of Houston, Texas. See page 434 at the back of this issue for the answer.

Prevalence of protozoan parasites in small and medium mammals in Texas, USA.

Wildlife interaction with humans increases the risk of potentially infected ticks seeking an opportunistic blood meal and consequently leading to zoonotic transmission. In the United States, human babesiosis is a tick-borne zoonosis most commonly caused by the intraerythrocytic protozoan parasite, Babesia microti. The presence of Babesia microti and other species of Babesia within Texas has not been well characterized, and the molecular prevalence of these pathogens within wildlife species is largely unknown. Small (e.g. rodents) and medium sized mammalian species (e.g. racoons) represent potential reservoirs for specific species of Babesia, though this relationship has not been thoroughly evaluated within Texas. This study aimed to characterize the molecular prevalence of Babesia species within small and medium sized mammals at two sites in East Texas with an emphasis on detection of pathogen presence in these two contrasting wild mammal groups at these sites. To that end, a total of 480 wild mammals representing eight genera were trapped, sampled, and screened for Babesia species using the TickPath layerplex qPCR assay. Two sites were selected for animal collection, including The Big Thicket National Preserve and Gus Engeling Wildlife Management Area. Molecular analysis revealed the prevalence of various Babesia and Hepathozoon species at 0.09% each, and Sarcocystis at 0.06% . Continued molecular prevalence surveys of tick-borne pathogens in Texas wild mammals will be needed to provide novel information as to which species of Babesia are most prevalent and identify specific wildlife species as pathogen reservoirs.

Biotic and spatial factors potentially explain the susceptibility of forests to direct hurricane damage

BackgroundEcologists continue to investigate the factors that potentially affect the pattern and magnitude of tree damage during catastrophic windstorms in forests. However, there still is a paucity of research on which trees are more vulnerable to direct damage by winds rather than being knocked down by the fall of another tree. We evaluated this question in a mixed hardwood–softwood forest within the Big Thicket National Preserve (BTNP) of southeast Texas, USA, which was substantially impacted by Hurricane Rita in September 2005.ResultsWe showed that multiple factors, including tree height, shade-tolerance, height-to-diameter ratio, and neighborhood density (i.e., pre-Rita stem distribution) significantly explained the susceptibility of trees to direct storm damage. We also found that no single factor had pervasive importance over the others and, instead, that all factors were tightly intertwined in a complex way, such that they often complemented each other, and that they contributed simultaneously to the overall susceptibility to and patterns of windstorm damage in the BTNP.ConclusionsDirectly damaged trees greatly influence the forest by causing secondary damage to other trees. We propose that directly and indirectly damaged (or susceptible) trees should be considered separately when assessing or predicting the impact of windstorms on a forest ecosystem; to better predict the pathways of community structure reorganization and guide forest management and conservation practices. Forest managers are recommended to adopt a holistic view that considers and combines various components of the forest ecosystem when establishing strategies for mitigating the impact of catastrophic winds.

Disturbance after Disturbance: Combined Effects of Two Successive Hurricanes on Forest Community Structure

Our attempts to gain knowledge from studying the effects of a single windstorm might be complicated by one or more other events that pass through the same system before it recovers from prior damage. In this article, we had the opportunity to examine permanent plots affected by two consecutive catastrophic storms of comparable intensity within a short time frame (less than a decade). We compared tree damage patterns resulting from Hurricane Rita in 2005 and Hurricane Ike in 2008, which struck the same five forest plots (40 m × 50 m each; 1 ha total) established in the Big Thicket National Preserve of southeast Texas. The results showed that the post-Rita forest structure was characterized by intense damage to short, shade-tolerant stems and increased canopy openness. Hence, trees damaged by Ike were, in general, taller, more shade intolerant, and more spatially distant from their undamaged counterparts than trees damaged by Rita. These contrasting damage patterns indicate that Ike affected the plots differently to a normal windstorm occurring in isolation (after a long absence of prior windstorms). We anticipate that the cumulative, compounded effects of these two storms will potentially have long-lasting footprints on the structure and function of the study forest. The need to account for compounding disturbance interactions in forest research and management will grow, because many atmospheric scientists predict increases in both the intensity and frequency of hurricanes in conjunction with future climate change scenarios. Key Words: Big Thicket, disturbance interaction, forest structure, hurricane, spatial point pattern analysis.

A New Species of Dieffluvium (Cestoda: Caryophyllidea) from Smallmouth Buffalo (Ictiobus bubalus) from the Big Thicket National Preserve, Texas, U.S.A.

Dieffluvium nidulorum n. sp. is described from smallmouth buffalo, Ictiobus bubalus, collected from Menard Creek in the Big Thicket National Preserve, Texas, U.S.A. The new species is characterized by a scolex with 2 medial acetabula, 4 lateral loculi, and a terminal disc; a uterus that extends far anterior of the cirrus sac in 2 lateral loops; and a very large and muscular external seminal vesicle. Postovarian vitellaria may be present or absent. The new species is a member of the Caryophyllaeidae, and most closely resembles Dieffluvium unipapillatum, Rowardleus pennensis, and some species of Biacetabulum. We amend the genus Dieffluvium to reflect additional information provided by the discovery of the new species, and precisely differentiate its members from other similar taxa.

Searching for the Immature Stages of Ixodes scapularis (Acari: Ixodidae) in Leaf Litter and Soil in Texas.

The standard tick collection methods of flagging and dragging are successful for collecting all stages of the blacklegged tick, Ixodes scapularis (Say) (Acari: Ixodidae), in the northern United States. However, for unknown reasons, these methods are unsuccessful for collecting the immature stages of I. scapularis in the southern United States. Thus, a different collection strategy was employed to search for the immature stages of I. scapularis in the southern state of Texas. Monthly sampling of three types of microhabitats potentially harboring ticks was conducted for 17 mo at the Big Thicket National Preserve. Samples of leaf litter, topsoil, and subsoil were placed within Berlese funnels to determine if the immature stages of I. scapularis are residing in these layers. No ticks were found in any of the 600 substrate samples examined. Along nearby trail edges in the same area, 656 adult I. scapularis (an average of 22.6 per 1,000 m2), as well as 268 immatures of other species (i.e., Amblyomma americanum (Linnaeaus) (Acari: Ixodidae) and Dermacentor variabilis (Say) (Acari: Ixodidae)) were collected using flagging and dragging. These results suggest that unlike speculations from previous studies in the southern United States, the immature stages of I. scapularis may not be residing in the leaf litter and soil layers in Texas. We hypothesize that they may be residing in their host's nests and burrows. Perhaps I. scapularis in the south is exhibiting a stage specific mixed host-seeking strategy by residing in nests and burrows as immatures, contributing to the geographical difference in Lyme disease prevalence between the northern and southern United States.

Responses to Prescribed Fire at Big Thicket National Preserve, Texas, USA

US Federal land managers have utilized hand ignited prescribed fire at Big Thicket National Preserve in efforts to restore the structure and diversity of the longleaf pine (Pinus palustris) forest. A fire ecology study was initiated by Rice University in the early 1990’s and the National Park Service has continued monitoring the plots. Ordination was applied to species abundance data to examine changes in vegetation communities from a variety of prescribed fire treatments and controls. The vegetation data was separated by size class to include overstory, small tree, large sapling and seedling data. Across the size classes and treatments, the sandhill and wetland savanna vegetation types remained less effected by fire treatments and only the upland pine responded to changes in the overstory. Upon reviewing fire return interval histories, it became evident that prescribed fire alone was not changing vegetation communities. Most of the plots did not have longleaf pine trees or seedlings present and only two plots that were mechanical treated showed distinction among other treatment regimes. Restoration treatments including the mechanical and chemical application and seedling plantings are necessary to ensure restoration of the longleaf pine forest structure and diverse understory vegetation.

A New Species of Caecincola (Trematoda: Cryptogonimidae) from Largemouth Bass (Micropterus salmoides) in the Big Thicket National Preserve, Texas, U.S.A.

ABSTRACT: Caecincola septimus n. sp. is described from the intestine of largemouth bass (Micropterus salmoides) collected from Turkey Creek and Menard Creek in the Big Thicket National Preserve, Texas, U.S.A. Members of the new species are most easily distinguished from Caecincola longiscens and Caecincola cookorum by having ceca that do not extend past the anterior testis or into the posttesticular space, and from the remaining species in the genus (Caecincola autumnae, Caecincola latostoma, Caecincola parvulus, and Caecincola wakullata) by a combination of body size and shape, arrangement of the testes, number of ovarian lobes, and size of the oral sucker. This is the fourth species of Caecincola described from largemouth bass, the others being C. parvulus from Wisconsin, C. wakullata from Florida, and C. latostoma from Louisiana.

Myxobolus lepomis n. sp. (Cnidaria: Myxobolidae), a gill myxozoan infecting Lepomis marginatus Holbrook and Lepomis miniatus Jordan (Perciformes: Centrarchidae), in the Big Thicket National Preserve, Texas, USA.

A parasitological survey of freshwater fishes in the Big Thicket National Preserve in southeast Texas revealed myxozoan infections in two species of sunfish, Lepomis marginatus Holbrook and Lepomis miniatus Jordan (Perciformes: Centrarchidae). Pseudocysts were elongate-oval, 988 × 485 µm (ex L. marginatus) and 800 × 606 µm (ex L. miniatus) and demonstrated a predilection to the edge of the primary gill lamellae. Myxospores consistent with the genus Myxobolus were oblong, 16.8-21.3 (19.0 ± 0.9) µm long, 7.0-8.8 (7.9 ± 0.5) µm wide and 5.3-6.1 (5.8 ± 0.3) µm thick (ex L. marginatus) and 17.2-20.3 (18.8 ± 0.7) µm long, 7.5-9.9 (8.7 ± 0.6) µm wide, and 6.8-7.2 (7.0 ± 0.2) µm thick (ex L. miniatus); with 2 pyriform polar capsules 8.3-9.8 (9.0 ± 0.5) µm long, 2.2-2.7 (2.5 ± 0.2) µm wide (ex L. marginatus) and 9.2-10.5 (10.0 ± 0.4) µm long, 2.2-3.0 (2.8 ± 0.2) µm wide (ex L. miniatus). Statistically, the measurements of spore body width, polar capsule length, and polar capsule width were significantly different between myxospores from L. marginatus and L. miniatus. However, intraspecific genetic variability between isolates at the 18S rRNA gene was negligible, with < 0.8% variability across > 2,000 bp of sequence. The isolates shared no significant sequence similarity with any myxozoan deposited in the GenBank nucleotide database. Phylogenetic analysis inferred from the 18S rRNA gene from both L. marginatus and L. miniatus placed the isolates within a clade of myxozoan parasites of perciform fishes. Based on shared tissue and host family tropism, overlapping morphological characters and high degrees of sequence conservation at the 18S rRNA gene, we propose these isolates as morphologically distinct, genetically conspecific representatives of M. lepomis n. sp. from the gills of L. marginatus and L. miniatus in the Big Thicket National Preserve in Texas, USA.

NOCTURNAL ARBOREALITY IN SNAKES IN THE SWAMPLANDS OF THE ATCHAFALAYA BASIN OF SOUTH-CENTRAL LOUISIANA AND BIG THICKET NATIONAL PRESERVE OF SOUTHEAST TEXAS

The southeastern United States is home to a diverse assemblage of snakes, but only one species, the Rough Greensnake (Opheodrys aestivus), is considered specialized for a predominantly arboreal lifestyle. Other species, such as Ratsnakes (genus Pantherophis) and Ribbonsnakes/Gartersnakes (genus Thamnophis), are widely known to climb into vegetation and trees. Some explanations given for snake climbing behavior are foraging, thermoregulation, predator avoidance, and response to flood. Reports of arboreality in snake species typically not associated with life in the trees (such as terrestrial, aquatic, and even fossorial species) usually come from single observations, with no knowledge of prevalence of the behavior. Here, we report on arboreality of snake species detected during 8 years of night surveys in the Atchafalaya Basin of south-central Louisiana and 5+ years of night surveys in Big Thicket National Preserve in southeast Texas. We recorded a total of 1,088 detections of 19 snake species between the two study areas, with 348 detections above ground level (32%). The Rough Greensnake and Western Ribbonsnake (Thamnophis proximus) accounted for nearly 75% of total arboreal detections among the two study areas. However, with one exception, all snake species detected more than once between both study areas had at least one arboreal detection. These observations demonstrate that snakes with widely varying natural histories may be found in the trees at night, and for some species, this behavior may be more common than previously believed.

Comparison of Metazoan Parasite Diversity in Catfishes Within and Outside the Big Thicket National Preserve, Texas, U.S.A.

Species richness and composition of the metazoan parasite communities of 2 ictalurid catfishes (yellow bullhead [Ameiurus natalis] and channel catfish [Ictalurus punctatus]) were compared from within the Big Thicket National Preserve in southeastern Texas, U.S.A., to areas outside the preserve. Ninety-five fishes were sampled from 2009 to 2013 from 6 sites each inside and outside the Preserve, and 31 species of parasites were recovered (27 species from inside and 14 species from outside). Comparison of species accumulation curves utilizing recently developed methods demonstrated significant differences in the species richness and composition, the abundance distributions for parasite communities as a whole, or both, and of the community of channel catfish considered alone. Additional univariate and multivariate analyses and observations confirmed significant differences in the species composition and abundance of these parasite communities. The parasite community inside the Preserve is dominated by adult endohelminths representing both ictalurid specialists that are either absent or less abundant outside the Preserve. Additionally, generalist parasites more commonly parasitizing other fishes were more speciose and abundant inside the Preserve. The differences observed in the present investigation suggest that the waters of the Big Thicket National Preserve harbor more diverse and abundant fish, invertebrate communities, or both, thus leading to higher diversity and abundance of their parasite communities.

Habitat quantity of Red-cockaded Woodpecker Picoides borealis (Aves: Piciformes: Picidae) in its former historic landscape near the Big Thicket National Preserve, Texas, USA

&lt;p&gt;We quantified pine-forested habitat suitable for Red-cockaded Woodpecker &lt;em&gt;Picoides borealis&lt;/em&gt; in the former historic range of the species to assess the potential for possible re-colonization. We used a remotely-sensed image and geographic information systems (GIS) to create a land-use/land (LU/LC) binary cover map, from which we calculated the habitat suitability index (HSI) based on an estimated home range of 50ha. A sensitivity analysis revealed the necessity for more data to make an accurate estimate, but our analysis of landscape metrics indicates more than 930ha of suitable habitat patches. These patches are heavily fragmented and mostly located on private lands. They can be assessed for understory and herbaceous vegetation and can be restored for possible re-establishment of approximately 18 groups/colonies of Red-cockaded Woodpeckers.&lt;/p&gt;&lt;div&gt; &lt;/div&gt;

A New Species of Prosorhynchoides (Trematoda: Bucephalidae) from White Bass, Morone chrysops (Moronidae), in the Big Thicket National Preserve, Texas, U.S.A

ABSTRACT: Prosorhynchoides fabulus n. sp. (Trematoda: Bucephalidae) is described from the intestine of white bass Morone chrysops (Moronidae) collected from the Neches River in the Big Thicket National Preserve in Texas, U.S.A. The new species is characterized by a relatively large cirrus sac extending anteriorly to the level of the ovary and cecum, a mouth nearly exactly midbody, obliquely arranged testes, a serpentine excretory bladder limited to the hindbody, and small size (<500 μm). The extent of the cirrus sac distinguishes P. fabulus n. sp. from most other species in the genus in North America. The new species displays similarities to Prosorhynchoides carvajali, Prosorhynchoides labiatus, and Prosorhynchoides megacirrus in the extent of the cirrus sac but differs from these species in combinations of the location of the vitellaria, position of the pharynx and mouth, extent of the excretory bladder, arrangement and position of the gonads, and body size.

Metazoan Parasites of Catfishes in the Big Thicket National Preserve and Surrounding Areas, Texas, U.S.A.

ABSTRACT: A survey of 2 species of ictalurid catfishes, channel catfish (Ictalurus punctatus) and yellow bullhead (Ameiurus natalis), was conducted in southeastern Texas, United States. Sixty-nine channel catfish and 26 yellow bullhead were collected from 6 sites within the Big Thicket National Preserve and 6 sites in surrounding bodies of water. Thirty-one species of parasites were found including 11 trematodes, 8 nematodes, 5 copepods, 3 cestodes, and 1 each of an acanthocephalan, leech, monogene, and myxozoan. Channel catfish harbored 23 species of parasites, yellow bullhead harbored 17, and 9 species occurred in both host species. Adult endohelminths dominated the fauna (18 species). Trematodes (Alloglossidium corti, Alloglossidium kenti, Polylekithum catahoulensis), a cestode (Megathylacoides giganteum), a nematode (Dichelyne robusta), and an ectoparasitic copepod (Ergasilus cerastes) constituted over 75% of the total parasite abundance. Although this constitutes the highest species diversity report...

A New Species ofAzygia(Trematoda: Azygiidae) from Pirate Perch,Aphredoderus sayanus(Aphredoderidae), in the Big Thicket National Preserve, Texas, U.S.A

Azygia aphredoderi n. sp. is described from the stomach of the pirate perch Aphredoderus sayanus (Aphredoderidae) collected from the Menard Creek Corridor Unit of the Big Thicket National Preserve in Texas, U.S.A. The new species is similar to Azygia angusticauda in that the ventral sucker and gonads are placed posteriorly, characteristics that allow both species to be distinguished from all others in North America. Members of the new species are characterized by a ventral sucker that is larger than the oral sucker, small body size (<2 mm), small length-to-width ratio, and a forebody-to-hindbody ratio of nearly 1.0, all of which allow them to be distinguished from A. angusticauda.

Lone Star Bears: The Tardigrada of Big Thicket National Preserve, Texas

We completed an all taxa biological inventory (ATBI) for water bears (Phylum Tardigrada) in the Big Thicket National Preserve (BTNP) of southeastern Texas begun in 2006. Our inventory is based on methods used in a tardigrade ATBI of the Great Smoky Mountains National Park (GSMNP). We sampled lichens, mosses, liverworts, leaf litter, soil, and aquatic vegetation. Tardigrades were present in 47% of terrestrial and 3% of freshwater samples. We identified 631 tardigrade specimens and 63 eggs, representing 13 genera and 37 species. Tardigrade species richness in BTNP is approximately half that in GSMNP. Lower diversity in BTNP is partly explained by the absence of the altitudinal variation characteristic of GSMNP. Freshwater tardigrades were especially poorly represented at BTNP. Streams and lakes in BTNP are eutrophic and muddy, and may be poor habitats for tardigrades. This study confirms previous findings that the high tardigrade diversity found in mountainous areas may not be typical of other landscapes, and that in North America, tardigrades are less numerous and diverse in southern coastal plains and flatlands than in northern forests and mountains.

A New Genus and Species of Caryophyllaeid (Cestoda: Caryophyllidea) from Spotted Suckers,Minytrema melanops(Catostomidae), in the Big Thicket National Preserve, Texas, U.S.A

Homeomorpha mackiewiczi n. gen. n. sp. is described from spotted suckers, Minytrema melanops, collected from a small stream in the Big Thicket National Preserve, Texas, U.S.A. The new genus is a member of the Caryophyllaeidae and is characterized by a uterus that loops anteriorly to the cirrus sac by more than the width of the uterus, preovarian vitelline follicles in distinct lateral rows, H-shaped ovary, 2 gonopores with genital atrium, an external seminal vesicle, postovarian vitellaria, and a cuneiloculate scolex. The new genus most closely resembles Hypocaryophyllaeus and Glaridacris, but members of Hypocaryophyllaeus do not possess postovarian vitellaria and members of Glaridacris have a uterus that does not loop anteriorly of the cirrus sac.

Myxomycetes isolated from submerged plant material collected in the Big Thicket National Preserve, Texas

Samples of submerged plant material obtained from streams and other bodies of water at 11 different collecting sites in management units of the Big Thicket National Preserve in Texas were used to prepare 90 moist chamber cultures for the isolation of myxomycetes. These cultures were maintained in the laboratory for 10 weeks, during which they yielded 14 species representing 12 genera. This total included five species (Licea belmontiana, Craterium concinnum, Diachea bulbillosa, Oligonema schweinitzii, and Physarum echinosporum) not recorded previously for the Big Thicket National Preserve and one species (D. bulbillosa) new for the state of Texas. Although usually not included in biodiversity surveys for myxomycetes, our data suggest that submerged plant material may support a few species that may be missed if only terrestrial habitats are considered.

Redescription of Polylekithum catahoulensis (Trematoda) and Anatomical Differentiation from Polylekithum ictaluri

New collections of Polylekithum from catfishes in the Big Thicket National Preserve, Texas, U.S.A., provided material for a redescription of Polylekithum catahoulensis and an evaluation of the characters used to diagnose species in the genus. The new collections demonstrated that the relative size of the forebody is not a reliable diagnostic feature of P. catahoulensis, because the feature changes linearly as worms grow; similarly, the location of the maximum width of worms is not diagnostic because it depends on the number of eggs in the uterus. However, egg size reliably distinguishes between P. catahoulensis (small eggs) and Polylekithum ictaluri (large eggs). Other morphometric and relational characteristics did not distinguish between species.

Neochaetosphaerella thaxteriospora gen. et sp. nov. and Tympanopsis texensis sp. nov. (Coronophorales, Ascomycota) from Texas, USA

Ascomata of three species of coronophoraceous fungi collected from the Big Thicket National Preserve and an area immediately adjacent to the preserve were examined with a scanning electron microscope to reveal the distinctive features of the ascomatal surface. Based on the results of the examination, two new species (Neochaetosphaerella thaxteriospora and Tympanopsis texensis) are herein described and discussed. Both a description and an illustration of Scortechinia acanthostroma are also provided.