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Although the quality of the spermatozoa is a key factor for reproductive success, there is few information describing the sperm quality for most marine invertebrates, especially corals. Given the high mortality rates and several threats currently faced by coral reefs, ways of assessing coral spermatozoa viability are needed. Thus, in this study we proposed a morphological classification for coral spermatozoa using Mussismilia harttii as model. In addition, we evaluated the relationship of morphology with the percentage and duration of motility. Spermatozoa were first classified into two main morphological categories: normal and abnormal. Then, we classified morphological abnormalities in the head and flagellum together with proposing subcategories that better described it. In general, 68.77 ± 6.50% of the spermatozoa had their whole structure intact, while 31.23 ± 6.51% had morphological abnormalities. Most abnormalities were in the flagellum (five types in total), while only two abnormalities were located in the head. Coiled flagellum and shortened flagellum were the most representative abnormalities, accounting for 24% of the total detected. We observed that reduction of sperm motility is directly related to increased morphological abnormalities and they are influenced by the cell ageing. Our results reinforce how the characterization of sperm morphology can be a practical and useful tool that can help to better understand the effects of multiple stressors on coral reproduction. Graphical abstract, Author(s): Amanda Amaral [sup.1] [sup.2] , Yugo Pastrana [sup.3] , Cristiano Pereira [sup.4] [sup.5] , Wanderson Valente [sup.6] , Leandro Godoy [sup.1] [sup.4] [sup.7] Author Affiliations: (1) Graduate Program in [...]

Grazing fishes farm algae, and consume algae, detritus and sediment and consequently differentially modify benthic communities. Manipulations of cleaner fish Labroides dimidiatus on reefs show that cleaners affect fish abundance differently according to grazer functional group. Accordingly, whether reefs are grazed differently, with consequences for the benthos (fouling material tile.sup.-1), was tested using reefs kept free of L. dimidiatus for 10 years compared with undisturbed control reefs. We recorded on video the grazing density (bites tile.sup.-1 h.sup.-1 reef.sup.-1) on settlement tiles and the natural benthos (roving fishes only), according to territorial algal farmer (Pomacentridae) and roving grazer (Acanthuridae, Labridae, Siganidae) functional groups, and measured the accumulation of fouling material tile.sup.-1 after 10 months. Grazing density on tiles (dominated by 'indeterminate' farmers, and roving 'sediment-removing' detritivore Ctenochaetus striatus) and the natural benthos (dominated by Ct. striatus and other grazers) was not measurably affected by cleaner presence. The composition of fouling material (dominated by detritus > turf algae > sediment > other) and organic and inorganic dry weight of material tile.sup.-1 were also not measurably affected by cleaner presence. This points to resilience of the benthic community to loss of cleaners. The likely complex interactions between cleaner fish presence, grazer abundance and mobility, and the often-opposite effects of territorial farmers and roving grazers on the benthos underscore the challenge in determining indirect effects of cleaners on benthic community structure. However, a lack of cleaners has negative ramifications for fish populations and physiology and thus their loss remains problematic for client fishes., Author(s): A. S. Grutter [sup.1] , S. Bejarano [sup.1] [sup.2] , D. Sun [sup.1] , P. J. Mumby [sup.1] Author Affiliations: (1) grid.1003.2, 0000 0000 9320 7537, School of Biological [...]

Non-indigenous species (NIS) can invade marine ecosystems worldwide not only because of higher growth rates and reproductive potential but also due to their ability to escape from native consumers either by defensive traits or by the colonization of spatial refuges. Spatial consumption refuges can be present in tidepools, especially in those from the high shore, with harsh environmental conditions. In order to test this hypothesis, we quantified consumer pressure on NIS in tidepools with different tidal elevations. We deployed tethering assays within 73 tidepools at 30° S (Chile) in 2021 using the following four bait types: two NIS (the green seaweed Codium fragile and the tunicate Ciona robusta) and two reference baits (blades of the kelp Lessonia and dried squid). The two reference baits as well as the two NIS were consumed across all tidepools. Thus, there was no tidal gradient in NIS consumption: higher tidepools did not offer a spatial refuge as native consumers can reach them and consume NIS. Possibly, on wave-exposed coasts, high shore tidepools are frequently splashed, mitigating harsh conditions, and, therefore, reducing the potential for spatial refuges from consumption. While both NIS were eaten by native consumers in tidepools, they are nevertheless successful invaders. Therefore, our results suggest that NIS can compensate for consumer losses in tidepools, which allows them to colonize tidepool systems even if these do not offer spatial refuges from consumption. Tidepools might represent a first invasion window for NIS to enter natural communities, potentially causing important effects on biodiversity of rocky intertidal habitats., Author(s): Eva Rothäusler [sup.1] , Moisés A. Aguilera [sup.2] , Rene Matías Arias [sup.3] , David Jofré-Madariaga [sup.3] [sup.4] , Oscar Pino [sup.3] , Sabine Rech [sup.3] [sup.5] , Martin [...]

Copepods serve as a major link in marine food webs, bridging the energy transfer from primary producers to higher trophic levels. Oceanic warming is linked to reduced concentrations of essential fatty acids (FA) in phytoplankton, namely eicosapentaenoic acid (EPA, 20:5[omega]3) and docosahexaenoic acid (DHA, 22:6[omega]3), and it remains largely unknown if copepods have the capacity to endure. The calanoid Temora longicornis and the harpacticoid Platychelipus littoralis were chosen to analyse their FA and biosynthesis activity in response to a long-chain polyunsaturated FA (LC-PUFA) deficient diet (Dunaliella tertiolecta) along a temperature gradient. Copepods were fed D. tertiolecta labelled with the stable isotope carbon-13 (.sup.13C) to quantify carbon assimilation into their total FA and de novo EPA and DHA biosynthesis after 6 days incubated at 11, 14, 17, 20 and 23 °C. The calanoid had increased mortality with warming, whereas the harpacticoid exhibited high survival across the thermal gradient. After the incubation, P. littoralis assimilated minimal amounts of dietary carbon into its total FA in comparison to T. longicornis. T. longicornis depleted their field EPA and DHA stores more rapidly, whereas P. littoralis maintained its relative storage of EPA and DHA and absolute concentrations of DHA. T. longicornis displayed higher fractions of de novo EPA and DHA biosynthesis than P. littoralis at all temperatures, with the exception of DHA at 23 °C. Within our experimental incubation period both species were unable to meaningfully upgrade the LC-PUFA deficient algae to biosynthesize de novo EPA and DHA as a relevant source for higher trophic levels., Author(s): Robyn Sahota [sup.1] , Jens Boyen [sup.1] , Ilias Semmouri [sup.2] , Samuel Bodé [sup.3] , Marleen De Troch [sup.1] Author Affiliations: (1) grid.5342.0, 0000 0001 2069 7798, Marine [...]

Gaidropsarus Rafinesque, 1810 is a genus of marine teleost characterized by a high ecological diversity and by species inhabiting from the intertidal zone to the deep-sea. Several taxonomic conundrums have been historically present in this taxon due to its conservative morphology and the lack of available specimens. Species delimitation analyses were carried out in multiple datasets combining both mitochondrial (COI, CytB, ND2) and nuclear (Rho, ZIC1) genetic markers. Despite some incongruence between mitochondrial and nuclear data, the analyses supported the synonymy between Gaidropsarus biscayensis and Gaidropsarus macrophthalmus and the molecular confirmation of a recently new described species Gaidropsarus gallaeciae, in the North Atlantic Ocean. Furthermore, recent speciation events can explain the close relationships among several Gaidropsarus species, including Gaidropsarus granti-Gaidropsarus vulgaris and Gaidropsarus argentatus-Gaidropsarus ensis. These results support previous findings highlighted through DNA Barcoding analyses. Incongruences between mtDNA and nDNA have arisen between Gaidropsarus guttatus and Gaidropsarus mediterraneus, therefore, further analyses will be necessary to unravel the phenomena related to them., Author(s): David Barros-García [sup.1] , Ángel Sebastián Comesaña [sup.2] , Rafael Bañón [sup.3] [sup.4] , Francisco Baldó [sup.5] , Juan Carlos Arronte [sup.6] , Elsa Froufe [sup.1] , Alejandro De [...]

The chain-forming dinoflagellate Gymnodinium catenatum is the only known gymnodinioid dinoflagellate that produces paralytic shellfish toxins (PST). Dense blooms caused by the dinoflagellate have been frequently reported in coastal waters of Fujian, China since 2017. While there is still limited understanding of the major physiological characteristics of G. catenatum isolated from Fujian coastal waters, the growth and toxin production of the G. catenatum strain were examined in batch cultures with different levels of irradiance, temperature, salinity, nitrate, and phosphate conditions. The results indicated that the highest maximum cell density of the strain was achieved at 70 [micro]mol m.sup.-2 s.sup.-1, with the highest growth rate at 120 [micro]mol m.sup.-2 s.sup.-1. The strain grew well within the temperature range of 15-30 °C, with maximum growth rate and cell density achieved at 20 °C. The dinoflagellate also showed higher tolerance to salinity variation (20-40), with the highest growth rate at salinity 25. Meanwhile, G. catenatum showed higher demand for nitrogen and phosphorus as indicated by its higher half-saturation constant. A decrease in nitrate and phosphate greatly inhibited the growth of G. catenatum. The toxin profile of the G. catenatum strain was conservative and dominated mainly by the N-sulfcarbamoyl C-toxins (> 95%), indicating its hypotoxicity. The cellular toxicity increased with the algal growth, with the highest cellular toxicity observed at the stationary growth phase. The cellular toxicity of G. catenatum also responded to environmental variations including lower temperature (15 °C), lower salinity (20), nitrate-repletion, and phosphate-depletion conditions which enhanced the cellular toxicity, while irradiance exerted non-significant influence. The present study depicted the physiological characteristics of the particular G. catenatum strain and provided valuable insight on the ecophysiology of G. catenatum in natural coastal waters., Author(s): Jingyuan Shi [sup.1] [sup.4] , Yun Liu [sup.1] [sup.2] , Haifeng Gu [sup.3] , Caiwen Li [sup.1] [sup.2] [sup.4] Author Affiliations: (1) grid.9227.e, 0000000119573309, CAS Key Laboratory of Marine [...]

Social hierarchies within groups define the distribution of resources and provide benefits that support the collective group or favor dominant members. The progression of individuals through social hierarchies is a valuable characteristic for quantifying population dynamics. On coral reefs, some clownfish maintain size-based hierarchical communities where individuals queue through social ranks. The cost of waiting in a lower-ranked position is outweighed by the reduced risk of eviction and mortality. The orange clownfish, Amphiprion percula, maintains stable social groups with subordinate individuals queuing to be part of the dominant breeding pair. Strong association with their host anemone, complex social interactions, and relatively low predation rates make them ideal model organisms to assess changes in group dynamics through time in their natural environment. Here, we investigate the rank changes and isometric growth rates of A. percula from 247 naturally occurring social groups in Kimbe Island, Papua New Guinea (5° 12' 13.54' S, 150° 22' 32.69' E). We used DNA profiling to assign and track individuals over eight years between 2011 and 2019. Over half of the individuals survived alongside two or three members of their original social group, with twelve breeding pairs persisting over the study period. Half of the surviving individuals increased in rank and experienced double the growth rate of those that maintained their rank. Examining rank change in a wild fish population provides new insights into the complex social hierarchies of reef fishes and their role in social evolution., Author(s): L. M. Fitzgerald [sup.1] [sup.2] , H. B. Harrison [sup.3] [sup.4] , D. J. Coker [sup.1] , P. Sáenz-Agudelo [sup.5] , M. Srinivasan [sup.3] [sup.6] , J. E. Majoris [...]

As climate change continues, anticipating species' responses to rising temperatures requires an understanding of the drivers of thermal sensitivity, which itself may vary over space and time. We measured metabolic rates of three representative marine invertebrate species (hermit crabs Pagurus hirsutiusculus, periwinkle snails Littorina sitkana, and mussels Mytilus trossulus) and evaluated the relationship between thermal sensitivity (Q.sub.10) and thermal history. We tested the hypothesis that thermal history drives thermal sensitivity and quantified how this relationship differs over time (short-term to seasonal time scales) and between species. Organisms were collected from tide pools in Sitka, Alaska where we also recorded temperatures to characterize thermal history prior to metabolic rate assays. Using respirometry, we estimated mass-specific oxygen consumption (MO.sub.2) at ambient and increased temperatures for one individual per species per tide pool across three seasons. We evaluated relationships between thermal sensitivity and pool temperatures for time periods ranging from 1 day to 1 month prior to collection. For all species, thermal sensitivity was related to thermal history for the shorter time periods (1 day to 1 week). However, the direction of the relationships and most important thermal parameters (i.e., maximum, mean, or range) differed between species and seasons. We found that on average, P. hirsutiusculus and L. sitkana were more thermally sensitive than M. trossulus. These findings show that variability in thermal history over small spatial scales influences individuals' metabolic response to warming and may be indicative of these species' ability to acclimate to future climate change., Author(s): Racine E. Rangel [sup.1] , Cascade J. B. Sorte [sup.1] Author Affiliations: (1) grid.266093.8, 0000 0001 0668 7243, Department of Ecology and Evolutionary Biology, University of California - Irvine, [...]

Salinity is a common stressor restricting the distribution of various decapod crustaceans. The interactive effects of such regional stressors with global climate change drivers are important to be considered when aiming to realistically predict the potential of a species' dispersal and further spread into new habitats. Within species, their larval stages commonly determine a species tolerance and with this their potential to invade and successfully develop a sustaining population. This laboratory study investigated the combined effect of salinity (6 levels, 10-25) and temperature (19 and 23 °C) on larval survival, development to megalopa, and feeding (in Zoea I, III, and V) of the decapod Hemigrapsus takanoi. Larval development and survival to megalopa were generally favored by increasing salinity. While no larva developed to the megalopa stage at 23 °C and a salinity of 16, in 19 °C some larvae could successfully develop under a salinity as low as 16. All larval stages fed generally more with increasing salinity and temperature, but there was no interaction between the two factors. The results revealed that the H. takanoi population from Kiel Fjord (southwestern Baltic Sea) is capable of completing its larval development under the current Kiel Fjord environmental conditions. The geographical spread of this H. takanoi population into the wider Baltic Proper may, however, be restricted mainly due to the inability to establish and maintain a self-sustaining population under lower salinity conditions. Furthermore, the projected desalination of the Baltic Sea together with rising temperatures due to global warming and heat waves in summer may likely exert additional stress to this existing population, unless H. takanoi adapts at appropriate rates., Author(s): Ola Mohamed Nour [sup.1] [sup.2] , Christian Pansch [sup.3] , Meike Stumpp [sup.4] Author Affiliations: (1) grid.7155.6, 0000 0001 2260 6941, Department of Biology and Geology, Faculty of Education, [...]

While outbreaks of the coral-killing sponge Terpios hoshinota are now being increasingly reported across the Western Pacific and Indian Oceans, no studies have yet investigated the effects of T. hoshinota on coral reef fishes. We compared the abundance, species richness, and community composition of fishes across three habitat types (live corals, Terpios-covered corals, and dead corals) at Lanyu and Lyudao, Taiwan. The abundance and composition of different fish species groups (cryptic, resident, or transient) were also examined between habitat types to assess potential variation depending on fish-coral interactions. Obligate coral-dependent fishes (corallivores and coral-dwellers) were lastly examined between habitat types due to their susceptibility to reductions in live coral cover. The presence of T. hoshinota had limited effects on the overall fish community, as well as within fish species groups, with many species displaying limited or no preference between habitat types. On the contrary, obligate coral-dependent fishes were almost twice as likely to occur, and up to five times more abundant on live corals compared to Terpios-covered corals. These findings suggest that although T. hoshinota appears to have limited effects on the majority of fishes at the individual colony scale, mass outbreaks could potentially cause affected fish communities to become dominated by habitat generalists, at the expense of obligate coral-dependent species. Further research should therefore investigate community-level responses to large outbreaks of T. hoshinota., Author(s): Yu-De Pei [sup.1] [sup.2] , Nathan William Price [sup.1] , Joseph Heard [sup.1] [sup.2] , Chieh-Hsuan Lee [sup.1] , Hsuan Tsang [sup.1] , Colin Kuo-Chang Wen [sup.1] [sup.3] Author [...]

The aim of the present preclinical study was to investigate the capability of a new formulation of biphasic calcium phosphate (BCP) in achieving new bone formation either by itself or in combination with different concentrations of growth factors. Twentyfour 3-month-old male New Zealand white rabbits (weight range, 2.5 to 3.0 kg) that had been bred exclusively for biomedical research purposes and obtained from a licensed vendor were used. Four calvarial defects were created in each animal, for a total of 96 defects. Each defect received alloplastic BCP (Osteon III, Genoss) that was composed of 60% hydroxyapatite and 40% β-tricalcium phosphate) (porosity, ~80%; macropore size, 200 to 400 μm; crystallinity, 95%) combined with different concentrations of recombinant human platelet–derived growth factor BB (rhPDGF-BB), human recombinant basic fibroblast growth factor-2 (rhFGF-2), or recombinant human bone morphogenetic protein-2 (rhBMP-2). A custom-made polycarbonate tube was fixed to each defect site by applying slight pressure, and a mixture of bone graft and growth factor was implanted into the tubes. Data were collected 2, 4, and 8 weeks after creation of the defects to assess early and late healing. Various amounts of newly formed bone and remnant BCP particles formed inside of the tube throughout the study period. The BCP + 0.5 mg/mL rhBMP-2 group exhibited the most bone formation. At 8 weeks, more new bone formation was noted in the Osteon III + rhBMP-2 combined group than in other groups. The present study results indicate that BCP can be combined with different concentrations of rhBMP-2, rhFGF-2, and rhPDGF-BB to produce new bone formation within a polycarbonate tube in calvarial defects in a rabbit model. [ABSTRACT FROM AUTHOR]

This article investigates constructions of gender and difference in biomedical research on anterior cruciate ligament injuries. This injury is of interest because evidence shows a higher risk among females in some sports and there is extensive research on this topic. The analysis examined consensus statements from 6 anterior cruciate ligament research retreats spanning 11 years. The initial mission of the retreats was to examine factors related to a possible gender bias in incidence. Over time there was increasing emphasis on explaining the mechanisms of the injury and injury prevention. Conceptualizations of gender were multifaceted and as research evolved showed a tendency to move away from essentialist and categorical constructions. The discussion suggests that the location of this research in a broader agenda of injury prevention helped to distance it from a narrow focus on gender difference and provided the context for increasingly nuanced conceptualizations of gender. [ABSTRACT FROM PUBLISHER]

Author(s): Stephanie M. Melillo Author Affiliations: Hominin footprints at Laetoli reveal a walk on the wild side The human version of walking on two legs, known as striding bipedalism, is [...], Bipedalism is a defining feature of the human lineage, but not all hominin species walked in the same way. New data from a famous palaeoanthropology site reveal that at least two differently bipedal hominins roamed eastern Africa. Ancient footprints at Laetoli now assigned to a cross-stepping hominin.

Background: Biomedical research plays an important role in improving health. There seems to exist a negative correlation between the amount of biomedical research funding and disease burden from all Sub-Saharan African countries. In this study, we describe funding patterns for biomedical research, explore the correlation between funding and burden of diseases, and quantify inequalities in funds distribution across diseases in Gabon over the period 2005-2015.Methods: Data on medical research funds from 2005 to 2015 were retrieved through a structured questionnaire distributed to Gabonese biomedical research institutions and by consulting online databases. Data on the burden of diseases were gathered from the World Health Organization and the Institute for Health Metrics and Evaluation. We used Kendall rank correlation coefficient to explore the correlation between cumulative funds over time and the burden of disease. The inequality distribution of funding across diseases was assessed through Gini coefficient and Lorenz curve.Results: Biomedical research funding was characterized by a remarkable growth from 2005 to 2010 and a decline from 2010 to 2014. Funds were mostly from external sources and from partnerships. There was inequality in research funds allocation across diseases and malaria was far the most funded disease. There was a significant negative correlation between cumulative funding and the burden of HIV, tuberculosis, and of Helminthiasis (from 2006 to 2010) suggesting that research may be contributing to the management of such diseases. A positive, although not significant, correlation was found between cumulative funds and malaria burden.Conclusions: The negative correlation between HIV and tuberculosis cumulative funding and burden suggests that research may be contributing to the management of such diseases but further research is needed to assess the causal direction of such as relationship. As the burden of non-communicable diseases is increasing, more research funds should be focused on those. While research partnerships have been and will remain fundamental, Gabon should increase the amount of national funds to overcome periods of reduced research funding flows from abroad. [ABSTRACT FROM AUTHOR]

An interview with Benjamin Staude, a German mathematician, is presented. Topics include studying mathematics to doing a doctorate in brain research to founding a start-up with substantive mathematics; and involved in working with a physicist who is an insanely theoretical superstructure with mathematical service provider in a biological research group as mathematician in neuroscience.

To improve the outcomes of research and medicine, government-based international research funding agencies have implemented various types of policies and mechanisms with respect to sex as a biological variable and gender as a sociocultural factor. After the 1990s, the US National Institutes of Health (NIH), the Canadian Institutes of Health Research (CIHR), and the European Commission (EC) began requesting that applicants address sex and gender considerations in grant proposals, and offering resources to help the scientific community integrate sex and gender into biomedical research. Although it is too early to analyze data on the success of all of the policies and mechanisms implemented, here we review the use both of carrots (incentives) and sticks (requirements) developed to motivate researchers and the entire scientific research enterprise to consider sex and gender influences on health and in science. The NIH focused on sex as a biological variable (SABV) aligned with an initiative to enhance reproducibility through rigor and transparency; CIHR instituted a sex- and gender-based analysis (SGBA) policy; and the EC required the integration of the "gender dimension," which incorporates sex, gender, and intersectional analysis into research and innovation. Other global efforts are briefly summarized. Although we are still learning what works, we share lessons learned to improve the integration of sex and gender considerations into research. In conjunction with refining and expanding the policies of funding agencies and mechanisms, private funders/philanthropic groups, editors of peer-reviewed journals, academic institutions, professional organizations, ethics boards, health care systems, and industry also need to make concerted efforts to integrate sex and gender into research, and we all must bridge across silos to promote systemwide solutions throughout the biomedical enterprise. For example, policies that encourage researchers to disaggregate data by sex and gender, the development of tools to better measure gender effects, or policies similar to SABV and/or SGBA adopted by private funders would accelerate progress. Uptake, accountability for, and a critical appraisal of sex and gender throughout the biomedical enterprise will be crucial to achieving the goal of relevant, reproducible, replicable, and responsible science that will lead to better evidence-based, personalized care for all, but especially for women. [ABSTRACT FROM AUTHOR]

The Japan Society for Biomedical Research on Trace Elements decided to publish the new journal "Metallomics Research" from October, 2021, instead of their previous journal "Biomedical Research on Trace Elements" (BRTE). On this occasion, the history of trace element study in Japan and the progress of metallomics as integrated biometal science proposed about 20 years ago are reviewed. In the latter part of this review, basic concepts of metallomics research are discussed in relation to homeostasis and all-present theory, and finally it is considered that metallomics research has a mission to contribute to our humans and nature through the SDGs (Sustainable Development Goals), mainly with focusing on health science and environmental/green science as multidisciplinary science. [ABSTRACT FROM AUTHOR]

Author(s): Kamila Naxerova Author Affiliations: Mutation fingerprints encode cellular histories The human body consists of trillions of cells that perform innumerable tasks as members of different organ systems. They are [...], Cells continually acquire mutations and pass them on to their progeny. The mutation profiles of human cells shine a light on the cells' developmental history and their dynamics in adult tissue. Lineage relationships among cells of the human body traced.

Mechanisticapproachestoplanktonfood-websoftenrelyonsize-basedmodels.Thesemodelsdescribe predator-preyrelationshipsbasedonpredator body or cell size. However, size-based representations of trophic relationships fail to encompass the diverse feeding behavior of dinoflagellates, which play an essential role in the food-web due to their abundance and ubiquity. Here, we introduce the specialization factor (s) as an effective trait, which aggregates over aspects of morphology, trophic strategy, and feeding behavior and quantifies the degree of specialization towards a specific prey size. We found that specialization to either the upper or lower edge of the prey size spectrum is connected to size independent trophic relations. As a result, dinoflagellates can be divided into three groups with distinct dependencies of optimal prey size on predator size: (1) mixotrophic engulfers specialized on small prey ( [Formula omitted]), (2) pallium feeders on large prey ( [Formula omitted]), and (3) neutral feeders ( [Formula omitted]) encompassing generalist engulfers and tube feeders. Our trait based approach elucidates the evolutionary significance of diverse feeding modes and specialization in dinoflagellates compared to phylogenetically older groups such as ciliates. It furthermore leads to a more accurate representation of trophic relationships of dinoflagellates in models and can provide, more generally, an efficient description of complex and diverse feeding relations in plankton food-webs., Author(s): Ovidio García-Oliva [sup.1] , Kai Wirtz [sup.1] Author Affiliations: (1) grid.24999.3f, 0000 0004 0541 3699, Institute of Coastal Systems-Analysis and Modeling, Helmholtz-Zentrum Hereon, , Max-Planck-Straße 1, 21502, Geesthacht, Germany [...]

Littorinids, such as Littoraria flava, are attractive models for local adaptation studies in the rocky shore intertidal zone. The wide heterogeneity of the rocky shore might play a role shaping the evolution of communities distributed in its many micro environments. We extracted the L. flava mitogenome using RNA-seq reads, followed by selection tests at coding gene level using 69 Caenogastropoda species. Here, we present L. flava partial mitogenome with 15,807 bp and 13 PCGs, 21 tRNAs and two rRNAs. Using this new matrix, we produced the most comprehensive mitogenome phylogeny of Caenogastropoda, where we were able to recover the monophyly of Architaenioglossa, Cerithimorpha and Latrogastropoda. The phylogenetic reconstruction shows Littorinimorpha as paraphyletic, supporting that the Vermetidae classification should be re-evaluated. Littoraria flava presents a fragment of nd1 gene duplicated and three tRNAs not presenting the expected cloverleaf structure. We detected positive selection in a phosphoserine codon in nd2 gene from individuals living closer to the ocean, suggesting a hypoxia stress response. Conversely, cytb, cox1, nd1, nd4 and nd6 were under purifying selection and no correlation with the distance to ocean was observed. Our findings corroborate previous studies on evidence of local adaptation at a microscale distribution where few meters may require precise adjustments in energy metabolism, due to the determinant tide influence., Author(s): Camilla A. Santos [sup.1] , Flávia O. Bezerra [sup.1] , Sónia C. S. Andrade [sup.1] Author Affiliations: (1) grid.11899.38, 0000 0004 1937 0722, Departamento de Genética e Biologia Evolutiva, [...]

Many aquatic invertebrates undergo an indirect development, a biphasic life cycle which encompasses the transformation of free-swimming larvae into benthic juveniles via settlement and metamorphosis. During this transition, metamorphic competence is a crucial developmental stage that allows larvae to swim and feed in the planktonic realm while retaining the ability to settle and metamorphose in response to environmental cues. Although there have been substantial efforts to decipher the molecular mechanisms underlying this event in several molluscan species, the conserved biological pathways that are crucial to enable this transition across species are not well understood. Here, we performed a comparative analysis of the developmental transcriptomes between bivalve Crassostrea gigas and gastropod Rapana venosa. We particularly explored the common gene expression signatures that may underlie their larval competence. We showed that, although the developmental transcriptomes differed remarkably between C. gigas and R. venosa, they likely shared a plethora of genes (n = 690) that exhibited similar expression signatures during their larval competence. Gene Ontology enrichment and expression analyses further indicated that competent larvae of both species exhibited up-regulation of pathways associated with response to stimuli, metal ion binding and transport, and neuronal development, but showed down-regulation of pathways that were mainly involved in cilium assembly and organ development. Using oyster and whelk as models, our study suggests that regulation of these conserved pathways is crucial for their subsequent settlement and metamorphosis and may represent a universal mechanism that enables the pelagic-to-benthic transition in a broader range of marine invertebrates., Author(s): Zhen Zeng [sup.1] , Chongyi Jiang [sup.2] , Qianglai Tan [sup.1] , Bozeng Tang [sup.3] , Zixia Huang [sup.3] Author Affiliations: (1) Xiamen Key Laboratory of Marine Medical Natural [...]

Ectotherms display substantial demographic variation across latitudinal gradients of temperature. Higher temperatures are often associated with smaller size, rapid initial growth rates, and early maturation, generally described as the Temperature-Size Rule (TSR). The longevity of most ectotherms also declines at warmer, lower latitudes. However, these patterns may be modified by increases in food resources that can flow on to continuous growth and large adult size. The present study estimates age-based demographic parameters of large-bodied tropical wrasses (Hemigymnus melapterus, H. fasciatus, Cheilinus fasciatus, and Oxycheilinus digramma) collected from Philippine fish markets (9-11°N) and sampled from Palm (18.53-18.70°S) and Whitsunday (20.05-20.21°S) reefs on the Great Barrier Reef, Australia (GBR). Differences in longevity, initial growth rates, and the age at sexual maturation at a biogeographic scale, between the Philippines and GBR, conformed to predictions of the TSR. However, Philippine specimens exhibited greater relative body condition and sustained periods of growth beyond sexual maturity resulting in larger adult size than GBR samples. Size-structure data from Philippine marine reserves and fished sites indicated that these differences were not confounded by fishery-dependent sampling. Moreover, latitudinal length-weight relationships could not be explained by lower densities of the focal wrasses in the Philippines or by relative gonad size. Less pronounced patterns of demographic variation that differed across species were evident at a regional scale, among Palm and Whitsunday reefs. Patterns of demographic variation between the Philippines and GBR strongly suggest that differences in food resource levels will be important in explaining the observed geographic variation., Author(s): J. R. Lowe [sup.1] [sup.2] , G. R. Russ [sup.1] [sup.2] , A. A. Bucol [sup.3] , R. A. Abesamis [sup.3] , B. L. Stockwell [sup.4] , J. H. [...]

The presence of plastic waste in the marine environment has driven the scientific community to make significant efforts to study and mitigate its possible effects. One of the critical aspects is to determine if and how an increase in ingestion events may occur as a result of the accumulation of plastic waste on the seabed. In this study, G. melastomus is examined for its ability to indirectly provide information on the amount of macroplastics accumulating on the seafloor. Plastic ingestion is explored by describing the feeding habits of the species, which have the potential to provide very useful information regarding biological or ecological issues. The diet of G. melastomus mainly consisted of cephalopods, bathypelagic fishes, and decapod crustaceans, increasing in diversity during growth. The generalist-opportunistic feeding behaviour of this species leads to the incidental ingestion of plastic particles (N = 47, with a mean (± SD) of 1.47 ± 0.28 per specimen) which can be indirectly associated to the presence of macroplastics on the seafloor. Indeed, our results indicate a significant relationship between the amount of macroplastics present on the seabed and the frequency of ingestion of plastic particles by blackmouth catshark. We propose G. melastomus as an excellent candidate for developing a valid monitoring strategy for the presence of plastics on the seabed, as requested by the EU Marine Strategy Framework Directive., Author(s): Alice Sbrana [sup.1] [sup.2] , Alessandro Cau [sup.3] [sup.4] , Davide Cicala [sup.1] , Simone Franceschini [sup.5] , Tommaso Giarrizzo [sup.6] , Maria Flavia Gravina [sup.1] [sup.4] , Alessandro [...]

Ocean warming and marine heatwaves caused by climate change are adversely affecting the health, structure, and function of coral reefs globally. As seawater temperature continues to rise, and with the intensity and duration of heat stress events expected to increase, it is pertinent to understand the environmental drivers of variability in coral thermal tolerance under both chronic and acute warming. We assessed the performance of three species of corals, Acropora nana, Pocillopora acuta, and Porites lutea, sourced from reefs with distinct thermal regimes (variable vs. stable) in southern Taiwan, when exposed to chronic long-term temperature conditions (12 weeks at 26 °C or 30 °C) and then, using a subset of corals, subsequently exposed to acute short-term elevated temperature conditions (8 days at 32 °C). Under chronic temperature exposure we found clear species-specific responses, and some differences between reef sites and temperature treatments. Despite being perceived as relatively thermally sensitive, A. nana had the most stable maximum quantum yield (F.sub.v/F.sub.m), consistent growth, and the highest survival among the study species. Survival of P. acuta under chronic warming showed the clearest reef site effect and was lower in coral nubbins sourced from the thermally stable reef than the thermally variable reef. Porites lutea showed the greatest decline in F.sub.v/F.sub.m and lowest overall growth under chronic temperature exposure. All coral species, regardless of source reef site or previous chronic temperature exposure, experienced substantial bleaching (50-100% of all nubbins) upon acute exposure to elevated temperature. We found that, overall, corals were able to tolerate chronic warming above seasonal mean temperatures, but that bleaching occurred after acute exposure to a temperature ~ 2 °C above their mean summer maxima., Author(s): Crystal J. McRae [sup.1] [sup.2] [sup.4] , Shashank Keshavmurthy [sup.3] , Pei-Jie Meng [sup.4] [sup.5] , Sabrina L. Rosset [sup.6] , Wen-Bin Huang [sup.1] , Chaolun Allen Chen [sup.3] [...]

Given the current threatening scenario faced by coral reefs, reproductive biotechnologies can be a helping hand in the fight against extinction. Therefore, safe methods to assess viability of coral gametes are essential. In this study, we aimed to develop a reliable method to assess oocyte viability for scleractinian corals using Mussismilia harttii as model. We chose trypan blue (TB) test and the thiazolyl blue tetrazolium bromide (MTT) assay. TB tests were performed in two conditions. First, oocytes were exposed to 1, 3, 5, 7 and 9 mol.sup.-1 dimethyl sulfoxide (DMSO) for 20 min, then incubated in 0.4% TB and had their membrane integrity assessed. Second, to identify if TB was able to stain efficiently, dead oocytes were incubated in TB diluted in filtered seawater or sodium dodecyl sulfate (SDS). For MTT experiments, a serial dilution assay was performed using DMSO as cytotoxic compound. TB was able to cross the oocyte membrane, but because of their high lipid content, the observation of blue color was not possible, making this test unfeasible for oocytes of M. harttii. We were able to standardize the MTT assay for determining mitochondrial activity in mature coral oocytes, and consequently assessing their viability. Equally, the positive linear correlation between MTT concentration and DMSO dilution allowed us to set a safe DMSO concentration (1.4 M) to work with coral oocytes. These results provide a new technique to be applied for assessing coral oocyte viability, which can add efforts in reef monitoring programs and conservation strategies., Author(s): Nayara Oliveira da Cruz [sup.1] , Andrea Giannotti Galuppo [sup.1] , Allison Gonçalves Silva [sup.2] [sup.3] , Luciano da Silva Lima [sup.2] , Danilo Pedro Streit Jr. [sup.1] , [...]