Species In California Research Articles

Controlled temperature contrasts of three native and one highly invasive annual plant species in California.

Plant responses to changes in temperature can be a key factor in predicting the presence and managing invasive plant species while conserving resident native plant species in dryland ecosystems. Climate can influence germination, establishment, and seedling biomass of both native and invasive plant species. We tested the hypothesis that common and widely distributed native and an invasive plant species in dryland ecosystems in California respond differently to increasing temperatures. To test this, we examined the effects of temperature variation on germination, establishment, and per capita seedling biomass of three native and one invasive plant species (Bromus rubens) in independent 6 week growth trial experiments in a controlled greenhouse. Higher relative temperatures reduced the germination and establishment of the tested invasive species and two tested native species, however, per capita biomass was not significantly affected. Specifically, germination and establishment of the invasive species B. rubens and the native species Phacelia tanacetifolia was significantly reduced. This invasive species can often outcompete natives, but increasing temperature could potentially shift the balance between the germination and establishment of natives. A warming climate will likely have negative impacts on native annual plant species in California tested here because increasing temperatures can co-occur with drought. This study shows that our tested native annual plant species tested here have some resilience to relatively significant increases in temperature, and this can favor at least one native species relative to at least one highly noxious invasive plant species.

Identification of fossil juniper seeds from Rancho La Brea (California, USA): drought and extirpation in the Late Pleistocene.

Juniperus spp. are keystone shrubs in western North America and important climatic indicators in paleo-records. However, a lack of taxonomic resolution among fossil species limits our ability to track past environmental changes. Plant macrofossils at Rancho La Brea (RLB) allow for reconstructions of juniper occurrence to species across 60 000 yr. We use microscopy, image analysis, species distribution modeling (SDM), and radiocarbon dating to identify an unknown Juniperus species at RLB and put it into chronological context with fossil Juniperus californica at the site to infer past environmental conditions. We identify the unknown taxon as Juniperus scopulorum Sargent, 1897. The Pleistocene occurrence of this species in California expands its known distribution and documents its extirpation. Temporal ranges of the two fossil junipers alternate, revealing a pattern of differential climatic sensitivity throughout the end of the Pleistocene. Occurrence patterns suggest sensitivity to temperature, moisture availability, and the presence of two mega-droughts at c. 48-44.5 ka and c. 29.3-25.2 ka. Extirpation of both taxa by c. 13 ka is likely driven by climate, megafaunal extinction, and increasing fire. The extirpation of fossil junipers during these past climatic events demonstrates vulnerability of juniper species in the face of global change.

Impact of salinity and body size on sperm motility in three California smelt species

Three smelt species in California, USA—the endangered delta smelt Hypomesus transpacificus and longfin smelt Spirinchus thaleichthys and the introduced wakasagi H. nipponensis—experience ecological pressures, including habitat alterations, temperature changes, and fluctuating salinity levels that can affect their survival and reproductive success. The present study investigates how salinity during the spawning process influences sperm motility by analyzing 13 sperm motility traits across three salinity levels (0.4, 5, and 10 ppt). Using Principal Component Analysis, we found that the first two principal components accounted for over 65 % of the total variance. Consequently, two predominant traits from each principal component were selected to evaluate sperm motility. Specifically, the amplitude of lateral head displacement (ALH), linearity coefficient (LIN), curvilinear velocity (VCL), progressive motility (PM), and wobble coefficient (WOB) predominantly contributed to these components for both longfin smelt and wakasagi. Results showed that the salinity significantly impacts these traits, except for ALH in delta smelt and longfin smelt, and WOB and LIN in wakasagi. In addition, we found the salinity and temperature difference between the activating water and extender interact differently across species. In delta smelt, interactions between the activating water and extender temperatures significantly affected most traits, whereas in wakasagi, only the interaction between activating water salinity and extender temperature showed significant effects. No significant influence from these interactions was observed in longfin smelt. Additionally, the impact of body size (e.g., fork length) on sperm motility varies across species, with a significant influence observed in longfin smelt, while no effect was detected in delta smelt and wakasagi. Future research should focus on exploring the physiological mechanisms behind the observed effects of salinity, temperature, and body size on sperm motility, as well as examining these interactions in other species to develop broader conservation strategies under changing environmental conditions.

Sensitive Hydraulic and Stomatal Decline in Extreme Drought Tolerant Species of California Ceanothus.

Identifying the physiological mechanisms by which plants are adapted to drought is critical to predict species responses to climate change. We measured the responses of leaf hydraulic and stomatal conductances (Kleaf and gs, respectively) to dehydration, and their association with anatomy, in seven species of California Ceanothus grown in a common garden, including some of the most drought-tolerant species in the semi-arid flora. We tested for matching of maximum hydraulic supply and demand and quantified the role of decline of Kleaf in driving stomatal closure. Across Ceanothus species, maximum Kleaf and gs were negatively correlated, and both Kleaf and gs showed steep declines with decreasing leaf water potential (i.e., a high sensitivity to dehydration). The leaf water potential at 50% decline in gs was linked with a low ratio of maximum hydraulic supply to demand (i.e., maximum Kleaf:gs). This sensitivity of gs, combined with low minimum epidermal conductance and water storage, could contribute to prolonged leaf survival under drought. The specialized anatomy of subg. Cerastes includes trichomous stomatal crypts and pronounced hypodermis, and was associated with higher water use efficiency and water storage. Combining our data with comparative literature of other California species, species of subg. Cerastes show traits associated with greater drought tolerance and reliance on leaf water storage relative to other California species. In addition to drought resistance mechanisms such as mechanical protection and resistance to embolism, drought avoidance mechanisms such as sensitive stomatal closure could contribute importantly to drought tolerance in dry-climate adapted species.

The genus Tetralicia Harrison (Hemiptera: Sternorrhyncha: Aleyrodidae) in California, U.S.A., with the description of five new species and a redescription of Tetralicia granulata Sampson & Drews, 1941.

Nineteen species of Tetralicia Harrison are recorded from California, United States of America, of which five are new to science and are described here: Tetralicia agrifoliae sp. nov., T. guajavae sp. nov., T. hoelmeri sp. nov., T. lantanae sp. nov., and T. salsolae sp. nov., and four are new records for the State: T. abnormis (Quaintance, 1900), T. eriogonum (Carapia-Ruiz, 2020), T. mexicana (Carapia Ruiz & Sánchez Flores in Carapia Ruiz, Sánchez Flores, García Martínez & Castillo Gutiérrez, 2018), and T. nevadensis (Dooley in Dooley, Lambrecht & Honda, 2010). Neotypes are designated for California species for which types were not designated originally and for which type material is apparently lost: Aleuropleurocelus acaudatus Drews & Sampson, 1958, A. coachellensis Drews & Sampson, 1958, A. laingi Drews & Sampson, 1956, A. oblanceolatus Drews & Sampson, 1958, and A. ornatus Drews & Sampson, 1958. All Tetralicia species found in California are keyed, fully illustrated, measured, and accompanied by species accounts based on their puparia including characterization, diagnosis, hosts, and distribution. Tetralicia granulata Sampson & Drews, 1941 is redescribed based on its type material, and it is believed to be currently known only from its type series from Mexico. The earlier nymphal instars of four species (T. guajavae, T. hoelmeri, T. hyptisemoryi, and T. lantanae) and the adults of three species (T. guajavae, T. hoelmeri, and T. lantanae) are described, illustrated, and diagnosed from known congeners.

Polymodal K+ channel modulation contributes to dual analgesic and anti-inflammatory actions of traditional botanical medicines

Pain and inflammation contribute immeasurably to reduced quality of life, yet modern analgesic and anti-inflammatory therapeutics can cause dependence and side effects. Here, we screened 1444 plant extracts, prepared primarily from native species in California and the United States Virgin Islands, against two voltage-gated K+ channels - T-cell expressed Kv1.3 and nociceptive-neuron expressed Kv7.2/7.3. A subset of extracts both inhibits Kv1.3 and activates Kv7.2/7.3 at hyperpolarized potentials, effects predicted to be anti-inflammatory and analgesic, respectively. Among the top dual hits are witch hazel and fireweed; polymodal modulation of multiple K+ channel types by hydrolysable tannins contributes to their dual anti-inflammatory, analgesic actions. In silico docking and mutagenesis data suggest pore-proximal extracellular linker sequence divergence underlies opposite effects of hydrolysable tannins on different Kv1 isoforms. The findings provide molecular insights into the enduring, widespread medicinal use of witch hazel and fireweed and demonstrate a screening strategy for discovering dual anti-inflammatory, analgesic small molecules.

An assemblage-level comparison of genetic diversity and population genetic structure between island and mainland ant populations.

Island biotas provide unparalleled opportunities to examine evolutionary processes. Founder effects and bottlenecks, e.g., typically decrease genetic diversity in island populations, while selection for reduced dispersal can increase population structure. Given that support for these generalities mostly comes from single-species analyses, assemblage-level comparisons are needed to clarify how (i) colonization affects the gene pools of interacting insular organisms, and (ii) patterns of genetic differentiation vary within assemblages of organisms. Here, we use genome-wide sequence data from ultraconserved elements (UCEs) to compare the genetic diversity and population structure of mainland and island populations of nine ant species in coastal southern California. As expected, island populations (from Santa Cruz Island) had lower expected heterozygosity and Watterson's theta compared to mainland populations (from the Lompoc Valley). Island populations, however, exhibited smaller genetic distances among samples, indicating less population subdivision. Within the focal assemblage, pairwise Fst values revealed pronounced interspecific variation in mainland-island differentiation, which increases with gyne body size. Our results reveal population differences across an assemblage of interacting species and illuminate general patterns of insularization in ants. Compared to single-species studies, our analysis of nine conspecific population pairs from the same island-mainland system offers a powerful approach to studying fundamental evolutionary processes.

Temporal Changes in Geographic Range and Population Size of the Santa Cruz Black Salamander

Abstract The Santa Cruz black salamander Aneides niger is a priority 3 California species of special concern with a restricted geographic range confined to the Santa Cruz Mountains. Anecdotal observations suggest that the species was relatively abundant in the early 1900s, but it has become more difficult to find in the past few decades. To better understand if the species has undergone population size fluctuations, we analyzed mitochondrial and nuclear sequence data to examine levels of genetic variation and phylogeographic structure, and test for signatures of population size change. We then reconstructed the climatic suitability for the species to 1) determine if past climate fluctuations could have influenced range size and genetic diversity, and 2) estimate the effects of future climate change on geographic range suitability as a proxy for possible future population size change. Genetic analyses detected low levels of genetic variation and a general lack of genetic structuring, suggesting a recent genetic bottleneck. While neutrality tests of individual loci were nonsignificant, skyline plot and isolation-with-migration analyses detected a relatively recent reduction in population size. Interpretation of these genetic results should consider the limited number of localities and individuals sampled for this species. Climatic suitability for Santa Cruz black salamanders was much lower during the last glacial maximum, which could be the cause of the detected historical change in population size. Future projections of climatic suitability under a high-emission scenario suggest a dramatic geographic range restriction to coastal areas. These projections highlight the need for the protection of coastal habitat patches to preserve existing coastal populations, and to maintain connectivity between coastal and inland habitats to allow the westward movement of populations and genes in response to climate change.

Two novel heat-tolerant, culturable rhizosphere-inhabiting, plant growth-promoting ascomycete fungi associated with native plants in desert habitats of southwestern USA

During an investigations on Monosporascus cannonballus, the causal agent of root rot and vine decline of melons, in 1999, a previously unknown rhizosphere fungus was encountered in the desert soils of southern California. The fungus, herein named Desertella arida Stanghellini & Mohammadi sp. nov., was associated with roots of diverse plants including brassica (Sahara mustard (Brassica tournefortii), shepherd's purse (Capsella bursa-pastoris)) and plantain (Plantago ovata Forsk). The fungus forms extensive multinucleate, septate hyphae (6–17 μm in diameter) bearing hundreds of large spherical to pear-shaped unicellular asexual spores (50–120 μm in diameter), either singly or in large clusters. The spores are beige to cream-colored, thin-walled, and contain a dense, granular cytoplasm. Further investigation on the distribution of D. arida in soils of desert habitats in the southwestern USA led to the discovery of a second fungus belonging to a different species herein named Desertella americanense Mohammadi & Stanghellini sp. nov., in California, Arizona, Nevada, and Utah. The two species are morphologically similar. Spores from both fungi in native soil survived heat treatment up to 100 °C. Both species are culturable and colonized roots of monocots and dicots forming abundant hyphae and spores as early as 10 days post-inoculation. Desertella arida significantly enhanced shoot growth in broccoli, lettuce, Plantago ovata and flax. In conclusion, we discovered two desert-dwelling ascomycete fungi that were associated with the roots of native plant species in southern California. They were culturable on a synthetic medium, heat-tolerant and promoted growth on several crop species. These fungi appeared to exist in other neighboring states such as Arizona and Nevada.

How and why do species break a developmental trade-off? Elucidating the association of trichomes and stomata across species.

Previous studies have suggested a trade-off between trichome density (Dt) and stomatal density (Ds) due to shared cell precursors. We clarified how, when, and why this developmental trade-off may be overcome across species. We derived equations to determine the developmental basis for Dt and Ds in trichome and stomatal indices (it and is) and the sizes of epidermal pavement cells (e), trichome bases (t), and stomata (s) and quantified the importance of these determinants of Dt and Ds for 78 California species. We compiled 17 previous studies of Dt-Ds relationships to determine the commonness of Dt-Ds associations. We modeled the consequences of different Dt-Ds associations for plant carbon balance. Our analyses showed that higher Dt was determined by higher it and lower e, and higher Ds by higher is and lower e. Across California species, positive Dt-Ds coordination arose due to it-is coordination and impacts of the variation in e. A Dt-Ds trade-off was found in only 30% of studies. Heuristic modeling showed that species sets would have the highest carbon balance with a positive or negative relationship or decoupling of Dt and Ds, depending on environmental conditions. Shared precursor cells of trichomes and stomata do not limit higher numbers of both cell types or drive a general Dt-Ds trade-off across species. This developmental flexibility across diverse species enables different Dt-Ds associations according to environmental pressures. Developmental trait analysis can clarify how contrasting trait associations would arise within and across species.

A draft reference genome assembly of California Pipevine, Aristolochia californica Torr.

The California Pipevine, Aristolochia californica Torr., is the only endemic California species within the cosmopolitan birthwort family Aristolochiaceae. It occurs as an understory vine in riparian and chaparral areas and in forest edges and windrows. The geographic range of this plant species almost entirely overlaps with that of its major specialized herbivore, the California Pipevine Swallowtail Butterfly Battus philenor hirsuta. While this species pair is a useful, ecologically well-understood system to study co-evolution, until recently, genomic resources for both have been lacking. Here, we report a new, chromosome-level assembly of A. californica as part of the California Conservation Genomics Project (CCGP). Following the sequencing and assembly 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. Our genome assembly, the first for any species in the genus, contains 531 scaffolds spanning 661 megabase (Mb) pairs, with a contig N50 of 6.53 Mb, a scaffold N50 of 42.2 Mb, and BUSCO complete score of 98%. In combination with the recently published B. philenor hirsuta reference genome assembly, the A. californica reference genome assembly will be a powerful tool for studying co-evolution in a rapidly changing California landscape.

Reference genome of Townsend's big-eared bat, Corynorhinus townsendii.

Townsend's big-eared bat, Corynorhinus townsendii, is a cave- and mine-roosting species found largely in western North America. Considered a species of conservation concern throughout much of its range, protection efforts would greatly benefit from understanding patterns of population structure, genetic diversity, and local adaptation. To facilitate such research, we present the first de novo genome assembly of C. townsendii as part of the California Conservation Genomics Project (CCGP). Pacific Biosciences HiFi long reads and Omni-C chromatin-proximity sequencing technologies were used to produce a de novo genome assembly, consistent with the standard CCGP reference genome protocol. This assembly comprises 391 scaffolds spanning 2.1 Gb, represented by a scaffold N50 of 174.6 Mb, a contig N50 of 23.4 Mb, and a benchmarking universal single-copy ortholog (BUSCO) completeness score of 96.6%. This high-quality genome will be a key tool for informed conservation and management of this vulnerable species in California and across its range.

Rethinking local seed sourcing for the restoration of a foundational grass species in California

Restricting seed collecting to local populations is a common practice in restoration because it is assumed that most plants are adapted to local environmental conditions. However, there is still considerable debate about whether local seed collection should be the default seed‐provenancing strategy as the effects of climate change are increasingly considered in restoration planning. It is especially important to explore whether local seed provenance is necessary for dominant species used in restoration because the success of these projects often rests on these species. Stipa pulchra is one such species that is commonly used in grassland restoration projects in California. To explore how different seed‐provenancing strategies affected the establishment and growth of S. pulchra, we established three common garden experiments distributed across a latitudinal gradient in California. We collected seeds from seven wild populations, germinated seeds in a common greenhouse, then planted all populations at the three common gardens. We assessed growth and reproduction for 2 years. We found limited evidence that restricting seed sourcing to local populations increased the establishment of S. pulchra compared to seeds from more distant populations. Instead, we found evidence to support the use of regional admixture seed sourcing to increase resiliency to environmental variation. In particular, we found being sourced from a dry location during the dry 2018 season was a benefit, highlighting the importance of including dry‐adapted populations to increase climate resilience. Our experiment highlights the importance of exploring multiple seed‐provenancing methods when designing a project to improve long‐term success.

The Intersection of Wastewater Treatment Plants and Threatened and Endangered Species in California, USA Watersheds

AbstractA changing climate and often unregulated water extractions have exposed over 2 billion people to water stress worldwide. While water managers have explored a portfolio of options to reduce this stress, supply augmentation through reuse of treated municipal wastewater is becoming increasingly attractive. Wastewater treatment plants protect water quality and prevent sewage from contaminating waterways. Increasingly, this resource is utilized for numerous human (e.g., irrigation, drinking water, groundwater recharge) and conservation (e.g., stream and river recharge) needs in water stressed regions. To understand the role treated municipal wastewater plays in impacting conservation objectives we identified the intersection of wastewater treatment plant locations and occurrences of threatened and endangered (T&E) species in California and compared the permitted contribution of effluent to baseflow quantities of the receiving waterbody to assess the degree to which changes in effluent could affect instream waterbodies. We found a positive correlation between the presence of treatment plants and T&E species in California watersheds—a quarter of species have 100% of their range in watersheds with at least one treatment plant. This correlation is greatest for species associated with terraces and riparian habitat, followed by aquatic habitat and aquatic emergent vegetation. One‐third of watersheds in our analysis can receive most of their cumulative watershed baseflow from effluent and are characterized by dense urbanization or agriculture. Our analysis demonstrates that the fates of T&E species and effluent are interconnected in ways important for water policy, suggesting that species conservation goals should be considered when making decisions about effluent reuse.

Stonefly drumming behavior descriptions of three Soliperla Ricker, 1952 species (Plecoptera: Peltoperlidae)

One new drumming call signal description and two updated call descriptions of three Soliperla Ricker, 1952 species in the stonefly family Peltoperlidae are presented. It was determined after recording and analysis that these signals differed from the previous descriptions, warranting a revision. Percussive signal interval patterns for the three species are described for the first time. The previous monophasic call signal pattern descriptions of Soliperla quadrispinula (Jewett, 1954) and S. thyra (Needham & Smith, 1916) are updated to the repeated monophasic pattern. The male call and response of S. sierra Stark, 1983 and the response signal of S. quadrispinula are described for the first time. The call descriptions of the three California species consist of one to six monophasic signals with inconsistent inter-call intervals. Sequenced monophasic female answers did not follow all repeated male calls. Male monophasic responses occasionally followed female answers in sequenced 3-way exchanges.

Assessing spatial and temporal variation in obligate resprouting, obligate seeding, and facultative seeding shrub species in California’s Mediterranean-type climate region

Mediterranean-climate region (MCR) shrublands have evolved a set of regeneration strategies in response to periodic, high intensity wildfires: obligate seeding (OS), obligate resprouting (OR), and facultative seeding (FS) species. In the North American MCR, data on their spatial and temporal variability is currently lacking, which is a significant information gap for resource managers. We developed a multinomial model using dynamic and static variables to predict the distribution of the three shrub post-fire regeneration strategies, plus trees and herbs, in southern California. Cross-validation showed 50% of the predicted values for each of the five plant groups were within 8–24 percent of the actual value. We assessed variation in shrub regeneration strategies in three ways. First, we found the three major shrub community types (mixed chaparral, chamise-redshank chaparral, and coastal sage scrub) had proportionally greater biomass of FS (37–43% of total biomass) than OR or OS. Second, we assessed the spatial variability using (a) moisture availability (climatic water deficit and solar radiation) and found FS accounted for an increasingly greater proportion of total aboveground live biomass as water became limited, while OR biomass decreased; and (b) ecosystem productivity (NDVI) which showed the proportion of OS, OR, and tree biomass increased with productivity (with a corresponding dramatic decrease in herb biomass). We also assessed temporal variability using time since fire and found OS represented an initially small proportion of total biomass immediately post-fire (8–10%) which increased with time since fire (13–17%). Third, spatial outputs from the multinomial model indicated FS dominated pixels were most widely distributed across the study area (~3.4 million ha, 71%), compared to OR and OS covering 5% each. FS also occurred more frequently on warmer, south facing slopes and summits whereas OR preferred cooler, north facing slopes and valleys (p < 0.0001). Better understanding the distribution of OS, OR, and FS shrubs is important for resource management, including quantifying shrubland carbon storage and identifying areas for post-fire restoration, as described in a case study of the Bobcat Fire on the Angeles National Forest.

Grimmia shevockii and G. insolita, two new species endemic to California

ABSTRACT Introduction California is a biodiversity hotspot for bryophytes, and its northern counties are among the most endemic-rich areas for bryophytes in North America. Having 29 species in California, Grimmia Hedw. is the third richest moss genus in the state, but recent fieldwork suggests that this number is an underestimate. The identity of some specimens endemic to the Klamath Mountains of California and previously identified as G. brevirostris R.S.Williams remains unclear, and they potentially represent a new species. Two further specimens of Grimmia from Siskiyou County, California, do not correspond to any species described so far. Here we present morphological and phylogenetic arguments for recognising these plants as two new moss species in the genus Grimmia subg. Orthogrimmia Schimp. Methods Morphological characters across potential new species were reviewed and compared with those of related species. Phylogenetic analyses based on the plastid trnS–trnF and nuclear ITS regions were conducted. Key results and conclusions The molecular and morphological analyses revealed two new species of Grimmia for California, which are described and illustrated: G. shevockii J.Muñoz, I.Solano & D.Quandt and G. insolita J.Muñoz, I.Solano & D.Quandt. The former is resolved in a monophyletic clade with high support, whereas the latter has incongruent positions in the plastid and nuclear phylogenies, thus it is hypothesised that it could have a hybrid origin. Both of the two new species and G. hamulosa undoubtly pertain to Grimmia. The richness of the bryophyte flora of California provides a clear warrant for future research.

Status of intertidal populations of Pismo clams (Tivela stultorum) across their range in California

Long-term monitoring programs are critical to understanding a species’ population dynamics through time and to inform policy decisions. Pismo clams, Tivela stultorum (Mawe, 1823), are an iconic species in California and once supported commercial, recreational, and subsistence harvest for many decades. Despite their economic and cultural importance, little is known about their current population status and monitoring efforts in California are spatially and temporally limited. This project aimed to: (1) collect standardized baseline data on Pismo clam abundance across their range in California; (2) identify factors associated with Pismo clam presence to inform future monitoring efforts and to begin developing testable hypotheses about population drivers; and (3) synthesize historical surveys of Pismo clam populations in California. We conducted intertidal field surveys for Pismo clams at 38 sites in California during 2018 and 2019. We observed no legal sized clams (4.5 in/114 mm) and only 2% of individuals were half of legal size across all survey locations. Clam populations are in lower abundance and comprise smaller sizes than historical accounts. We detected small individuals at most sites, suggesting that successful recruitment has occurred on the majority of beaches where clams were present; however, population recovery may require many years. Finally, we found that median sediment grain size is an important predictor for clam presence on open coast beaches in California. Future research will need to examine a number of factors and their interactions across spatial scales to disentangle Pismo clam population drivers.

Different approaches to processing environmental DNA samples in turbid waters have distinct effects for fish, bacterial and archaea communities

Coastal lagoons are an important habitat for endemic and threatened species in California that have suffered impacts from urbanization and increased drought. Environmental DNA has been promoted as a way to aid in the monitoring of biological communities, but much remains to be understood on the biases introduced by different protocols meant to overcome challenges presented by unique systems under study. Turbid water is one methodologic challenge to eDNA recovery in these systems as it quickly clogs filters, preventing timely processing of samples. We investigated biases in community composition produced by two solutions to overcome slow filtration due to turbidity: freezing of water prior to filtration (for storage purposes and long-term processing), and use of sediment (as opposed to water samples). Bias assessments of community composition in downstream eDNA analysis was conducted for two sets of primers, 12S (fish) and 16S (bacteria and archaea). Our results show that freezing water prior to filtration had different effects on community composition for each primer, especially for the 16S, when using a filter of larger pore size (3 μm). Nevertheless, pre-freezing water samples can still be a viable alternative for storage and processing of turbid water samples when focusing on fish communities (12S). The use of sediment samples as an alternative to processing water samples should be done with caution, and at minimum the number of biological replicates and/or volume sampled should be increased.

Revision of Corynosoma australe Johnston, 1937 (Acanthocephala: Polymorphidae) from a North American population using novel SEM images, Energy Dispersive X-ray Analysis, and molecular analysis.

We describe a population of the acanthocephalan Corynosoma australe Johnston, 1937 (Polymorphidae) from a California sea lion Zalophus californianus (Lesson, 1828) in California using novel scanning electron microscopy (SEM) images, Energy Dispersive x-ray analysis (EDXA), and molecular analysis for the first time. The taxonomic history of C. australe is replete with accounts using only line drawings some of which proved erroneous. The distribution of ventral spines on the female trunk has been the primary distinction between C. australe and Corynosoma obtuscens Lincicome, 1943, its junior synonym; being continuous in the latter but discontinuous posteriorly in the former species. The distribution of ventral spines is invariably discontinuous in males. Our redescription and SEM images help to resolve this issue further validating the synonymy. Morphological variability has been documented between our California population and others from various host species in California, South Australia, South Shetlands, and the Argentinian coast. Our SEM images document features not previously detectable in line drawings, erroneously reported or missed in previous accounts. The EDXA spectra show high levels of calcium and phosphorous and low levels of sulfur characteristic of C. australe. EDXA for other species of Corynosoma Lühe, 1904 provide support for the diagnostic distinction of C. australe. EDXA spectra were shown to be species specific and have diagnostic value in the taxonomy of the Acanthocephala. Our molecular analysis used amplification of 18S of ribosomal DNA and cytochrome c oxidase 1 (Cox1) gene. Phylogenetic analyses for Cox1 gene revealed a close relationship between Corynosoma hannae Zdzitowiecki, 1984 and C. australe. The phylogenetic trees confirmed that the isolates belonged to C. australe. The haplotype network inferred by Cox1 with C. australe sequences revealed that haplotypes clearly separated from each other and formed clusters related to samples from the Northern Hemisphere (the USA and Mexico), and the second from the Southern Hemisphere (Argentina, Brazil and Peru).