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2.
Sci Data ; 11(1): 32, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177140

RESUMO

National parks and other protected areas are important for preserving landscapes and biodiversity worldwide. An essential component of the mission of the United States (U.S.) National Park Service (NPS) requires understanding and maintaining accurate inventories of species on protected lands. We describe a new, national-scale synthesis of amphibian species occurrence in the NPS system. Many park units have a list of amphibian species observed within their borders compiled from various sources and available publicly through the NPSpecies platform. However, many of the observations in NPSpecies remain unverified and the lists are often outdated. We updated the amphibian dataset for each park unit by collating old and new park-level records and had them verified by regional experts. The new dataset contains occurrence records for 292 of the 424 NPS units and includes updated taxonomy, international and state conservation rankings, hyperlinks to a supporting reference for each record, specific notes, and related fields which can be used to better understand and manage amphibian biodiversity within a single park or group of parks.


Assuntos
Biodiversidade , Parques Recreativos , Animais , Anfíbios , Conservação dos Recursos Naturais , Estados Unidos
3.
Genome Biol Evol ; 15(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38056449

RESUMO

Urosaurus nigricaudus is a phrynosomatid lizard endemic to the Baja California Peninsula in Mexico. This work presents a chromosome-level genome assembly and annotation from a male individual. We used PacBio long reads and HiRise scaffolding to generate a high-quality genomic assembly of 1.87 Gb distributed in 327 scaffolds, with an N50 of 279 Mb and an L50 of 3. Approximately 98.4% of the genome is contained in 14 scaffolds, with 6 large scaffolds (334-127 Mb) representing macrochromosomes and 8 small scaffolds (63-22 Mb) representing microchromosomes. Using standard gene modeling and transcriptomic data, we predicted 17,902 protein-coding genes on the genome. The repeat content is characterized by a large proportion of long interspersed nuclear elements that are relatively old. Synteny analysis revealed some microchromosomes with high repeat content are more prone to rearrangements but that both macro- and microchromosomes are well conserved across reptiles. We identified scaffold 14 as the X chromosome. This microchromosome presents perfect dosage compensation where the single X of males has the same expression levels as two X chromosomes in females. Finally, we estimated the effective population size for U. nigricaudus was extremely low, which may reflect a reduction in polymorphism related to it becoming a peninsular endemic.


Assuntos
Lagartos , Animais , Feminino , Masculino , Lagartos/genética , México , Cromossomos , Genoma , Sintenia
4.
Environ Sci Technol ; 57(45): 17511-17521, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37902062

RESUMO

Mercury (Hg) is a toxic contaminant that has been mobilized and distributed worldwide and is a threat to many wildlife species. Amphibians are facing unprecedented global declines due to many threats including contaminants. While the biphasic life history of many amphibians creates a potential nexus for methylmercury (MeHg) exposure in aquatic habitats and subsequent health effects, the broad-scale distribution of MeHg exposure in amphibians remains unknown. We used nonlethal sampling to assess MeHg bioaccumulation in 3,241 juvenile and adult amphibians during 2017-2021. We sampled 26 populations (14 species) across 11 states in the United States, including several imperiled species that could not have been sampled by traditional lethal methods. We examined whether life history traits of species and whether the concentration of total mercury in sediment or dragonflies could be used as indicators of MeHg bioaccumulation in amphibians. Methylmercury contamination was widespread, with a 33-fold difference in concentrations across sites. Variation among years and clustered subsites was less than variation across sites. Life history characteristics such as size, sex, and whether the amphibian was a frog, toad, newt, or other salamander were the factors most strongly associated with bioaccumulation. Total Hg in dragonflies was a reliable indicator of bioaccumulation of MeHg in amphibians (R2 ≥ 0.67), whereas total Hg in sediment was not (R2 ≤ 0.04). Our study, the largest broad-scale assessment of MeHg bioaccumulation in amphibians, highlights methodological advances that allow for nonlethal sampling of rare species and reveals immense variation among species, life histories, and sites. Our findings can help identify sensitive populations and provide environmentally relevant concentrations for future studies to better quantify the potential threats of MeHg to amphibians.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Odonatos , Poluentes Químicos da Água , Animais , Poluentes Químicos da Água/análise , Mercúrio/análise , Anfíbios , Monitoramento Ambiental
5.
Ecol Evol ; 13(9): e10460, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37745784

RESUMO

Information on diet breadth and preference can assist in understanding links between food resources and population growth and inform habitat restoration for rare herbivores. We assessed the diet of the endangered Pacific pocket mouse using metabarcoding of fecal samples and compared it to plant community composition in long-term study plots in two populations on Marine Corps Base Camp Pendleton, San Diego County, CA. Fecal samples (n = 221) were collected between spring 2016 and fall 2017 during monthly live-trap surveys. Concurrently, percent cover and plant phenology were measured in plots centered on trap locations. Fecal samples were sequenced with paired-end reads of the internal transcribed spacer 2 region of the nuclear ribosomal gene, and the resulting amplicons were matched to a regionally specific database. Seventy-three plant taxa were detected, which were mostly forbs and perennial herbs (70-90%). Diet composition differed between populations, years, seasons, and plots. Overall, diet and local habitat composition in plots were significantly correlated. However, we detected some differences in above-ground seed availability and proportion in fecal samples that indicate diet preferences for some forbs, perennial herbs, and native bunch grasses over perennial shrubs and non-native grasses. This is the first study of PPM to pair plant phenology surveys with diet metabarcoding to estimate resource selection, and results suggest that managing habitat for diverse native forb communities and reducing non-native grass cover may be beneficial for this critically endangered species.

6.
BMC Ecol Evol ; 23(1): 51, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37700256

RESUMO

BACKGROUND: Biodiversity is generally reduced when non-native species invade an ecosystem. Invasive crayfish, Procambarus clarkii, populate California freshwater streams, and in the Santa Monica Mountains (Los Angeles, USA), their introduction has led to trophic cascades due to omnivorous feeding behavior and a rapid rate of population growth. The native California newt, Taricha torosa, possesses a neurotoxin, tetrodotoxin (TTX), that affects freshwater animal behavior. Given P. clarkii has a limited evolutionary history with TTX, we hypothesized that TTX may affect crayfish feeding behaviors. To determine if TTX affects P. clarkii behavior, we measured cumulative movement and various feeding behaviors of P. clarkii exposed to (i) waterborne, ecologically realistic concentrations of TTX (~ 3.0 × 10- 8 moles/L), (ii) an anuran chemical cue to account for intraguild cues, or (iii) a T. torosa chemical cue with quantitated TTX in it (~ 6.2 × 10- 8 moles/L). RESULTS: We found that the presence of TTX in any form significantly reduced crayfish movement and decreased the amount of food consumed over time. Crayfish responses to the anuran treatment did not significantly differ from controls. CONCLUSION: Our laboratory results show that naturally occurring neurotoxin from native California newts limits invasive crayfish foraging and feeding rates, which may play a role in preserving local stream ecosystems by limiting invasive crayfish behaviors that are detrimental to biodiversity.


Assuntos
Toupeiras , Neoplasias Cutâneas , Toxinas Biológicas , Animais , Neurotoxinas , Rios , Astacoidea , Ecossistema , Biodiversidade , Alimentos Marinhos , Tetrodotoxina/toxicidade , Anfíbios
7.
J Hered ; 114(6): 690-697, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37688363

RESUMO

Snakes in the family Colubridae include more than 2,000 currently recognized species, and comprise roughly 75% of the global snake species diversity on Earth. For such a spectacular radiation, colubrid snakes remain poorly understood ecologically and genetically. Two subfamilies, Colubrinae (788 species) and Dipsadinae (833 species), comprise the bulk of colubrid species richness. Dipsadines are a speciose and diverse group of snakes that largely inhabit Central and South America, with a handful of small-body-size genera that have invaded North America. Among them, the ring-necked snake, Diadophis punctatus, has an incredibly broad distribution with 14 subspecies. Given its continental distribution and high degree of variation in coloration, diet, feeding ecology, and behavior, the ring-necked snake is an excellent species for the study of genetic diversity and trait evolution. Within California, six subspecies form a continuously distributed "ring species" around the Central Valley, while a seventh, the regal ring-necked snake, Diadophis punctatus regalis is a disjunct outlier and Species of Special Concern in the state. Here, we report a new reference genome assembly for the San Diego ring-necked snake, D. p. similis, as part of the California Conservation Genomics Project. This assembly comprises a total of 444 scaffolds spanning 1,783 Mb and has a contig N50 of 8.0 Mb, scaffold N50 of 83 Mb, and BUSCO completeness score of 94.5%. This reference genome will be a valuable resource for studies of the taxonomy, conservation, and evolution of the ring-necked snake across its broad, continental distribution.


Assuntos
Colubridae , Animais , Colubridae/genética , Genômica , Genoma , América do Norte , Filogenia
8.
J Hered ; 114(6): 681-689, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37493092

RESUMO

Rattlesnakes play important roles in their ecosystems by regulating prey populations, are involved in complex coevolutionary dynamics with their prey, and exhibit a variety of unusual adaptations, including maternal care, heat-sensing pit organs, hinged fangs, and medically-significant venoms. The western rattlesnake (Crotalus oreganus) is one of the widest ranging rattlesnake species, with a distribution from British Columbia, where it is listed as threatened, to Baja California and east across the Great Basin to western Wyoming, Colorado and New Mexico. Here, we report a new reference genome assembly for one of six currently recognized subspecies, C. oreganus helleri, as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genomic sequencing strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 698 scaffolds spanning 1,564,812,557 base pairs, has a contig N50 of 64.7 Mb, a scaffold N50 of 110.8 Mb, and BUSCO complete score of 90.5%. This reference genome will be valuable for studies on the genomic basis of venom evolution and variation within Crotalus, in resolving the taxonomy of C. oreganus and its relatives, and for the conservation and management of rattlesnakes in general.


Assuntos
Crotalus , Ecossistema , Serpentes Peçonhentas , Animais , México , Crotalus/genética
9.
J Hered ; 114(5): 521-528, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37335574

RESUMO

Spiny lizards (genus Sceloporus) have long served as important systems for studies of behavior, thermal physiology, dietary ecology, vector biology, speciation, and biogeography. The western fence lizard, Sceloporus occidentalis, is found across most of the major biogeographical regions in the western United States and northern Baja California, Mexico, inhabiting a wide range of habitats, from grassland to chaparral to open woodlands. As small ectotherms, Sceloporus lizards are particularly vulnerable to climate change, and S. occidentalis has also become an important system for studying the impacts of land use change and urbanization on small vertebrates. Here, we report a new reference genome assembly for S. occidentalis, as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genomics strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 608 scaffolds spanning 2,856 Mb, has a contig N50 of 18.9 Mb, a scaffold N50 of 98.4 Mb, and BUSCO completeness score of 98.1% based on the tetrapod gene set. This reference genome will be valuable for understanding ecological and evolutionary dynamics in S. occidentalis, the species status of the California endemic island fence lizard (S. becki), and the spectacular radiation of Sceloporus lizards.


Assuntos
Genoma , Lagartos , Animais , México , Ecossistema , Genômica , Lagartos/genética
10.
J Hered ; 114(4): 410-417, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37195437

RESUMO

Genome assemblies are increasingly being used to identify adaptive genetic variation that can help prioritize the population management of protected species. This approach may be particularly relevant to species like Blainville's horned lizard, Phrynosoma blainvillii, due to its specialized diet on noxious harvester ants, numerous adaptative traits for avoiding predation (e.g. cranial horns, dorsoventrally compressed body, cryptic coloration, and blood squirting from the orbital sinuses), and status as Species of Special Concern in California. Rangewide decline since the early 20th century, the basis of its conservation status, has been driven mainly by habitat conversion, over-collecting, and invasion of a non-native ant that displaces its native ant prey base. Here, we report on a scaffold-level genome assembly for P. blainvillii as part of the California Conservation Genomics Project (CCGP), produced using Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology. The de novo assembly has 78 scaffolds, a total length of ~2.21 Gb, a scaffold N50 length of ~352 Mb, and BUSCO score of 97.4%. This is the second species of Phrynosoma for which a reference genome has been assembled and represents a considerable improvement in terms of contiguity and completeness. Combined with the landscape genomics data being compiled by the CCGP, this assembly will help strategize efforts to maintain and/or restore local genetic diversity, where interventions like genetic rescue, translocation, and strategic land preservation may be the only means by which P. blainvillii and other low-vagility species can survive in the fragmented habitats of California.


Assuntos
Lagartos , Animais , Lagartos/genética , Genoma , Genômica , Cromossomos , América do Norte
11.
Virus Evol ; 9(1): veac122, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36694819

RESUMO

Spatially heterogeneous landscape factors such as urbanisation can have substantial effects on the severity and spread of wildlife diseases. However, research linking patterns of pathogen transmission to landscape features remains rare. Using a combination of phylogeographic and machine learning approaches, we tested the influence of landscape and host factors on feline immunodeficiency virus (FIVLru) genetic variation and spread among bobcats (Lynx rufus) sampled from coastal southern California. We found evidence for increased rates of FIVLru lineage spread through areas of higher vegetation density. Furthermore, single-nucleotide polymorphism (SNP) variation among FIVLru sequences was associated with host genetic distances and geographic location, with FIVLru genetic discontinuities precisely correlating with known urban barriers to host dispersal. An effect of forest land cover on FIVLru SNP variation was likely attributable to host population structure and differences in forest land cover between different populations. Taken together, these results suggest that the spread of FIVLru is constrained by large-scale urban barriers to host movement. Although urbanisation at fine spatial scales did not appear to directly influence virus transmission or spread, we found evidence that viruses transmit and spread more quickly through areas containing higher proportions of natural habitat. These multiple lines of evidence demonstrate how urbanisation can change patterns of contact-dependent pathogen transmission and provide insights into how continued urban development may influence the incidence and management of wildlife disease.

12.
Proc Natl Acad Sci U S A ; 119(51): e2122354119, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36508667

RESUMO

Islands support unique plants, animals, and human societies found nowhere else on the Earth. Local and global stressors threaten the persistence of island ecosystems, with invasive species being among the most damaging, yet solvable, stressors. While the threat of invasive terrestrial mammals on island flora and fauna is well recognized, recent studies have begun to illustrate their extended and destructive impacts on adjacent marine environments. Eradication of invasive mammals and restoration of native biota are promising tools to address both island and ocean management goals. The magnitude of the marine benefits of island restoration, however, is unlikely to be consistent across the globe. We propose a list of six environmental characteristics most likely to affect the strength of land-sea linkages: precipitation, elevation, vegetation cover, soil hydrology, oceanographic productivity, and wave energy. Global databases allow for the calculation of comparable metrics describing each environmental character across islands. Such metrics can be used today to evaluate relative potential for coupled land-sea conservation efforts and, with sustained investment in monitoring on land and sea, can be used in the future to refine science-based planning tools for integrated land-sea management. As conservation practitioners work to address the effects of climate change, ocean stressors, and biodiversity crises, it is essential that we maximize returns from our management investments. Linking efforts on land, including eradication of island invasive mammals, with marine restoration and protection should offer multiplied benefits to achieve concurrent global conservation goals.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Humanos , Biodiversidade , Espécies Introduzidas , Mudança Climática , Mamíferos
13.
Mol Ecol ; 31(24): 6515-6530, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36205603

RESUMO

Habitat loss, flood control infrastructure, and drought have left most of southern California and northern Baja California's native freshwater fish near extinction, including the endangered unarmoured threespine stickleback (Gasterosteus aculeatus williamsoni). This subspecies, an unusual morph lacking the typical lateral bony plates of the G. aculeatus complex, occurs at arid southern latitudes in the eastern Pacific Ocean and survives in only three inland locations. Managers have lacked molecular data to answer basic questions about the ancestry and genetic distinctiveness of unarmoured populations. These data could be used to prioritize conservation efforts. We sampled G. aculeatus from 36 localities and used microsatellites and whole genome data to place unarmoured populations within the broader evolutionary context of G. aculeatus across southern California/northern Baja California. We identified three genetic groups with none consisting solely of unarmoured populations. Unlike G. aculeatus at northern latitudes, where Pleistocene glaciation has produced similar historical demographic profiles across populations, we found markedly different demographics depending on sampling location, with inland unarmoured populations showing steeper population declines and lower heterozygosity compared to low armoured populations in coastal lagoons. One exception involved the only high elevation population in the region, where the demography and alleles of unarmoured fish were similar to low armoured populations near the coast, exposing one of several cases of artificial translocation. Our results suggest that the current "management-by-phenotype" approach, based on lateral plates, is incidentally protecting the most imperilled populations; however, redirecting efforts toward evolutionary units, regardless of phenotype, may more effectively preserve adaptive potential.


Assuntos
Smegmamorpha , Animais , México , Smegmamorpha/genética , Evolução Biológica , Repetições de Microssatélites , Demografia
14.
Mol Ecol ; 31(20): 5214-5230, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35962747

RESUMO

Identifying how natural (i.e., unaltered by human activity) and anthropogenic landscape variables influence contemporary functional connectivity in terrestrial organisms can elucidate the genetic consequences of environmental change. We examine population genetic structure and functional connectivity among populations of a declining species, the Blainville's horned lizard (Phrynosoma blainvillii), in the urbanized landscape of the Greater Los Angeles Area in Southern California, USA. Using single nucleotide polymorphism data, we assessed genetic structure among populations occurring at the interface of two abutting evolutionary lineages, and at a fine scale among habitat fragments within the heavily urbanized area. Based on the ecology of P. blainvillii, we predicted which environmental variables influence population structure and gene flow and used gravity models to distinguish among hypotheses to best explain population connectivity. Our results show evidence of admixture between two evolutionary lineages and strong population genetic structure across small habitat fragments. We also show that topography, microclimate, and soil and vegetation types are important predictors of functional connectivity, and that anthropogenic disturbance, including recent fire history and urban development, are key factors impacting contemporary population dynamics. Examining how natural and anthropogenic sources of landscape variation affect contemporary population genetics is critical to understanding how to best manage sensitive species in a rapidly changing landscape.


Assuntos
Variação Genética , Lagartos , Animais , Ecossistema , Fluxo Gênico , Variação Genética/genética , Genética Populacional , Humanos , Lagartos/genética , Los Angeles , Solo
15.
J Hered ; 113(6): 632-640, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-35939354

RESUMO

The glossy snake (Arizona elegans) is a polytypic species broadly distributed across southwestern North America. The species occupies habitats ranging from California's coastal chaparral to the shortgrass prairies of Texas and southeastern Nebraska, to the extensive arid scrublands of central México. Three subspecies are currently recognized in California, one of which is afforded state-level protection based on the extensive loss and modification of its preferred alluvial coastal scrub and inland desert habitat. We report the first genome assembly of A. elegans occidentalis as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genome strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technologies to produce a de novo assembled genome. The assembly comprises a total of 140 scaffolds spanning 1,842,602,218 base pairs, has a contig NG50 of 61 Mb, a scaffold NG50 of 136 Mb, and a BUSCO complete score of 95.9%, and is one of the most complete snake genome assemblies. The A. e. occidentalis genome will be a key tool for understanding the genomic diversity and the basis of adaptations within this species and close relatives within the hyperdiverse snake family Colubridae.


Assuntos
Colubridae , Animais , Colubridae/genética , Arizona , Genômica , Genoma , Cromossomos
16.
Biodivers Conserv ; 31(8-9): 2045-2062, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35633848

RESUMO

Cryptic ecologies, the Wallacean Shortfall of undocumented species' geographical ranges and the Linnaean Shortfall of undescribed diversity, are all major barriers to conservation assessment. When these factors overlap with drivers of extinction risk, such as insular distributions, the number of threatened species in a region or clade may be underestimated, a situation we term 'cryptic extinction risk'. The genus Lepidodactylus is a diverse radiation of insular and arboreal geckos that occurs across the western Pacific. Previous work on Lepidodactylus showed evidence of evolutionary displacement around continental fringes, suggesting an inherent vulnerability to extinction from factors such as competition and predation. We sought to (1) comprehensively review status and threats, (2) estimate the number of undescribed species, and (3) estimate extinction risk in data deficient and candidate species, in Lepidodactylus. From our updated IUCN Red List assessment, 60% of the 58 recognized species are threatened (n = 15) or Data Deficient (n = 21), which is higher than reported for most other lizard groups. Species from the smaller and isolated Pacific islands are of greatest conservation concern, with most either threatened or Data Deficient, and all particularly vulnerable to invasive species. We estimated 32 undescribed candidate species and linear modelling predicted that an additional 18 species, among these and the data deficient species, are threatened with extinction. Focusing efforts to resolve the taxonomy and conservation status of key taxa, especially on small islands in the Pacific, is a high priority for conserving this remarkably diverse, yet poorly understood, lizard fauna. Our data highlight how cryptic ecologies and cryptic diversity combine and lead to significant underestimation of extinction risk. Supplementary Information: The online version contains supplementary material available at 10.1007/s10531-022-02412-x.

17.
Ecol Evol ; 12(4): e8796, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35462981

RESUMO

Prolonged drought due to climate change has negatively impacted amphibians in southern California, U.S.A. Due to the severity and length of the current drought, agencies and researchers had growing concern for the persistence of the arroyo toad (Anaxyrus californicus), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least 20 years. In 2017-2020, we conducted collaborative surveys for arroyo toads at historical locations. We surveyed 88 of the 115 total sites having historical records and confirmed that the arroyo toad is currently extant in at least 61 of 88 sites and 20 of 25 historically occupied watersheds. We did not detect toads at almost a third of the surveyed sites but did detect toads at 18 of 19 specific sites delineated in the 1999 Recovery Plan to meet one of four downlisting criteria. Arroyo toads are estimated to live 7-8 years, making populations susceptible to prolonged drought. Drought is estimated to increase in frequency and duration with climate change. Mitigation strategies for drought impacts, invasive aquatic species, altered flow regimes, and other anthropogenic effects could be the most beneficial strategies for toad conservation and may also provide simultaneous benefits to several other native species that share the same habitat.

18.
Ecol Evol ; 12(4): e8817, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35475179

RESUMO

The importance of terrestrial coastal ecosystems for maintaining healthy coral reef ecosystems remains understudied. Sea kraits are amphibious snakes that require healthy coral reefs for foraging, but little is known about their requirements of terrestrial habitats, where they slough their skin, digest prey, and breed. Using concurrent microclimate measurements and behavior surveys, we show that a small, topographically flat atoll in Fiji with coastal forest provides many microhabitats that relate to the behaviors of Yellow Lipped Sea Kraits, Laticauda colubrina. Microclimates were significantly related to canopy cover, leaf litter depth, and distance from the high-water mark (HWM). Sea kraits were almost exclusively observed in coastal forest within 30 m of the HWM. Sloughing of skins only occurred within crevices of mature or dying trees. Resting L. colubrina were significantly more likely to occur at locations with higher mean diurnal temperatures, lower leaf litter depths, and shorter distances from the HWM. On Leleuvia, behavior of L. colubrina therefore relates to environmental heterogeneity created by old-growth coastal forests, particularly canopy cover and crevices in mature and dead tree trunks. The importance of healthy coastal habitats, both terrestrial and marine, for L. colubrina suggests it could be a good flagship species for advocating integrated land-sea management. Furthermore, our study highlights the importance of coastal forests and topographically flat atolls for biodiversity conservation. Effective conservation management of amphibious species that utilize land- and seascapes is therefore likely to require a holistic approach that incorporates connectivity among ecosystems and environmental heterogeneity at all relevant scales.

19.
Evolution ; 76(2): 346-356, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34878663

RESUMO

Sex-related differences in mortality are widespread in the animal kingdom. Although studies have shown that sex determination systems might drive lifespan evolution, sex chromosome influence on aging rates have not been investigated so far, likely due to an apparent lack of demographic data from clades including both XY (with heterogametic males) and ZW (heterogametic females) systems. Taking advantage of a unique collection of capture-recapture datasets in amphibians, a vertebrate group where XY and ZW systems have repeatedly evolved over the past 200 million years, we examined whether sex heterogamy can predict sex differences in aging rates and lifespans. We showed that the strength and direction of sex differences in aging rates (and not lifespan) differ between XY and ZW systems. Sex-specific variation in aging rates was moderate within each system, but aging rates tended to be consistently higher in the heterogametic sex. This led to small but detectable effects of sex chromosome system on sex differences in aging rates in our models. Although preliminary, our results suggest that exposed recessive deleterious mutations on the X/Z chromosome (the "unguarded X/Z effect") or repeat-rich Y/W chromosome (the "toxic Y/W effect") could accelerate aging in the heterogametic sex in some vertebrate clades.


Assuntos
Caracteres Sexuais , Cromossomos Sexuais , Envelhecimento/genética , Anfíbios/genética , Animais , Feminino , Masculino , Processos de Determinação Sexual , Cromossomo Y
20.
Zootaxa ; 4999(1): 87-100, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34810501

RESUMO

The widespread parthenogenetic gecko Lepidodactylus lugubris is comprised of several clonal lineages, at least one of which has been known for some time to have originated from hybridization between its maternal ancestor, Lepidodactylus moestus, and a putatively undescribed paternal ancestor previously known only from remote islands in the Central Pacific. By integrating new genetic sequences from multiple studies on Lepidodactylus and incorporating new genetic sequences from previously sampled populations, we recovered a phylogenetic tree that shows a close genetic similarity between the generally hypothesized paternal hybrid ancestor and a recently described species from Maluku (Indonesia), Lepidodactylus pantai. Our results suggest that the paternal hybrid ancestor of at least one parthenogenetic clone of L. lugubris is conspecific with L. pantai and that the range of this species extends to Palau, the Caroline Islands, the Kei Islands, Wagabu, and potentially other small islands near New Guinea. Deeper genetic structure in the western (Palau, Maluku) versus eastern (eastern Melanesia, Micronesia, Polynesia) part of this species range suggests that the western populations likely dispersed via natural colonization, whereas the eastern populations may be the result of human-mediated dispersal. The potential taxonomic affinities and biogeographic history should be confirmed with further morphological and genetic analyses, including research on L. woodfordi from its type locality, which would have nomenclatural priority if found to be conspecific with L. pantai. We recommend referring to the wide-ranging sexual species as Lepidodactylus pantai until such a comparison can be made.


Assuntos
Lagartos , Animais , Hibridização Genética , Lagartos/genética , Partenogênese , Filogenia
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