Integrative and Comparative Biology最新文献

Echinometra spp. are pantropical echinoids found in benthic marine habitat throughout the Caribbean, Atlantic, and Indo-West Pacific oceanic regions. Currently, morphology and molecular data are sparse for echinoids observed along the northeastern coast of Toco, Trinidad, where they are relatively common. Additionally, accurate species identity for Echinometra spp. remains dynamic at both northernmost and southernmost parts of the Caribbean Sea. Although distribution of sea urchins in the genus Echinometra have extensively been studied throughout the Atlantic and Indo-West Pacific, information on its range of distribution at the edge of the Caribbean Sea is lacking. In this study, the mitochondrial Cytochrome c Oxidase subunit I (mt COI) gene was amplified using polymerase chain reaction, then sequenced. Based on successfully obtained gene sequences for 581 base pairs, the echinoid species Echinometra lucunter and Echinometra viridis were identified for black and red color morphotypes from Trinidad (n = 23) and Key Largo, Florida (n = 6), respectively. Furthermore, these specimens were genetically identical to species identified in other studies for Puerto Rico, Panamá, Honduras, and Belize. Although morphological variations, such as spine and test color occur throughout Echinometra spp., molecular identification using the barcoding technique confirmed E. lucunter color morphs for the first time in Trinidad. Since the status of E. lucunter populations, specifically at the most northern and southern regions of the Caribbean Sea is dynamic, further studies using gene markers are essential in determining species distribution, in light of current trends in climate change.

Microplastic pollution is an emerging stressor of concern to coral reef ecosystems, which are already threatened by additional global and local level anthropogenic stressors. The effects of ingesting microplastics alone on corals have been well studied, but the effects of the chemical composition of these particles have been understudied. Many microplastic-associated chemicals are endocrine disrupters potentially posing a threat to organismal reproduction. Therefore, the goal of this study was to determine if differences exist between the effects of microplastics themselves and microplastic leachate on Montipora capitata fertilization due to changes in fatty acid quantity and composition. Assays were conducted two years in a row which exposed M. capitata gamete bundles to either one of four types of recently manufactured, virgin microspheres (nylon, polypropylene, high-density polyethylene, or low-density polyethylene) at three concentrations (50, 100, or 200 particles/L) or microplastic leachates, presumably including plastic additives from these microspheres. Gamete fertilization was not impacted by microplastic particles themselves, but some of the microplastic leachate treatments with the same polymer type significantly reduced fertilization rates for M. capitata. Additionally, a total of 17 fatty acids were seen in both years, but neither fatty acid quantity nor composition correlated with observed declines in fertilization. Instead, fertilization and fatty acid data independently varied by concentration and polymer type, likely due to the presence of different chemicals. This study is the first to directly test the toxicity of microplastic leachate to coral reproduction. These findings show that microplastic-associated chemicals are an important stressor affecting successful coral fertilization and fatty acid quantity and composition and provide evidence for the negative effects of microplastic leachate to coral reproduction. Thus, plastic additives could pose an additional threat to coral replenishment and persistence in coral reef ecosystems.

Global ocean warming is affecting keystone species distributions and fitness, resulting in the degradation of marine ecosystems. Coral reefs are one of the most diverse and productive marine ecosystems. However, reef-building corals, the foundational taxa of coral reef ecosystems, are severely threatened by thermal stress. Models predict 40-80% of global coral cover will be lost by 2100, which highlights the urgent need for widespread interventions to preserve coral reef functionality. There has been extensive research on coral thermal stress and resilience, but 95% of studies have focused on adult corals. It is necessary to understand stress during early life stages (larvae, recruits, and juveniles), which will better inform selective breeding programs that aim to replenish reefs with resilient stock. In this review, we surveyed the literature on coral thermal resilience in early life stages, and we highlight that studies have been conducted on relatively few species (commonly Acropora spp.) and in limited regions (mainly Australia). Reef-building coral management will be improved by comprehensively understanding coral thermal resilience and fitness across life stages, as well as in diverse species and regions.

Marine science is widely recognized as one of the least diverse fields within geoscience. Despite substantial investments in diversity initiatives and resources aimed at engaging underserved communities, the representation and recognition of Black individuals in marine science remain limited. This lack of representation highlights a broader issue: a shortage of professionals who are attuned to the pressing issues within Black communities. Black In Marine Science (BIMS) is making waves by tackling systemic and cultural issues that have historically excluded Black talent from marine science, and this article outlines actionable solutions we have developed to drive meaningful change. BIMS has created a blueprint that can help others increase diversity, equity, and inclusion in scientific spaces with the goal of ocean justice for all. Further than what BIMS has done inside the organization, joy-centered partnerships and direct membership feedback have led to the development of this entire journal issue. Dedicated to highlighting the scientific achievements of BIMS scholars, the BIMS Issue is a manifestation of the outcomes achieved once the BIMS Blueprint is successfully implemented.

The field of phylogenetics employs a variety of methods and techniques to study the evolution of life across the planet. Understanding evolutionary relationships is crucial to enriching our understanding of how genes and organisms have evolved throughout time and how they could possibly evolve in the future. Eucopia sculpticauda Faxon, 1893 is a deep-water peracarid in the order Lophogastrida Boas, 1883, which can often be found in high abundances in pelagic trawls. The species can be found along the Mariana Trench, in the Mid-Atlantic Ridge, west Atlantic and east Pacific Oceans, and in the Gulf of Mexico and as deep as 7526 m. Recent collections of E. sculpticauda in the Gulf of Mexico have revealed putative cryptic diversity within the species based on both molecular and morphological evidence. Previous studies have documented two different morphotypes of the telson: the terminal part of the pleon (abdomen) and part of the tail fan. In adults, the morphotypes can be distinguished by lateral constrictions in the telson. This evidence, combined with a previous barcoding study, led to the speculation that telson morphology may be a distinguishing character useful to define cryptic diversity within E. sculpticauda. This study presents additional molecular data from the mitochondrial genes cytochrome c oxidase subunit I, and the large ribosomal subunit (16S), and the nuclear histone 3 gene (H3) to investigate telson morphotypes in relation to evolutionary history within this species. Molecular data identified two strongly supported clades, lending support for potential cryptic diversification within the Gulf of Mexico. Investigations into telson morphology suggest that this character may be informative, but the morphotypes were sometimes ambiguous and additional characters could not be found that discriminate clades. At present, our data suggest early evidence for cryptic diversification within Gulf of Mexico populations, but additional morphological characters and geographic sampling are needed before a new species can be described.

Immunopathology, or the harm caused to an organism's own tissues during the activation of its immune system, carries substantial costs. Moreover, avoiding this self-harm may be an important mechanism underlying tolerance of infection, helping to reducing fitness costs without necessarily clearing parasites. Despite the apparent benefits of minimizing immunopathology, such damage persists across a range of host species. Prior work has explored a trade-off with resistance during a single infection as a potential driver of this persistence, with some collateral damage being unavoidable when killing parasites. Here, we present an additional trade-off that could favor the continued presence of immunopathology: robust immune responses during initial infection (e.g., innate immunity in vertebrates) can induce stronger memory (adaptive immunity), offering protection from future infections. We explore this possibility in an adaptive dynamics framework, using theoretical models parameterized from an ecologically relevant host-parasite system, house finches (Haemorhous mexicanus) infected with the bacterial pathogen, Mycoplasma gallisepticum. We find that some degree of immunopathology is often favored when immunopathology during first infection either reduces susceptibility to or enhances recovery from second infection. Further, interactions among factors like transmission rate, recovery rate, background mortality, and pathogen virulence also shape these evolutionary dynamics. Most notably, the evolutionary stability of investment in immunopathology is highly dependent upon the mechanism by which hosts achieve secondary protection (susceptibility vs. recovery), with the potential for abrupt evolutionary shifts between high and low investment under certain conditions. These results highlight the potential for immune memory to play an important role in the evolutionary persistence of immunopathology and the need for future empirical research to reveal the links between immunopathology during initial infections and longer-term immune protection.

Movement is integral to animal life, and most animal movement is actuated by the same engine: striated muscle. Muscle input is typically mediated by skeletal elements, resulting in musculoskeletal systems that are geared: at any instant, the muscle force and velocity are related to the output force and velocity only via a proportionality constant G, the "mechanical advantage". The functional analysis of such "simple machines" has traditionally centered around this instantaneous interpretation, such that a small vs large G is thought to reflect a fast vs forceful system, respectively. But evidence is mounting that a comprehensive analysis ought to also consider the mechanical energy output of a complete contraction. Here, we approach this task systematically, and deploy the theory of physiological similarity to study how gearing affects the flow of mechanical energy in a minimalist model of a musculoskeletal system. Gearing influences the flow of mechanical energy in two key ways: it can curtail muscle work output, because it determines the ratio between the characteristic muscle kinetic energy and work capacity; and it defines how each unit of muscle work is partitioned into different system energies, that is, into kinetic vs "parasitic" energy such as heat. As a consequence of both effects, delivering maximum work in minimum time and with maximum output speed generally requires a mechanical advantage of intermediate magnitude. This optimality condition can be expressed in terms of two dimensionless numbers that reflect the key geometric, physiological, and physical properties of the interrogated musculoskeletal system, and the environment in which the contraction takes place. Illustrative application to exemplar musculoskeletal systems predicts plausible mechanical advantages in disparate biomechanical scenarios, yields a speculative explanation for why gearing is typically used to attenuate the instantaneous force output ($G_{text{opt}} lt 1)$, and predicts how G needs to vary systematically with animal size to optimize the delivery of mechanical energy, in superficial agreement with empirical observations. A many-to-one mapping from musculoskeletal geometry to mechanical performance is identified, such that differences in G alone do not provide a reliable indicator for specialization for force vs speed-neither instantaneously, nor in terms of mechanical energy output. The energy framework presented here can be used to estimate an optimal mechanical advantage across variable muscle physiology, anatomy, mechanical environment, and animal size, and so facilitates investigation of the extent to which selection has made efficient use of gearing as a degree of freedom in musculoskeletal "design."

Understanding how the structure of biological systems impacts their resilience (broadly defined) is a recurring question across multiple levels of biological organization. In ecology, considerable effort has been devoted to understanding how the structure of interactions between species in ecological networks is linked to different broad resilience outcomes, especially local stability. Still, nearly all of that work has focused on interaction structure in presence-absence terms and has not investigated quantitative structure, i.e., the arrangement of interaction strengths in ecological networks. We investigated how the interplay between binary and quantitative structure impacts stability in mutualistic interaction networks (those in which species interactions are mutually beneficial), using community matrix approaches. We additionally examined the effects of network complexity and within-guild competition for context. In terms of structure, we focused on understanding the stability impacts of nestedness, a structure in which more-specialized species interact with smaller subsets of the same species that more-generalized species interact with. Most mutualistic networks in nature display binary nestedness, which is puzzling because both binary and quantitative nestedness are known to be destabilizing on their own. We found that quantitative network structure has important consequences for local stability. In more-complex networks, binary-nested structures were the most stable configurations, depending on the quantitative structures, but which quantitative structure was stabilizing depended on network complexity and competitive context. As complexity increases and in the absence of within-guild competition, the most stable configurations have a nested binary structure with a complementary (i.e., anti-nested) quantitative structure. In the presence of within-guild competition, however, the most stable networks are those with a nested binary structure and a nested quantitative structure. In other words, the impact of interaction overlap on community persistence is dependent on the competitive context. These results help to explain the prevalence of binary-nested structures in nature and underscore the need for future empirical work on quantitative structure.

Examples of resilience in nature give us hope amid a growing biodiversity crisis. While resilience has many definitions across disciplines, here I discuss resilience as the ability to continue to adapt and persist. Naturally, as biologists, we seek to uncover the underlying mechanisms that can help us explain the secrets of resilience across scales, from individuals to species to ecosystems and beyond. Perhaps we also ponder what the secrets to resilience are in our own lives, in our own research practices, and academic communities. In this paper, I highlight insights gained through studies of amphibian resilience following a global disease outbreak to uncover shared patterns and processes linked to resilience across amphibian communities. I also reflect on how classical resilience heuristics could be more broadly applied to these processes and to our own academic communities. Focusing on the amphibian systems that I have worked in-the Golden Frogs of Panama (Atelopus zeteki/varius) and the Mountain Yellow-Legged Frogs of California (Rana muscosa/sierrae)-I highlight shared and unique characteristics of resilience across scales and systems and discuss how these relate to adaptive renewal cycles. Reflecting on this work and previous resilience scholarship, I also offer my own thoughts about academia and consider what lessons we could take from mapping our own adaptive trajectories and addressing threats to our own community resilience.

The Deepwater Horizon (DWH) oil spill in the northern Gulf of Mexico, occurred in 2010 at 1525 meters depth, releasing approximately 507 M liters of oil. Research cruises in 2010 and 2011 were conducted to assess the initial and subsequent effects of the oil spill on deep-sea infauna. The spatial-temporal response of the deep-sea meiofaunal harpacticoid community composition to the DWH oil spill was investigated at 34 stations ranging from < 1 km to nearly 200 km from the wellhead in 2010 and 2011. The pattern of reduced harpacticoid diversity in impacted zones compared to non-impacted zones in 2010 persisted in 2011. However, an increase in Hill's diversity index (N1) and the family richness across the two years in some of the impacted stations could suggest a first signal of a tentative recovery and an improvement of environmental conditions. The multivariate analysis of harpacticoid family composition revealed the persistence of an impact in 2011 with moderately high values of turnover diversity in the harpacticoid communities through time (37%) and space (38-39%). The consistent presence in all years and stations of long-term tolerant families (e.g., Ameiridae), the sharp decrease of fast-responding opportunistic families (e.g., Tisbidae), and the increase of more sensitive ones (e.g., Ectinosomatidae, Canthocamptidae, Cletopsyllidae, and Laophontidae) lead to the preliminary conclusion that some initial signals of recovery are evident. However, as impacts were still evident in 2011, and because recruitment and succession rates can be extremely slow in the deep sea, full community recovery had not yet occurred one year after the DWH disaster. This study confirmed that harpacticoid copepod family diversity can offer an accurate assessment of oil-spill impacts on deep-sea benthic communities over space and time as well as a better understanding of the recovery mode of the system after an oil spill event.