The microbial community inhabiting the root-soil contact interface, rhizobiomes, represent a critical link between plant, ecosystems, and geomorphic processes. In landslides where fresh silicate rocks are exposed, rhizobiomes ...

Plant-pollinator interactions provide a crucial ecosystem service for which many depend upon. These interactions can be threatened by many different anthropogenic and natural disturbances. While most studies on plant-pollinator ...

Palm crops worldwide are experiencing adverse effects in crop yields and survivorship from exposure to phytopathogens, including phytoplasmas (Ntushello et al., 2013). Phytoplasmas are plant-pathogenic bacteria that are associated with over 1000 plant diseases. (Duan et al., 2013; Ntushello et al., 2013). The 16SrIV group of phytoplasmas is associated with lethal yellowing diseases that affect at least 30 species of palms worldwide. Available information for Puerto Rico indicates the existence of 16SrIV phytoplasma group in some palm species, including the Royal palm Roystonea borinquena O. F. Cook, the Fishtail palm Caryota mitis Lour, the Carpentaria palm Carpentaria acuminata (H. Wendl. & Drude) Becc., and the Coconut palm Cocos nucifera L. The visual symptoms of the diseases include leaf discoloration (e.g., yellowing, bronzing), flower malformation, premature nuts drop, and death of the plant. This work aimed to identify and characterize palm species, phytoplasma, and associated Auchenorrhyncha occurrence in Puerto Rico. For this study, we collected samples from over 1,027 palms between July 2015 to May 2017 around the island of Puerto Rico. The samples comprise 40 palm species representing species native to the island and introduced ornamental ones. Sixty percent of the collected palms presented symptoms associated with phytoplasma diseases, mainly with premature leave yellowing and decay. We used the coding ribulose-bisphosphate carboxylase gene (rbcL) and maturase K gene (matK) to determine their power to distinguish between species in the palm family Arecaceae in Puerto Rico. Our study found that rbcL and matK place the species with 100% accuracy at the family and subfamily levels. However, additional markers may be needed to identify species within the Arecaceae. To amplify the phytoplasma DNA, we carried out direct and nested PCRs to a sub-sample of 192 palms from the initial sample (n=1,027). Forty-three percent of the samples tested showed amplification using specific primers in the nested PCR. Of these, only 1.5% of the samples were positive for phytoplasma 16SrIV-D associated with lethal bronzing disease of palms. The three confirmed sequences of phytoplasma were from positive samples: two from Dypsis lutescens and one Aiphanes minima, both collected at the UPR Botanical Garden. Phloem feeder insects are the vectors of phytoplasmas. The suborder Auchenorrhyncha contains phloem-feeder insects that are listed as vectors of phytoplasmas. We surveyed Auchenorrhyncha insects associated with palms in three localities of different altitudes between August 2016 to October 2018: the UPR Botanical Garden in San Juan, Punta Santiago Natural Reserve in Humacao, and El Verde Field Station (El Yunque) in Rio Grande. Thirty-three species of planthoppers and leafhoppers were sweep-collected from palms and associated weeds. Genetic analyses evaluated the mitochondrial gene region for cytochrome c oxidase subunit I (COI) to support morphological identification. A subsample of (n=120) insects was screened for hytoplasma by direct and nested PCR assays. We found seven samples that tested positive for phytoplasma. Three samples belonged to Hortensia similis (Walker) and four to Xyphon reticulatum (Signoret), all collected from C. nucifera in Humacao. To our knowledge, this is the first report of these Cicadellidae species associated with phytoplasma in Puerto Rico. The early detection and characterization of phytoplasma-related diseases and the identification of vector species can help reduce the spread of this organism and avoid the negative impact on crop yields in palm species of agricultural importance....

<strong>Chapter I abstract:</strong> The Caribbean region is expected to face an increase in frequency and intensity of climatic disturbances, such as hurricanes. Amphibians and reptiles are especially vulnerable to local abiotic regimes and their response to changes are limited by physiological constraints intrinsic to their evolutionary history. In September of 2017, El Yunque National Forest in Puerto Rico experienced extensive forest damage by the effect of hurricane Maria. In this study, we assessed the effect of hurricane Maria on the abundance, age-specific survivorship, detection probability, and expected gains of a well-studied high-elevation population of Eleutherodactylus coqui. We hypothesize that the population structure would change due to the canopy loss and consequent habitat disturbances caused by the storm blowout. To measure abundance estimates, we used a multi-state N-mixture model to analyze the changes in age-specific demographics on&nbsp;E. coqui population. We found that hurricane Maria had a negative impact on local expected gains and abundance estimates of E. coqui that caused a disruption in the typical demographic pattern as age classes transition through the warm-wet and cool-dry seasons in Puerto Rico. However, no drastic declines were observed. These results point to plasticity in the response of E. coqui to severe environmental events. Recording changes in high-elevation E. coqui population structure may offer insight to how other endangered sympatric species would respond to such phenomena. As stronger and more frequent tropical storms are predicted soon, this study provides baseline data that can help predict, compare, and evaluate future changes to biodiversity in critical areas. <strong>Chapter II abstract:</strong> Amphibians are declining drastically due, in part, to a pathogenic fungal parasite named Batrachochytrium dendrobatidis (Bd). In addition, extreme climatic events, like hurricanes, are increasing in frequency and intensity and this points to the need to understand the way they influence host-pathogen dynamics. Studies in the Americas have advanced our understanding on how environmental factors affect virulence and dispersion of Bd in wild populations. However, in some amphibian communities where Bd is enzootic, the dynamics of the disease may be driven by pathogen overdispersion. Under these circumstances, it is important to understand how Bd infection intensity and prevalence influences host survival and reproduction because this may explain the underlying mechanisms of persistence or extinction. In this study, we evaluate the effect of severe natural disturbances on the dynamics of Bd infections across seasons in a population of highland Eleutherodactylus coqui in Puerto Rico. We found significant differences in Bd infection intensities in the population of E. coqui after the hurricane, suggesting a hurricane effect on the vulnerability of hosts. In addition, a zero-inflated regression model distinguished the effects of the hurricane, seasons and their interaction on the population-level prevalence of Bd. Our work highlights the value of long-term field studies because they provide time-sensitive data necessary to evaluate population responses to global change. <strong>Chapter III abstract:</strong> Marking juveniles of terrestrial direct-developing frogs is challenging because of their small size (&lt; 18 mm) and fragility. This difficulty has limited studies on demography or population dynamics where empirical data on the survivorship of juveniles or their recruitment to adulthood are missing. In a controlled laboratory experiment we tested the survivorship of wild caught juvenile Eleutherodactylus coqui Thomas, 1966 to marking with a single colour Visual Internal Elastomer (VIE) in the thigh with and without additional ventral skin-swabbing for disease or microbiome monitoring. Results revealed 100 % survival in all groups, and all juveniles remained unharmed, moved freely, and fed actively during three days after treatments suggesting that this type of manipulation does not cause direct mortality. After 17 months of the experiment, we have recaptured 11 % of the marked juveniles as adults indicating that they can survive to recruitment age. We propose the use of a single VIE colour as a method to mark and follow date-specific cohorts of juvenile direct-developing frogs or young metamorphs until they reach older and larger age classes. This marking method can be used safely together with skin swabbing and provide valuable information for studies on population biology and age-specific response to environmental or disease stressors....

How sociality interacts with other behaviours is a long standing question in insect biology. Simultaneously, in chronobiology, there is an unanswered question concerning how sociality influences patterns of daily activity. ...

Echinoderms comprise a group of animals with the capability of replacing complex internal organs following injury or autotomy. In holothurians or sea cucumbers, cellular processes of intestinal regeneration have been extensively studied, however, the molecular machinery behind this faculty remains to be understood. In this study, a de novo transcriptome was assembled and annotated using RNA-seq data consisting of regenerating and non-regenerating intestinal tissues from the sea cucumber Holothuria glaberrima. Comparisons of differential expression were made using the mesentery as a reference against 24 hours and 3 days regenerating intestine, revealing numerous differentially expressed transcripts. Gene ontology and pathway enrichment analysis showed evidence of increasing transcriptional activity. Further analysis of transcripts associated with transcription factors revealed diverse expression patterns with developmental and cancer-related mechanisms linked with regenerative responses. This study demonstrates the diverse gene expression profile during the early stages of regeneration using the mesentery as a focal point....

Species in the genus Toxonotus (Lacordaire, 1866) are described for the first time in Puerto Rico and its jurisdictions. Two new species are described, annotated with digital images, and added to a key to the genus: Toxonotus borboroulous n. sp. from Puerto Rico and Vieques Island and Toxonotus ochrothrixus n. sp. from Mona Island. These species belong to the family Anthribidae, commonly known as Fungus Weevils, which are a group of beetles with some species that feed on fungus. Specimens were described morphologically using comparisons to digitally imaged specimens and published records. Diagnostic characteristics were used to place both species into a new key for the entire genus Toxonotus. Supplemental habitus images and genitalia line drawings were edited digitally. Both new species were nearly identical to described Nearctic species and were differentiated by vestiture and color. Types are stored at the University of Puerto Rico Invertebrate Collection (UPRM INVCOL)....
Se describen por primera vez especies del g&eacute;nero Toxonotus (Lacordaire, 1866) en Puerto Rico y sus jurisdicciones. Se describen dos especies nuevas, se anotan con im&aacute;genes digitales y se agregan a una clave del g&eacute;nero: Toxonotus borboroulous n. sp. de Puerto Rico y la Isla Vieques y Toxonotus ochrothrixus n. sp. de la isla de Mona. Estas especies pertenecen a la familia Anthribidae, com&uacute;nmente conocidas como gorgojos del hongo, que son un grupo de escarabajos con especies que se alimentan de hongos. Las muestras se describieron morfol&oacute;gicamente mediante comparaciones con muestras obtenidas con im&aacute;genes digitales y registros publicados. Se utilizaron caracter&iacute;sticas de diagn&oacute;stico para colocar a ambas especies en una nueva clave para todo el g&eacute;nero Toxonotus. Se editaron digitalmente im&aacute;genes suplementarias de habitus y dibujos de genitales. Ambas especies nuevas eran casi id&eacute;nticas a las especies ne&aacute;rticas descritas y se diferenciaban por vestiduras y colores. Los tipos se almacenan en la Colecci&oacute;n de Invertebrados de la Universidad de Puerto Rico (UPRM INVCOL)....

In this paper we describe the gut microbiome of the Puerto Rican keystone sea urchin Diadema antillarum. We also used next generation sequencing of the cytochrome b region to examine the phylogenetic relationships among ...

Invasive species have brought ecological and economical losses worldwide and are expected to increase with continuing globalization. Ecologically, invasive species pose threats to local fauna through competition and/or ...

The genus "Aristida" (Poaceae) is a varied and well-distributed group of grass within the subfamily Aristidoideae. In Puerto Rico, we count with an endemic species, "Aristida portoricensis", commonly known as "Pelos del ...