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Showing 15 results for Larva


Volume 1, Issue 3 (9-2013)
Abstract

Fish larvae have a high requirement of amino acid (AA) for energy production and growth. This study was aimed to increase knowledge of AA profile during feral carp larval ontogeny and estimate larval AA requirements. Larvae were collected randomly at 1, 3, 7, 11, 15, 19, 26 and 33 days post hatch for growth and AA analysis. The composition of total AA changed significantly during ontogeny. The essential AA profile of marine carp showed low correlation with rotifers (R2=0.22). High correlation was found between dry food and early larval ages (R2≥0.7) but was lower in late stage (R2≥0.37). At day 7, when larvae were fed on rotifers, methionine seemed to be the limiting AA and when larvae were fed dry food at day 11, 15, 19, 26 and 33, arginine seemed to be the limiting AA. Larval indispensible AA profile can be used as index of the IAA requirements of carp larvae. Supplementation of larval diet used with limiting AA is one way for compensating the deficient amino acid.

Volume 2, Issue 1 (3-2013)
Abstract

This paper reviews the research on taxonomy of the Trombidioidea in Iran, with an updated checklist of 32 species (+5 undetermined species) belonging to five families and 22 genera. Among them, 27 species (+1 undetermined species) are reported based on larvae only, three undetermined species based on adults only, and six species based on both larval and post-larval stages. Also, 14 species (+3 undetermined species) and 10 genera belonging to the family Trombidiidae, one undetermined species belonging to the family Podothrombiidae, 13 species (+1 undetermined species) and seven genera belonging to the family Microtrombidiidae, three species, three genera belonging to the family Neothrombiidae and two species and one genus belonging to the family Achaemenothrombiidae. Major contributions to the Iranian fauna of the Trombidioidea were made by Alireza Saboori and his colleagues, and Zhi-Qiang Zhang. There have been some studies on the biology and the application of the Trombidioidea in biological control in Iran.
Hamed Kolangi Miandare, Omid Jaafari, Maryam Nasrolah Pourmoghadam,
Volume 2, Issue 4 (3-2014)
Abstract

Oxygen concentration the environment and cellular organisms is one of the effective factors during normal development of organisms. In the present study, the transcription levels of the hypoxia-inducible factors (hif-1, hif-2) were evaluated during development of an ancient fish species Acipenser persicus, in the normal oxygen density of environment. The transcription of hif-1, hif-2 detected in all developmental time-points defined, from embryo to juvenile stages. Target genes transcriptions were normalized using RPL6 as reference gene. Changes in normalized hif-1, hif-2 mRNA expression were statistically significant throughout developmental points (p<0.05). Our data revealed that the mRNA expression of hifs were low during embryonic development and then upregulated significantly at hatching and early larval time-points. Then, in the late larval development and juvenile stage the expression of hifs started to decline. The comparison between hif-1 and hif-2 mRNA transcription showed that maximum gene expressions of hif-1and hif-2 occurred in 15 and 20 days after hatching, respectively. The increased expression of hifs suggests their association with two important events in the larval evolution, viz. internal feeding (yolk absorption) and external feeding. Also, the observed increase in mRNA expression of hifs during larval development of A. persicus can be attributed to increase in oxygen demand.
Ghadir Ghorbanzadeh, Gholamreza Rafiee, Soheil Eagderi, Hadi Poorbagher, Iraj Efatpanah,
Volume 3, Issue 2 (9-2014)
Abstract

The early morphological development and allometric growth pattern of Caspian kutum (Rutilus frisii kutum) during early development (from 0-35 days post hatch=dph) was studied. Morphological data were obtained using ImageJ software from 2D pictures and allometric growth patterns were computed based on Log10 y = Log10 α + βLog x function. Based on inflexion point of morphological traits and body shape changes, the early developmental of kutum were divided into Eleuthero-embryo, Propterygio-larval, Pterygio-larval” and younger juvenile phases, each of which included vital developmental events. Rapid and intense changes occurred during Eleuthero-embryo and Propterygio-larvae stages such as development of gills, depletion of yolk-sac and exogenous feeding, development of feeding apparatus, sense organs and organs related to swimming performance. The results also revealed that developmental changes occurred in agreement with the inflexion points of morphological characters and their developmental priority imply on functional importance of feeding, respiration and swimming related structures.
Manizheh Biabani Asrami, Mohammad Sudagar, Mohammad Mazandarani, Siamak Yousefi,
Volume 6, Issue 1 (6-2017)
Abstract

The effect of Spirulina powder at levels of 0 (control), 3, 7, and 10%, of food ratio on growth, survival, and total carotenoids of dwarf gourami fry (Trichogasterlalius) of 3.6 g average weight as well as its larval stage was investigated for a period of 8 weeks. Carotenoids was significantly increased with increase in spirulina level up to 7% (p<0.05), but not significantly different from 10% level (p> 0.05). Survival showed no significant difference (p> 0.05). In larvae, survival, total carotenoids and total length increased significantly with increasing spirulina powder (p<0.05). Overall, the spirulina powder at 3% improved the growth and total carotenoids factors in pre-adult gourami and 10% level for larval stage as the best treatments in this study.
Parisa Moradi, Hojatollah Jafaryan, Mehdi Soltani, Hosna Gholipour Kanani, Javad Sahandi,
Volume 6, Issue 1 (6-2017)
Abstract

In a completely randomized experiment, the effect of Daphnia magna meal on growth performance and carcass composition of rainbow trout (Oncorhynchus mykiss) larvae (body weight 0.538±0.197 g) was evaluated for a period of 60 days. Five diets with the same protein content (crude protein 52.70%) were prepared, including two diets containing fermented daphnia meal T1 (20%), T2 (30%), two diets containing raw meal T3 (20%) and T4 (30%), and a basal diet without daphnia meal as the control. The bacterial species used for fermenting included five commercial probiotic species. Fermented daphnia meal brought about significantly higher growth and the lowest feed conversion ratios, viz. T1 (1.27 ± 0.35) and T2 (1.31 ± 0.46), in comparison with T3 (1.38 ± 0.37), T4 (1.41 ± 0.42) and the control (1.84 ± 0.69) (p<0.05). The result of carcass composition analyzes showed that the highest protein percentage (68.23 ± 0.48%) was in T2 and the highest percentage of fat and energy (11.26 ± 0.50% , 4761.63 ±48.88 Cal g-1) were in T4 (p<0.05). The overall results of this experiment indicated that daphnia could be considered as a suitable partial protein source in rainbow trout larval feed.
H. Jamali, S. Meshkini,
Volume 7, Issue 4 (12-2018)
Abstract

The huge attention toward dried food in ornamental fish culture is caused by the difficulty related to live-food preparation. This study investigated the effects replacement of live feed by commercial feed TetraMin on growth, survival rate and resistance to environmental stress in Oscar fish (Astronotus ocellatus) larvae. The experimental setup was completely randomized design comprised of five treatments including, namely T1 (Forty days Artemia nauplii), T2 (Thirty days Artemia ten days of commercial food), T3 (Twenty days Artemia twenty days of commercial food), T4 (Ten days Artemia thirty days of commercial food) and T5 (Forty days commercial feed). All treatments were performed in triplicate. In this study, fish larvae were fed 4 times a day and to apparent satiation, commercial feed and live feed. After a 40-day feeding experimental period, all the larvae each aquarium were sampled for and growth determination. Fish larvae in T1, T2, and T3 treatments showed the highest total length, weight and survival rate. Lowest total length, weight and survival rate were recorded in T5 treatment (p<0.05). Also, against challenge tests in T1, T2 and T3 treatments was significantly in comparison with T5 (p<0.05). The results of the present study demonstrate that the Oscar fish larvae could consume commercial feed starting from the 20 without any difference in growth with live food.

Volume 9, Issue 0 (3-2010)
Abstract

Aim: This study investigates the intraspecific competition, for food and density amongst larvae of Anopheles stephensi (main malaria vector in south Iran). Material & Methods: The effects of 4 selected food quantities (1x,2x,4x,6x) and 5 larval densities (0.1 to 3 larva/cm2) were tested individually or in combination on 7 biological indexes of the vector and the results were statistically analyzed. The competition starts when the food quantity decreases from 6x to x and the larval density increases from 0.1 up to 3 larva/cm2. Results & Discussion: The biological indexes that showed significant alterations at competing conditions (reduced food quantity and increased larval density) were as follows. Increasing of the larval, pupal and total mortality, alteration of the sex ratio in favor of male production, and decrease of the speed of larval development and survival rate. However, body sizes did not show any significant difference among individuals of both sexes. Conclusion: So, reducing the food quantity and increasing the larval density make a decrease in abundance and activity of An. Stephensi and it may provide a useful method for control of this mosquito population.

Volume 9, Issue 2 (4-2007)
Abstract

The ultrastructure of the cells, Na+, K+-ATPase activity and immunolocalization were examined in the barnchial chamber of Libellula lydia (Drury, 1773) larvae. Na+,K+-ATPase activity and localization were performed through biochemical techniques and immunofluorescence light microscopy using a mouse monoclonal antibody IgGα5, respectively. The branchial chamber possesses six pair gills lamellae that extend into the rectal lumen. A thickened epithelial layer and a modified fat body cells layer are present at the base of the each gill lamella. Epithelial cells covered by a thin cuticle and they possess apical microvilli and baso-lateral membrane infoldings associated with mitochondria. The cytoplasm of the modified fat body cells is filled with mitochondria, glycogen and a few lipid droplets. The Na+,K+-ATPase activity was significantly higher (15.36 µM Pi mg-1 protein h-1) in the branchial chamber. Na+,K+-ATPase immunofluorescence staining was observed in the epithelial layer cells of the basal pads of the rectal gill lamellae, with a consistently high immunoreactivity. These findings show that the epithelial cells present cytological features of the ionocytes, a high activity and concentration of Na+,K+-ATPase, confirming their participation in osmoregulation through active ion exchanges.
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Volume 9, Issue 2 (4-2020)
Abstract

The present study was conducted in Electric Blue Cichlid Sciaenochromis fryeri in early larval developmental stages from the fifth day post hatching (DPH) until 51 DPH to determine day of transforming from embryo to juvenile. Morphological characteristics were evaluated by using ImageJ software. Allometric growth patterns were calculated based on the formula Y=aXb. Yolk sac depletion was occurred on day 9. Scales were developed on day 19 and finaly developed juvenile shape. allometric pattern of different body segments were calculated according to isometry, positive, and negative allometry. Positive allometry of head and tail prior to inflexion point and variation in allometric growth pattern in different body segment determine priorities of organogenesis for survival in fish early life history. The obtained results showed consistency between the larval morphological changes and development of organs related to sensory movements and larval behavior. Every morphological change in larvae displays the development and evolution of one of the organs involved in feeding, breathing, swimming and sensory organs.
Abdoljabbar Irani, Naser Agh,
Volume 11, Issue 3 (8-2022)
Abstract

A recirculating hatchery system (RHS) and a flow-through system (FTS) in terms of major macro elements (Ca, Mg, Na and k), some microelements (Fe and Cu), total bacteria and quality characteristics of Rainbow trout eggs and larvae were comparatively studied. A recirculating system (RHS) and a flow-through system (FTS) were designed for incubating the eggs and rearing the yolk-sac larvae. Fertilized eggs were distributed (5000 eggs in each tray) in four replicates and incubated under the standard conditions until yolk sac absorption. Total bacteria and macro/micro elements were measured at one-week interval. Eyed egg percentage, hatching rate, growth, and survival rate of larvae were measured. In the FTS and RHS, percentages of the eyed eggs were 79.75% and 79.01% respectively, and hatching rates were 70.31% and 63.65%, respectively. There were no significant differences amongst the values of Ca, Mg, and Na during the experimental period and between two systems. K Values in the RHS were significantly higher than in the FTS during the egg incubation period. Fe Values in the RHS were more than in the FTS, and increased during the study period in both systems. The values of total bacteria in the RHS were significantly higher than in the FTS.  Despite the differences observed between the experimental systems, the designed RHS can be used for incubating the eggs and rearing the yolk-sac larvae in rainbow trout hatcheries, because of its simplicity, low water consumption, and acceptable efficiency.


Volume 12, Issue 1 (2-2023)
Abstract


Diasemiopsis ramburialis and Nomophila noctuella are moths from Spilomelinae (Lepidoptera: Crambidae) with an overlapping feeding period on Azolla spp. in northern Iran. Due to some morphological similarities, immature stages often lead to confusion. A five-year study conducted in laboratory and natural environments revealed that, despite these morphological similarities, distinct characteristics in both morphology and behavior can facilitate their primary identification in the field. Diasemiopsis ramburialis eggs, and first instar larvae are opaque to pale orange, while those of N. noctuella are pale to creamy. Additionally, the last instar larvae of D. ramburialis feature orange head capsules with smaller body sizes and tend to pupate near the feeding site. In contrast, Nomophila noctuella's last instar larvae have black head capsules, larger body sizes, and pupate at a distance from the feeding site. Both species exhibit shelter-building behavior, binding Azolla spp. leaves together using silken webs to create protective enclosures. However, D. ramburialis larvae construct more robust shelters and produce more webs. They primarily remain within these shelters and navigate through web-formed corridors. On the other hand, N. noctuella larvae prefer to move along the feeding site margins within corridors formed by bound-up leaves and display a more wandering behavior. The study's findings indicate that Azolla spp. serves as the primary host plant for D. ramburialis, while N. noctuella appears to choose its host plants randomly.


 


Volume 12, Issue 1 (2-2023)
Abstract

Two chalcidoid parasitic wasps (Hym.: Chalcidoidea) of two lepidopterous pests on willow trees, Salix spp., were collected in Tehran and Alborz provinces, Iran. Ooencyrtus populicola Myartseva, 1995 (Hym.: Encyrtidae) and Colpoclypeus florus (Walker, 1938) (Hym.: Eulophidae) were reared on Ceruravinula (L., 1758) (Lep.: Notodontidae) and Nycteola asiatica (Krulikovsky, 1904) (Lep.: Nolidae), respectively. Ooencyrtus populicola is a parasitoid of egg and C. florus is an ectoparasitoid of larval stage. Ooencyrtus populicola is a new record for Iran, but C. florus was previously reported as a parasitoid of an unknown leaf-roller larva.


 

Volume 21, Issue 3 (5-2019)
Abstract

The study investigated the toxicity of Parthenium extracts in comparison with Neem extracts against 3rd and 4th instar larvae of the diamondback moth, Plutella xylostella L.. The side effect of Parthenium extracts was also examined against larval parasitoid, Cotesia plutellae. Extracts obtained from their respective plants were dissolved independently to get stock solutions, which were further diluted to different concentrations (1%, 2%, and 3%) with distilled water. The experiment was laid out in completely randomized design with four treatments, including the control, and replicated six times in vitro. Results showed that Parthenium crude extracts was very effective in comparison with the control against P. xylostella, whilst the highest mortality was recorded at 3% concentration of Neem in comparison with Parthenium extracts against both stages of P. xylostella. Overall, the highest mortality was recorded at 3% concentration of Neem extracts followed by 2% Neem extracts, 3% Parthenium extracts, 1% neem, 2% and 1% Parthenium extracts. The lowest mortality was noted in the control (i.e. 70%, 58.33%, 51.67%, 35%, 33.33%, 18.33% and 16.67% in case of 3rd instar mortality whilst 61.67%, 50%, 41.67%, 30%, 16.67% and 15% in case of 4th instar mortality, respectively). Less harmful effect was observed for larval parasitoid, C. plutellae. Finally, it was concluded that all the treatments had the ability to control P. xylostella to some extent, but Parthenium crude extract was less efficient in comparison with Neem extract, as 3% crude extract of Neem had a sufficiently toxic effect on the P. xylostella.
 

Volume 28, Issue 1 (2-2025)
Abstract

Introduction: Malaria, transmitted by Anopheles mosquitoes, remains a significant public health concern. The aim of this study is to evaluate the canonical correlation between physiological traits and growth parameters of two Anopheles stephensi biotypes: intermediate and mysorensis.
Methods: A total of 25 males and 25 females were reared under controlled laboratory conditions (27 ± 2°C, 75 ± 5% relative humidity, 12:12 light-dark cycle), and parameters such as egg lifespan, larval stages, pupal duration, and adult longevity were examined. Growth parameters, including the finite rate of population increase, life expectancy, net reproductive rate, and average generation time, were analyzed separately.
Results: Canonical correlation analysis revealed that only the first canonical variable was significant, explaining 87.24% of the data fit. The first canonical variable exhibited the highest cumulative percentage (87.32), canonical square (0.94), and eigenvalue (23.59). Among growth parameters, life expectancy had the highest canonical correlation coefficient (r = 0.942). Significance tests indicated that Wilks' Lambda produced the highest eigenvalues, while other methods yielded Hotelling-Lawley Trace: 0.38, Pillai’s Trace: 1.43, and Roy’s Greatest Root: 37.40.
Conclusion: Findings indicate that growth parameters, such as net reproductive rate and average generation time, are directly correlated. A higher net reproductive rate corresponds with a longer average generation time, leading to an increased intrinsic rate of population growth and life expectancy. These insights into Anopheles stephensi population dynamics may contribute to improved vector control strategies.



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