Modeling feeding processes: a test of a new model for sea bream (Sparus aurata) larvae

2005 ◽  
Vol 62 (2) ◽  
pp. 425-435 ◽  
Author(s):  
Konstadia Lika ◽  
Nikos Papandroulakis
Keyword(s):  
Feeding Rate ◽  
Developmental Stages ◽  
Sparus Aurata ◽  
Fish Larvae ◽  
Sea Bream ◽  
Type Ii ◽  
Response Curves ◽  
Functional Representation ◽  
Early Developmental ◽  
Type Ii Functional Response

An organism's feeding rate is governed by constraints imposed by processes associated with consumption. We present a general feeding model that incorporates encounter, successful pursuit, handling, and digestion in one functional representation where we treat digestion as a parallel process. The model produces type II functional response curves. However, the asymptotic maximum feeding rate is determined by the sum of the time spent for handling and digesting a prey minus the gain in time, since the digestion process is parallel to the handling process. We use our model in combination with existing models of encounter, successful pursuit, and digestion to evaluate the feeding rate of fish larvae. We test the model against experimental data for sea bream (Sparus aurata) larvae and find a very close quantitative correspondence between predictions and experiments. Sensitivity analysis shows that for the early developmental stages, the model is sensitive to parameters related to the visual and locomotion abilities of larvae to detect and capture the prey. Later, when they establish these abilities, the choice of accepting or not the prey becomes more important.

scholarly journals Heat shock protein (HSP) expression and mitogen-activated protein kinase (MAPK) phosphorylation during early embryonic developmental stages of the Gilthead sea bream (Sparus aurata)

2018 ◽  
pp. 240 ◽  
Author(s):  
CHRYSOULA ROUFIDOU ◽  
KONSTANTINOS FEIDANTSIS ◽  
ELENI MENTE ◽  
ELENA SARROPOULOU ◽  
EFTHIMIA ANTONOPOULOU
Keyword(s):  
Heat Shock ◽  
Protein Expression ◽  
P38 Mapk ◽  
Developmental Stages ◽  
Sparus Aurata ◽  
Sea Bream ◽  
Mapk Phosphorylation ◽  
Early Developmental Stages ◽  
Mitogen Activated Protein ◽  
Early Developmental

Both heat shock proteins (HSPs), which have key roles in vital cell functions, as well as members of the mitogen-activated protein kinases (MAPKs), which adjust gene expression by transducing cellular signals to the nucleus, are necessary for normal embryonic development in vertebrates. Therefore, protein expression levels of HSP70 and HSP90 and the activation of members of the MAPK protein family, such as p38 MAPK, ERKs, and JNKs were studied in the early developmental stages of the Gilthead sea bream, Sparus aurata Linnaeus, 1758. The protein expression of HSP70 and the phosphorylation ratio of JNKs remained at equal levels at all examined developmental stages, while the other examined proteins exhibited a differential profile. HSP90 levels were mostly increased at the 16-cell stage and towards the morula stages, and the lowest values were observed at the two- to four-cell and one-half epiboly stages. While p38 MAPK phosphorylation ratio exhibited increased values mostly in the early developmental stages, the opposite was observed concerning ERK phosphorylation ratio, where increased values were observed in the later embryonic stages (high blastula to one-half epiboly stages). These differential profiles of the examined protein expression levels highlight the importance of these proteins during embryogenesis and pave the way for further research to unveil their distinct role in early development.

Functional response in coccinellid beetles (Coleoptera: Coccinellidae) is modified by prey-density experience

2022 ◽  
Vol 154 ◽  
Author(s):  
Desh Deepak Chaudhary ◽  
Bhupendra Kumar ◽  
Geetanjali Mishra ◽  
Omkar
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Biological Control Agent ◽  
Handling Time ◽  
Control Agent ◽  
Type Ii ◽  
Response Curves ◽  
Late Instar ◽  
Rearing Density ◽  
Type Ii Functional Response

Abstract In the present study, we assessed functional response curves of two generalist coccinellid beetles (Coleoptera: Coccinellidae), specifically Menochilus sexmaculatus and Propylea dissecta, using fluctuating densities of aphid prey as a stimulus. In what may be the first such study, we investigated how the prey density experienced during the early larval development of these two predatory beetle species shaped the functional response curves of the late instar–larval and adult stages. The predators were switched from their rearing prey-density environments of scarce, optimal, or abundant prey to five testing density environments of extremely scarce, scarce, suboptimal, optimal, or abundant prey. The individuals of M. sexmaculatus that were reared on either scarce- and optimal- or abundant-prey densities exhibited type II functional response curves as both larvae and adults. However, individuals of P. dissecta that were reared on scarce- and abundant-prey densities displayed modified type II functional response curves as larvae and type II functional response curves as adults. In contrast, individuals of P. dissecta reared on the optimal-prey density displayed type II functional response curves as larvae and modified type II functional response curves as adults. The fourth-instar larvae and adult females of M. sexmaculatus and P. dissecta also exhibited highest prey consumption (T/Th) and shortest prey-handling time (Th) on the scarce-prey rearing density. Thus, under fluctuating-prey conditions, M. sexmaculatus is a better biological control agent of aphids than P. dissecta is.

scholarly journals Evaluating the Death and Recovery of Lateral Line Hair Cells Following Repeated Neomycin Treatments

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1180
Author(s):  
Alexandra Venuto ◽  
Timothy Erickson
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Developmental Stages ◽  
Fish Larvae ◽  
Larval Survival ◽  
Repeated Treatment ◽  
Functional Maturation ◽  
Cellular Regeneration ◽  
Swim Bladder Inflation ◽  
Early Developmental

Acute chemical ablation of lateral line hair cells is an important tool to understand lateral line-mediated behaviors in free-swimming fish larvae and adults. However, lateral line-mediated behaviors have not been described in fish larvae prior to swim bladder inflation, possibly because single doses of ototoxin do not effectively silence lateral line function at early developmental stages. To determine whether ototoxins can disrupt lateral line hair cells during early development, we repeatedly exposed zebrafish larvae to the ototoxin neomycin during a 36 h period from 3 to 4 days post-fertilization (dpf). We use simultaneous transgenic and vital dye labeling of hair cells to compare 6-h and 12-h repeated treatment timelines and neomycin concentrations between 0 and 400 µM in terms of larval survival, hair cell death, regeneration, and functional recovery. Following exposure to neomycin, we find that the emergence of newly functional hair cells outpaces cellular regeneration, likely due to the maturation of ototoxin-resistant hair cells that survive treatment. Furthermore, hair cells of 4 dpf larvae exhibit faster recovery compared to 3 dpf larvae. Our data suggest that the rapid functional maturation of ototoxin-resistant hair cells limits the effectiveness of chemical-based methods to disrupt lateral line function. Furthermore, we show that repeated neomycin treatments can continually ablate functional lateral line hair cells between 3 and 4 dpf in larval zebrafish.

scholarly journals Evaluating the Death and Recovery of Lateral Line Hair Cells Following Repeated Neomycin Treatments

2021 ◽  
Author(s):  
Alexandra Venuto ◽  
Timothy Erickson
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Developmental Stages ◽  
Fish Larvae ◽  
Larval Survival ◽  
Repeated Treatment ◽  
Functional Maturation ◽  
Cellular Regeneration ◽  
Swim Bladder Inflation ◽  
Early Developmental

Acute chemical ablation of lateral line hair cells is an important tool to understand lateral line-mediated behaviors in free-swimming fish larvae and adults. However, lateral line-mediated behaviors have not been described in fish larvae prior to swim bladder inflation, possibly because single doses of ototoxin do not effectively silence lateral line function at early developmental stages. To determine if ototoxins can effectively silence the lateral line during early development, we repeatedly expose zebrafish larvae to the ototoxin neomycin during a 36-hour period from 3-4 days post-fertilization (dpf). We use simultaneous transgenic and vital dye labeling of hair cells to compare 6- hour and 12-hour repeated treatment timelines and neomycin concentrations between 0–400 µM in terms of larval survival, hair cell death, regeneration, and functional recovery. Following exposure to neomycin, we find that the emergence of newly functional hair cells outpaces cellular regeneration, likely due to the maturation of ototoxin-resistant hair cells that survive treatment. Furthermore, hair cells of 4 dpf larvae exhibit faster recovery compared to 3 dpf larvae. Our data suggest that the rapid functional maturation of ototoxin-resistant hair cells limits the effectiveness of chemical-based methods to disrupt lateral line function. Furthermore, we show that repeated neomycin treatments can continually ablate lateral line hair cells between 3–4 dpf in larval zebrafish.

Functional and numerical responses of Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) to different biological stages of Eutetranychus orientalis (Klein) (Acari: Tetranychidae)*

2021 ◽  
Author(s):  
İsmail Döker ◽  
Kemal Yalcin ◽  
Kamil Karut ◽  
Cengiz Kazak
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Handling Time ◽  
Predatory Mite ◽  
Type Ii ◽  
Adult Males ◽  
Response Curves ◽  
Iphiseius Degenerans ◽  
Eggs And Larvae ◽  
Type Ii Functional Response

Functional and numerical responses of the predatory mite, Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) to four different biological stages (egg, larva, protonymph and adult male) of the citrus brown mite, Eutetranychus orientalis (Klein) (Acari: Tetranychidae) were determined under laboratory conditions. In the experiments, six different prey densities (5, 10, 20, 40, 60 and 80) for each biological stage of the prey were provided to the predatory mite for 24 hours. Results showed that the proportion of prey consumption of I. degenerans decelerated with increasing prey densities of all biological stages of the prey. Logistic regression analysis indicated that I. degenerans showed a Type II functional response regardless of prey stage. The attack rate (α) and the handling time (Th) varied based on the biological stages. The highest α (1.596) and the lowest Th (0.014) values were determined when the predator fed on adult males and larvae of E. orientalis, respectively. The numerical response curves were similar to those of Type II functional response. The efficiency of conversion of ingested food (ECI) of female I. degenerans decreased on all biological stages when prey density increased. The highest and the lowest average daily mean number of eggs laid by I. degenerans were found as 0.45 and 1.90 when it fed on eggs and larvae of its prey, respectively. According to the results, I. degenerans has a potential to be used as a predator in biological control of E. orientalis.

scholarly journals Parental nutritional programming and a reminder during juvenile stage affect growth, lipid metabolism and utilisation in later developmental stages of a marine teleost, the gilthead sea bream (Sparus aurata)

2017 ◽  
Vol 118 (7) ◽  
pp. 500-512 ◽  
Author(s):  
Serhat Turkmen ◽  
Maria J. Zamorano ◽  
Hipólito Fernández-Palacios ◽  
Carmen M. Hernández-Cruz ◽  
Daniel Montero ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Developmental Stages ◽  
Sparus Aurata ◽  
Linseed Oil ◽  
Regulation Of Gene Expression ◽  
Fish Growth ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Nutritional Programming ◽  
Long Chain

AbstractNutrition during periconception and early development can modulate metabolic routes to prepare the offspring for adverse conditions through a process known as nutritional programming. In gilthead sea bream, replacement of fish oil (FO) with linseed oil (LO) in broodstock diets improves growth in the 4-month-old offspring challenged with low-FO and low-fishmeal (FM) diets for 1 month. The present study further investigated the effects of broodstock feeding on the same offspring when they were 16 months old and were challenged for a second time with the low-FM and low-FO diet for 2 months. The results showed that replacement of parental moderate-FO feeding with LO, combined with juvenile feeding at 4 months old with low-FM and low-FO diets, significantly (P<0·05) improved offspring growth and feed utilisation of low-FM/FO diets even when they were 16 months old: that is, when they were on the verge of their first reproductive season. Liver fatty acid composition was significantly affected by broodstock or reminder diets as well as by their interaction. Moreover, the reduction of long-chain PUFA and increase in α-linolenic acid and linoleic acid in broodstock diets lead to a significant down-regulation of hepatic lipoprotein lipase (P<0·001) and elongation of very long-chain fatty acids protein 6 (P<0·01). Besides, fatty acid desaturase 2 values were positively correlated to hepatic levels of 18 : 4n-3, 18 : 3n-6, 20 : 5n-3, 22 : 6n-3 and 22 : 5n-6. Thus, this study demonstrated the long-term nutritional programming of gilthead sea bream through broodstock feeding, the effect of feeding a ‘reminder’ diet during juvenile stages to improve utilisation of low-FM/FO diets and fish growth as well as the regulation of gene expression along the fish’s life-cycle.

scholarly journals Structural and functional characterizations of activin type 2B receptor (acvr2b) ortholog from the marine fish, gilthead sea bream, Sparus aurata: evidence for gene duplication of acvr2b in fish

2012 ◽  
Vol 49 (3) ◽  
pp. 175-192 ◽  
Author(s):  
Bruria Funkenstein ◽  
Ekaterina Krol ◽  
Elena Esterin ◽  
Yong-soo Kim
Keyword(s):  
Transforming Growth Factor ◽  
Sparus Aurata ◽  
Fish Larvae ◽  
Larval Growth ◽  
Amino Acid Sequences ◽  
Negative Regulator ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Luciferase Assay

Myostatin (MSTN), a negative regulator of muscle growth and a member of the transforming growth factor-β superfamily, can bind the two activin type 2 receptors (ACVR2). It has been previously shown that WT mice injected with ACVR2B extracellular domain (ACVR2B-ECD) had higher muscle mass. Likewise, fish larvae immersed inPichia pastorisculture supernatant, containing goldfish Acvr2b-ECD, showed enhanced larval growth. However, it is not clear whether fish Mstn1 and Mstn2 signal through the same receptor and whether fish express more than oneacvr2bgene. In the current study, three cDNAs encodingacvr2b(saacvr2b-1, saacvr2b-2a, and saacvr2b-2b) were cloned from gilthead sea bream. All three contain the short extracellular binding domain, a short transmembrane region, and a conserved catalytic domain of serine/threonine protein kinase. Bioinformatics analysis provided evidence for the existence of twoacvr2bgenes (acvr2b-1 andacvr2b-2) in several other fish species as well, probably as a result of gene or genome duplication. The two isoforms differ in their amino acid sequences. The direct inhibitory effect of Acvr2b-ECD on Mstn activity was testedin vitro. The saAcvr2b-1-ECD was expressed in the yeastP. pastoris. Evidence is provided for N-glycosylation of Acvr2b-1-ECD. The affinity-purified Acvr2b-1-ECD inhibited recombinant mouse/rat/human mature MSTN activity when determinedin vitrousing the CAGA-luciferase assay in A204 cells. A lower inhibitory activity was obtained when unprocessed purified, furin-digested, and activated saMstn1 was used. Results of this study demonstrate for the first time the existence of twoacvr2bgenes in fish. In addition, the study shows that bioactive fish Acvr2b-ECD can be produced fromP. pastoris.

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