Body Length Of Larvae Research Articles

Fipronil-induced toxic effects in zebrafish (Danio rerio) larvae by using digital gene expression profiling

Fipronil residue has caused widespread concern around the world, especially after the recent “toxic eggs” event in seven European countries. To evaluate the effects of fipronil on vertebrates, zebrafish larvae were used as an animal model to examine the lethal effect, developmental phenotypes at high doses, and possible mechanisms of toxicity by employing digital gene expression (DGE) profiling at environmentally relevant doses. The results of acute toxicity test indicated that treatment with fipronil from 75 h post-fertilization (hpf) led to the death of larvae with a 96-h LC50 value of 459 μg/L, as well as abnormal development including bent spine and shortened body length. Besides, we obtained high-quality-sequencing DGE profilings at fipronil concentrations of 0.5, 5, and 50 μg/L, respectively. The results revealed that 44 differentially expressed genes, 10 GO terms, and 3 KEGG pathways were overlapped among the three concentrations. MIDN, one of the 44 differentially expressed genes, showed dose-dependent responses at the transcriptional level, indicating that it was possibly a potential biomarker to reflect fipronil toxicity in zebrafish. Furthermore, we presumed that the changing transcriptional level of AP-1 family was possibly a reason for bent spine and shortened body length in larvae exposed to fipronil. Concurrently, altered abundance of transcripts of the ELOVL family in a key step of fatty acid elongation could possibly lead to the accumulation of long-chain fatty acids. Collectively, our results suggested that exposure to fipronil caused lethal and developmental toxicity in zebrafish larvae, and demonstrated the need for a comprehensive understanding of the potential mechanisms of fipronil toxicity due to fipronil's frequent presence in the environment and its potential threat to human health.

The Regulatory Effect of Low-Intensity Radiation in the Near-Infrared Region on the Early Development of Zebrafish (Danio rerio)

The effects of exposure to low-intensity continuous radiation in the red and near-infrared regions of the spectrum, as well as to infrared pulsed radiation, on the early development of zebrafish (Danio rerio) were studied. It was found that the use of continuous radiation at the red and infrared wavelengths (633 nm, 930 nm, dose 24 mJ/m2) leads to accelerated development of the embryo. In contrast, exposure to low-intensity single pulsed infrared radiation (864 nm) in the entire range of the doses studied (2.4–2400 mJ/cm2) negatively affected the early development of zebrafish, resulting in a significant dose-dependent delay in the hatching time of embryos and a reduction in the body length of larvae.

Snakehead Fish (Channa Striata) : Semi-Induced Breeding and Larval Growth

Objectives:The purposes of the present study are to produce technology of the snakehead fish breeding in Central Kalimantan region of Indonesia and to analyze the growth of larvae produced. Methods/Statistical Analysis:The experiments are conducted using twenty four of the broodstock and a pairof the fish isplaced to the hapa.The ovaprim doses injected on dorsal of the fish in this experiment are A: 0 ml/kg (control), B: 0.3 ml/kg, C: 0.5 ml/kg and D: 0.7 ml/ kg body weight of fish. The parameters are observed that the natural spawning of the fish and total larval body length of larvae. Findings:Spawning is observed 30-37 hours after application of ovaprim with dose 0.5 ml/kg, followed by application of 0.3 ml /kg ovaprim dose with spawning latency time of 4-5 days.During the early stages total length growth is increasedgradually and sharply. It is increased further and after 20 daysfrom hatching until the end of experiment as well as digestive tract development. Improvement/Applications: At day 25 after hatching coinciding to presence of pyloric caeca the fish may be introduced artificial feeds.

Quantitative investigation of the mechanisms of microplastics and nanoplastics toward zebrafish larvae locomotor activity.

This study investigated the direct and indirect toxic effects of microplastics and nanoplastics toward zebrafish (Danio rerio) larvae locomotor activity. Results showed that microplastics alone exhibited no significant effects except for the upregulated zfrho visual gene expression; whereas nanoplastics inhibited the larval locomotion by 22% during the last darkness period, and significantly reduced larvae body length by 6%, inhibited the acetylcholinesterase activity by 40%, and upregulated gfap, α1-tubulin, zfrho and zfblue gene expression significantly. When co-exposed with 2μg/L 17 α-ethynylestradiol (EE2), microplastics led to alleviation on EE2's inhibition effect on locomotion, which was probably due to the decreased freely dissolved EE2 concentration. However, though nanoplastics showed stronger adsorption ability for EE2, the hypoactivity phenomenon still existed in the nanoplastics co-exposure group. Moreover, when co-exposed with a higher concentration of EE2 (20μg/L), both plastics showed an enhanced effect on the hypoactivity. Principal component analysis was performed to reduce data dimensions and four principal components were reconstituted in terms of oxidative stress, body length, nervous and visual system related genes explaining 84% of total variance. Furthermore, oxidative damage and body length reduction were evaluated to be main reasons for the hypoactivity. Therefore, nanoplastics alone suppressed zebrafish larvae locomotor activity and both plastic particles can change the larvae swimming behavior when co-exposed with EE2. This study provides new insights into plastic particles' effects on zebrafish larvae, improving the understanding of their environmental risks to the aquatic environment.

Photoperiod induced developmental effects on silkmoth, Bombyx mori

Bombyx mori is most common silkmoth used for the commercial production of the silk. The different environmental conditions may affect development of silkmoth and hence the output of silkworm. Present study investigated effects of different photoperiodic conditions on the development of silkmoth. Three experiments were performed on newly hatched larvae. In experiment1, larvae were divided into three groups; group 1, 8L:16D (8 h light and 16 h dark), group 2, 12L:12D (12 h light and 12 h dark) and group 3, 16L:8D (16 h light and 8 h dark). In experiment 2, larvae were exposed to either continuous light or continuous dark. In experiment 3, larvae were divided into three groups. Each group received light of similar duration (16L:8D) and intensity (1.1 ± 0.1 PAR) but of different wavelengths; i.e. long wavelength red light (640 nm), short wavelength blue light (450 nm) and white light. Larvae were fed on young mulberry (Morus alba) leaves. Temperature and humidity were maintained at 26 (±2) °C and 75 (±5)%, respectively, throughout the study. Observations on change in body length of larvae were made on every alternate day. We also calculated the shell ratio, time taken in cocoon formation and emergence. Results from experiment show that the larvae underwent significant change in body length but with faster growth rate under 12L:12D photoperiod in comparison to 8L:16D and 16L:8D. Time taken in cocoon formation and hatching was significantly less, while shell ratio was significantly higher in 12L:12D in comparison to other groups. We did not observe much effect of monochromatic light on the development of silkmoth.

Toxic Effects of Bromothalonil and Flutolanil on Multiple Developmental Stages in Zebrafish.

In this study, we applied various developmental stages of zebrafish to address the potential environmental risk and aquatic toxicity of bromothalonil and flutolanil. This results demonstrated that the acute toxicity of bromothalonil to the three phases of zebrafish were 4.34 (embryo)<3.27 (12h old larvae)<2.52mg/L (adult fish) and that of flutolanil were 5.47 (embryo)<4.09 (72h old larvae)<3.91 (12h old larvae)<2.70mg/L (adult). Sublethal effects induced by both bromothalonil and flutolanil on zebrafish embryos were noted, including growth inhibition, abnormal spontaneous movement, slower heart rate, complete hatching failure, and morphological deformities. In addition, both bromothalonil and flutolanil could cause notochord deformation and short body length of larvae. This study provides a foundation for future investigation into the mechanism of bromothalonil and flutolanil toxicity in zebrafish.

Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae

Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water.

Occurrence and Ecological Characteristics of Chiasmia cinerearia (Bremer et Grey)(Lepidoptera: Geometridae) Attacking Sophora japonica

Chiasmia cinerearia (Bremer et Grey) belonging to the subfamily Ennominae(Lepidoptera: Geometridae) is a new forestry pest attacking to Sophora japonica in Gyeonggi province. Chiasmia cinerearia oviposited about 250~300 eggs per female on leaves. Larva had five instar stages. Adults emerged twice a year in early May and late July. The period of one generation was about 48 days. Body length of larvae was 25~30 mm and body color was light green with dark yellow lateral lines in abdomen. The wingspan of adults was 30 to 35 mm in length. The color of forewings was greyish brown with quadrilateral patterns on outer lines.

PERKEMBANGAN DAN GAMBARAN ANATOMIS LARVA INFEKTIF (L3) Haemonchus contortus YANG DIBIAKKAN DENGAN VERMICULLITE (Development and Anatomical Description of Infektive Larvae (L3) Haemonchus contortus Cultured with Vermicullite)

This study was aimed at obtaining basic information about bioecology of Haemonchus contortus, related to larval development and anatomical description of infective larvae (L3). In this study, the ova of Haemonchus contortus were harvested out of the intestines of goats, those were slaughtered in municipal slaughterhouse in Kampung Jawa Banda Aceh. The ova of Haemonchus contortus were then cultured using vermiculite as media, and observed daily until the larvae reached 3rd stage larvae. The result revealed that the larvae need 7 days to reach from eggs into infective larvae. Larvae obtained has uniform morphology, with a body diameter of 22 μm, tail length up to 55 μm hyaline, esophagus posterior to the tail of 592 μm, length of esophagus anterior to posterior esophagus 145 μm, and a total body length of larvae 737 μm.

Interannual variations in the hatching pattern, larval growth and otolith size of a sand-dwelling fish from central Chile

The interannual variation (2010–2013) of larval abundance, growth and hatching patterns of the Chilean sand stargazer Sindoscopus australis (Pisces: Dactyloscopidae) was investigated through otolith microstructure analysis from samples collected nearshore (<500 m from shore) during austral late winter-early spring off El Quisco bay, central Chile. In the studied period, the abundance of larval stages in the plankton samples varied from 2.2 to 259.3 ind. 1000 m−3; larval abundance was similar between 2010 and 2011, and between 2012 and 2013, but increased significantly from 2011 to 2012. The estimated growth rates increased twice, from 0.09 to 0.21 mm day−1, between 2011 and 2013. Additionally, otolith size (radius, perimeter and area), related to body length of larvae, significantly decreased from 2010 to 2012, but increases significantly in 2013. Although the mean values of microincrement widths of sagitta otoliths were similar between 2010 and 2011 (around 0.6–0.7 μm), the interindividual variability increases in 2011 and 2013, suggesting large environmental variability experienced by larvae during these years. Finally, the hatching pattern of S. australis changed significantly from semi-lunar to lunar cycle after 2012.

Teratogenic effects of organic extracts from the Pearl River sediments on Xenopus laevis embryos

Toxicity of organic extracts from the Pearl River sediments was investigated with Xenopus laevis embryos. The effects of sediment organic extracts on the mortality, body length and malformation of X. laevis embryos were tested by the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). The 96-h LC50 values for X. laevis embryos ranged from 62 to 137g/L (g extracted sediment per L), and the toxicity effect on body length of larvae was not significant under 20g/L. However, the teratogenic effects produced by sediment organic extracts were diverse, including edema, hypopigmentation, cardiac and ocular malformations, abdomen recurved and curved spine. The percentage of malformations increased with increasing sediment organic extracts, and even reached almost 100% at 10 and 20g/L in Guangzhou district. A gradient of pollution in the Pearl River sediments was discerned from the teratogenic toxicity. Guangzhou district showed higher teratogenic toxicity compared with Panyu and Nansha districts as a possible consequence of high levels of PAHs, PCBs, OCPs and NP in the sediments. The teratogenic effects of organic extracts from the Pearl River sediments were successfully assessed which indicated the feasibility of teratogenic potential studies of sediments using X. laevis embryos.

Differentiation and development of the gill in &lt;I&gt;Trachinotus ovatus&lt;/I&gt; during larval and juvenile development

We documented the differentiation and development of the gill and the relationship between gill struc-ture and function in Trachinotus ovatus using histology and scanning electron microscopy.Development of the gill was divided into three stages in the larvae and juveniles.Stage I included organ-primordium formation between 0–3 days after hatching(DAH).During this stage,gill-primordia were present but undifferentiated,there were no gill rakers,and respiration occurred primarily via the finfold,skin,and the microvascular surface of the yolk-sac.Stage II occurred between 4–17 DAH and was characterized by differentiation and development of gill filaments.Gill arches,filaments,secondary gill lamella,and gill rakers developed gradually and the basic structure and morphology of the gill were established.Stage III was initiated at 18 DAH,at which time the gill organs(e.g.,arches,filaments,secondary gill lamella,and rakers) resembled the adult in terms of morphology and function.The total number of gill filaments increased with the increasing body weight and body length in larvae and juve-niles.Thus,the single secondary gill lamella area and total respiratory area also increased with an increase of body weight.The differentiation and development of the gill was in accordance with growth,development,and function in larval and juvenile T.ovatus.

Stepwise Embryonic Toxicity of Silver Nanoparticles onOryzias latipes

The developmental toxicity of silver nanoparticles (AgNPs) was investigated following exposure of Oryzias latipes (medaka) embryos to 0.1−1 mg/L of homogeneously dispersed AgNPs for 14 days. During this period, developmental endpoints, including lethality, heart rate, and hatching rate, were evaluated by microscopy for different stages of medaka embryonic development. To compare toxic sensitivity, acute adult toxicity was assessed. There was no difference in acute lethal toxicity between embryo and adult medaka. Interestingly, we found that the increase in stepwise toxicity was dependent on the developmental stage of the embryo. Lethal embryonic toxicity increased from exposure days 1 to 3 and exposure days 5 to 8, whereas there was no change from exposure days 3 to 5. In addition, 7 d exposure to 0.8 mg/L AgNPs resulted in significant heart beat retardation in medaka embryos. AgNPs also caused a dose-dependent decrease in the hatching rate and body length of larvae. These results indicate that AgNP exposure causes severe developmental toxicity to medaka embryos and that toxicity levels are enhanced at certain developmental stages, which should be taken into consideration in assessments of metallic NPs toxicity to embryos.

Polyaniline nanofibers: Acute toxicity and teratogenic effect on Rhinella arenarum embryos

The fate and effect of nanomaterials in the environment is of paramount importance towards the technological application of the materials. This work shows the ecotoxicological potential of polyaniline (PANI) nanofibers in the larvae Rhinella arenarum by means of AMPHITOX test. Acute toxicity of PANI nanofibers towards embryos of the common South American toad R. arenarum (Anura: bufonidae) was evaluated in the premetamorphosis (stage 25) larvae. The exposure of R. arenarum larvae to at dose of 150, 250 and 400mgL−1 resulted in 100% viability within 96h exposure. The embryos at 2–4 blastomers stage (early life stage teratogenic test) revealed that embryos were not killed and no teratogenic effects were observed when embryos were incubated with PANI nanofibers (150 and 250mgL−1), while only a growth retardation of embryos was induced at levels of 250mg PANI nanofibersL−1. On the other hand, at 400mgL−1 concentration, a reduction in the body length of larvae and tail malformation was observed. This results suggest that a concentration-dependent toxicity is operative, typified by phenotypes that had abnormal body axes. The presence of PANI nanofibers in gut contents and its excretion by larval stages of R. arenarum was confirmed by UV–visible spectroscopy.

Growth and morphological development of laboratory-reared larval and juvenile three-spot gourami Trichogaster trichopterus

Morphological development, including the body proportions, fins, pigmentation and labyrinth organ, in laboratory-hatched larval and juvenile three-spot gourami Trichogaster trichopterus was described. In addition, some wild larval and juvenile specimens were observed for comparison. Body lengths of larvae and juveniles were 2.5 ± 0.1 mm just after hatching (day 0) and 9.2 ± 1.4 mm on day 22, reaching 20.4 ± 5.0 mm on day 40. Aggregate fin ray numbers attained their full complements in juveniles >11.9 mm BL. Preflexion larvae started feeding on day 3 following upper and lower jaw formation, the yolk being completely absorbed by day 11. Subsequently, oblong conical teeth appeared in postflexion larvae >6.4 mm BL (day 13). Melanophores on the body increased with growth, and a large spot started forming at the caudal margin of the body in flexion postlarvae >6.7 mm BL, followed by a second large spot positioned posteriorly on the midline in postflexion larvae >8.6 mm BL. The labyrinth organ differentiated in postflexion larvae >7.9 mm BL (day 19). For eye diameter and the first soft fin ray of pelvic fin length, the proportions in laboratory-reared specimens were smaller than those in wild specimens in 18.5–24.5 mm BL. The pigmentation pattern of laboratory-reared fish did not distinctively differ from that in the wild ones. Comparisons with larval and juvenile morphology of a congener T. pectoralis revealed several distinct differences, particularly in the numbers of myomeres, pigmentations and the proportional length of the first soft fin ray of the pelvic fin.

Effect of rotifer enrichment with herbal extracts on growth and resistance of red sea bream, Pagrus major (Temminck &amp; Schlegel) larvae against Vibrio anguillarum

The effects of the dietary medicinal herbs Massa medicata, Crataegi fructus (Cf), Artemisia capillaries, Cnidium officinale and their mixture (HM), on growth and resistance against Vibrio anguillarum were examined using larval red sea bream, Pagrus major. The methanol extracts of Cf and HM inhibited the proliferation of seven infectious bacterial strains including the genera Aeromonas, Edwasiella, Photobavterium, Pseudomonas and Vibrio. Rotifers enriched with emulsified bonito oil containing extracts of Cf and HM lowered the bacterial counts in their body on TCBS medium for the genus Vibrio in comparison with rotifers enriched by emulsified bonito oil alone. Although statistically not significant, larvae fed rotifer fortified with Cf from 3 to 20 days after hatching showed the best growth and final body weight followed by those given rotifer with HM and control enrichment. However, final body length of larvae fed rotifer with Cf was significantly larger than larvae fed on rotifers enriched with other herb extracts. After a challenge test with V. anguillarum, survival of larvae fed rotifer with Cf and HM was significantly higher than for the control treatment. These results revealed that Cf and HM in rotifer is useful to promote growth and resistance against V. anguillarum in red sea bream larvae, providing a new technology for mass production of disease-resistant fry and fingerlings.

The optimal feeding frequency of large yellow croaker (Pseudosciaena crocea, Richardson) larvae

A 30-day feeding experiment was conducted to determine the effects of feeding frequency on the growth, survival and specific activity of digestive enzymes in large yellow croaker larvae (13days after hatch) with an initial weight of 4.08±0.1mg. Feeding frequency of 2, 4, 8 and 12 times daily as four treatments were evaluated against a control without feeding in triplicate tanks. The fish were fed to satiation each time. The results showed that treatment of 8 meals per day (meals d−1) had significantly higher survival (P<0.05) compared with other treatments. Specific growth rate (SGR) in 8 meals d−1 treatment was significantly higher than those in 2 meals d−1 or 4 meals d−1 treatments (P<0.05), but was not significantly different from that in 12 meals d−1 treatment (P>0.05). No significant differences in coefficient variations (CV%, P>0.05) of fish larvae body length were observed among the treatments, but there was a significant negative dependency between CV and feeding frequency (CV=−0.1476×feeding frequency+17.55, R2=0.9352). Both crude protein and crude lipid in fish larvae significantly increased with increasing feeding frequency. There were no significant differences in fatty acid composition of fish larvae. The specific activity of trypsin, both in pancreatic and intestinal segments, first significantly increased (from 2 meals d−1 to 8 meals d−1) and then kept at a constant level (from 8 meals d−1 to 12 meals d−1). There were no significant differences in specific activities of amylase among dietary treatments. Results of this study suggest that the optimal feeding frequency was 8 meals d−1 in the culture of large yellow croaker larvae.

Toxicity of zinc oxide nanoparticles to zebrafish embryo: a physicochemical study of toxicity mechanism

The biological impact of engineered nanomaterials released into the aquatic environment is a major concern. In this work, the properties of ZnO nanoparticles (nano-ZnO, 30 nm) were characterized in a water suspension (E3 medium), and a zebrafish 96-h post fertilization (hpf) embryo–larval test was performed to assess the toxicity of nano-ZnO suspension. Nano-ZnO was found to readily form aggregates with different sizes; small aggregates (142.4–517.7 nm) were still suspended in E3 medium, but large aggregates (>1 μm) quickly deposited on the bottom of 24-well plates; nano-ZnO was partially dissolved to Zn species (Zn(dis)) in E3 medium. In the nano-ZnO suspension, small aggregates, Zn(dis), and large aggregates might jointly exert influence on the development of zebrafish embryos. The embryo toxicity test revealed that nano-ZnO killed zebrafish embryos (50 and 100 mg/L), retarded the embryo hatching (1–25 mg/L), reduced the body length of larvae, and caused tail malformation after the 96 hpf exposure. Zn(dis) only partially contributed to the toxicity of nano-ZnO. This research highlights the need to further investigate the ecotoxicity of nano-ZnO in the water environment.

Effects of a uranium mine effluent in the early-life stages of Rana perezi Seoane

Amphibians have been reported as sensitive organisms whose survival has been impaired by several environmental factors. Nevertheless, sometimes amphibians are found inhabiting extreme environments. Thus, in order to perceive how Iberian green frogs ( Rana perezi Seoane) are able to survive in the ponds of a uranium mine (Central Portugal) this study aimed to assess the ecotoxicological effects promoted by the mine effluent in the early-life stages of this species. To attain this objective, eggs (collected in a nearby reference river) and laboratory hatching larvae were exposed during 96 h to different dilutions of the effluent. All the effects on the hatch success were recorded. The highest concentration of the effluent produced a significant decrease in body length of larvae, as well as a decrease in stimulus reactions and an increase in pigmentation along with tail deformities. A recovery assay showed an increased bioaccumulation of metals, uranium included, resulting from increased effluent exposure.

Effects of environmental humidity on the survival and development of pine caterpillars, Dendrolimus tabulaeformis (Lepidoptera: Lasiocampidae)

AbstractThe pine caterpillar, Dendrolimus tabulaeformis is one of the most important pests on Pinus tabulaeformis and other pine species in North China. In the present study, effects of relative humidity (RH) on the development and survival of pine caterpillars and soil moisture (SM) on their diapausing larvae were investigated. Low RH (20%) deferred the development of eggs and larvae, reduced egg hatching and larval surviving compared to 40%, 60% and 80% RH. Both low (20%) and high (100%) RH reduced egg hatching, but only 20% RH deferred the development of larvae, prolonged developmental duration and reduced the body mass and body length of larvae. The SM influenced the survival of diapausing larvae significantly. The dry treatment significantly reduced the supercooling points (SCPs), whereas increased the mortality and reduced body mass from 56.9 to 36.5 mg and body water content from 78% to 63% after 2 weeks' exposure. Therefore, higher RH is more favorable for the development of early instars and survival of diapausing larvae of the pine caterpillars.