Search

Ophryotrocha diademais an outcrossing, simultaneous hermaphroditic polychaete with external fertilization. In isolated pairs, mature worms take turn contributing eggs upon the condition that their partners reciprocate egg donation. In dense populations, these worms do not reciprocate. Instead, they strongly compete for mating in their preferred male role and produce few eggs. This plastic sex allocation may result in an overall different reproductive performance: mean individual reproductive output will be larger in sparse than in dense populations. We tested this hypothesis by measuring the individual reproductive output (paternal and maternal offspring) of worms in sparse and dense replicated populations. In dense populations, mean individual reproductive output was fourfold lower than that in sparse populations. We hypothesise that such dramatic demographic costs are potentially widespread in outcrossing simultaneous hermaphrodites with external fertilization and plastic sex allocation. The reproductive output of hermaphroditic organisms is a function of population density (i.e. the number of conspecifics) and studies on population growth and reproductive performance should take this effect into account. [ABSTRACT FROM PUBLISHER]

Glyphosate is the most widely used systemic herbicide. There is ample scientific literature on the effects of this compound and its metabolite aminomethylphosphonic acid (AMPA), whereas their possible combined genotoxic action has not yet been studied. With the present study, we aimed to determine the level of genomic damage caused by glyphosate and AMPA in cultured human lymphocytes and to investigate the possible genotoxic action when both compounds were present at the same concentrations in the cultures. We used a micronuclei assay to test the genotoxicity of glyphosate and AMPA at six concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 μg/mL), which are more realistic than the highest concentrations used in previous published studies. Our data showed an increase in micronuclei frequency after treatment with both glyphosate and AMPA starting from 0.050 μg/mL up to 0.500 μg/mL. Similarly, a genomic damage was observed also in the cultures treated with the same concentrations of both compounds, except for exposure to 0.0065 and 0.0125 μg/mL. No synergistic action was observed. Finally, a significant increase in apoptotic cells was observed in cultures treated with the highest concentration of tested xenobiotics, while a significant increase in necrotic cells was observed also at the concentration of 0.250 μg/mL of both glyphosate and AMPA alone and in combination (0.125 + 0.125 μg/mL). Results of our study indicate that both glyphosate and its metabolite AMPA are able to cause genomic damage in human lymphocyte cultures, both alone and when present in equal concentrations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aminomethylphosphonic acid (AMPA) is the main metabolite in the degradation of glyphosate, a broad-spectrum herbicide, and it is more toxic and persistent in the environment than the glyphosate itself. Owing to their extensive use, both chemicals pose a serious risk to aquatic ecosystems. Here, we explored the genotoxicological and physiological effects of glyphosate, AMPA, and the mixed solution in the proportion 1:1 in Lymnaea stagnalis, a freshwater gastropod snail. To do this, adult individuals were exposed to increasing nominal concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 µg/mL) in all three treatments once a week for four weeks. The genotoxicological effects were estimated as genomic damage, as defined by the number of micronuclei and nuclear buds observed in hemocytes, while the physiological effects were estimated as the effects on somatic growth and egg production. Exposure to glyphosate, AMPA, and the mixed solution caused genomic damage, as measured in increased frequency of micronuclei and nuclear buds and in adverse effects on somatic growth and egg production. Our findings suggest the need for more research into the harmful and synergistic effects of glyphosate and AMPA and of pesticides and their metabolites in general., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Glufosinate-ammonium (GLA), an organophosphate herbicide, is released at high concentrations in the environment, leading to concerns over its potential genotoxic effects. However, few articles are available in the literature reporting the possible cellular and nuclear effects of this compound. We assessed, by in vitro and in vivo micronucleus assays, the genotoxicity of GLA on cultured human lymphocytes and Lymnaea stagnalis hemocytes at six concentrations: 0.010 (the established acceptable daily intake value), 0.020, 0.050, 0.100, 0.200, and 0.500 µg/mL. In human lymphocytes, our results reveal a significant and concentration-dependent increase in micronuclei frequency at concentrations from 0.100 to 0.500 μg/mL, while in L. stagnalis hemocytes, significant differences were found at 0.200 and 0.500 μg/mL. A significant reduction in the proliferation index was observed at all tested concentrations, with the only exception of 0.010 μg/mL, indicating that the exposure to GLA could lead to increased cytotoxic effects. In L. stagnalis, a significant reduction in laid eggs and body growth was also observed at all concentrations. In conclusion, we provided evidence of the genomic and cellular damage induced by GLA on both cultured human lymphocytes and a model organism's hemocytes; in addition, we also demonstrated its effects on cell proliferation and reproductive health in L. stagnalis .

Sturgeon farming is rapidly expanding in Europe, where Italy ranks first in farmed caviar production. A major threat to sturgeon health in captivity is infection with Acipenser European Iridovirus (AcIV-E), a viral disease definitively identified in 2016. Here we present data on the occurrence of AcIV-E in 482 sturgeons (age ≤ 12 months, species of the genus Acipenser and the species Huso huso ) collected from sturgeon farms in northern Italy between January 2021 and December 2023. The health status of each specimen was determined by necroscopy and virological assay. Virological analysis was performed on gill samples and real-time PCR specific to the MCP gene of the iridovirus viral capsid. Molecular analysis revealed positivity to the virus in 204 samples (42.68% of the total), while anatomopathological examination of nearly all fish with positive real-time PCR disclosed swollen abdomen, hepatic steatosis, splenomegaly, and increased gill volume. Two challenges to timely diagnosis are the absence of pathognomonic symptoms and the inability to isolate the virus on cell monolayers. Continuous and widespread health monitoring is therefore crucial for disease management and to effectively control spread of the virus.

Red mullet ( Mullus barbatus ) is a commercially relevant fish species, yet epidemiological data on anisakid nematode infestation in M. barbatus are scarce. To fill this gap, we report the occurrence of Anisakis larvae in red mullet in the Ligurian Sea (western Mediterranean). This survey was performed between 2018 and 2020 on fresh specimens of M. barbatus (n = 838) from two commercial fishing areas (Imperia, n = 190; Savona, n = 648) in the Ligurian Sea. Larvae morphologically identified as Anisakis spp. (n = 544) were characterized using PCR-RFLP as Anisakis pegreffii . The overall prevalence of A. pegreffii was 24.46%; the prevalence at each sampling site was 6.32% for Imperia and 29.78% for Savona. Furthermore, 3300 larvae of Hysterothylacium spp. were detected in the visceral organs of fish coinfected with A. pegreffii , showing that coinfection with two parasitic species is not rare. This study provides a timely update on the prevalence of ascaridoid nematodes in red mullet of the Ligurian Sea, an important commercial fishing area in the Mediterranean.

Benzophenone-3 (BP-3) is a lipophilic organic compound that occurs naturally in flower pigments. Since it adsorbs ultraviolet (UV) radiation in the UVA and UVB regions, it is one of the most common UV filters found in sunscreen and cosmetic products. We explored by in vivo micronuclei (MNi) assay the genotoxic effects of BP-3 on hemocytes from the freshwater gastropod Lymnaea stagnalis . We also studied its possible toxic effects on life-history traits: body growth in L. stagnalis and egg production of both L. stagnalis and the marine polychaete worm Ophryotrocha diadema. Adult individuals were exposed to increasing concentrations of BP-3 (0.025, 0.050, 0.100, and 0.200 mg/L) once a week for 4 weeks. In L. stagnalis, exposure to BP-3 at concentrations of both 0.2 and 0.1 mg/L produced genotoxic effects on the micronuclei frequencies, but only concentrations of 0.2 mg/L affected the NBUDs frequencies. Similarly, negative effects on body growth were observed at the concentrations of 0.2 and 0.1 mg/L and a significant reduction of egg production at 0.2 mg/L. In O. diadema , a negative correlation between egg production and increasing BP-3 concentrations was observed. Our findings suggest the need for more stringent measures to reduce the presence of BP-3 in the environment.

Hermaphrodites are characterized by plastic sex allocation, by which they adjust their allocation of reproductive resources according to mating opportunities. However, since the plasticity of sex allocation is influenced by environmental conditions, it may also be affected by species-specific life-history traits. In this study, we explored the trade-off between nutritional stress due to food deficiency and the investment of resources in female allocation and somatic growth in the simultaneously hermaphroditic polychaete worm, Ophryotrocha diadema . To achieve this, we exposed adult individuals to three food supply levels: (1) ad libitum-100% food supply, (2) intense food deficiency-25% food resources, and (3) extreme food deficiency-0% food resources. Our findings show a progressive decrease in female allocation in the numbers of cocoons and eggs and in body growth rate of O. diadema individuals as the level of nutritional stress increased.

Glyphosate is a broad-spectrum herbicide widely employed in agriculture. Exposure to this genotoxic and endocrine-disrupting compound has adverse effects on terrestrial and aquatic organisms and on humans as well. Here, we explored the effects of glyphosate on female reproductive output and somatic growth rate in the marine polychaete worm, Ophryotrocha diadema. Adult focal individuals were exposed to different concentrations of pure glyphosate (0.0, 0.125 0.250, 0.500, 1.000 µg/mL) administered once a week for 3 weeks. Toxic effects and mortalities were observed at the three higher concentrations, whereas only a decrease in growth rate was noted after exposure to 0.125 µg/mL, which did not affect female allocation. An area of focus in future studies should be the effects of contaminants, their metabolites, and ecologically relevant human-driven stressors in the context of global warming.

Conditional reciprocity (help someone who helped you before) explains the evolution of cooperation among unrelated individuals who take turns helping each other. Reciprocity is vulnerable to exploitations, and players are expected to identify uncooperative partners who do not return the help they received. We tested this prediction in the simultaneously hermaphroditic worm, Ophryotrocha diadema, which engages in mutual egg donations by alternating sexual roles (one worm releases' eggs and the other fertilizes them). We set up dyads with different cooperativeness expectations; partners were either the same or a different body size (body size predicts clutch size). Large worms offered larger clutches and did so sooner when paired with large rather than small partners. They also released smaller egg clutches when they started egg donations than when they responded to a partners' donation, fulfilling the prediction that a players' first move will be prudent. Finally, behavioral bodily interactions were more frequent between more size-dissimilar worms, suggesting that worms engaged in low-cost behavioral exchanges before investing in such costly moves as egg donations. These results support the hypothesis that simultaneously hermaphroditic worms follow a conditional reciprocity paradigm and solve the conflict over sexual roles by sharing the costs of reproduction via the male and the female functions.

The increase in atmospheric carbon dioxide (CO 2 ) leads to rising temperatures and acidification in the oceans, which directly or indirectly affects all marine organisms, from bacteria to animals. We here ask whether the simplest-and possibly also the oldest-metazoan animals, the placozoans, are particularly sensitive to ocean warming and acidification. Placozoans are found in all warm and temperate oceans and are soft-bodied, microscopic invertebrates lacking any calcified structures, organs, or symmetry. We here show that placozoans respond highly sensitive to temperature and acidity stress. The data reveal differential responses in different placozoan lineages and encourage efforts to develop placozoans as a potential biomarker system.

Sex allocation theory predicts that, in hermaphroditic organisms, individuals allocate a fixed amount of resources divided among male and female functions to reproduction and that the proportion devoted to each sex depends on the mating group size. As the mating group size increases, hermaphrodites are predicted to allocate proportionally more resources to the male and less resources to the female function (approaching equal allocation to both sexes) to face increased sperm competition. Up to now little experimental evidence has been provided to support the theory in hermaphroditic animals. Facultative shift between male and female allocation in response to variation in local group size does occur in several taxa but not always in the expected direction and not with similar patterns. In the protandric and then simultaneously hermaphroditic polychaete worm Ophryotrocha diadema reproductive resources are flexibly allocated in the protandrous and the hermaphroditic phase. The cost of male reproduction during adolescence is spread over the whole energy budget of the animal as shown by the shortening of lifespan and the lowering of growth rate in individuals with enhanced male expenditure during the protandrous phase. Moreover, in this species, short term sex allocation adjustments differ from those described in other taxa. Individuals regulate their reproductive output so that where reproductive competitors are present, the number of female gametes is strongly reduced but the number of male gametes (although it changes) is not significantly increased. Resources subtracted from the female function are not directly allocated to sperm production, but to expensive male behaviors that are likely to enhance male reproductive success. These results are discussed in the light of the relevance of sexual selection in large populations of hermaphrodites.