Journal of Experimental Marine Biology and Ecology最新文献

{"title":"Incubation duration and predicted hatchling sex ratios of leatherback turtles (Dermochelys coriacea) in the southwestern Atlantic Ocean (1988–2021)","authors":"Liliana P. Colman ,&nbsp;Cecília Baptistotte ,&nbsp;Brendan J. Godley ,&nbsp;João C.A. Thomé ,&nbsp;Ana C. Marcondes ,&nbsp;Jonathan R. Monsinjon ,&nbsp;Alexsandro Santos ,&nbsp;Ana Rita Caldas Patrício ,&nbsp;Gustavo Stahelin ,&nbsp;Annette C. Broderick","doi":"10.1016/j.jembe.2025.152100","DOIUrl":"10.1016/j.jembe.2025.152100","url":null,"abstract":"<div><div>Knowledge of sex ratios of species with temperature-dependent sex determination (TSD) is key to provide baseline information which can be used to inform management strategies and predictions of how climate change can affect populations. In marine turtles, increased incubation temperatures can lead to extreme biases in sex ratios and reduced hatching success. Here we present a long-term analysis (34 years) of incubation durations of leatherback turtles (<em>Dermochelys coriacea</em>) in Brazil, the only population of this species breeding in the Southwest Atlantic, and estimate offspring sex ratios. We deployed data loggers recording nest temperatures in 2015, 2016, 2017 and 2019 (<em>n</em> = 28 clutches), to predict offspring sex ratios based on incubation temperatures during the thermosensitive period when sex is determined. The overall mean incubation duration for leatherback turtle clutches in Brazil (1988–2021) was 66.3 days (range 52–91, SD = 6.4, <em>n</em> = 867), decreasing by 4.4 days between the first and last 10 years of monitoring and varying latitudinally across the nesting range of the population. When modelled to the overall nesting season and accounting for nesting seasonality, we estimated the current (2012−2021) mean season-wide primary sex ratio to be 46.9 % female (range 32.7 % to 84.8 %). Hindcasting for the first ten years of monitoring (1988–1997) showed the average predicted offspring sex ratios would have been 34.6 % female (range 7.7 % to 68.1 %). This population has not shown a phenological shift in the timing of nesting over the period 1988–2021. These findings suggest that, although the primary sex ratio of this population has likely become more female-biased in recent decades, the spatial and temporal variation observed demonstrates some resilience to the effects of increasing temperatures under climate change.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"586 ","pages":"Article 152100"},"PeriodicalIF":1.8,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705891","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":"Flexible foraging strategies of a tropical seabird in the western Atlantic Ocean","authors":"Júlia Jacoby ,&nbsp;Amédée Roy ,&nbsp;Sophie Lanco ,&nbsp;Christophe Barbraud ,&nbsp;Karine Delord ,&nbsp;Leandro Bugoni ,&nbsp;Guilherme T. Nunes","doi":"10.1016/j.jembe.2025.152099","DOIUrl":"10.1016/j.jembe.2025.152099","url":null,"abstract":"<div><div>Tropical oceans are typically oligotrophic but can feature productive environments, such as islands, which can promote high prey availability, influencing predators' foraging strategies in time and space. This study investigates interannual and sex-specific variations in the foraging ecology of the masked booby (<em>Sula dactylatra</em>) in the Fernando de Noronha Archipelago, western tropical Atlantic Ocean. During the 2017, 2018, 2019, and 2022 breeding seasons, blood from birds and muscle samples from regurgitated prey were analyzed for stable isotopes of carbon (<em>δ</em>¹³C) and nitrogen (<em>δ</em>¹⁵N). Simultaneously, birds were tracked with GPS devices and their dives were recorded by pressure sensors and later predicted by deep learning tools to estimate foraging areas. Tracking data revealed foraging areas eastward of the archipelago in all years, potentially driven by the Island Mass Effect. The <em>δ</em>¹³C and <em>δ</em>¹⁵N values varied significantly across the four years, but isotopic niches overlapped, except in 2022. Mixing models estimated the fourwing flying fish <em>Hirundichthys affinis</em> as an important prey source from 2017 to 2019, shifting to false herring <em>Harengula clupeola</em> in 2022. Simultaneously, foraging areas were closer to the archipelago in 2022, with shorter foraging trip duration and length. Stable isotope differences between sexes were occasional, with overlapping niches and foraging areas consistent across years. These findings showcase potential predictability in foraging areas, and also their interannual variability, suggesting shifts in prey availability and distribution around the archipelago. Our results highlight the ecological plasticity of masked boobies in tropical environments and their potential as monitors of fish community dynamics.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"586 ","pages":"Article 152099"},"PeriodicalIF":1.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680478","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":"Major and trace nutrient concentrations in sub-Antarctic forage fish around the Kerguelen Islands: All are not equal for nutrient recycling by top predators","authors":"Lola Gilbert ,&nbsp;Tiphaine Jeanniard-du-Dot ,&nbsp;Yves Cherel ,&nbsp;Jérôme Spitz","doi":"10.1016/j.jembe.2025.152097","DOIUrl":"10.1016/j.jembe.2025.152097","url":null,"abstract":"<div><div>While the nutrient content of forage species is crucial to study how marine top predators release nutrients in their waste (faeces and urine) and possibly facilitate nutrient recycling at lower trophic levels of the food webs, it is poorly documented in many ecosystems. Here, we analyse the concentrations of five major nutrients, eight essential trace nutrients, and four non-essential nutrients in 34 mesopelagic and demersal forage fish species from the Kerguelen Plateau area (Southern Indian Ocean). This biogeochemically singular region benefits from natural iron (Fe) fertilisation and is an oasis for marine life in the high nutrient low chlorophyll Southern Ocean. Its nutrient dynamics have been subject to intense research for decades, but the contribution of the biota remain unexplored. Local forage fish were found to be significantly heterogeneous in their absolute nutrient concentrations, and in their relative nutrient content. Using hierarchical clustering, we showed that some species were enriched in nutrients found in limited concentrations in Southern Ocean surface waters, such as Fe and manganese (Mn), whereas others were enriched in nutrients likely limiting primary productivity in terrestrial ecosystems, such as phosphorus (P) or calcium (Ca). These fish species could be major contributors to these nutrients' biological cycling in different ecosystems when consumed by predators. This functional typology further demonstrates that prey are not interchangeable. The consumption of one or another prey species modulates not only the ability of the predator to meet its requirements and exposure to contaminants, but also predator-mediated nutrient recycling. This work provides valuable baseline knowledge that can be used in studies of nutrition, nutrient dynamics, and contaminant transfer. It also paves the way for the inclusion of predator-prey relationships in local biogeochemical studies to help unravel the complex processes at work in this unique ecosystem.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"586 ","pages":"Article 152097"},"PeriodicalIF":1.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680479","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":"Automatic periphyton sampler (APS): A new technique for precise in-situ sampling of periphyton in aquatic environments","authors":"Yundong Wu ,&nbsp;Wenxuan Zou ,&nbsp;Panpan Zhou ,&nbsp;Chengrong Peng ,&nbsp;Dunhai Li ,&nbsp;Genbao Li","doi":"10.1016/j.jembe.2025.152098","DOIUrl":"10.1016/j.jembe.2025.152098","url":null,"abstract":"<div><div>Periphyton are important component indicators in ecosystems, the traditional method of sampling periphyton is not only time-consuming and laborious, but difficult to quantify accurately, which easily causes sample loss and distorts data. On the other hand, the traditional method also requires high proficiency of researchers for sampling. At the same time, when a large number of samples of periphyton need to be collected, the traditional method is inefficient in sampling, so a unified and highly efficient sampling tool is desperately required. Here we present a simple structure, easy operation and low-cost sampling device, Automatic Periphyton Sampler (APS), that can be used to collect periphyton fastly and precisely in a fixed areas of different types of natural substrates. Periphyton from three different natural substrates were collected at different sites using both APS and traditional method, based on the comparison of chlorophyll <em>a</em> content, ash-free dry mass, cell counts, and taxonomic composition. The results show that the APS is more suitable for the periphyton sampling. The study demonstrates that the APS is a portable, efficient, and automated tool that significantly enhances the efficiency of periphyton sampling in the field, and saving labor and time. The new technique can reduce the reliance on researchers and overcome the issue of collecting samples of periphyton on unpickable and stable substrates. Furthermore, modifications can be made to adapt the APS to various natural substrates and field environments.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"586 ","pages":"Article 152098"},"PeriodicalIF":1.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680476","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":"Screening of predatory fish species for larvae of Acanthaster solaris and quantitative analysis techniques of environmental DNA","authors":"Zhanbiao Hu ,&nbsp;Shigang Liu ,&nbsp;Wei Wang ,&nbsp;Zhongjie Wu ,&nbsp;Zhaoqun Liu ,&nbsp;Kar-Hoe Loh ,&nbsp;Yuan Li ,&nbsp;Longshan Lin","doi":"10.1016/j.jembe.2025.152093","DOIUrl":"10.1016/j.jembe.2025.152093","url":null,"abstract":"<div><div>In the context of ongoing outbreaks of the crown-of-thorns starfish, the outbreak of the South China Sea's crown-of-thorns starfish (<em>Acanthaster solaris</em>) has severely threatened coral reef ecosystems, highlighting the urgent need for research on related control and eradication technologies. Biological control offers environmental friendliness and long-term effectiveness, making research on predator fish species crucial for managing the crown-of-thorns starfish outbreaks. This study investigates the feeding effects of seven common coral reef fish species in the South China Sea on crown-of-thorns starfish larvae, aiming to identify suitable predator fish species for South China Sea reefs. Additionally, the study develops and validates eDNA quantitative detection technology for the most effective predator, providing technical support and data for subsequent stock enhancement, release effectiveness evaluation, and fishery management. The results indicate that <em>Pomacentrus coelestis</em> significantly outperforms other species in terms of both feeding amount and feeding rate on brachiolaria, making it the most optimal predator identified in this study with a consumption rate of 403 larvae/day. There is a significant positive correlation between the density of the <em>P. coelestis</em> and eDNA concentration, with eDNA concentration stabilizing after 96 h of cultivation. The linear function (eDNA concentration = 267,120,000 density − 234,320,000) shows a good fit (R² = 0.985), making it generally effective for assessing the resource levels of <em>P. coelestis</em> in stable water environments.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"586 ","pages":"Article 152093"},"PeriodicalIF":1.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680556","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":"Physiological effects of acute exposure to acidification conditions in embryos of the American lobster (Homarus americanus)","authors":"A.R. Sisti ,&nbsp;B.M. Jellison ,&nbsp;J.D. Shields ,&nbsp;E.B. Rivest","doi":"10.1016/j.jembe.2025.152095","DOIUrl":"10.1016/j.jembe.2025.152095","url":null,"abstract":"<div><div>Ocean and coastal acidification are altering carbonate chemistry conditions and inducing physiological stress in marine organisms. Early life history stages of marine invertebrates, including commercially important species like the American lobster (<em>Homarus americanus</em>) may have limited physiological capacity to tolerate changes in carbonate chemistry. Using American lobster embryos, we quantified physiological disturbances caused by acute changes in carbonate chemistry. We exposed freshly isolated lobster embryos to conditions ranging from 6.94 to 8.07 pH for 24 h at three points during embryo development. With more extreme conditions of acidification, protein carbonyl concentration (indicative of cellular damage from oxidative stress) increased, and Na⁺/K⁺-ATPase activity (associated with acid-base regulation) decreased at all stages of development examined. Although oxygen consumption rate and ferric-reducing antioxidant potential both increased over the course of embryogenesis, we found no evidence that the relationship between pH and these physiological metrics varied during ontogeny. Our results indicate that acid-base regulation and oxidative stress in American lobster embryos may be sensitive to acidification-induced hypercapnia within a 24-h period across a large portion of embryo development.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"585 ","pages":"Article 152095"},"PeriodicalIF":1.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562598","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 impact of environmental conditions on the heat tolerance of Acropora hyacinthus","authors":"Hongmin Wang ,&nbsp;He Zhao ,&nbsp;Wentao Zhu ,&nbsp;Junling Zhang ,&nbsp;Xiangbo Liu ,&nbsp;Ming Zhu ,&nbsp;Aimin Wang ,&nbsp;Xiubao Li","doi":"10.1016/j.jembe.2025.152096","DOIUrl":"10.1016/j.jembe.2025.152096","url":null,"abstract":"<div><div>While coral bleaching events are becoming increasingly frequent due to climate change, some nearshore zones exposed to high turbidity and cold-water upwelling may serve as thermal refuges to effectively mitigate the effects of heat stress. Understanding how corals in these zones adapt to environmental stressors can aid in coral management. In this study, we collected <em>Acropora hyacinthus</em> from two zones near Hainan Island: Changjiang, a nearshore coastal zone with high turbidity, and Wuzhizhou, a zone affected by the Qiongdong upwelling in the summer. The corals were subjected to heat stress in the laboratory up to 32 °C, and their responses were compared and analyzed. <em>A. hyacinthus</em> from Changjiang exhibited superior thermal tolerance, potentially due to its higher total energy reserves, consistent composition of symbiotic microbial communities (especially the photosynthetically active Symbiodiniaceae C1 and abundance of probiotic bacteria), and stability of metabolic activity. Upon heat stress, it up-regulated various metabolic pathways, including arachidonic acid metabolism, pantothenate and CoA biosynthesis, and ABC transporters, which indicated good adaptive capacity to high-temperature settings. Conversely, <em>A. hyacinthus</em> from Wuzhizhou was more vulnerable. Upon heat stress, it had a notable rise in bacterial diversity, a reduction in the abundance of probiotic bacteria, and down-regulated metabolic pathways. Thus, compared to corals in nearshore turbid zones, corals sheltered by the summer upwelling in the South China Sea east of Hainan Island are more sensitive to rising temperatures and are at a higher risk if the Qiongdong upwelling weakens due to further climate change.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"585 ","pages":"Article 152096"},"PeriodicalIF":1.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550703","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":"We are where we eat! The food selectivity of Copepoda Harpacticoida species on mangrove benthic diatoms and cyanobacteria influences their spatial distribution at a microscale level","authors":"Renata Lopes Trindade ,&nbsp;Ariadne do Nascimento Moura ,&nbsp;Adriane Pereira Wandness ,&nbsp;Bruna Martins Bezerra ,&nbsp;Paulo Jorge Parreira dos Santos","doi":"10.1016/j.jembe.2025.152094","DOIUrl":"10.1016/j.jembe.2025.152094","url":null,"abstract":"<div><div>Harpacticoida participate in important benthic processes but their specific interactions with other primary producers are still unknown. This study investigated Copepoda Harpacticoida's selectivity of diatoms and cyanobacteria and whether their microscale distribution is influenced by diatoms and cyanobacteria distribution. We conducted a laboratory controlled experiment, where diatoms and cyanobacteria and four Harpacticoid species (<em>Cletocamptus</em> cf. <em>deitersi</em>, <em>Mesochra</em> sp. <em>Robertsonia mourei</em> and <em>Metis holothuriae</em>) were isolated and cultivated from water and sediment samples collected in the midlittoral zone of the Santa Cruz Canal in Pernambuco, Northeast Brazil. The grazing experiment lasted 24 h. Concurrently, sediment samples were collected with 25 contiguous syringes (1.3cm²) at one centimeter depth to verify the microspatial relation in situ. We characterized the site through the levels of chlorophyll-a, phaeopigments, silt and clay percentage, organic matter percentage and salinity. We found that the species of Copepoda Harpacticoida from a mangrove area fed selectively on different diatoms and cyanobacteria species. Furthermore, our results also indicated that there was a very low overlap in the use of diatoms and cyanobacteria by these Harpacticoida species and that the size of diatoms and cyanobacteria seemed to partially influence their selectivity. For the set of nine diatoms for which there was strong or very strong evidence that the presence of harpacticoid animals decreased their densities due to herbivore-prey interactions, seven were grazed upon by a single harpacticoid species. Our field observational study demonstrates that the aggregated spatial pattern of diatom and cyanobacteria species explains, to a large extent, the spatial distribution of Copepoda Harpacticoida species in the estuarine mud flat. For all tested species, at least one of the diatoms and cyanobacteria selected as food in the laboratory was a significant predictor of harpacticoid species spatial distribution, showing the importance of species-specific relationships.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"585 ","pages":"Article 152094"},"PeriodicalIF":1.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521262","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":"Sponge species from New Zealand may transform and degrade dissolved organic matter","authors":"Tanja Stratmann ,&nbsp;Mario L.M. Miranda ,&nbsp;Anna de Kluijver ,&nbsp;Kathrin Busch ,&nbsp;Michelle Kelly ,&nbsp;Sadie Mills ,&nbsp;Peter J. Schupp","doi":"10.1016/j.jembe.2025.152092","DOIUrl":"10.1016/j.jembe.2025.152092","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Sponges are an important component of shallow- and deep-water ecosystems enhancing eukaryotic biodiversity via diverse endo- and epibiota and by providing three dimensional habitats for benthic invertebrates and fishes. Sponge biodiversity is particularly high in the waters around New Zealand (Southwest Pacific), where we collected two shallow- and two deep-water sponge species (&lt;em&gt;Tedania&lt;/em&gt; sp., &lt;em&gt;Suberea meandrina&lt;/em&gt;, &lt;em&gt;Farrea raoulensis&lt;/em&gt;, &lt;em&gt;Artemisina&lt;/em&gt; sp.) for &lt;em&gt;ex-situ&lt;/em&gt; incubation experiments to measure processing of dissolved organic matter (DOM). Several sponge species take up DOM and make it available to other fauna as detritus or as sponge biomass, a process known as sponge loop. However, it is unknown whether the selected sponge species are able to consume dissolved organic carbon (DOC) and/or total dissolved nitrogen (TDN).&lt;/div&gt;&lt;div&gt;We measured DOC and TDN fluxes and linked it to the bacterial communities of the sponge holobiont to address research hypothesis 1. It stated that high-microbial abundance (HMA) sponges consume more DOM than low-microbial abundance (LMA) sponges. Changes in fluorescent dissolved organic matter (FDOM) over time were investigated to address research hypothesis 2. It proposed that the fluorescence intensity F&lt;sub&gt;max&lt;/sub&gt; of fluorophores decreased in incubations that showed a significant loss in DOM. We assessed the biochemical and phospholipid-derived fatty acids (PLFAs) composition of sponge tissue to address hypothesis 3. It suggested that the PLFLA composition of sponges differs between sponge classes. Finally, we tried to better understand the role of these sponges in nutrient cycling around New Zealand by combining data from all analyses.&lt;/div&gt;&lt;div&gt;Based on the community composition of the sponge-associated bacteria, we classified &lt;em&gt;Tedania&lt;/em&gt; sp., &lt;em&gt;S. meandrina&lt;/em&gt;, and &lt;em&gt;Artemisina&lt;/em&gt; sp. as HMA sponges and &lt;em&gt;F. raoulensis&lt;/em&gt; as LMA sponge. We did not measure a significant DOC flux and only the release of TDN by &lt;em&gt;Tedania&lt;/em&gt; sp. was significantly different from 0 μmol TDN g org. C&lt;sup&gt;-1&lt;/sup&gt; d&lt;sup&gt;-1&lt;/sup&gt;. The presence of four fluorophores were detected in the FDOM pool: 2 tryptophan- and protein-like fluorophores (C1, C2), 1 humic-like fluorophore (C3), and 1 tyrosine-like fluorophore (C4). However, we could not validate hypothesis 2, because F&lt;sub&gt;max&lt;/sub&gt; of C1 decreased significantly in &lt;em&gt;S. meandrina&lt;/em&gt; incubations, whereas F&lt;sub&gt;max&lt;/sub&gt; of C2 grew in the same incubations. F&lt;sub&gt;max&lt;/sub&gt; of C3 increased in &lt;em&gt;Tedania&lt;/em&gt; sp. incubations, in which F&lt;sub&gt;max&lt;/sub&gt; of C4 decreased. In comparison, F&lt;sub&gt;max&lt;/sub&gt; of C4 in &lt;em&gt;S. meandrina&lt;/em&gt; rose. The PLFA composition of sponge tissue was dominated by long-chain fatty acids, saturated fatty acids, and monosaturated fatty acids, and most PLFAs were sponge- and bacteria-specific. We could not confirmed hypothesis 3, either, because the PLFA composition of the hexactinellid sponge i","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"585 ","pages":"Article 152092"},"PeriodicalIF":1.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512365","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":"Captive rearing reduces the sensitivity of Acartia tonsa copepods to predator cues","authors":"Eva J. Muir,&nbsp;Bradford J. Gemmell,&nbsp;Andrew M. Kramer","doi":"10.1016/j.jembe.2025.152091","DOIUrl":"10.1016/j.jembe.2025.152091","url":null,"abstract":"<div><div>Captive populations are often subject to different selective pressures than their wild counterparts, which could result in trait differences between these populations. This study investigates the effect of captive rearing on the swimming behavior and escape responses of <em>Acartia tonsa</em>, a species of marine copepod zooplankton that use hydromechanical signal detection to aid in finding food, locating mates, and avoiding predation. As captive populations of <em>A. tonsa</em> experience reduced interspecific predation and higher population densities compared to wild populations, it was hypothesized that these differences may drive adaptive evolution of swimming behavior in this species. Several components of routine swimming were compared (swimming speed, number of hops, distance of hops, frequency of hops) for groups of captive-reared and wild-caught <em>A. tonsa</em>, revealing that wild-caught copepods swim faster and hop more frequently than captive-reared copepods. However, when the escape responses of the captive-reared and wild-caught populations were compared using an artificial predator mimic, no significant differences were found in the number of sequential hops performed during the escape response, the maximum velocity of the response, or the total distance traveled during the response. Although the escape responses performed by the captive-reared and wild-caught copepods were similar, the captive-reared individuals often showed no response to the artificial predator mimic (34 % of individuals responded to the predator mimic), whereas wild individuals almost always showed a response (96 % responded). This suggests that captive rearing may have resulted in reduced sensitivity to hydromechanical signals in captive copepods compared to wild copepods, as responding to these signals in a predator-free captive environment would impose an unnecessary energy cost. This study offers new insight into how captive-rearing may impact copepod populations and provides evidence of how predator-driven evolution and density dependent selection may influence the behavior of copepod species.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"584 ","pages":"Article 152091"},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437906","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}