Initial Starvation Research Articles

Gut microbiota modulatory capacity of fermented ketchup in a validated in vitro model of the colon

This study aimed to evaluate the effects of fermented beetroot ketchup enriched with Lactobacillus johnsonii K4 and non-fermented beetroot ketchup on pooled fecal microbiota from healthy adults in in vitro colon model. The research focused on how these products influenced the composition and functionality of the gut microbiota, as well as metabolite production, using the validated dynamic in vitro colon model, TNO Intestinal Model (TIM-2). After an initial starvation phase, a single 60 g dose of predigested and freeze-dried ketchup was introduced into the model. The potential probiotic strain Lactobacillus johnsonii K4 was added over three days. A carbohydrate mixture of standard ileal effluent medium (SIEM) served as the control. Our analysis identified 21 bacterial taxa that were significantly modulated (q-value < 0.2) when comparing ketchup samples to control samples. Notably, the ketchup samples led to an increase in butyrate-producing taxa, including Faecalibacterium, Blautia, Ruminococcaceae, Ruminiclostridium 6, and Anaerostipes. Conversely, there was a reduction in potentially pathogenic genera Desulfovibrio and Escherichia-Shigella. Distinct profiles of short-chain fatty acids (SCFA) were observed among the fermented ketchup, non-fermented ketchup, and control samples. Non-fermented ketchup resulted in higher proportions of acetate, propionate, and butyrate compared to the other interventions. This may be related to the fermentation with lactic acid bacteria in fermented samples with lower levels of substrate for SCFAs production. However, fermented ketchup sample has higher relative abundance of beneficial bacteria like Lactobacillus, Weissella and Dorea in gut microbiota. These findings suggest that beetroot ketchup, can positively influence gut microbiota composition and function, highlighting its potential benefits for human health.

Resistance to initial starvation in stage I larvae of the American lobster Homarus americanus H. Milne Edwards, 1837 (Decapoda: Astacidea: Nephropidae)

Abstract Greater embryo mass confers an advantage in the face of sub-lethal starvation for larvae of the American lobster, Homarus americanusH. Milne Edwards, 1837. We reared larvae in the laboratory and recorded body size, molt increment, stage duration, and mortality during the three larval instars and postlarval stages. Larvae were either fed continuously or subjected to starvation periods immediately after hatching. Larval mass increased with embryo mass suggesting that energetic advantages of heavier embryos are conferred to the larvae. Stage I larvae hatched from clutches with heavier embryos and had lower mortality after five days without food. Stage I duration decreased with increasing embryo mass in treatments with initial periods without food of three, four, and five days. We also observed greater size increase at first molt and larger postlarval size in some treatments. Our results suggest that larger embryos produce larvae that are more resistant to starvation, which may provide a survival advantage when experiencing variable food supply due to the patchy distribution of their planktonic prey.

Nutritional vulnerability of early zoeal stages of the ornamental shrimp Lysmata ankeri (Decapoda: Caridea)

Abstract The evaluation of the effects of early starvation and feeding on survival and growth in the early stages of the life cycle of ornamental marine caridean shrimp species is fundamental to establish adequate feeding protocols in their culture. In this study, we determine the nutritional vulnerability in the early larval stages of ornamental shrimp Lysmata ankeri exposed to different periods of starvation or feeding. The larvae were separated into three groups (zoea I-ZI, zoea II with ZI fed, and zoea II with ZI unfed) and subjected to two experiments: (1) point-of-no-return (PNR), comprising one or two days of initial starvation followed by feeding; and (2) point-of-reserve-saturation (PRS), comprising one or two days of initial feeding followed by starvation. Each experiment was still composed of two control groups: continuous feeding and continuous starvation. Larvae tolerated some periods of starvation, with a high PNR value (2.00) and low PRS (0.50). Longer periods of starvation influenced both growth and survival rates in zoea II stages. The nutritional vulnerability index for zoea I was 0.25, which represents a low dependence on food supply. In this study, it was observed that ornamental shrimp L. ankeri larvae hatch with energy reserves, presenting facultative primary lecithotrophy, in which they are able to moult from zoea I to zoea II using such reserves in the absence of food. In this sense, the early larvae stages (zoeas I and II) can tolerate a certain period of starvation, indicating the great potential of this species for aquaculture.

Maujan.pk: Nothing Ventured; Nothing Gained

The case helps the students explore a capacity utilization problem faced by the CEO of Maujan.pk. The financial statements from the fiscal year 2013–2014 put the CEO, Tahir, in a difficult spot. According to these reports, his main business, which was online discount coupons, has been outpaced in growth by his side business, Facebook management. Tahir had launched the Facebook management business as an afterthought; his strategic business decisions never factored it as a major consideration. Now, Tahir is forced to reflect on this matter, especially because of resource constraints. Being a small company with six employees, he has had to share resources between the two businesses. Now that his side business has grown faster than the main business, Tahir finds himself understaffed. Meanwhile, the original business is slowing down, and few avenues of growth are forthcoming due to network congestion (network effects model). Keeping this in mind, a decision must be made to choose one of the two businesses or expand and continue them both. The expansion would mean significant logistic overhead and initial resource starvation. This is perplexing for someone like Tahir, who is a real hands-on manager. Eventually, inaction would lead him to these problems, as the business would continue to grow to further compete for the same resources. Each decision has its merits and demerits in a fast-moving Pakistani digital market where copycat businesses can spring up within days, and customer loyalty is mercurial at best.

Effect of initial starvation on growth performance and length-weight relationship of striped murrel Channa striata (Bloch, 1793) larvae

The study evaluated the effect of delayed initial feeding on the growth performance and length-weight relationship of Channa striata (Bloch, 1793) larvae. C. striata larvae [3 days post-hatch (dph); mean length: 5.960±0.32 mm] were reared in experimental tanks (10 l) at the stocking density of 5 larvae l-1 for 28 days in five treatments. The five treatments in triplicates were, T1 (3 dph, 0-day delay in initial feeding), T2 (4 dph - 1day delay in initial feeding), T3 (5 dph - 2 days delay in initial feeding), T4 (6 dph - 3 days delay in initial feeding) and T5 (7 dph - 4 days delay in initial feeding). One-way ANOVA results showed that delayed initial feed had a significant (p&lt;0.05) effect on weight gain, daily weight gain, specific growth rate and survival rate. Weight gain was highest in 2 days delayed initial feeding (280.50 mg ±9.5) and lowest in 1 day delayed initial feeding (207.87 mg ±3.2). Similar pattern was also observed for the specific growth rate and survival. The length-weight relationship of larvae exhibited the lowest b value (2.006) in 3-days delayed feeding and the highest (2.627) in 1-day delayed feeding, which indicates negative allometric growth in the experimental groups. A better condition factor of 0.85 was noticed in 2 days of delayed initial feeding compared to all other treatment groups. The growth, survival and length-weight relationship data of the study suggested that 2 days of delay in first feeding yielded better growth and survival of C. striata larvae. Thus the information generated in this study might help in better management of the initial larval stages of C. striata.Keywords: Channa striata, Growth and survival, Larval rearing, Length-weight relationship, Starvation, Striped murrel

Phenotypic Convergence in Sea Bass (Dicentrarchus labrax) Escaping From Fish Farms: The Onset of Feralization?

The impact of fish escaping from fish farms may depend on the extent to which escapees adapt to the natural environment, resemble wild conspecifics, and become feral. Yet, little is known about the process of feralization in marine fish. We examined phenotypic changes in body shape, body condition, and scale growth profiles of sea bass escaping from fish farms in the Canary Islands and quantified the extent to which escapees had diverged from farmed conspecifics. Most feral sea bass had sizes that overlapped with those of farmed fish, indicating that they had escaped throughout the production cycle. However, 29% of escapees were larger than the maximum size at harvesting, indicating growth in the wild. Analysis of scale growth profiles showed that some escapees had grown in the wild as fast as cultured fish, albeit at more variable growth rates. Feral sea bass tended to converge towards a similar body shape, having more streamlined bodies, lower body condition, and lower hepatosomatic indices (HSI) than fish in cages. Although our study cannot discriminate between phenotypic plasticity and differential mortality of escapees, we interpret phenotypic convergence as the likely result of a period of initial starvation, phenotypic plasticity, and selection against maladapted phenotypes. Our results warn against the risks of rearing sea bass in open-net cages and suggest that sea bass escapees could pose a threat to shallow coastal assemblages, particularly in areas where the species is not naturally found.

Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod.

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host’s diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose. A total of 72 digestive microbiota were analyzed according to the type of the diet (standard or enriched in cellulose, lignin, or hemicellulose) and the period following dysbiosis. The results showed that microbiota from the hepatopancreas were very stable and resilient, while the most diverse and labile over time were found in the hindgut. Dysbiosis and selective diets may have affected the host fitness by altering the structure of the microbiota and its predicted functions. Overall, these modifications can therefore have effects not only on the holobiont, but also on the “eco-holobiont” conceptualization of macroorganisms.

Evaluation of a newly modified eight-chamber-olfactometer for attracting German cockroaches Blattella germanica (Dictyoptera: Blattellidae)

Attractive Toxic Bait (ATB) is a low risk practical method to cockroach control. This study aimed to evaluate efficacy of a newly modified eight-chamber-olfactometer for attractiveness experiments. Different stages of German cockroaches were exposed to carbohydrate-rich and protein-rich foods and their attractions were tested both at ambient conditions and in the modified olfactometer. In the latter method, cockroaches were released into the main chamber of olfactometer and their attraction to food compounds placed in test chambers were recorded as the number of captured cockroaches in test chambers. The direct attractiveness test was performed in plastic pans. Repellency of fipronil insecticide was performed with prepared bait powder using olfactometer. Data were subjected to analysis of variance with Tukey’s Test,P ≤ 0.05. Different notes should be considered when using introduced olfactometer like precision when opening the test chambers valves, the fan speed, placement of cardboard shelter in both test and main chambers, and initial starvation of cockroaches. Roasted peanut, banana and biscuits powder were the most attractive foods for cockroaches. The females significantly preferred roasted peanut and the males significantly preferred banana and roasted peanut. These results were similar to the results of direct attracted cockroaches. The cockroaches have repellency to fipronil but attractiveness of bait with 0.01% concentration was significantly higher than cockroach diet. Generally, three factors should be considered in formulation of ATB like un-repellency of the a.i, attractiveness of bait compositions, and palatability of bait texture. The olfactometer introduced in this study could be used by researchers to study cockroach behaviors.

Specific “Unlocking” of a Nanozyme‐Based Butterfly Effect To Break the Evolutionary Fitness of Chaotic Tumors

AbstractChaos and the natural evolution of tumor systems can lead to the failure of tumor therapies. Herein, we demonstrate that iridium oxide nanoparticles (IrOx) possess acid‐activated oxidase and peroxidase‐like functions and wide pH‐dependent catalase‐like properties. The integration of glucose oxidase (GOD) unlocked the oxidase and peroxidase activities of IrOx by the production of gluconic acid from glucose by GOD catalysis in cancer cells, and the produced H2O2 was converted into O2 to compensate its consumption in GOD catalysis owing to the catalase‐like function of the nanozyme, thus resulting in the continual consumption of glucose and the self‐supply of substrates to generate superoxide anion and hydroxyl radical. Moreover, IrOx can constantly consume glutathione (GSH) by self‐cyclic valence alternation of IrIV and IrIII. These cascade reactions lead to a “butterfly effect” of initial starvation therapy and the subsequent pressure of multiple reactive oxygen species (ROS) to completely break the self‐adaption of cancer cells.

Specific “Unlocking” of a Nanozyme‐Based Butterfly Effect To Break the Evolutionary Fitness of Chaotic Tumors

Chaos and the natural evolution of tumor systems can lead to the failure of tumor therapies. Herein, we demonstrate that iridium oxide nanoparticles (IrOx ) possess acid-activated oxidase and peroxidase-like functions and wide pH-dependent catalase-like properties. The integration of glucose oxidase (GOD) unlocked the oxidase and peroxidase activities of IrOx by the production of gluconic acid from glucose by GOD catalysis in cancer cells, and the produced H2 O2 was converted into O2 to compensate its consumption in GOD catalysis owing to the catalase-like function of the nanozyme, thus resulting in the continual consumption of glucose and the self-supply of substrates to generate superoxide anion and hydroxyl radical. Moreover, IrOx can constantly consume glutathione (GSH) by self-cyclic valence alternation of IrIV and IrIII . These cascade reactions lead to a "butterfly effect" of initial starvation therapy and the subsequent pressure of multiple reactive oxygen species (ROS) to completely break the self-adaption of cancer cells.

Food Restrictions Affect the Larval Metamorphosis and Early Juvenile Performance in a Neotropical Mangrove Fiddler Crab (Leptuca cumulanta).

Sporadic fluctuations in food availability may affect larval biology and post-metamorphic development in many marine invertebrates. In an experimental study in the laboratory, we investigated whether different regimes (1, 3, and 5 days) of initial starvation or feeding affect the survival and duration of the last planktotrophic larval stage (i.e., megalopa) of the neotropical mangrove fiddler crab Leptuca cumulanta. Newly metamorphosed crabs originating from megalopae starved for 1 and 3 days were cultured through the first 5 juvenile stages to further evaluate whether prior nutritional experience affects the post-larval performance of this species. All megalopae that were starved continuously died, while 80% of the larvae that were fed constantly metamorphosed successfully into the juvenile stage. Megalopae initially starved for 3 and 5 days exhibited lower survival (55% and 30% of larval metamorphosis, respectively) than larvae starved for only 1 day (85%) or fed constantly. The starvation periods (1, 3, and 5 days) also significantly prolonged the mean megalopal stage duration (12.8, 13.9, and 14.3 days, respectively) compared to the continuous feeding regime (10.6 days). Survival of the megalopae subjected to different periods of initial feeding (1, 3, and 5 days) was significantly lower (15.0%, 57.5%, and 62.5%, respectively) than survival of the larvae fed constantly. The mean megalopal stage duration, by contrast, did not vary among megalopae initially fed for 3 and 5 days or fed continuously (10.4 days). The larval starvation did not affect survival and carapace shape of juveniles, but it did alter their intermolt period, growth, and body size. These carryover effects were stronger in the first juvenile crab stage than in other juvenile stages. Our results indicate that the timing and duration of the starvation or feeding regime experienced by the megalopae may affect their successful survival and developmental period until metamorphosis to juvenile life. In addition, the preceding larval starvation associated with a prolonged larval period may also affect early juvenile performance in specific crab stages of L. cumulanta.

Impacts of nutritional stress on the survival and developmental time to metamorphosis in megalopa larvae of the exploited mangrove crab, Ucides cordatus (Ucididae)

ABSTRACTTemporal variation in food availability may affect the early life-history stages of many decapod crustaceans in the pelagic environment. Here, we investigated whether temporary food restrictions affect the survival and developmental period in the last larval stage (i.e. megalopa) of the mangrove crab Ucides cordatus. We further examined whether the prior nutritional history experienced during the megalopal life affects the body size (carapace width) of the first juvenile crab stage of this species. Megalopae were subjected to five different periods (1, 3, 5, 7, and 9 days) of initial starvation followed by constant feeding (‘Point of No Return’ experiment), or initial feeding with subsequent food deprivation (‘Point of Reserve Saturation’ experiment). They were also starved or fed (Artemia sp. nauplii) constantly in two control groups. Our results showed that U. cordatus megalopae may tolerate only one day without food, but need to feed for at least three, five or seven days at the beginning of their development to avoid a significantly lower survival and/or a delay in larval metamorphosis when compared to larvae fed constantly. However, megalopae initially fed from one to seven days may produce juveniles of smaller body size than those larvae fed for nine days or constantly.

Transcriptome dynamics at Arabidopsis graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration

The ability for cut tissues to join and form a chimeric organism is a remarkable property of many plants; however, grafting is poorly characterized at the molecular level. To better understand this process, we monitored genome-wide gene expression changes in grafted Arabidopsis thaliana hypocotyls. We observed a sequential activation of genes associated with cambium, phloem, and xylem formation. Tissues above and below the graft rapidly developed an asymmetry such that many genes were more highly expressed on one side than on the other. This asymmetry correlated with sugar-responsive genes, and we observed an accumulation of starch above the graft junction. This accumulation decreased along with asymmetry once the sugar-transporting vascular tissues reconnected. Despite the initial starvation response below the graft, many genes associated with vascular formation were rapidly activated in grafted tissues but not in cut and separated tissues, indicating that a recognition mechanism was activated independently of functional vascular connections. Auxin, which is transported cell to cell, had a rapidly elevated response that was symmetric, suggesting that auxin was perceived by the root within hours of tissue attachment to activate the vascular regeneration process. A subset of genes was expressed only in grafted tissues, indicating that wound healing proceeded via different mechanisms depending on the presence or absence of adjoining tissues. Such a recognition process could have broader relevance for tissue regeneration, intertissue communication, and tissue fusion events.

Resistance to starvation of first-stage juveniles of the Caribbean spiny lobster.

The non-feeding postlarva (puerulus) of spiny lobsters actively swims from the open ocean to the coastal habitats where it settles and molts to the first-stage juvenile (JI). Because pueruli use much of their energy reserves swimming and preparing for the post-settlement molt, the survival of JIs presumably depends on resuming feeding as soon as possible. To test this hypothesis, the resistance to starvation of JIs of the Caribbean spiny lobster, Panulirus argus, was evaluated by measuring their point-of-no-return (PNR, minimum time of initial starvation preventing recovery after later feeding) and point-of-reserve-saturation (PRS, minimum time of initial feeding allowing for food-independent development through the rest of the molting cycle) in a warm and a cold season. Each experiment consisted of eight groups: a continuously fed control (FC) group, a continuously starved control (SC) group, and six groups subjected to differential periods of either initial starvation and subsequent feeding (PNR experiments) or initial feeding and subsequent starvation (PSR experiments). No JIs molted under continuous absence of food (SC). In both PNR experiments (temperature in warm season: 29.79 ± 0.07°C, mean ± 95% CI; in cold season: 25.63 ± 0.12°C) mortality increased sharply after 9 d of initial starvation and intermolt periods increased with period of initial starvation, but were longer in the cold season. The PNR50 was longer in the warm season (12.1 ± 1.2 d, mean ± 95% CI) than in the cold season (9.5 ± 2.1 d). In PRS experiments (temperature in warm season: 29.54 ± 0.07 °C; in cold season: 26.20 ± 0.12 °C), JIs that molted did so near the end of the feeding period; all JIs initially fed for up to 6 d succumbed, and no JIs molted after 13 d of starvation despite having fed previously. The PRS50 did not differ between the cold (13.1 ± 0.7 d) and warm seasons (12.1 ± 1.1 d). JIs of P. argus exhibit a remarkable resistance to starvation considering that the previous non-feeding, energy-demanding puerulus phase lasts for ∼3 weeks. However, JIs appear to have a relatively higher degree of dependence on food to complete development to JII during the cold season than during the warm season. Therefore, JIs of P. argus would appear to be more resistant to starvation during the warm season.

A Repertoire of MicroRNAs Regulates Cancer Cell Starvation by Targeting Phospholipase D in a Feedback Loop That Operates Maximally in Cancer Cells

We report a negative feedback loop between the signaling protein phospholipase D (PLD), phosphatidic acid (PA), and a specific set of microRNAs (miRNAs) during nutrient starvation of breast cancer cells. We show that PLD expression is increased in four breast cancer cell lines and that hypoxia, cell overcrowding, and nutrient starvation for 3 to 6 h increase expression even further. However, after prolonged (>12-h) starvation, PLD levels return to basal or lower levels. The mechanism for this is as follows. First, during initial starvation, an elevated PA (the product of PLD enzymatic activity) activates mTOR and S6K, known to inhibit apoptosis, and enhances cell migration especially in post-epithelial-to-mesenchymal transition (post-EMT) cancer cells. Second, continued PA production in later starvation induces expression of PLD-targeting microRNA 203 (miR-203), miR-887, miR-3619-5p, and miR-182, which reduce PLD translation. We provide direct evidence for a feedback loop, whereby PLD induction upon starvation leads to PA, which induces expression of miRNAs, which in turn inhibits PLD2 translation. The physiological relevance for breast cancer cells is that as PA can activate cell invasion, then, due to the negative feedback, it can deprive mTOR and S6K of their natural activator. It can further prevent inhibition of apoptosis and allow cells to survive nutrient deprivation, which normal cells cannot do.

Effects of starvation on survival, growth and development ofExopalaemon carinicaudalarvae

This study aimed at evaluating the effects of two starvation modes (fasting-feeding mode and feeding-fasting mode) on survival, growth and development of mysis larvae of Exopalaemon carinicauda. It showed that food restriction significantly affected the survival, growth and development in both starvation modes. With the extension of initial starvation period, a significantly reduced survival rate during metamorphosis was observed. In the fasting-feeding mode, the duration of metamorphosis was extended and the body lengths of the individuals, which experienced successful metamorphosis to the post-larval stage 1, were much shorter. In the feeding-fasting mode, the extension of initial feeding period led to dramatically increased survival rate and body lengths, while there was no significant difference in duration of metamorphosis of those groups that reached to post-larval stage. The 50% point-of-no-return and the 50% point-of-reserve-saturation were 3.85 days and 4.81 days respectively. The results of this study indicate that E. carinicauda mysis have the ability to withstand or recover from relatively extended starvation, but to ensure the success of commercial seedling, timely and adequate feeding is necessary. The information obtained from this study could provide a basis to optimize the feeding schedule of artificial seedling of E. carinicauda.

Assessment of railway curve lubricant performance using a twin-disc tester

Tests have been carried out to assess the performance of ten different grease types used as curve lubricants. All greases tested have been designed for wayside flange lubrication and some are currently used on the UK’s rail network. Each grease's performance was assessed in terms traction coefficient, retentivity (how long a fixed amount of grease provided lubrication), and wear. Two series of tests were carried out: one running the test until the traction level reached that of a dry contact, referred to as a “lubricant starvation test”, and the other running the test up to the point where the traction started to rise i.e. when there was still grease on the disc, referred to as a “fully lubricated test”. In initial starvation tests slip was varied along with amount of grease applied. In both series repeat tests were carried out on the same disc pairs to monitor the effect of changes in surface roughness on grease performance.Grease retentivity was found to be greater with lower roughness and with more grease applied. Repeat tests with discs used for starvation tests led to very high wear rates. This was thought to arise as cracks initiated as the first run reached dry conditions were pressurised by grease reapplied in the subsequent tests causing crack growth and intersection and associated pitting and spalling. Clear differences were seen between the greases in terms of their retentivity performance although there was considerable scatter. Coefficients of traction (COT) in the early stages of the starvation tests and during the fully lubricated tests were below 0.1 and very consistent. Again differences could be found between greases under the test conditions used.

Nutritional vulnerability of early zoea larvae of the crab Maja brachydactyla (Brachyura, Majidae)

We investigated the nutritional vulnerability of Zoeae I of the spider crab Maja brachydactyla in experimental treatments with differential periods of starvation. As response vari- ables, the moulting and survival rates, the point-of-reserve-saturation (PRS), the point-of-no- return (PNR), dry mass, elemental composition (carbon, hydrogen, nitrogen; CHN), hepatopan- creas lipid vacuoles and activities of digestive enzymes were measured. Average median time spans when 50% of the larvae reached PNR or PRS (PNR50 and PRS50) values were 2.8 and 1.9 d, respectively. In PNR treatments, complete mortality occurred only after extended initial starvation periods of ≥5 d, and in PRS treatments, Zoeae I were capable of completing the moulting cycle after a short initial feeding period (1 d). In continuously starved control larvae, the moulting cycle was arrested at the onset of apolysis. Concomitantly, considerable amounts of biomass were lost and the C:N ratio decreased, indicating lipid degradation during starvation. This effect was also microscopically visible as a decline of lipid vacuoles in the hepatopancreas. Feeding after previ- ous starvation periods of <7 d resulted in a re-establishment of the lipid vacuoles, indicating suc- cessful capture and ingestion of food, but this did not necessarily allow for completing the moult- ing cycle. In fed Zoea I larvae, digestive enzyme activities increased during the moulting cycle, while a significant decrease of enzyme activities occurred under starvation conditions. In newly moulted Zoeae II, biomass values and enzyme activities were linearly correlated with the duration of the feeding periods in Zoeae I. This study shows that biomass, elemental composition, the occurrence of lipid vacuoles in the hepatopancreas and activities of digestive enzymes are suitable indicators of the nutritional condition of early zoeal stages of M. brachydactyla.

Yield Potential, Nutrient Uptake, Metal Fractionation and Effect on Soil Properties under Integrative Use of Varied C:N Ratio Composts, Fly Ash and Inorganic Fertilizer Nitrogen in Rice Grown on Inceptisol

Field experiment was conducted to evaluate the effect of incorporating fly ash and spent mushroom composts of varied C:N ratio with and without fertilizer nitrogen on yield, trace metal content, nitrogen uptake, metal fractions and soil properties. Fertilizer nitrogen, fly ash and white button spent mushroom compost of narrow C:N ratio increased whereas oyster spent mushroom compost of wider C:N ratio decreased the paddy and straw yield. Cd and Ni content in paddy and straw, in the treatment comprising oyster spent mushroom compost did not vary significantly, however addition of fly ash or white button spent mushroom compost enhanced their content in paddy and straw. Zn content of paddy and straw in composts were higher as compared to fertilizer nitrogen, fly ash. Uptake of nitrogen by paddy and straw was higher under integrated nutrient treatments, however oyster spent mushroom compost resulted in initial nitrogen starvation, so reduction in nitrogen uptake. Compost mainly one with wider C: N ratio has shown more influence on adsorption of metals especially Zn. The exchangeable, organic matter bound and residual fractionation percentage were higher for Cd, Zn and Ni respectively in compost, especially one with wider C:N ratio.

Larval biomass and chemical composition at hatching in two geographically isolated clades of the shrimp Macrobrachium amazonicum: intra- or interspecific variation?

The shrimp Macrobrachium amazonicum (Heller 1862) has an extremely large geographic range (>4000 km across) in northern and central South America, comprising estuarine and fully limnic inland populations, which are hydrologically isolated from each other. Significant variations in ecology, physiology, reproduction, and larval development suggest an at least incipient allopatric speciation due to limited genetic exchange. In a comparative experimental investigation with shrimps from the Pantanal (upper Paraguay River basin) and the Amazon delta, respectively, we measured larval body size, dry weight (W), biochemical (total protein; lipid; fatty acids, FA), and elemental composition (carbon, hydrogen, nitrogen; collectively CHN) at hatching. All these early larval traits are relevant for the degree of developmental dependence on planktonic food sources. Various consistent differences were observed between the two populations: Newly hatched larvae produced by shrimps from the Amazon delta were significantly smaller and showed lower values of W, CHN, protein, and unsaturated FA compared to those from the Pantanal. On the other hand, they contained significantly higher quantities of total lipid and saturated FA and, in consequence, higher ratios of lipid:protein, C:N, and saturated:unsaturated FA. All these differences in biomass and chemical composition suggest that the larvae of the Amazon population are energetically better adapted to planktonic food limitation, which likely occurs during riverine downstream transport toward coastal marine waters, also explaining previous observations of much stronger initial starvation tolerance in larvae from the Amazon versus those from the Pantanal. The latter develop in highly productive lentic inland waters, where large body size, an early onset of feeding, and a strong musculature (indicated by a high protein content) should facilitate their role as planktonic predators and allow for fast growth. An initial independence from food (lecithotrophy in the zoea I stage) as well as a preference for oligohaline rather than fully limnic conditions observed in the Pantanal larvae are interpreted as traits that have persisted from an ancestral coastal marine clade. Altogether, consistent ontogenetic differences between shrimps from the Pantanal and the Amazon estuary support the hypothesis that the taxon M. amazonicum comprises a complex of closely related but separate species.