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Upper thermal limits in many fish species are limited, in part, by the hearts ability to meet increased oxygen demand during high temperatures. Cardiac plasticity induced by developmental temperatures can therefore influence thermal tolerance. Here, we determined how incubation temperatures during the embryonic stage influence cardiac performance across temperatures during the sensitive larval stage of the imperiled longfin smelt. We transposed a cardiac assay for larger fish to newly hatched larvae that were incubated at 9°C, 12°C or 15°C. We measured heart rate over increases in temperature to identify the Arrhenius breakpoint temperature (TAB), a proxy for thermal optimum and two upper thermal limit metrics: temperature when heart rate is maximized (Tpeak) and when cardiac arrhythmia occurs (TArr). Higher incubation temperatures increased TAB, Tpeak and TArr, but high individual variation in all three metrics resulted in great overlap of individuals at TAB, Tpeak and TArr across temperatures. We found that the temperatures at which 10% of individuals reached Tpeak or TArr and temperatures at which number of individuals at TAB relative to Tpeak (ΔN(TAB,Tpeak)) was maximal, correlated more closely with upper thermal limits and thermal optima inferred from previous studies, compared to the mean values of the three cardiac metrics of the present study. Higher incubation temperatures increased the 10% Tpeak and TArr thresholds but maximum ΔN(TAB,Tpeak) largely remained the same, suggesting that incubation temperatures modulate upper thermal limits but not Topt for a group of larvae. Overall, by measuring cardiac performance across temperatures, we defined upper thermal limits (10% thresholds; Tpeak, 14.4-17.5°C; TArr, 16.9-20.2°C) and optima (ΔN(TAB,Tpeak), 12.4-14.4°C) that can guide conservation strategies for longfin smelt and demonstrated the potential of this cardiac assay for informing conservation plans for the early life stages of fish.

The Caspian kutum, Rutilus frisii, is an anadromous fish native to Iran and despite the development of its hatchery production, its larval development has been poorly described; hence describing its morphological growth pattern was the aim of this study. The Caspian kutum larval period in the early development was divided into three stages, namely eleuthero-embryo (0–5 dph), propterygio-larvae (5–13 dph), pterygio-larvae (13–20 dph) and after larval period early juvenile was initiated (> 20 dph). The eleuthero-embryo stage was characterized by the commencement of mix-feeding while the yolk-sac remains, while propterygio-larvae absorbed the yolk-sac and continued to develop feeding apparatus and fin-folds. In pterygio-larvae, the fins developed and squamation began to appear. During the eleuthero-embryo stage, allometry in the head, trunk and tail were nearly isometric, negative, and positive, respectively. In propterygio-larvae, the head and tail allometry were positive, while the trunk was still negative. By the pterygio-larval stage, the tail and trunk allometry were nearly isometric but the head was positive. After metamorphosis, the growth pattern changed as the head and trunk allometry became nearly isometric and positive, respectively, but the tail allometry remained almost isometric. The results confirmed that morphological development and growth patterns during early life stages in R. frisii closely match its immediate required function. [ABSTRACT FROM AUTHOR]

The life history of the Taiwanese spider wasp Minotocyphus formosanus (Pompilidae: Pepsinae) is reported, including the developmental process of the immature stages. The larva was attached by the spider wasp to the abdomen of the funnel-web spider Macrothele hungae (Mygalomorphae: Macrothelidae). In terms of mode of life, M. formosanus was established as a koinobiont ectoparasitoid. These biological findings are the first reports for not only the species M. formosanus, but also the genus Minotocyphus. [ABSTRACT FROM AUTHOR]

The linkage between growth rate and feeding success has been shown to strengthen the effects of early growth rate on later growth rate in the early life history of fish. However, the growth–feeding linkage largely remains to be tested at the individual level within the same populations/cohorts. We examined the growth–feeding linkage for multiple populations/cohorts in Japanese anchovy Engraulis japonicus larvae and Pacific round herring Etrumeus micropus larvae, through otolith microstructure analysis, based on samples collected from the commercial fishery for larval fish in the Kii Channel, Japan. The three growth–feeding mechanisms, which are based on the respective potential advantages of larger somatic size, higher growth rate, and earlier morphological development for achieving feeding success, were tested to understand how growth rate relates to feeding success. The "somatic size" mechanism was supported for all of six samples for anchovy larvae and three of four samples for round herring larvae. The "growth rate" mechanism was supported for two of six samples for anchovy larvae and three of four samples for round herring larvae. The "morphological development" mechanism was supported for three of four samples for anchovy larvae and all of three samples for round herring larvae. Overall, the present analysis supported the growth–feeding linkage but revealed the dynamics of the growth–feeding mechanisms. All the mechanisms were shown to operate at least for certain populations/cohorts, but none of them were universally effective over all populations/cohorts across the two species. Understanding the dynamics of the growth–feeding mechanisms would provide precious hints for considering strategies of predicting recruitment dynamics. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of the proviron, oral anabolic steroid on undifferentiated Nile tilapia (Oreochromis niloticus) larvae sex reversal and to compare its effect with that of 17 α-methyltestosterone. Thus, doses of 25 mg, 50 mg and 75 mg proviron versus 60 mg/kg for 17 α-methyltestosterone were incorporated in the diet of 10-days-post-fertilization old larvae for 28 days. At the end of the treatment and after pre-growth until 90 days post-fertilization, we carried out sexing. Results displayed male rates ranged from 65.7 ± 3.1% to 96.7 ± 1.1% for treatments with 25 mg and 75 mg proviron, respectively and was 99 ± 0.1% for that with 17 α-methyltestosterone. However, no significant difference (p > .05) was found between the average male rate of larvae fed the feed containing 75 mg of proviron and that of larvae fed the feed that containing 17 α-methyltestosterone. [ABSTRACT FROM AUTHOR]

Simple Summary: The cultivation of the Pacific fat sleeper (Dormitator latifrons) is of commercial interest in the Eastern Central Pacific. Its domestication potential is affected by the presence of pathogens. This study aimed to identify two trichodinid ectoparasites that are associated with D. latifrons larval mortality. We evaluated a total of 4320 fish larvae, 1080 fish larvae per treatment, revealing the presence of T. acuta and T. compacta in one treatment. Larval mortality in the infected treatment reached up to 58% by the fourth day post-hatching, at 28 °C, due to Trichodina infestation, resulting in significantly lower survival in the infected tanks compared to the uninfected tanks. This is the first geographical record of these protozoan parasites in a species that is native to the East Central Pacific Basin and intended for culture. Trichodinidae, a prevalent group of protozoan ectoparasites in aquaculture, cause rapid mortality in fish hatcheries. Despite their significance, knowledge about these parasites in farmed fish in South America, especially in native species that are currently being domesticated for aquaculture, remains limited. This study morphologically characterized the Trichodinid species that are infecting Pacific fat sleeper (Dormitator latifrons) larvae and evaluated their impact on larval rearing. Four pairs of broodstock were induced with GnRHA implants and placed in tanks containing 200 L of freshwater, with a water temperature of 28 ± 1.0 °C and a dissolved oxygen level of 4.00 ± 1.23 mg L−1, with partial water exchanges being performed daily. The larvae hatched 7 to 8 h after fertilization and were transferred to tanks containing water with the same quality parameters. Twelve hours post-hatching, the presence of Trichodina was observed. Every 24 h, 60 larvae per tank (n = 180 per treatment) were sedated, and larval wet mounts were prepared, air-dried at room temperature, and impregnated with silver nitrate. Infection parameters and daily mortality were calculated. Trichodina was observed to parasitize the pelvic fins, caudal fins, and heads of fish larvae, which showed lethargy and erratic swimming movements. The Trichodina species showed a daily increase in the infection parameters, and a 58% rate of larval mortality was observed at the fourth day post-hatching (dph) in the infected tanks. In captivity, D. latifrons larvae typically survive up to 7 days post-hatching (dph) before reaching their point of no return due to the lack of adequate diet and feeding regimes. However, our study indicates that Trichodina infestation accelerates mortality, causing infected larvae to die more quickly than uninfected ones. [ABSTRACT FROM AUTHOR]

Benthic organisms typically possess a planktonic propagule stage in the form of larvae or spores, which enables them to spread over large distances before settlement, and promotes tight pelago-benthic coupling. However, factors driving dispersal and epibenthos recruitment in shallow hard-bottom Arctic communities are poorly known. We therefore conducted a year-round in situ colonization experiment in Isfjorden (Svalbard), and found out that variation in early-stage epibenthic assemblages was explained by the combination of: abiotic (45.9%) and biotic variables (23.9%), and their interactions (30.2%). The upward-facing experimental plates were dominated by coralline algae, and this is the first study showing that at high latitudes coralline algae Lithothamnion sp. settle in high numbers on available substrates during the polar night in winter. The downward-facing plates, which had much less exposure to light, contained more diverse organisms, with a predominance of polychaetas and bryozoans. However, in summer, the barnacle Semibalanus balanoides outcompeted all the other recruits, as a result of massive occurrence of meroplanktonic Cirripedia larvae, triggered by the phytoplankton bloom. In conclusion, the rate and success of epibenthic settlements were dependent mostly on light availability and temperature, suggesting that larval settlement will be impacted by global warming with some taxa benefitting, while others losing. [ABSTRACT FROM AUTHOR]

Despite its impressive economic growth, Bangladesh faces a persistent malnutrition challenge, costing over US$1 billion annually. The broiler industry plays a vital role in addressing nutritional needs by providing essential protein through meat and eggs. However, small and medium enterprises (SMEs) in this sector struggle with high feed prices, impacting their profitability and growth. Black Soldier Fly Larvae (BSFL) offers a sustainable and cost-effective alternative to conventional poultry feed, addressing both rising costs and environmental impacts. This study examined different aspects of BSFL, such as broiler feed, and farmers' perceptions of them in some selected areas of the Sylhet region of Bangladesh. A total of 60 respondents from three subdistricts in Sylhet district were selected using the purposive sampling technique. Data were analyzed through descriptive statistics, discriminative power value, binary logistic regression model, and profitability equation. Among the respondents, 70% (42) had a favorable attitude toward BSFL, and 30% (18) had a highly favorable attitude towards BSFL. Among eight socioeconomic attributes examined for the likeliness of adopting BSFL as broiler feed, the respondents' average income (p < 0.01), years of schooling (p < 0.05), and years of broiler farming experience (p < 0.01) were found to be significant. Further, farms using 50% BSFL and 50% traditional feed had a net return of BDT (Bangladeshi Taka) 35,045.67 (USD 419.71), higher than those using traditional feed, which had a net return of BDT 29670.67 (USD 355.38). Further, farms using 50% BSFL and 50% traditional feed had a benefit–cost ratio (BCR) of 1.16, compared to other farms with a BCR of 1.11. The study also found some problems causing slow growth in the adoption rate of BSFL in the study region, such as lack of training programs, extension campaigns, the uncertainty of input supply, and financial assistance. The study suggests making adequate measures to raise awareness about the profitability of BSFL as broiler feed, conducting training at the root level, and making inputs easily available to farmers. [ABSTRACT FROM AUTHOR]

Predicting the response of aquatic species to environmental contaminants is challenging, in part because of the diverse biological traits within communities that influence their uptake and transfer of contaminants. Nanoplastics are a contaminant of growing concern, and previous research has documented their uptake and transfer in aquatic food webs. Employing an established method of nanoplastic tracking using metal-doped plastics, we studied the influence of biological traits on the uptake of nanoplastic from water and diet in freshwater predators through two exposure assays. We focused on backswimmers (Anisops wakefieldi) and damselfly larvae (Xanthocnemis zealandica) - two freshwater macroinvertebrates with contrasting physiological and morphological traits related to feeding and respiration strategies. Our findings reveal striking differences in nanoplastic transfer dynamics: damselfly larvae accumulated nanoplastics from water and diet and then efficiently eliminated 92% of nanoplastic after five days of depuration. In contrast, backswimmers did not accumulate nanoplastic from either source. Differences in nanoplastic transfer dynamics may be explained by the contrasting physiological and morphological traits of these organisms. Overall, our results highlight the importance and potential of considering biological traits in predicting transfer of nanoplastics through aquatic food webs. [ABSTRACT FROM AUTHOR]

Sparisoma species (parrotfish) comprise an important functional group contributing to coral‐reef resilience. The morphological diagnostic characteristics for species identification are clearly described for adult forms but not for the early stages. Consequently, many taxonomical listings of Sparisoma larvae are restricted to the genus level. The aims of this study are to determine whether the morphological and molecular identification techniques are useful to assign the species taxonomic level to Sparisoma larvae occurring in the Gulf of Mexico and whether there is a set of diagnostic features that could be used to discriminate between species in larvae of different developmental stages. Morphological assignment of Sparisoma was performed based on morphological and meristic features for 30 larvae collected in the Gulf of Mexico from late August to mid‐September 2015. To corroborate and complement the morphological assignments, molecular identification was carried out using DNA sequences from regions of two mitochondrial genes, mitochondrial cytochrome oxidase I (mtDNA COI) and mitochondrial 16S rRNA (mtDNA 16S rRNA). COI and 16S gene trees for Sparisoma and related fish taxa were constructed using sequences available in the NCBI (National Center for Biotechnology Information) GenBank and BOLD (Barcode of Life Data) databases. Two morphotypes were identified based on morphology, but no diagnostic characteristics for species discrimination were found. Molecular identification, in contrast, successfully discriminated four early development stages of Sparisoma atomarium, three stages of Sparisoma radians, and two stages of Sparisoma chrysopterum and Sparisoma aurofrenatum, therefore demonstrating the successful and necessary application of molecular taxonomic approaches for species‐level identifications of Sparisoma larvae. [ABSTRACT FROM AUTHOR]

This study elucidated the role of DHA-modulated genes in the development and growth of Atlantic bluefin tuna (Thunnus thynnus) larvae ingesting increasing levels of DHA in their rotifer prey. The effect of feeding low, medium, and high rotifer (Brachionus rotundiformis) DHA levels (2.0, 3.6 and 10.9 mg DHA g−1 DW, respectively) was tested on 2–15 days post hatching (dph) bluefin tuna larvae. Larval DHA content markedly (P < 0.05) increased in a DHA dose-dependent manner (1.5, 3.9, 6.1 mg DHA g−1 DW larva, respectively), that was positively correlated with larval prey consumption and growth (P < 0.05). Gene ontology enrichment analyses of differentially expressed genes (DEGs) demonstrated dietary DHA significantly (P < 0.05) affected different genes and biological processes at different developmental ages. The number of DHA up-regulated DEGs was highest in 10 dph larvae (491), compared to 5 (12) and 15 dph fish (34), and were mainly involved in neural and synaptic development in the brain and spinal cord. In contrast, DHA in older 15 dph larvae elicited fewer DEGs but played critical roles over a wider range of developing organs. The emerging picture underscores the importance of DHA-modulated gene expression as a driving force in bluefin tuna larval development and growth. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster exhibits multiple highly sophisticated temperaturesensing systems, enabling its effective response and navigation to temperature changes. Previous research has identified three dorsal organ cool cells (DOCCs) in fly larvae, consisting of two A-type and one B-type cell with distinct calcium dynamics. When subjected to hypertonic conditions, calcium imaging shows that A-type DOCCs maintain their responses to cool temperatures. In contrast, a subset of B-type DOCCs does not exhibit detectable GCaMP baseline signals, and the remaining detectable B-type DOCCs exhibit reduced temperature responses. The activation of both A-type and B-type DOCCs depends on the same members of the ionotropic receptor (IR) family: IR21a, IR93a, and IR25a. A-type DOCCs exhibit a higher somal level of IR93a than B-type DOCCs. Overexpression of Ir93a restores B-type calcium responses to cool temperatures, but not the proportion of B-type cells with a detectable GCaMP baseline, in a hypertonic environment, suggesting a selective role of IR93a in maintaining the temperature responses under hypertonic conditions. Our findings identify a novel function of B-type DOCCs in integrating temperature and tonic stimuli. [ABSTRACT FROM AUTHOR]

Objectives: Acute temperature stress was explored in Hippocampus abdominalis through a comprehensive RNA-seq analysis. Methods: RNA-seq was conducted on 20-day-old H. abdominalis after 24 h of temperature stress. Four experimental conditions were established: a control group (18 °C) and three temperature treatment groups (21, 24, and 27 °C). Results: Seahorse larvae were found to be unaffected by 21 °C and 24 °C and were able to survive for short periods of time during 24 h of incubation, whereas mortality approached 50% at 27 °C. The sequencing process produced 75.63 Gb of high-quality clean data, with Q20 and Q30 base percentages surpassing 98% and 96%, respectively. A total of 141, 333, and 1598 differentially expressed genes were identified in the 21, 24, and 27 °C groups vs. a control comparison group, respectively. Notably, the number of up-regulated genes was consistently higher than that of down-regulated genes across all comparisons. Gene Ontology functional annotation revealed that differentially expressed genes were predominantly associated with metabolic processes, redox reactions, and biosynthetic functions. In-depth KEGG pathway enrichment analysis demonstrated that down-regulated genes were significantly enriched in pathways related to steroid biosynthesis, terpenoid backbone biosynthesis, spliceosome function, and DNA replication. Up-regulated genes were enriched in pathways associated with the FoxO signaling pathway and mitophagy (animal). The results indicated that temperature stress induced extensive changes in gene expression in H. abdominalis, involving crucial biological processes such as growth, biosynthesis, and energy metabolism. Conclusions: This study provided key molecular mechanisms in the response of H. abdominalis to temperature stress, offering a strong basis for future research aimed at understanding and mitigating the effects of environmental stressors on marine species. [ABSTRACT FROM AUTHOR]

Ocean acidification presents a major threat to marine life, and a large body of evidence has documented its negative effects on various marine species and ecosystems. Recent meta-analyses highlight the key role of local adaptation and have linked species' sensitivity to extremes of the present range of pH variability. More specifically, 'physiological tipping points' can be correlated with the lowest experienced pH where the organisms live. We verified this hypothesis by comparing the responses of larvae of the collector urchin Tripneustes gratilla originating from two neighbouring seagrass meadows at Inhaca Island in southern Mozambique. The two seagrass meadows experience different conditions: the site at the Inhaca Marine Biology Research Station (Estação de Biologia Marítima de Inhaca, EBMI) is subtidal, and the site at Banguá is intertidal. Larvae of adults collected from the two sites were cultured in the laboratory under four different target pH treatments (8.04, 7.67, 7.46 and 7.29) for 7 days. The results showed an overall negative effect of lower pH on survival and growth as well as on an index of symmetry. Larvae originating from the intertidal seagrass habitat at Banguá which experiences large pH fluctuations were more sensitive to a lower pH than those from the subtidal seagrass habitat at EBMI. This finding suggests that different mechanisms for pH tolerance and local adaptation may apply in subtidal versus intertidal environments. Consequently, the unifying principle that physiological tipping points are correlated with the extreme low pH in the present range of variability, may reach its limit in increasingly extreme environments under natural conditions. [ABSTRACT FROM AUTHOR]

Efficacy of two Indian isolates of entomopathogenic nematodes (EPNs) viz., Heterorhabditis bacteriophora MK256358 and Steinernema feltiae MK256355 were tested in laboratory against the larvae of cabbage butterfly, Pieris brassicae. Larval mortality was found directly proportional to initial inoculum level of infective juveniles (IJs). Susceptibility of larvae varied with respect to their variable size. H. bacteriophora MK256358 @ 25 IJs/larva caused 100% mortality to 3rd instar larvae at 72 h but @ 75 IJs/larva, the same mortality was achieved in 48 h. S. feltiae MK256355 @ 100 IJs/larva caused 100% mortality to 3rd instar larvae of P. brassicae at 48 h. H. bacteriophora MK256358 @ 25 and 100 IJs/larva resulted in 100% mortality to 4th and 5th instar larvae, respectively at 72 h, however S. feltiae MK256355 was unable to cause 100% mortality to either 4th or 5th instar larvae at any inoculum level or time period used in the study. LD50 and LT50 values of H. bacteriophora MK256358 were lower than S. feltiae MK256355 indicating that less nematode dose and time is required to kill 50% pest population. Reproduction capacity of nematode within the host was directly proportional to individual larval size and nematode inoculum level and for H. bacteriophora MK256358, it was higher and statistically significant (P ≤ 0.05) from S. feltiae MK256355. Our experimental findings open new avenues for utilization of EPNs against P. brassicae and set the basis for safe insect pest management programme. [ABSTRACT FROM AUTHOR]

The across‐shore transport of meroplanktonic larvae is predominantly driven by coastal physical processes, resulting in episodic recruitment of benthic species. Historically, due to the sampling challenges associated with resolving these advective mechanisms across the continental shelf, relevant components of larval transport have been difficult to isolate and understand. We use three‐dimensional temperature and velocity data from an array of 29 moorings to identify fundamental physical processes that could have generated successful across‐shore transport and settlement of meroplankton. The dense spatial and temporal sampling from this array allows us to use Lagrangian particle tracking to estimate the influences of wind conditions and the internal tide on the across‐shore transport of planktonic larvae. Settlement was found to be episodic at all depths studied. Above mid‐water, modeled larvae were successfully transported onshore by the internal tide during wind relaxations. Surprisingly, abundant pulses of shallow‐water larvae were supplied to the coast on occasions when strong, upwelling‐favorable winds (> 4 m s−1) drove offshore‐flowing surface waters, revealing a complex, potentially topographically influenced flow. These intense upwelling‐favorable winds also contributed to subsurface onshore flows that created large pulses of larval settlement in deeper waters (> 20 m). Our analyses from this highly resolved data set provide novel insights into the interactions of physical drivers in creating episodic pulses of coastal larval recruitment. [ABSTRACT FROM AUTHOR]

Fish stocks composed of several populations are considered to have more stable productivity than stocks containing only one or few populations. This stability is attributed to complementary or independent dynamics among the populations within the stock—the so-called portfolio effect. Declines of populations within stocks that have delayed recovery potentially increase risk to productivity and local extinctions. Portfolio effects may be relevant in the Baltic Sea, where autumn-spawning herring was the dominant herring ecotype until the early/mid-20th century. The current fishery assessment and management in the area assumes that the abundance of autumn spawning herring has been negligible since the 1970s; the share of spring spawning herring has become dominant and is considered to be the only ecotype. Data from a multi-annual ichthyoplankton survey in the southern Baltic Sea (Bornholm Basin) during autumn 2002–2019 show that abundance and spatial distribution of the smallest larval stages have increased significantly. This pattern could be due to an increase in autumn spawners in the area. Genetic studies confirm that these larval herring are offspring from true autumn spawners. Preserving intraspecific diversity is critical for a species' future abilities to adapt to and survive in changing environmental conditions. Thus, our results not only provide new insights to the temporal dynamics of herring ecotypes and challenge the current understanding of central Baltic herring stock processes in general, but are also important in the context of monitoring, assessment, and spatial management of herring in the Baltic Sea. [ABSTRACT FROM AUTHOR]

The link between the northeastern Atlantic and Mediterranean Sea created by the Strait of Gibraltar and the adjacent Iberian and Moroccan coasts marks remarkable transition areas between distinct environments that harbour a diverse mixture of species. The area is interesting regarding marine connectivity and the transport of pelagic invertebrate larvae, crucial knowledge to manage over-exploited populations, and minimize the impacts of climate change and anthropogenic activities. Biophysical models were developed, combining oceanic and particle-tracking Lagrangian simulations with in situ zooplankton distribution data. The conditions driving the larval exchange between the sub-basins and the connectivity throughout the region were explored, using crustacean decapod larvae as biological references. The potential exchange between both sub-basins was confirmed, although specific larval traits revealed contrasting scenarios. The simulations showed that slope-dwelling and mesopelagic larvae have advantage when crossing from the Alboran into the Atlantic, in comparison with shelf-dwelling and epipelagic larvae. Transport pathways and retention areas were identified, and passive drifts were shown to increase the dispersal range of the simulations. The spatial origin of the larval release, larval duration, vertical distribution, and the interaction of larvae with the oceanic features are presented as the main factors impacting the effective larval input into the Atlantic or Mediterranean basins. [ABSTRACT FROM AUTHOR]

There is increasing evidence that host–parasitoid interactions can have a pronounced impact on the microbiome of host insects, but it is unclear to what extent this is caused by the host and/or parasitoid. Here, we compared the internal and external microbiome of caterpillars of Pieris brassicae and Pieris rapae parasitized by Cotesia glomerata or Cotesia rubecula with nonparasitized caterpillars. Additionally, we investigated the internal and external microbiome of the parasitoid larvae. Both internal and external bacterial densities were significantly higher for P. brassicae than P. rapae , while no differences were found between parasitized and nonparasitized caterpillars. In contrast, parasitism significantly affected the composition of the internal and external microbiome of the caterpillars and the parasitoid larvae, but the effects were dependent on the host and parasitoid species. Irrespective of host species, a Wolbachia species was exclusively found inside caterpillars parasitized by C. glomerata , as well as in the corresponding developing parasitoid larvae. Similarly, a Nosema species was abundantly present inside parasitized caterpillars and the parasitoid larvae, but this was independent of the host and the parasitoid species. We conclude that parasitism has pronounced effects on host microbiomes, but the effects depend on both the host and parasitoid species. [ABSTRACT FROM AUTHOR]

Counting shrimp larvae is an essential part of shrimp farming. Due to their tiny size and high density, this task is exceedingly difficult. Thus, we introduce an algorithm for counting densely packed shrimp larvae utilizing an enhanced You Only Look Once version 5 (YOLOv5) model through a regional segmentation approach. First, the C2f and convolutional block attention modules are used to improve the capabilities of YOLOv5 in recognizing the small shrimp. Moreover, employing a regional segmentation technique can decrease the receptive field area, thereby enhancing the shrimp counter's detection performance. Finally, a strategy for stitching and deduplication is implemented to tackle the problem of double counting across various segments. The findings from the experiments indicate that the suggested algorithm surpasses several other shrimp counting techniques in terms of accuracy. Notably, for high-density shrimp larvae in large quantities, this algorithm attained an accuracy exceeding 98 % . [ABSTRACT FROM AUTHOR]

The gregarious lifestyle of lepidopteran larvae is diverse and shaped by a complex interplay of ecological and evolutionary factors. Our review showed that the larval‐aggregation behavior has been reported in 23 lepidopteran families, indicating multiple evolution of this behavior. Some larvae live in sibling groups throughout all larval instars and even pupation stages, which may result from the kin‐selection. In contrast, group fusion may occur among different sibling or foraging groups of larvae and form larger aggregates, and the gregariousness of these species might be driven by the group‐selection. While group size and foraging patterns vary greatly across species, it is generally associated with improved larval survivorship and accelerated development. However, the advantages of group living, such as facilitating feeding activities, adjusting the temperature, and defending natural enemies, may diminish along with development, with strong intraspecific competition occurring at later instars, even when food is abundant. Therefore, the group sizes and fission–fusion dynamics of certain gregarious lepidopteran larvae may be a consequence of their cost–benefit balance depending on various biotic and abiotic factors. Trail and aggregation pheromones, silk trails, or body contact contribute to collective movement and group cohesion of gregarious lepidopteran larvae. However, frequent contact among group members may cause the horizontal transmission of pathogens and pesticides, which may bring an integrated pest management strategy controlling gregarious lepidopteran pests. [ABSTRACT FROM AUTHOR]

The influence of gene expression on female caste determination in social Hymenoptera is one of the best-characterized examples of developmental polyphenism. We used mRNA-seq to profile differentially expressed genes (DEGs) between workers and queens at four development stages (early larvae: 1-day-old larvae; mid larvae: 5-day-old larvae; late larvae: 9-day-old larvae; and 7-day-old adult bee) of Bombus terrestris. When DEGs of different female castes were compared, it was found that there were more DEGs at the mid larval and adult stages than at other stages. Caste differentiation may be linked to candidate genes such as Vitellogenin, Kr-h1, Dnmt3, Hexamerin, Yellow, and Chymotrypsin-2. Additionally, the gene expression profiles were observed differently among the four development stages. Comparing one stage to the next showed that, more number of DEGs were found in queens than workers. In the investigation of how gene expression affects larval caste determination, WGCNA showed that five modules were closely associated with larval caste determination. The functions of genes were mainly enriched in energy metabolism and energy production within mitochondria, suggesting that the energy requirements during the larval development process varied between caste determination. The current study sheds light on the patterns of gene expression in the female caste of Bombus terrestris, which will be useful for future research on polyphenism through differential gene expressions. [ABSTRACT FROM AUTHOR]

We recorded the morphological characteristics and effect of preservation methods on the structure of the egg veils of Lophius litulon found in field investigations. The egg veils were characterized as translucent sheet‐shape with parallel opaque creases spaced approximately 2 cm apart. The egg veils were found to be composed of pentagonal or hexagonal chambers with rounded corners arranged in one layer, and each chamber enveloped one to three embryos. Cryopreservation is recommended to prevent structural changes in the egg veil rather than ethanol solution and neutral buffered formalin solution. [ABSTRACT FROM AUTHOR]

Patterns of population connectivity shape ecological and evolutionary phenomena from population persistence to local adaptation and can inform conservation strategy. Connectivity patterns emerge from the interaction of individual behavior with a complex and heterogeneous environment. Despite ample observation that dispersal patterns vary through time, the extent to which variation in the physical environment can explain emergent connectivity variation is not clear. Empirical studies of its contribution promise to illuminate a potential source of variability that shapes the dynamics of natural populations. We leveraged simultaneous direct dispersal observations and oceanographic transport simulations of the clownfish Amphiprion clarkii in the Camotes Sea, Philippines, to assess the contribution of oceanographic variability to emergent variation in connectivity. We found that time‐varying oceanographic simulations on both annual and monsoonal timescales partly explained the observed dispersal patterns, suggesting that temporal variation in oceanographic transport shapes connectivity variation on these timescales. However, interannual variation in observed mean dispersal distance was nearly 10 times the expected variation from biophysical simulations, revealing that additional biotic and abiotic factors contribute to interannual connectivity variation. Simulated dispersal kernels also predicted a smaller scale of dispersal than the observations, supporting the hypothesis that undocumented abiotic factors and behaviors such as swimming and navigation enhance the probability of successful dispersal away from, as opposed to retention near, natal sites. Our findings highlight the potential for coincident observations and biophysical simulations to test dispersal hypotheses and the influence of temporal variability on metapopulation persistence, local adaptation, and other population processes. [ABSTRACT FROM AUTHOR]

Background: The contribution of interspecies interactions between coinfecting pathogens to chronic refractory infection by affecting pathogenicity is well established. However, little is known about the impact of intraspecific interactions on infection relapse, despite the cross-talk of different strains within one species is more common in clinical infection. We reported a case of chronic refractory pulmonary infection relapse, caused by two methicillin-sensitive S. aureus (MSSA) strains (SA01 and SA02) and revealed a novel strategy for relapse via intraspecific cooperation. Methods: The hemolytic ability, growth curve, biofilm formation, virulence genes and response of G. mellonella larvae to S. aureus infection were analysed to confirm this hypothesis. Results: SA02 hemolytic activity was inhibited by SA01, along with the expression of hemolysin genes and the virulence factor Hla. Additionally, SA01 significantly enhanced the biofilm formation of SA02. AIP-RNAIII may be a possible pathway for this interaction. Compared with mono-infection, a worse outcome (decreased larval survival and increased microbial burden) of the two MSSA strains coinfected with G. mellonella confirmed that intraspecific interactions indeed enhanced bacterial survival in vivo. Conclusion: The intraspecific interaction of S. aureus could lead to chronic refractory infection via pathogenicity changes. [ABSTRACT FROM AUTHOR]

We performed a detailed ultrastructural reconstruction of the "passive" miracidium of Derogenes varicus Muller, 1784 , a species from the Hemiurata group. The miracidium is highly miniaturized and simplified in comparison with the "active" miracidia. For the first time we elucidated the nature of the spines on the surface of the hemiuroid larva: they are derivatives of the epithelial plates. The anterior end of the larva is equipped with three epithelial plates that bear both spines and cilia. The major part of the miracidial surface is formed by the tegument. The nervous and excretory systems of the D. varicus miracidium are extremely reduced. Single undifferentiated cell comprises the germinal material of the miracidium. We discuss the trends of evolution of hemiuroid miracidia that are associated with the transition to passive strategy of infection. [ABSTRACT FROM AUTHOR]

We compared the effects of lambda‐cyhalothrin as the pure active ingredient and as a formulated product (Zero®), on the larval stage of the autochthonous species Boana pulchella. We evaluated ecotoxicological endpoints, behavioral and developmental alterations, and the biochemical detoxifying, neurotoxic, and oxidative stress responses, covering a wide concentration range from environmental to high application levels. Both pyrethroid preparations displayed similar ecotoxicity (median lethal concentration of ~0.5 mg/L), with the lethal effect of Zero® being more pronounced than that of the active ingredient. Sublethal behavioral alterations in natatory activity were observed at 1000 times lower concentrations, indicating the ecological hazard of tadpole exposure to this pyrethroid at environmentally relevant concentrations. Biochemical endpoints in B. pulchella larvae showed significant responses to lambda‐cyhalothrin in the ng/L range; these responses were different for the pure or the formulated product, and they were variable at higher concentrations. Principal components analysis confirmed the prevalence of biochemical responses as early endpoints at the lowest lambda‐cyhalothrin concentrations; the Integrated Biomarker Response Index proportionally increased with pyrethroid concentration in a similar way for the pure and the formulated products. We conclude that lambda‐cyhalothrin is of concern from an environmental perspective, with particular emphasis on autochthonous anuran development. The battery of biochemical biomarkers included in our study showed a consistent integrated biomarker response, indicating that this is a potent tool for monitoring impacts on amphibians. Environ Toxicol Chem 2024;43:2134–2144. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Leptus (Leptus) mahtabaesp. nov. (Acari: Erythraeidae), collected as an ectoparasite of Mesobuthus rakhshanii (Scorpiones: Buthidae) from Sistan and Baluchestan province, southeast Iran, is described and illustrated based on the morphological characteristics of the larvae. The position of solenidia on Ti II of Charletonia damavandica Karimi Irvanlou, Kamali & Talebi, 2002, is corrected. [ABSTRACT FROM AUTHOR]

Bonefishes and other elopomorphs have a unique, transparent leptocephalus larval stage that is challenging to study due to its cryptic nature. Understanding life history is important especially considering adult bonefishes in Hawaiʻi are highly sought gamefish valued for their tenacious fight on rod-and-reel and delicate taste. In this study light traps were used to capture leptocephali at three nearshore locations around Oʻahu, Hawaiʻi. Across 130 + h of trapping, 59 larvae were captured, most during 2000–2100 h on rising tides. Lengths ranged from 54 to 66 mm, indicating late stage I larvae. Otolith analyses (N = 26) revealed ages from 28 to 72 days with an average age of about 48 days. Genetic species identification on a subset of the larvae showed that one of 28 total specimens was Albula virgata, which is endemic to Hawaiʻi, and the remaining were the Indo-Pacific A. glossodonta. Along with calm inshore waters, estuarine habitat appears to be a critical element for leptocephali recruitment success. Reducing impacts to these estuarine habitats and protecting and restoring freshwater input may have positive impacts on leptocephali recruitment, the essential starting point for thriving bonefish fisheries in Hawaiʻi. [ABSTRACT FROM AUTHOR]

The golden mussel (Limnoperna fortunei) is an invasive bivalve that has established itself in several South American river systems, impacting ecosystem functioning. Reservoir cascades provide their larvae with the means of rapid dispersal, but the relationship between environmental variables and larval stage structure remains unclear. In this study, the density of three L. fortunei larval stages and quantitative detection using DNA are analyzed in a cascade of five reservoirs in the upper Uruguay River Basin and associated with spatiotemporal variation in environmental parameters. The analysis of L. fortunei eDNA presence and absence in freshwater systems appears to be a valuable mapping tool; however, no significant link was found between the eDNA magnitude and the overall larval density. The increase in larval density was related to the fluctuation of environmental parameters over a year, with the highest average larval densities observed in the CN and ITA reservoirs, though no significant difference was observed between the five reservoirs, where D-shaped larvae predominated. During winter, larval density decreased significantly, however, other variables also contribute to species activity and development in the upper Uruguay River Basin reservoirs and may be considered limiting factors. The relationships between environmental parameters were evaluated using a multivariate model. The interaction between reservoir area and precipitation, water temperature, electrical conductivity, and dissolved oxygen had a significant effect on larval density but showed specific influences on each larval stage. Any increase in density was regulated by dissolved oxygen and electrical conductivity content at all larval stages. Furthermore, total phosphorus affected the density of F1 and F3 larvae. The interaction between reservoir area and precipitation, nitrate content, phosphate concentrations, and water temperature had the most influence on the density of F2 and F3 larval stages; the F1 stage was mainly affected by calcium concentrations. The isolated effect of precipitation also contributed to the density of F2 and F3 larvae. Our findings shed light on the interaction between different phases of golden mussel larvae and the main nutrients found in reservoirs, which may be a determining factor in the rise in density of the non-native species in these systems. [ABSTRACT FROM AUTHOR]

Migration of Sakhalin sculpin Cottus amblystomopsis larvae from the river to the sea for early rearing—the primary dispersion, occurs in the form of passive downstream migration in the first 1.0–1.5 h after dark. Reaction of larvae to decrease of illumination ensures their involvement into the flow and the implementation of downstream migration. Total duration of primary dispersion period does not exceed 3 days. Body length of the larvae is on average 7.7 mm, their vertebrae and spinous processes are formed, the anlages of unpaired fins are noticeable, and pectoral fins are well developed. [ABSTRACT FROM AUTHOR]

Population recruitment of endangered rheophilic fish species strongly depends on the survival of critical egg and larvae life stages. However, the transportation and fate of eggs after spawning is not well understood. This study analyzed the egg transport and settling patterns of the endangered European nase (Chondrostoma nasus L.), testing the transferability of physical modelling approaches for simple solid sphere surrogates to the eggs of lithophilic fish species. This model approach was validated in both laboratory and field experiments, where wetted millet corns were used as surrogates excluding deformability and stickiness of natural nase eggs. The transport and settling patterns of the surrogate accurately modelled the transportation of C. nasus eggs. Results further indicate that transport processes of eggs are small-scaled in the range of less than 3 m. These findings provide helpful information for restoration planning of C. nasus spawning grounds. They also highlight the importance of the interstitial zone regarding the egg settling process, which conforms to the ecological relevance of this habitat for egg and larval development. While the surrogate was suitable for this model approach, further investigations are necessary to confirm transferability to other species. [ABSTRACT FROM AUTHOR]

Background: Trichinella spiralis (T. spiralis) is a parasitic helminth that causes a globally prevalent neglected zoonotic disease, and worms at different developmental stages (muscle larvae, adult worms, newborn larvae) induce immune attack at different infection sites, causing serious harm to host health. Several innate immune cells release extracellular traps (ETs) to entrap and kill most pathogens that invade the body. In response, some unicellular pathogens have evolved a strategy to escape capture by ETs through the secretion of nucleases, but few related studies have investigated multicellular helminths. Results: In the present study, we observed that ETs from neutrophils capture adult worms of T. spiralis, while ETs from macrophages trap muscle larvae and newborn larvae, and ETs had a killing effect on parasites in vitro. To defend against this immune attack, T. spiralis secretes plancitoxin-1, a DNase II-like protein, to degrade ETs and escape capture, which is essential for the survival of T. spiralis in the host. Conclusions: In summary, these findings demonstrate that T. spiralis escapes ET-mediated capture by secreting deoxyribonuclease as a potential conserved immune evasion mechanism, and plancitoxin-1 could be used as a potential vaccine candidate. [ABSTRACT FROM AUTHOR]

We studied the development of sporocysts of the trematode Leucochloridium paradoxum. For this purpose, their life cycle was traced experimentally. Eggs obtained from adult trematodes raised in chicks (Gallus gallus domesticus) were used to infect snails (Succinea putris, laboratory strain). Histological studies of sporocysts were conducted for 95 days after exposure. During this time, the embryos of sporocysts developed into a small stolon filled with numerous metacercarial embryos. We found that miracidia hatched in the stomach and in the proximal part of the snail's midgut. After the larvae migrated into the area of the hepatopancreas, their body was destroyed, and germinal cells were released. They cleaved to form the embryos of sporocysts, in which only metacercarial embryos developed. Our study showed that these trematodes lack the parasitic phase of the mother sporocyst and have only one generation of parthenitae, the daughter sporocysts. [ABSTRACT FROM AUTHOR]

Most host-parasite associations are explained by phylogenetically conservative capabilities for host utilization, and therefore parasite switches between distantly related hosts are rare. Here we report the first evidence of a parasitic spillover of the burrowing sea anemone Edwardsiella carnea from the invasive ctenophore Mnemiopsis leidyi to two scyphozoan hosts: the native Mediterranean barrel jellyfish Rhizostoma pulmo and the invasive Indo-Pacific nomad jellyfish Rhopilema nomadica, collected from the Eastern Mediterranean Sea. Edwardsiella carnea planulae found in these jellyfish were identified using molecular analyses of the mitochondrial 16S and nuclear 18S rRNA genes. Overall, 93 planulae were found on tentacles, oral arms, and inside of the gastrovascular canals of the scyphomedusae, whereas no infection was observed in co-occurring ctenophores. DNA metabarcoding approach indicated seasonal presence of Edwardsiella sp. in the Eastern Mediterranean mesozooplankton, coinciding with jellyfish blooms in the region. Our findings suggest a non-specific parasitic relationship between Edwardsiella carnea and various gelatinous hosts based on shared functionality rather than evolutionary history, potentially driven by shifts in host availability due to jellyfish blooms. This spillover raises questions about the ecological impacts of parasitism on native and invasive scyphozoan hosts and the potential role of Edwardsiella in controlling their populations. [ABSTRACT FROM AUTHOR]

Forty-seven faecal samples of wolves from Bejaia were examined for intestinal helminths. Five nematodes (Ancylostoma caninum (egg), Strongyloides stercoralis (larvae L1), Toxocara canis (egg), Toxascaris leonina (egg), and Trichuris vulpis (egg)), and one cestode (Dipylidium caninum) were identified. These nematodes were detected with a prevalence of 46.8%, 23.4%, 38.2%, 25.3%, and 2.12%, respectively; and a cestode, with a prevalence of 4.3%. Our results show a high relative abundance of Strongyloides stercoralis larvae L1 (37.5%), followed by eggs of Ancylostoma caninum, whether non-embryonated (16.77%) or embryonated (14.28%). Among the ascarids, Toxocara canis was represented with 18.1%, followed by Toxascaris leonina (8.1%). Finally, Dipylidium caninum and Trichuris vulpis were only poorly represented. This is the first study on helminth parasites in wild golden wolves in Bejaia. The results indicate the presence of six gastrointestinal helminths in the wolf population. [ABSTRACT FROM AUTHOR]

Since the couple of decades the demand for silk has been increasing day by day but the average silk production is not enough to meet its demand. In this study, we investigated the effect of with Maize extract in different concentration (0.5%,1.0 %,1.5 %,2.0%, 2.5 %)on the growth 5th stage silkworm larvae on the biological and commercial traits of Bombyx mori L. The silkworm larvae at 5th instar stage were taken and fed with fresh and healthy mulberry leaves coated with Maize extract in different concentration. Results of the current study revealed that the higher growth parameters of 5th stage silkworm larvae, the cocoon weight, shell weight, and shell ratio were increased, and thus improved the quality of silk as compared to the control. The commercial traits of larvae fed with Maize extract in different concentration leaves also improved significantly. The larvae fed with Maize extract in different concentration treated mulberry leaves showed the maximum cocoon weight, cocoon length, cocoon width, cocoon shell ratio and fibroin content as compared to the control group. It is evident from the results that the fed with Maize extract coated mulberry leaves have a positive effect on the commercial and biological traits of Bombyx mori (L.). [ABSTRACT FROM AUTHOR]

Introduction: Developmental processes continue in organisms in which sensory systems have reached functional maturity, however, little research has focused on the influence of sensory input on cell and tissue development. Here, we explored the influence of visual system activity on the development of skin melanophores in Xenopus laevis. Methods: Melanophore number was measured in X. laevis larvae after the manipulation of visual input through eye removal (enucleation) and/or incubation on a white or black substrate at the time when the visual system becomes functional (stage 40). To determine the developmental process impacted by visual input, migration, proliferation and differentiation of melanophores was assessed. Finally, the role of melatonin in driving melanophore differentiation was explored. Results: Enucleating, or maintaining stage 40 larvae on a black background, results in a pronounced increase in melanophore number in the perioptic region within 24 h. Time lapse analysis revealed that in enucleated larvae new melanophores appear through gradual increase in pigmentation, suggesting unpigmented cells in the perioptic region differentiate into mature melanophores upon reduced visual input. In support, we observed increased expression of melanization genes tyr, tyrp1, and pmel in the perioptic region of enucleated or black background-reared larvae. Conversely, maintaining larvae in full light suppresses melanophore differentiation. Interestingly, an extra-pineal melatonin signal was found to be sufficient and necessary to promote the transition to differentiated melanophores. Discussion: In this study, we found that at the time when the visual system becomes functional, X. laevis larvae possess a population of undifferentiated melanophores that can respond rapidly to changes in the external light environment by undergoing differentiation. Thus, we propose a novel mechanism of environmental influence where external sensory signals influence cell differentiation in a manner that would favor survival. [ABSTRACT FROM AUTHOR]

This study explores the potential of Tenebrio molitor larvae to valorize apple peels and assesses larval fermentation's impact on phenolics, growth potential and physicochemical properties of the larvae. Corn flour and apple peel were mixed in different ratios (1:1, 1:2, 1:4), and fermentation was conducted for 12 days. Significant changes occurred in the 1:1 ratio (EMB); larval weight increased by 62.2% compared to 58.6% in the control. After 12 days, the larvae showed increased ash, protein and carbohydrate contents, but reduced fat content. The phenolic content and antioxidant activities of the EMB medium significantly increased compared to the initial values, reaching their maximum level on day 8. Four quercetin derivatives were detected: quercetin-3-rutinoside, quercetin-3-O- glucoside, quercetin-3-O-galactoside and quercitrin. After 8 days, the amounts of quercitrin and quercetin-3-O-glucoside increased significantly. These findings suggest that T. molitor larvae can convert food waste into valuable functional food ingredients through phenolic release or conversion. [ABSTRACT FROM AUTHOR]

Rearing experiments are reported for Micropterix calthella (L.). Eggs and early instar larvae were observed, measured and photographed; larvae were video recorded. Potential larval foodplants are discussed. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSFL) treatment offers a promising avenue for manure valorization. However, there is a lack of larval density studies and ton-scale exploration in swine manure bioconversion. This study delves into the efficiency of larval fatty acid (FA) bioconversion, examining the impact of larval density on a kilogram scale and extending the analysis to a ton scale. Across a range of 50 to 600 larvae/kg, the larval FA content decreased from 15.3% to 7.85%. The peak larval FA yield, at 3.04% (based on manure dry matter), occurred at a density of 200 larvae/kg. Both low (50 larvae/kg) and high (600 larvae/kg) densities adversely affected BSFL bioconversion performance. Dominant larval FAs included C12:0 (39.7%), C16:1 (24.2%), C18:1 (17.5%), and C16:0 (8.3%). The scaling-up process maintained a consistent larval FA content and composition but resulted in decreased larvae FA yield due to increased larval mortality. Ultimately, each ton of swine manure yielded 12.4 kg of fresh larvae or 0.71 kg of larval FA components, corresponding to a 1.14% larval FA yield. This study underscores the feasibility of upscaling swine manure treatment using BSFL for FA bioconversion and emphasizes the necessity for large-scale studies to enhance larval survivorship and bioconversion efficiency. [ABSTRACT FROM AUTHOR]

The genus Cernotina Ross, 1938 is represented in the southeastern United States by three nominal species: Cernotina calcea Ross, 1938, Cernotina spicata Ross, 1938, and Cernotina truncona Ross, 1947. Of all Cernotina species, only the larva of C. spicata has been described to date. The goal of this paper is to describe, illustrate, and diagnose the larva of C. truncona using ecologically associated specimens. In addition, we used publicly available mitochondrial DNA barcoding data to evaluate the genetic relationships of these species. The larvae of Cernotina truncona can be distinguished from those of C. spicata by differences in setal placement and number on the meso- and metanota, mandibular morphology, head width, and distal setation of the tarsi. The ultrastructure of the anal claw is figured, highlighting the novel finding of small spines on the concave margin of a larva of Cernotina. With this new description, just the second described larva from this genus, only C. calcea remains unknown in the southeastern United States. The information provided herein enables the in-depth study of the ecology and life history of this diminutive caddisfly. [ABSTRACT FROM AUTHOR]

Kynurenic acid (KYNA) is a metabolite of tryptophan formed on the kynurenine pathway. Its pharmacological effects are relatively well characterized in mammals, whereas its role in fish is poorly understood. Therefore, the aim of the study was to expand the knowledge of KYNA's presence inside a fish's body and its impact on fish development and function. The study was performed on zebrafish larvae and adult rainbow trout. We provide evidence that KYNA is present in the embryo, larva and mature fish and that its distribution in organs varies considerably. A study of KYNA's effect on early larval development suggests that it can accelerate larval maturation, especially under conditions that are suboptimal for fish growth. Moreover, KYNA in concentrations over 1 mM caused morphological impairment and death of larvae. However, long-lasting exposure of larvae to subtoxic concentrations of KYNA does not affect the behavior of 5-day-old larvae kept under standard optimal conditions. We also show that ingestion of KYNA-supplemented feed can lead to KYNA accumulation, particularly in the pyloric caeca of mature trout. These results shed new light on the relevance of KYNA and provide new impulse for further research on the importance of the kynurenine pathway in fish. [ABSTRACT FROM AUTHOR]

Taraba State, located in the north-eastern part of Nigeria harbours some of the hyper endemic onchocerciasis sites in the country. The distribution of simuliids larvae along the river contiguous with these sites has been documented but unpublished. Larval sampling was conducted along the tributaries adjoining the hyper-endemic focus in Gashaka Local Government Area of Taraba State, between December 2006 and January 2007. This study therefore presents the distribution of simuliid species and physico-chemical parameters of the breeding sites along the tributaries of the endemic foci in Gashaka LGA of Taraba State. The physico-chemical parameters of breeding sites were measured using standardized equipment, and larvae of various Simulium species were collected, fixed in Carnoy's solution and subsequently identified in the laboratory. Eleven tributaries were examined, with only 3(25.0%) serving as breeding sites during the collection period. A total of 552 simuliids larvae were identified; Simulium damnosum, 490 (86.96%); S. medusaeforme hargreavesi, 51(9.24%); S. colas belcouri, 11(1.99%); S. vorax, 7(1.27%) and S. bovis, 3(0.54%). S. damnosum were the most predominant, collected from all breeding sites, with 95.95% (284/296) in Ngam Ngam, 100% (90/90) in Kam, and 63.86% (106/166) in Mayo Selbe. The physico-chemical parameters of the tributaries range from 6.6-6.9 for pH, 45-82µs/cm for conductivity, 140-157m/s for water velocity, 20-22oC for temperature, 146-246m for river width, 185-455m for altitude and clear turbidity across the sampling sites. Larvae of S. damnosum, S. medusaeforme, S. colas, S. vorax, and S. bovis had strong positive correlations (r2 = 0.5-1.0) with pH and altitude parameters of breeding sites. This study provides baseline data on the identity and abundance of simuliid larvae, which are useful for comparative assessments with recent entomological surveys across breeding sites in the focus. [ABSTRACT FROM AUTHOR]

By using a scaffold hopping/ring equivalent and intermediate derivatization strategies, a series of compounds of 2,5-diphenyl-1,3-oxazoline with substituent changes at the 5-phenyl position were prepared, and their acaricidal activity was studied. However, the synthesized 2,5-diphenyl-1,3-oxazolines showed lower activity against mite eggs and larvae compared to the 2,4-diphenyl-1,3-oxazolines with the same substituents. We speculate that there is a significant difference in the spatial extension direction of the substituents between the two skeletons of compounds, resulting in differences in their ability to bind to the potential target chitin synthase 1. This work is helpful in inferring the internal structure of chitin synthase binding pockets. [ABSTRACT FROM AUTHOR]

To better understand the limitations of dormancy on Odontomyia Meigen, 1803 (Diptera: Stratiomyidae) survival and body condition, we conducted a series of laboratory-based microcosm experiments. We found that Odontomyia larvae can survive at least two extended dry periods (≥30 days) through dormancy. The presence of moisture in the substrate during dormancy is not necessary to survive and had no effect on survival or larval body mass in our experiments. Energy and bodily water loss likely limit survival in dormant stages. Although these results suggest Odontomyia are fairly resistant to drying, more data is needed on body mass, pupation, and reproductive success across hydroregimes. The more we understand about the survival limitations of rock pool aquatic invertebrates, the more successful conservation efforts will be for their unique aquatic biota. [ABSTRACT FROM AUTHOR]

Lacustrine environments from Northern Patagonia are exposed to volcanic events from the Southern Volcanic Zone. Chironomid larvae are an important paleo-proxy because, in addition to their environmental sensitivity, their chitinous cephalic capsules are well preserved in lacustrine sediments, allowing their recovery and identification. We analysed the effects of a recent volcanic eruption (Puyehue-Cordón Caulle Volcanic Complex 2011) on the chironomid community based on their cephalic remains accumulated following the ash deposition process. Two pulses of ash deposition were distinguished: a first stage comprising the immediate coarse ash fall and a delayed finer volcanic deposition. An abrupt decline in chironomid taxa and their densities were noted during the first coarse pulse, followed by an attempt of community recovery through the second finer pulse, characterised by main taxa turnover, observing an alternative community functional structure. Based on these results and comparing with past volcanic depositions, we observed different chironomid responses according to their particular ecological habits, and we noted possible percolation effects, mainly in coarse tephras, and probably a delayed record of very low abundance taxa. Our results suggest caution in analysing chironomid assemblages within and adjacent to tephra deposition as local volcanic eruption could affect chironomid community with possible consequences on paleoreconstructions. [ABSTRACT FROM AUTHOR]

The orange-spotted grouper (Epinephelus coioides) is one of the most popular fish in aquaculture due to its high economic value. However, the random occurrence of slow-growing population has led to profit loss. Therefore, transcriptomic analysis was performed to identify the molecular mechanisms involved in driving slow and fast growth, towards addressing this issue. Results show that low expression of developmental genes such as bone morphogenetic protein 1 (BMP 1) and somatostatin (SST), as well as GH/IGF axis-related genes (IGF-1, IGF2, IGFBP1, IGFBP2) and its downstream signalling pathways are correlated with the metabolism and digestive-system-related pathways in slow-growing groupers. Enrichment analysis further revealed that cellular process and biological regulation, as well as several pathways including glycolysis/gluconeogenesis, linoleic acid metabolism, protein digestion and absorption, and cholesterol metabolism were differentially expressed in slow-growing groups. The findings implied that the genomic architecture of growth between the different families raised and the likely problem of inbreeding have led to significantly reduced growth. It is also suggested that better husbandry practices (optimal dietary requirement) is also vital in supporting the success of a genetic improvement programme. These findings recommend growth improvement of orange-spotted groupers via molecular monitoring and artificial selection, complemented by specific dietary feeding. [ABSTRACT FROM AUTHOR]

Entomopathogenic nematodes (EPNs), especially Heterorhabditis bacteriophora, are promising candidates for biological control of Popillia japonica larvae. Thus, there is a need to study native strains to ensure biological agents adapted to specific environmental conditions to improve their effectiveness in field applications. This work aimed to test the pathogenicity of five Azorean isolates of H. bacteriophora strains to third‐instar larvae of P. japonica under laboratory and semi‐field conditions. All EPNs were able to quickly infect larvae with LT50's ranging between 3.66 and 4.54 days in controlled laboratory conditions. The semi‐field experiment consisted of an EPN application in buried tubes containing five larvae each in May and October. After 15 days, larvae were recovered and confirmed for nematode parasitism. In May, Az29, Az148, Az170, and Az171 displayed a mean of 37% infected larvae per tube. In contrast, EPNs showed a lower infection ability during the experiment in October, and only Az148 maintained the number of parasitized larvae, with a proportion of 40% of infectivity. The results suggest that native EPNs, like Az148, could be better adapted to climatic and edaphic conditions to control P. japonica larvae. [ABSTRACT FROM AUTHOR]

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