Journal of Experimental Marine Biology and Ecology最新文献

{"title":"A rockling's choice: The trade-off between thermal preference and physical structure in the five bearded rockling, Ciliata mustela","authors":"Bass Dye ,&nbsp;Ingrid Tulp ,&nbsp;Anieke van Leeuwen ,&nbsp;Ewout Blom ,&nbsp;Edward Schram","doi":"10.1016/j.jembe.2023.151959","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151959","url":null,"abstract":"<div><p>Changes in the environment can alter the suitability of habitats for organisms. In marine systems, fish species have their own specific requirements in terms of temperature and other habitat features. Behavioral responses such as thermoregulatory behavior in ectothermic species allow mobile organisms to respond to detrimental changes and search for more suitable habitats. However, for many species, limited information exists on the ecological requirements to help explain species abundance in a changing habitat. An example of a quickly changing habitat is the Wadden Sea, where five bearded rockling (<em>Ciliata mustela</em>) abundance has increased, unlike other Wadden Sea species. The increasing abundance of rockling has coincided with increasing average sea water temperatures and the recovery of mussel and Pacific oyster beds. Warming waters and increased structural habitat may have provided rockling with a more desirable habitat. Therefore, to better understand why rockling abundance is increasing within a changing Wadden Sea, a water temperature preference chamber was used to determine rockling's preferred temperature range. In addition, rockling's affinity for structural habitat and the trade-off between preferred temperature was examined by following their response to the systematic removal of artificial physical structures within the preferred temperature conditions. The preferred temperature range of rockling was found to be 10.4–15.7 °C. Following structure removals, rockling repeatedly moved away from their chosen temperatures to adjacent compartments with different temperatures but containing physical structure, indicating that the presence of physical structure was more important than preferred temperature until 18.6 °C. These novel findings provide insight and experimental support for the hypothesis explaining rockling's increase in the Wadden Sea: 1) mean annual temperatures have been steadily increasing towards rockling's preferred thermal range and 2) increasing mussel and Pacific oyster beds are plausibly providing structural habitat, an important habitat requirement for rockling. When fish display a strong association with physical structure it is necessary to link physiological and habitat preferences to better understand climate change related responses.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"570 ","pages":"Article 151959"},"PeriodicalIF":2.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022098123000916/pdfft?md5=e4f0f522f921554659167c9828dce00b&pid=1-s2.0-S0022098123000916-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92059039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishment of oxidative stress biomarkers in oocytes from healthy and bleached scleractinian corals","authors":"Daniel Castro Martignago ,&nbsp;Leandro Godoy ,&nbsp;Amanda Pereira Amaral ,&nbsp;Guendalina Turcato Oliveira","doi":"10.1016/j.jembe.2023.151963","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151963","url":null,"abstract":"<div><p>Corals have a symbiotic relationship with photosynthetic dinoflagellates associated with the host's tissue, those responsible for most of their daily energy gain. Warming ocean water breaks down symbiosis, leading to a phenomenon known as bleaching. Without their primary nutritional source, corals depend on heterotrophy to survive, which can stagnate the reproductive cycle. There are corals, however, that manage to maintain gametogenesis even when bleached. However, the physiology of these gametes in such a situation is unknown. Our study is the first to evaluate the effects of bleaching on the oocytes of a scleractinian coral, as well as the strategies of these cells to maintain the balance of the antioxidant system and cellular homeostasis. We evaluated and quantified markers of oxidative balance in oocytes released from colonies of <em>Mussismilia harttii</em> with different physiological conditions: bleached and healthy. Healthy and bleached coral oocytes were collected considering a post-spawning time curve (0, 5 and 10 h) and frozen to evaluate the relationship between oxidative balance markers and the physiological conditions of coral colonies. Total protein levels, the activity of the antioxidants superoxide dismutase (SOD) and catalase (CAT), and the levels of lipoperoxidation (TBARS), a marker of lipid damage, were measured. The oocytes presented a significant difference between 0 h and 5 h after spawning for all the parameters regardless of the colony's health. Health status modulated SOD activity and TBARS levels, with oocytes from the bleached colony suffering the most lipid damage. These organisms seem to preserve the quality of female gametic cells even 10 h after spawning in both colonies, suggesting a robust antioxidant system capable of prolonging their lifespan and, possibly, their fertilization capability. This response may be related to an intensification of heterotrophy, ensuring nutritional support and thus reproductive effort and quality of gametes even in bleached corals.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"570 ","pages":"Article 151963"},"PeriodicalIF":2.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71770870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Choanocyte dimensions and pumping rates in the demosponge Halichondria panicea","authors":"Hans Ulrik Riisgård ,&nbsp;Rachael A. Kealy ,&nbsp;Josephine Goldstein ,&nbsp;Jonathan R. Brewer ,&nbsp;Vita Solovyeva ,&nbsp;Peter Funch","doi":"10.1016/j.jembe.2023.151957","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151957","url":null,"abstract":"<div><p>The individual choanocyte pumping rate in choanocyte chambers (<em>CC</em>s) is important for understanding the hydrodynamics in sponges and has hitherto been based on measured volume-specific filtration rate and estimated <em>CC</em> density. However, the <em>CC</em> density may vary in different regions of the sponge and to circumvent this uncertainty and to get precise measurements of the individual choanocyte pumping rate, a new experimental approach was developed. Here the aim was to measure the individual pumping rate of choanocytes based on live dimensions of <em>CC</em> elements and particle tracking to measure the speed of small particles entering into the <em>CC</em>s. This was done by using combined live-cell imaging in sandwich cultures of the marine demosponge <em>Halichondria panicea</em> and video-tracking of particles. Small 2 μm-beads and cyanobacteria (<em>Cyanobium bacillare</em>) in the incurrent canal enter the <em>CC</em>s via a 3.3 ± 0.9 μm diameter prosopyle to be subsequently captured by the choanocytes whereas larger algal cells (<em>Rhodomonas salina</em>) and 10 μm-beads are captured in the incurrent canals. <em>CC</em> diameters were positively correlated to the diameter of choanocytes, indicating a total of 84 choanocytes per <em>CC</em> with mean diameter 22.9 ± 6.2 μm. The pumping rate per choanocyte (<em>Q</em>_c) was estimated to be between 54 and 68 μm³ s⁻¹. Regardless of demosponge species and based on data in the literature, a choanocyte is suggested to pump between 50 and 100 μm³ s⁻¹.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151957"},"PeriodicalIF":2.0,"publicationDate":"2023-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022098123000898/pdfft?md5=9f222eb3ce43e74d5cbf8edabf63038e&pid=1-s2.0-S0022098123000898-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92061979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of UV radiation on photosynthesis of Sargassum muticum","authors":"Zhiguang Xu ,&nbsp;Baoqi Li ,&nbsp;Lingxue Li ,&nbsp;Ning Wang ,&nbsp;Yu Wang ,&nbsp;Hui Wang ,&nbsp;Fang Yan ,&nbsp;Menglin Bao ,&nbsp;Shasha Zang ,&nbsp;Hongyan Wu ,&nbsp;Shan Sun","doi":"10.1016/j.jembe.2023.151961","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151961","url":null,"abstract":"<div><p><span>As an invasive species<span> of macroalgae, </span></span><span><span>Sargassum muticum</span></span><span> (Yendo) Fensholt has invaded European shores and the Mediterranean, and even drifting individuals have been observed in sea area near the Canary Islands, becoming a potential species responsible for the “</span><em>Sargassum</em><span> golden tide”. When drifting on the sea surface, algae receive more ultraviolet radiation (UVR). However, photosynthetic responses and adaptation mechanism of </span><em>S. muticum</em><span> to UVR remain unclear. In this study, thalli of </span><em>S. muticum</em> were respectively exposed under two radiation treatments of 200 W m⁻² PAR (photosynthetically active radiation, 400–700 nm), and 200 W m⁻² PAR + 38 W m⁻² UVR (280–700 nm) for 120 mins, and then recovered at a low light (PAR) of 10 μmol photons m⁻² s⁻¹ for 240 mins. During this treatment, the photosynthetic properties of algae were measured, to investigate the responses and protection mechanism of <em>S. muticum</em> to UVR. The results showed that photosynthesis of thalli was significantly inhibited by UVR, reflected by decreased maximum photochemical quantum yield (<em>F</em>_<em>v</em><em>/F</em>_<em>m</em><span><span><span>) and chlorophyll content, and changes of parameters of rapid light response curve and chlorophyll fluorescence<span><span><span> induction curve in PAR and PAR + UVR treatments. Meanwhile, algae actively adopted several strategies to alleviate the inhibition caused by UVR, including photoprotection characterized by increased contents of UV-absorbing compounds (UVACs) and </span>carotenoids (Car), excess light </span>energy dissipation<span> by elevated non-photochemical quenching (NPQ) coupled to the xanthophyll cycle, and photorepair manifested as an accelerated synthesis of </span></span></span>D1 protein and enhanced antioxidant for scavenging </span>ROS. Benefiting from the effects of the above several pathways, after 240 mins of low light recovery, photosynthesis was greatly restored in these two radiation treatments, with the restoration of </span><em>F</em>_<em>v</em><em>/F</em>_<em>m</em> and parameters of rapid light response curve and chlorophyll fluorescence induction curve. Based on these results, we conservatively speculate that the photosynthesis of drifting <em>S. muticum</em> individuals may be restored in the evening with low light levels after being damaged by UVR on the surface of sea at midday, resulting in maintaining rapid growth and forming a golden tide.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151961"},"PeriodicalIF":2.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92046980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of territorial damselfish on corallivorous fish assemblage composition and coral predation in the Mauritian lagoon","authors":"I.C. Tiddy ,&nbsp;D. Kaullysing ,&nbsp;D.M. Bailey ,&nbsp;S.S. Killen ,&nbsp;A. Le Vin ,&nbsp;R. Bhagooli","doi":"10.1016/j.jembe.2023.151960","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151960","url":null,"abstract":"<div><p>Predation is a significant stressor for many coral species. Understanding how predation interacts with factors such as climate change is key to coral conservation. Territorial damselfish of the genus <em>Stegastes</em> form territories on branching corals (genus <em>Acropora</em>) on which they cultivate algae, and while defending these territories, provide corals with indirect protection from predation. However, it is not known how the protection afforded by <em>Stegastes</em> spp. varies with corallivorous fish assemblage composition, nor whether corallivore assemblages themselves may be affected by the presence of <em>Stegastes</em> spp. and their associated <em>Acropora</em> spp. habitats. This study examined relationships among predation protection by <em>Stegastes</em> spp., branching <em>Acropora</em> coral cover, and the number and species richness of corallivorous fish present within a given area, namely the Mauritian lagoon in the western Indian Ocean. Predation on bleaching-resilient massive <em>Porites lutea</em> corals within and outside <em>Stegastes</em> territories was surveyed at sites around Mauritius island. Corallivorous fish assemblages, branching coral cover, and <em>Stegastes</em> spp. density were also surveyed at each site visit. Results show that high predation was correlated with the presence of high numbers of corallivores, but predation was lower within <em>Stegastes</em> spp. territories irrespective of all observed corallivore densities. Greater numbers of <em>Stegastes</em> spp. were correlated with increasing density of obligate corallivores. Non-Acroporid coral cover was positively correlated with species richness of obligate corallivores, while branching <em>Acropora</em> coral cover was negatively correlated with overall corallivore density. This study shows for the first time that predation on bleaching-resilient massive corals is lower within <em>Stegastes</em> spp. territories regardless of the number of corallivores present, adding to the growing body of knowledge on the complex relationships between <em>Stegastes</em> spp. and their environment. The findings also indicate possible effects of the presence of <em>Stegastes</em> spp. and their branching <em>Acropora</em> habitats on corallivorous fish density in areas with low coral diversity, which may warrant further study.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151960"},"PeriodicalIF":2.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022098123000928/pdfft?md5=af81a9d3672883f997996a86632f9385&pid=1-s2.0-S0022098123000928-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92061978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empirical measurements of ammonium excretion in kelp forest fishes: Effects of body size, taxonomy and trophic guild","authors":"June Shrestha,&nbsp;Kenneth H. Coale,&nbsp;Scott L. Hamilton","doi":"10.1016/j.jembe.2023.151956","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151956","url":null,"abstract":"<div><p>Fishes and other consumers excrete metabolic waste products, including dissolved nutrients rich in nitrogen, which is an essential nutrient for primary production. Relatively little is known about the magnitude and variability of nutrients excreted by fishes in kelp forest ecosystems and whether consumer-derived nutrients are important for supporting kelp productivity. In this study, the supply of ammonium (NH₄⁺) excreted by the dominant fishes (30 species representing ∼85% of total fish biomass) was investigated on nearshore rocky reefs in California. Using rapid field incubations, the amount of excreted dissolved ammonium was measured as a function of body size (<em>n</em> = 460 individuals) and predictive models were developed relating mass to excretion rates at the family-level. Mass-specific excretion rates ranged from 0.08 to 3.45 μmol·g⁻¹·hr⁻¹, and per capita ammonium excretion rates ranged from 5.9 to 2765 μmol·individual·hr⁻¹. Ammonium excretion scaled with fish body mass to the ¾ power, as predicted by the metabolic theory of ecology; mass-specific excretion rates were higher in smaller fishes, but larger fishes contributed more ammonium per individual. When controlling for body size, ammonium excretion rates were greatest among surfperch (Embiotocidae), damselfish (Pomacentridae), and wrasses (Labridae), and the general trophic groups of planktivores and micro-carnivores. When body size differences were considered, the greatest mean excretion rates per individual were observed in larger-bodied species, such as California Sheephead (<em>Semicossyphus pulcher</em>) and Lingcod (<em>Ophiodon elongatus</em>). Empirical estimates of nutrient excretion by fishes, among the first measured in temperate kelp forests, were consistent with those in other aquatic systems. Ultimately, empirically derived excretion rates are the first step to quantifying the relative importance of consumers to nutrient cycling in kelp forest ecosystems.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151956"},"PeriodicalIF":2.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50193003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the impact of introduced crabs on the distribution and morphology of littorinid snails: Implications for the survival of the snail Littorina saxatilis","authors":"Christopher D. Wells ,&nbsp;Kaitlin S. Van Volkom ,&nbsp;Sara Edquist ,&nbsp;Sinead Marovelli ,&nbsp;John Marovelli","doi":"10.1016/j.jembe.2023.151958","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151958","url":null,"abstract":"<div><p><span>Introduced species can have profound impacts on communities by displacing and consuming native organisms. The intertidal communities in the Gulf of Maine have been radically altered through a suite of invasions in the early 1800s, including the herbivorous snail </span><span><em>Littorina</em><em> littorea</em></span> and the omnivorous European green crab <span><em>Carcinus maenas</em></span> leading to morphological and distributional changes in two native gastropod grazers (<em>Littorina saxatilis</em> and <em>Littorina obtusata</em><span>). Green crabs and native cancrid crabs occupy the mid to low intertidal zones, leaving the high intertidal zones relatively free from crab predation pressure. However, a more recent invasion in the 1980s by the intertidal omnivorous Asian shore crab </span><span><em>Hemigrapsus sanguineus</em></span>, has eliminated this predator-free zone in the high intertidal. This invasion is of particular concern to populations of <em>L. saxatilis</em>, which were relegated to the high intertidal through combined competition and predation pressure by <em>L. littorea</em> and <em>C. maenas.</em> In order to quantify the potential impact of <em>H. sanguineus</em> on native snails, we conducted both field and lab experiments, testing the susceptibility of different sized snails to predation by introduced crabs. Additionally, we measured the distribution, abundance, and morphology of intertidal snails and crabs. Smaller snails of all species were the most susceptible to predation, although susceptibility differed among snail species and predation capabilities differed among crab species. <em>L. saxatilis</em> was the most vulnerable snail species to predation, with 73 and 64% of the population susceptible to large <em>H. sanguineus</em> and small <em>C. maenas</em>, respectively, while &gt;96% of the <em>L. littorea</em> population was resistant to predation. <em>L. saxatilis</em> has been relegated to the high intertidal where there is high abiotic stress and poor-quality food, but until the invasion of <em>H. sanguineus</em><span>, there was little predation risk. This added predation pressure may further threaten populations of </span><em>L. sa</em>x<em>atilis,</em> especially as the upper intertidal becomes more hostile with increasing temperatures and possible species introductions.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151958"},"PeriodicalIF":2.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50193001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of temperature and feeding regime on cortisol concentrations in scales of Atlantic salmon post-smolts","authors":"Christina O'Toole ,&nbsp;Philip White ,&nbsp;Katie Thomas ,&nbsp;Niall O'Maoiléidigh ,&nbsp;Per Gunnar Fjelldal ,&nbsp;Tom Johnny Hansen ,&nbsp;Conor T. Graham ,&nbsp;Deirdre Brophy","doi":"10.1016/j.jembe.2023.151955","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151955","url":null,"abstract":"<div><p>Anadromous fish are vulnerable to anthropogenic and environmental stressors including pollution, rising temperatures, and changes in food availability. Knowledge of how fish respond to specific stressors aid our understanding of population declines and inform predictions of how populations will react to future environmental change. There is increasing interest in using cortisol measurements from fish scales to measure chronic stress in fish, however the effects of increased metabolic rate on scale cortisol dynamics must also be considered. This study examines the effect of temperature and feeding conditions on scale cortisol in Atlantic salmon (<em>Salmo salar</em>). Post-smolts were subjected to three different temperatures (6, 10.5 and 15 °C) and four feeding/starvation treatments over a 12-week period. Females held at 6 and 15 °C had significantly higher scale cortisol levels than those held at 10.5 °C, while rearing temperature had no effect on scale cortisol in males. The increase in scale cortisol at 6 °C indicated that temperature related differences were not driven solely by metabolic rate. A two-week starvation period produced an increase in scale cortisol in males and females held at 10.5 °C but not at 6 °C or 15 °C. The study demonstrates that scale cortisol fluctuations can be detected in a low amount (∼10 mg) of Atlantic salmon scales for monitoring of the physiological stress response. Scale cortisol shows potential for monitoring physiological responses during the marine phase in Atlantic salmon. However, the influence of environmental stressors on scale cortisol needs to be better understood, with consideration for sex-specific and interactive effects.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151955"},"PeriodicalIF":2.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50193002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of incubation duration and clutch relocation on hatchling morphology and locomotor performances of green turtle (Chelonia mydas)","authors":"Marion Steenacker ,&nbsp;Lyndsey K. Tanabe ,&nbsp;Mohd Uzair Rusli ,&nbsp;Denis Fournier","doi":"10.1016/j.jembe.2023.151954","DOIUrl":"https://doi.org/10.1016/j.jembe.2023.151954","url":null,"abstract":"<div><p><span>The carapacial scute pattern of sea turtles is a conserved trait that provides taxonomic information. But non-modal scute patterns (NMSPs), </span><em>i.e.</em> intraspecific individual variabilities, are observed for almost all species and occur relatively often, particularly in hatchlings. We surveyed 67 nests from 61 nesting green turtle females (<span><em>Chelonia mydas</em></span>) over an eight-week study duration on Redang Island, Malaysia. During this study, eight NMSP females laid two different clutches. For all newly emerged hatchlings from each nest (<em>n</em> = 4386), we analyzed their scute pattern (<em>i.e.</em><span> the number of vertebral and costal scutes). For a subsample of 1144 hatchlings, we compared their carapace size, weight, and their locomotor performances (self-righting ability, running and swimming speeds). The proportion of hatchlings with NMSP varied from 0 to 70.4% (mean ± SD = 16.4% ± 16.2) per nest. We compared the scute pattern of nesting females to that of their hatchlings and found that the scute pattern of the mother does not predestine that of her descendants. However, our results revealed that the main driver of scute pattern abnormalities and hatching success was the shorter incubation duration (</span><em>i.e.</em> warmer incubation temperatures). Eggs hatched after a short incubation period have lowered hatching success. Our data showed also that relocated nests have a greater proportion of NMSP hatchlings compared to <em>in situ</em><span> nest. Conversely, the scute pattern and clutch relocation do not appear to be linked to lower hatching success or slower locomotor speeds. Our work highlights the effects of incubation duration and clutch relocation techniques on the morphology and survival of green turtle and contributes to better informed management strategies as part of global research efforts to preserve an endangered species. Based on our findings, we suggest strictly following guidelines for relocating a sea turtle nest and applying clutch relocation to populations where hatching success is very low or only as a last resort for doomed nests.</span></p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"569 ","pages":"Article 151954"},"PeriodicalIF":2.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50193008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Burrowing crabs' influence on tidal marsh vegetation species composition and abundance in a temperate back-barrier marsh, Cape Cod, Massachusetts, USA","authors":"Megan C. Tyrrell ,&nbsp;Sofi Courtney ,&nbsp;Emily Brown ,&nbsp;Christian von Sperber","doi":"10.1016/j.jembe.2023.151931","DOIUrl":"10.1016/j.jembe.2023.151931","url":null,"abstract":"<div><p><span>Emergent vegetation in coastal marshes<span><span> across the Northeastern United States have been declining and changing in relative species composition due to abiotic factors such as accelerated </span>sea level rise<span>, storm intensity, excess nutrients<span>, and other anthropogenic disturbances. A possible biotic factor in marsh decline is increased perturbation from burrowing crabs. </span></span></span></span><span><em>Uca</em><em> pugilator</em></span> and <em>Minuca pugnax</em><span> (fiddler crabs) whose populations are increasing in many marshes in the eastern US, likely due to disruptions in food webs and expanding habitat from sea level rise. High densities of crab burrows contribute to creek bank erosion and possibly in other factors of marsh peat degradation. When burrowing crabs were excluded from large scale (9 m</span>²<span>) plots in a Cape Cod, MA, marsh for five months, vegetation species richness increased significantly, as did abundance of woody shrubs and the forb, </span><span><em>Suaeda</em><em> maritima</em></span> (L.). Conversely, burrowing crab exclusion resulted in less <span><em>Spartina</em><em> alterniflora</em></span> (Loisel) and less bare ground - indicating that the other types of vegetation were able to occupy more space in the absence of crab burrowing and sediment sorting activity. The experimental enclosure results were compared with vegetation and burrow density monitoring data taken from nearby long-term monitoring plots. Of the sixteen analyses, we found only one similar result between the 5 month exclusions and monitoring plots; high burrow densities were associated with higher density of <em>S. alterniflora</em>. In contrast to the exclusions, high burrow densities were positively correlated with abundance of <em>Iva frutescens</em> and <em>Suaeda maritima.</em> Six other species (or groupings of rare plants) were negatively associated with burrow densities, four of these are sensitive to inundation and are considered characteristic of the high marsh zone. Different interpretations of the effects of burrowing crabs will result depending on whether correlations are observed from monitoring plots or longer term, large-scale exclusions are conducted; both are needed to assess the rapid vegetation and faunal shifts that are occurring in temperate salt marshes. We suggest that <em>Uca pugilator</em> and <em>Minuca</em> sp. will benefit from sea level rise induced habitat expansion at the expense of the abundance and species richness of flooding-sensitive plants. The erosion and vegetation disturbance that high burrowing crab densities lead to will further exacerbate the decline of these species that are receding at the seaward edge of their distributions.</p></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"567 ","pages":"Article 151931"},"PeriodicalIF":2.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42534318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}