Highway Crossing Rates of Wild Felids Before, During, and After Wildlife Crossing Structure Installation.

In an environment increasingly dominated by roads, wildlife crossing structures (WCS) have been installed to decrease wildlife mortality and improve habitat linkages. In South Texas, vehicle collisions have been a major mortality source for the endangered ocelot (). To mitigate threats to this species, eight WCS, along with associated fencing, were strategically placed along Farm-to-Market Road 106 (FM106), which passes through ocelot habitat.

Road mitigation structures designed for Texas ocelots: Influence of structural characteristics and environmental factors on non-target wildlife usage.

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and modification along a South Texas highway and to determine whether environmental factors influenced use of WCS.

Spatial distribution and movement of Atlantic tarpon (Megalops atlanticus) in the northern Gulf of Mexico.

Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades.

Exploitation of environmental DNA (eDNA) for ecotoxicological research: A critical review on eDNA metabarcoding in assessing marine pollution.

The rise in worldwide population has led to a noticeable spike in the production, consumption, and transportation of energy and food, contributing to elevated environmental pollution. Marine pollution is a significant global environmental issue with ongoing challenges, including plastic waste, oil spills, chemical pollutants, and nutrient runoff, threatening marine ecosystems, biodiversity, and human health. Pollution detection and assessment are crucial to understanding the state of marine ecosystems.

Early corticosterone increases vocal complexity in a wild parrot: An organizational role of the hypothalamic-pituitary-adrenal axis in vocal learning?

The neuroendocrinology of vocal learning is exceptionally well known in passerine songbirds. Despite huge life history, genetic and ecological variation across passerines, song learning tends to occur as a result of rises in gonadal and non-gonadal sex steroids that shape telencephalic vocal control circuits and song. Parrots are closely related but independently evolved different cerebral circuits for vocal repertoire acquisition in both sexes that serve a broader suite of social functions and do not appear to be shaped by early androgens or estrogens; instead, parrots begin a plastic phase in vocal development at an earlier life history stage that favors the growth, maturation, and survival functions of corticosteroids.

New prospects of environmental RNA metabarcoding research in biological diversity, ecotoxicological monitoring, and detection of COVID-19: a critical review.

Ecosystems are multifaceted and complex systems and understanding their composition is crucial for the implementation of efficient conservation and management. Conventional approaches to biodiversity surveys can have limitations in detecting the complete range of species present. In contrast, the study of environmental RNA (eRNA) offers a non-invasive and comprehensive method for monitoring and evaluating biodiversity across different ecosystems.

Effects of elevated temperature on 8-OHdG expression in the American oyster (): Induction of oxidative stress biomarkers, cellular apoptosis, DNA damage and γH2AX signaling pathways.

Global temperature is increasing due to anthropogenic activities and the effects of elevated temperature on DNA lesions are not well documented in marine organisms. The American oyster ( an edible and commercially important marine mollusk) is an ideal shellfish species to study oxidative DNA lesions during heat stress. In this study, we examined the effects of elevated temperatures (24, 28, and 32 °C for one-week exposure) on heat shock protein-70 (HSP70, a biomarker of heat stress), 8‑hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of pro-mutagenic DNA lesion), double-stranded DNA (dsDNA), γ-histone family member X (γH2AX, a molecular biomarker of DNA damage), caspase-3 (CAS-3, a key enzyme of apoptotic pathway) and Bcl-2-associated X (BAX, an apoptosis regulator) protein and/or mRNA expressions in the gills of American oysters.

Vocal babbling in a wild parrot shows life history and endocrine affinities with human infants.

Prelinguistic babbling is a critical phase in infant language development and is best understood in temperate songbirds where it occurs primarily in males at reproductive maturity and is modulated by sex steroids. Parrots of both sexes are icons of tropical vocal plasticity, but vocal babbling is unreported in this group and whether the endocrine system is involved is unknown. Here we show that vocal babbling is widespread in a wild parrot population in Venezuela, ensues in both sexes during the nestling stage, occurs amidst a captive audience of mixed-aged siblings, and is modulated by corticosteroids.

Assessing changes in clusters of wildlife road mortalities after the construction of wildlife mitigation structures.

Collisions with vehicles can be a major threat to wildlife populations, so wildlife mitigation structures, including exclusionary fencing and wildlife crossings, are often constructed. To assess mitigation structure effectiveness, it is useful to compare wildlife road mortalities (WRMs) before, during, and after mitigation structure construction; however, differences in survey methodologies may make comparisons of counts impractical. Location-based cluster analyses provide a means to assess how WRM spatial patterns have changed over time.

Molecular characterization and expression of arginine vasotocin V1a2 receptor in Atlantic croaker brain: Potential mechanisms of its downregulation by PCB77.

The arginine vasotocin (AVT)-V1a receptor mediates critical reproductive behaviors of the nonapeptide vasotocin in the teleost brain. In this study, we report the molecular characterization of the AVT-V1a2 receptor and its messenger RNA (mRNA) and protein expressions in the Atlantic croaker brain after exposure to the planar polychlorinated biphenyl congener 3,3',4,4'-tetrachlorobiphenyl (PCB77). The full-length sequence of croaker AVT-V1a2 receptor complementary DNA (cDNA) is highly homologous to other teleost AVT-V1a2 receptor cDNAs.

Using Fish Population Metrics to Compare the Effects of Artificial Reef Density.

Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1-190 culverts.

Arginine vasotocin V1a2 receptor and GnRH-I co-localize in preoptic neurons of the sex changing grouper, Epinephelus adscensionis.

The arginine vasotocin/vasopressin (AVT/AVP) and gonadotropin releasing hormone (GnRH) systems are known to control sexual behaviors and reproduction, respectively, in different vertebrate groups. However, a direct functional connection between these two neuroendocrine systems has not been demonstrated for any vertebrate species. Therefore, the objective of this research was to test the hypothesis that AVT acts on the GnRH system via an AVT V1a receptor in a sex changing grouper species, the rock hind, Epinephelus adscensionis.

Distribution of nonapeptide systems in the forebrain of an African cichlid fish, Astatotilapia burtoni.

Nonapeptides and their receptors have important functions in mediating social behavior across vertebrates. Where these nonapeptides are synthesized in the brain has been studied extensively in most vertebrate lineages, yet we know relatively little about the neural distribution of nonapeptide receptors outside of mammals. As nonapeptides play influential roles in behavioral regulation in all vertebrates, including teleost fish, we mapped the distributions of the receptors for arginine vasotocin (AVT; homolog of arginine vasopressin) and isotocin (IST; homolog of oxytocin/mesotocin) throughout the forebrain of Astatotilapia burtoni, an African cichlid fish with behavioral phenotypes that are plastic and reversible based on the immediate social environment.

The distribution of an AVT V1a receptor in the brain of a sex changing fish, Epinephelus adscensionis.

The present study describes the distribution of an arginine vasotocin (AVT) V1a receptor (AVTr) throughout the brain of a sex-changing grouper, rock hind Epinephelus adscensionis. The objectives of this study were to describe the AVTr distribution in the brain of rock hind for potential linkages of the AVT hormone system with sex-specific behaviors observed in this species and to examine sex-specific differences that might exist. An antibody was designed for rock hind AVTr against the deduced amino acid sequence for the third intracellular loop.

Behavior, color change and time for sexual inversion in the protogynous grouper (Epinephelus adscensionis).

Hermaphroditism, associated with territoriality and dominance behavior, is common in the marine environment. While male sex-specific coloration patterns have been documented in groupers, particularly during the spawning season, few data regarding social structure and the context for these color displays are available. In the present study, we define the social structure and male typical behavior of rock hind (Epinephelus adscensionis) in the wild.