Larval and settlement periods of the northern searobin (Prionotus carolinus) and the striped searobin (P. evolans)

This study reports new information about searobin (Prionotus spp.) early life history from samples collected with a Tucker trawl (for planktonic stages) and a beam trawl (for newly settled fish) from the coastal waters of New Jersey. Northern searobin, Prionotus carolinus, were much more numerous than striped searobin, P. evolans, often by an order of magnitude. Larval Prionotus were collected during the period July–October and their densities peaked during September. For both species, notochord flexion was complete at 6–7 mm standard length (SL) and individuals settled at 8–9 mm SL. Flexion occurred as early as 13 days after hatching and settlement occurred as late as 25 days after hatching, according to ages estimated from sagittal microincrements. Both species settled directly in continental shelf habitats without evidence of delayed metamorphosis. Spawning, larval dispersal, or settlement may have occurred within certain estuaries, particularly for P. evolans; thus collections from shelf areas alone do not permit estimates of total larval production or settlement rates. Reproductive seasonality of P. carolinus and P. evolans may vary with respect to latitude and coastal depth. In this study, hatching dates and sizes of age-0 P. carolinus varied with respect to depth or distance from the New Jersey shore. Older and larger age-0 individuals were found in deeper waters. These variations in searobin age and size appear to be the combined result of intraspecific variations in searobin reproductive seasonality and the limited capability of searobin eggs and larvae to disperse.

Selective epitaxial growth in silicon on insulator: Planarity and mass flow

Seeded zone-melt recrystallization using a dual electron beam system has been performed on silicon-on-insulator material, which was prepared with single-crystal silicon filling of the seed windows by selective epitaxial growth. The crystal quality has been assessed by a variety of microscopic techniques, and it is shown that single-crystal films 0.5-1.0 μm thick over 1.0 μm of isolating oxide may be prepared by this method. These films have considerably less lateral variation in thickness than standard material, in which the windows are not so filled. The filling method is suitable for both single- and multiple-layer silicon-on-insulator, and gives the advantages of excellent layer uniformity after recrystallization and improved planarity of the whole chip structure. Experiments using various amounts of seed window filling have shown that the lateral variations of silicon film thickness seen in unplanarized material are due to stress relief in the cap oxide when the silicon film is molten, rather than the effect previously postulated in which they were assumed to be due to the contraction of silicon on melting.

Induced breeding, embryonic and larval development in Heteropneustes fossilis (Bloch) in the agro-climatic conditions of Maharashtra

Heteropneustes fossilis was induced bred for the first time in the agro-climatic conditions of Maharashtra, India. The embryonic development was completed within 16-18h after fertilisation. Head and tail ends were distinguishable after 3h and 11-12 somites were visible after 6-7h. The eggs started hatching after 14h of incubation. Average hatching time was 16-18h at 26 degrees C. In first day old pro-larva, notochord was deflected upwards, eyes were darkly pigmented and alimentary canal appeared. In fourth day old post-larva intestinal coiling could be seen and yolk was absorbed. Aerial respiration started by 8th day. The 10 day old post-larva was free swimming and fed voraciously attaining a length of 20 mm in 30 days.

Acute effect of sumithion on certain blood parameters and mortality rate of fish, Heteropneustes fossilis (Bloch)

The acute toxic effect of the toxicant sumithion (50% E.C.) on mortality rate (after 24, 48, 72, and 96 h), total RBC count and haemoglobin content (after 48 and 72 h) on Heteropneustes fossilis was investigated at four concentrations (9.7, 10.7 and 11.1 ppm). The sumithion treated fishes showed lower RBC and Hb levels than the untreated ones. A gradual decrease in the total RBC counts and Hb contents was recorded with increasing concentration of toxicant after 72 h but the blood showed fluctuating values after 48 h of treatment.

Laboratory reared eggs and larval stages of the clupeid fish, Opisthopterus tardoore (Cuvier)

The early embryonic and larval stages of Opisthopterus tardoore are described and discussed. The developing 3 eggs of stages up to 21hrs after collection and larvae up to 118hrs after hatching were reared in the laboratory. Seasonal occurrence of the eggs in the Vellar estuary, Porto Novo (lat. 11 29'N; 79 degree 46'E) was recorded for a period of 2 years (Nov. 1977 to Oct. 1979). Variation in myotomic counts in the larvae is critically reviewed with earlier works.

RESIDUAL DEFECTS FOLLOWING RAPID ANNEALING OF BORON IMPLANTED SILICON WITH AND WITHOUT PREAMORPHISATION BY SILICON IMPLANTATION.

Implants of boron into silicon which has been made amorphous by silicon implantation have a shallower depth profile than the same implants into silicon. This results in higher activation and restricted diffusion of the B implants after annealing, and there are also significant differences in the microstructure after annealing compared with B implants into silicon. Rapid isothermal heating with an electron beam and furnace treatments are used to characterize the defect structure as a function of time and temperature. Defects are seen to influence the diffusion of non-substitutional boron.

Short-channel polymer field-effect-transistor fabrication using spin-coating-induced edge template and ink-jet printing

A method to fabricate polymer field-effect transistors with submicron channel lengths is described. A thin polymer film is spin coated on a prepatterned resist with a low resolution to create a thickness contrast in the overcoated polymer layer. After plasma and solvent etching, a submicron-sized line structure, which templates the contour of the prepattern, is obtained. A further lift-off process is applied to define source-drain electrodes of transistors. With a combination of ink-jet printing, transistors with channel length down to 400 nm have been fabricated by this method. We show that drive current density increases as expected, while the on/off current ratio 106 is achieved. © 2005 American Institute of Physics.

In vitro phagocytic study of blood leucocytes and peritoneal macrophages of walking catfish Clarias batrachus ( Ham.) against Aeromonas hydrophila and Escherichia coli.

In observation of in vitro phagocytic activity against Aeromonas hydrophila isolate 34k (a virulent form) and Escherichia coli (an avirulent bacteria) of neutrophil- and monocyte-like cells of walking catfish Clarias batrachus showed phagocytosis. N eutrophils and monocytes phagocytized the avirulent form of bacterial isolate more than the virulent one. Other blood leucocytes did not show phagocytosis. Peritoneal macrophage of the fish were separated by glycogen elicitation and the macrophages were being adhered on plastic cover slips for studying their in vitro phagocytic activity. Most of the cells were alive after adherence and showed phagocytosis against the virulent and avirulent bacteria. The percent phagocytosis and phagocytic index were higher against the avirulent E. coli than the virulent A. hydrophila.

Effect of delayed icing on quality changes and shelf-life of some freshwater fish from Bangladesh

The quality and shelf-life of three freshwater fish species of Bangladesh, catla (Catla catla), magur (Clarias batrachus) and tilapia (Oreochromis niloticus) stored at room temperature and ice were evaluated. Live fishes were killed by cranial spiking and stored at room temperature (27-30 °C), ice stored immediately after death, 5 hr after death and 10 hr after death. The shelf-life and quality of the fishes were evaluated by organoleptic method, rigor-mortis studies and bacteriological assessment. Fishes kept at room temperature became organoleptically unacceptable within 16-20 hr duration. Ice stored fishes showed considerable differences in their shelf-life when icing was delayed for different duration. Shelf-life of catla ice stored immediately after death was 20 days but shelf-life reduced to 12 days when icing delayed for 10 hr after death. Similar trend was observed for two other fish species magur and tilapia. Rigor-index of the fishes stored under different conditions also considerably varied among the three fish species, particularly effect of delayed icing was very much evident. Bacteriological study showed patterns of Aerobic Plate Count (APC) at the end of shelflife study when fishes became organoleptically unacceptable were more or less similar for all the three fish species stored under different conditions. No definite pattern was observed in the generic distribution of bacteria in different fish species under different storage conditions. Micrococcus, Coryneforms, Pseudomonas and Achromobacter were the dominant groups of bacteria isolated from the fishes spoiled at room temperature and ice stored condition.

Microbiological evaluation and keeping quality of fishes reared in livestock sewage fed ponds without artificial feed

Livestock sewage has been utilized for fish culture. There is lack of information on microbiological evaluation and keeping quality of these fishes. This paper reveals the incidence, types of micro-organisms and keeping quality of fishes reared in livestock sewage fed ponds without artificial feed. These fishes revealed microbial incidence and keeping quality comparable to other fishes. Initial mesophilic and psychrophilic counts varied from 3.38 to 5.56 and 2.47 to 4.74. On an average, the counts reduced by about 40% after evisceration and washing. Whole as well as washed fishes had refrigerated (8 ± 1°C) life of not more than 4 days. The average psychrophilic and mesophilic counts of ice (0 to 1°C) stored whole fishes up to 10th day varied from 3.66 to 4.81, 4.61 to 5.24 and in eviscerated and washed fishes 2.17 to 3.69 and 2.78 to 4.41. Both remained acceptable till the 10th day. Qualitative study of surface slime and gills revealed presence of Aerobacter (Enterobacter), Aeromonas, Alcaligenes, Bacillus, Clostridia, E. coli, Klebsiella, Micrococci, Proteus and Pseudomonas.

Preservation of Indian oil sardine (Sardinella longiceps) in iced and chilled seawater. Part 2 - Changes during storage with particular reference to salt penetration and lipid deterioration during CSW holding

Oil sardines in prime condition were chilled on board. Two lots were chilled in CSW (samples C & CI), one lot ice (sample I) and a fourth lot was left un-iced on deck (sample AI). Sample AI was iced after landing and sample CI was taken out of the chilled seawater and. iced. All the four samples were kept in a chilled room for storage studies. Sample C, chilled and stored in CSW, recorded a gradual gain in weight and an increase in salt content of the muscle. Presence of salt did not seem to cause any excessive protein denaturation. Salt extractability decreased at a gradual rate in all cases. Presence of salt seemed to wield no noticeable influence on lipid hydrolysis and subsequent peroxidation. Results of chemical and sensory evaluations highlight this. Holding sardines in CSW gave a product of excellent quality for the first four to five days of storage. Beyond the fifth day of storage quality deteriorated rapidly and there was no noticeable superiority for this sample (sample C) over the on board iced fish. This was evident in the sensory evaluation as well. However, a storage life of five days in a readily acceptable state is sufficient for the fish to be disposed in the market at a premium sale price over other landings of the same species.

Structural and functional properties of the hemoglobin components from the Caspian Sea Acipenser persicus and Acipenser stellatus

Hemoglobin (Hb) variability is a commonly used index of phylogenetic differentiation and molecular adaptation in fish. In the current study, the structural and functional characteristics of Hbs from two Sturgeon species of the Southern Caspian Sea Basin were investigated. After extraction and separation of hemoglobin from whole blood , the polyacrylamide gel electrophoresis (SDSPAGE), native-PAGE and isoelectric focusing (IEF) were used to confirm Hb variability in these fishes. Ion-exchange on CM-cellulose chromatography was used for purification of the dominant Hbs from these fishes. The accuracy of the methods was confirmed by IEF and SDS-PAGE. Spectral studies using fluorescence spectrophotometery, circular dichroism spectropolarimetry (CD) analysis and UV–vis spectrophotometery. Oxygen affinities of these Hbs were compared using Hb-oxygen dissociation curves. Also, the dominant Hbs from these blood fishes were utilized for further experiments. The behavior of Hbs during the denaturation process by n-dodecyl trimethylammonium bromide (DTAB) is investigated by UV–vis spectrophotometer and circular dichroism spectropolarimetry. The thermal denaturation properties of the Hbs wereinvestigated by differential scanning calorimetry (DSC) and Hbs aggregation performed chemically in the presence of dithiotreitol (DTT) by UV–vis spectrophotometer and chemometric study. The results demonstrate a significant relationship between stability of fish hemoglobins and the ability of fish for entering to deeper depths. The UV–Vis absorption spectra identified species of hemoglobin and showed the concentration of oxyHb and metHb decreases and deoxyHb increases upon interaction with DTAB. Besides the UV–vis spectrophotometry, the interaction of DTAB with hemoglobins has been studied using circular dichroism spectropolarimetry analysis. This experiment was utilized to measure the unfolding mechanism and compared alpha-helix secondary structure under different conditions for Hbs. The results reveal that the Acipenser stellatus Hb in comparison with Acipenser persicus Hb has more stability and more structural compactness. Besides, the results confirm the hypothesis that there is a meaningful relation between average habitat depth, partial oxygen pressure, oxygen affinity, structural compactness of Hb, and its stability.

Histology and hormonal effect of Ghrelin on ovary of Benni (Barbus sharpeyi) in order to study sexual maturity, zygote and larval generation

Benni (Barbus sharpeyi) is valuable fish that Khuzastan fisheries office propagated it artificially in Susangerd Fish Propagation Center every year. Pituitary gland is used for this aim but female fish lost their fertilization power after 2-3 years, so in present research, new hormone, that is called Ghrelin. The aims of this research are histology, hormonal, zygote and larval generation studies and comparing the results with each other. Ghrelin is a multifunctional peptidyl hormone which increases GTH-II in fish, amphibian, and birds and mammalian so its effect on Benni sexual maturation was studied. Human Ghrelin (hGRL) was obtained from ANASPEC, Canada, with 28 amino acids. In the present study, three levels of ghrelin including 0 (sham treatments), 0.10 (treatment 1) and 0.15 μg/g (treatment 2) body wt and one level of pituitary gland 4000 μg/g (pituitary treatment) with two replications were used. 56 specimens were injected intraperitonealy and their ghrelin level was evaluated immediately after injection and after 24 h. Control fish(n=16) were just injected by physiological saline. For hormonal studies sham and experimental fish(n=40) were anesthetized with MS-222 at a concentration of 250 mg l-1, and blood samples were collected and kept at 4ْC, then spun to collect serum. Serum samples were stores at -20ْC until the RIA for CTH-II. For histology studies immediately after injection a piece of ovary was collected from control fish (Sham zero) after being anesthetized. The sampled ovaries were fixed in Buin solution and embedded in paraffin, and stained to Sections of 5–6 μm using haematoxylin and eosin. The ovarian samples were performed with a compound microscope. Histology and micrometry studies had done. The mature oocytes had given from mature fish, then weighted and the working fecundity were counted. The mature oocytes fertilized, the eggs were incubated and the percentage of fertilization was calculated. After 72h the eggs hatched and the percentage of hatch was counted. The percentage of hindrance was calculated after 6 days. Hormonal results indicate that ghrelin and pituitary increase significantly the GTH-II level in comparison to sham. Macroscopic observations (before taking ovary) showed that ovaries with green colored have couple oval structure located in the abdominal cavity. Microscopic studies of dissected ovaries indicated simultaneous growth of 127 oocytes with 6 stages. The type of the ovary is asynchronous. The results indicated that both of the ghrelin treatment increased the percentage of mature follicles followed by decrease of immature follicles. There were significant differences (P<0.05) between the number of mature and immature follicles. Average diameter of follicle in both of the ghrelin treatment was significantly (P<0.05) declined in the stages of the vitellogenesis when the result compared to the other treatment. Just treatment 1 and pituitary treatment can give mature oocytes. The fecundity of pituitary treatment significantly increase in comparision to ghrelin treatment (P<0.05). In food-restricted fish where endogenous ghrelin levels are known to be increased, a chronic administration of ghrelin induces overt negative effect in releasing mature oocytes. The percentage of fertilization was significantly increase (P<0.05) in ghrelin t. in comparison to pituitary t. and the percentage of hatch was significantly increase (P<0.05) in pituitary t. in comparison to ghrelin t. There was no significant difference (P>0.05) in terms of percentage of hindrance between treatments. In conclusion, the present study demonstrated that ghrelin has positive effect on the level of GTH-II, oocyte maturation, ovarian vitellogenesis and the number of mature follicles of Barbus sharpeyi ovary. Increasing of the mature follicles number reduces their average diameter, indicating stimulating effect of ghrelin in sexual maturation of Barbus sharpeyi.The ghrelin and pituitary treatment have equal chance in the post-stage of spawning.

In vivo and in vitro storage of kutum, Rutilus frisii kutum eggs

Effects of post-ovulatory and post-stripping retention time and temperature on egg viability rates were studied in kutum (Rutilus frisii kutum). Eggs were retained inside (in vivo storage) or outside the ovarian cavity with ovarian fluid (in vitro storage) at various temperatures. Two experiments were performed: 1) Partial volumes of eggs were stripped and fertilized at 24- hour intervals for 96 hours post-ovulation (HPO) (at 11 °C) and at 12-hour intervals for 72 HPO (at 14 °C), and 2) stored eggs were fertilized after 0, 2, 4, 6, and 8 hours post-stripping (HPS) at temperatures of 4, 10, 12, and 26 °C. In the first experiment, the highest eyeing and hatching rates (76% and 60% at 11 °C; 81% and 71% at 14 °C) and the lowest eyed-egg mortalities (20% at 11 °C; 12% at 14 °C) occurred in the eggs fertilized immediately (0–24 HPO at 11 °C and 0–12 HPO at 14 °C) after ovulation. Egg viability, as shown by successful eyeing and hatching rates, was completely lost by 72–96 HPO at 11 °C, and 60–72 HPO at 14 °C. In the second experiment, the maximum eyeing (87%) and hatching (75%) rates of eggs took place at 0 HPS followed by 8 HPS (> 80% and > 70%, respectively) at 4 °C. As storage temperature increased, egg viability decreased: 80%, 70%, and 50% viable at 8 HPS at 4, 10, and 12 °C, respectively. The eggs stored at 26 °C lost their viability almost completely after 4 HPS. Eyed-egg mortality increased from 13% at 0 HPS to 48.2% at 4 HPS at 26°C. These results demonstrate that egg stripping should take place within 168 °C-hours after ovulation and that complete loss of viability of the eggs occurs by 672°C-hours after ovulation. The in vivo storage method is more effective compared to in vitro storage. Also successful in vitro storage of eggs can be used atleast within 8 hours at temperatures ranging from 4 to 12ºC.

Physiological and biochemical study of over-ripened oocyte in the cultivated Caspian brown trout (Salmo trutta caspius) and determination of egg quality markers

To determine the best time for egg stripping after ovulation and over-ripened oocyte in the Caspian brown trout (Salmo trutta caspius), the eggs were retained in the parental abdominal cavity for 40 days post-ovulation (DPO) at 7±0.6°C. Eggs were stripped every 10-day interval in 4 treatment and were fertilized with a pool of semen obtained from 8 males. Also, the physiology and biochemistry of the eggs and ovarian fluids were studied. Results showed that the level of eyed eggs and hatched alevins declined with over-ripening time: that is, the expected amounts (90.65 ± 6.28% for eyeing and 86.33 ± 6.82% for hatching) in newly ovulated eggs (0–10 DPO) decreased to 0.67 ± 1.34% and 0.49 ± 0.98%, respectively, in over-ripened eggs (30–40 DPO). However, larval abnormalities remained constant for 30-days after ovulation. During the course of oocyte over-ripening, the pH of the ovarian fluid significantly decreased and the concentration of glucose, protein, calcium, iron, and aspartate aminotransferase activity significantly increased. Moreover, the concentration of protein, triglycerides, and aspartate aminotransferase activity in the eggs also changed. In the newly ovulated egg, the yolk consisted of homogenous tissue and its perivitelline space diameter had no considerable differences. With over-ripening, the yolk became heterogeneous, while chorion diameter and micropyle did not change. The perivitelline space diameter varied among different areas. The present study demonstrated that the best time to take Caspian brown trout eggs after ovulation at 7± 0.6°C was up to 10 DPO. Among the studied parameters of the egg and ovarian fluid, egg quality was related to both ovarian fluid parameters (e.g., pH, protein, aspartate aminotransferase, glucose, cholesterol, triglycerides, calcium, iron) and egg parameters (e.g., cholesterol, triglycerides, iron, aspartate aminotransferase). Thus, these parameters can be used as a egg quality markers in this species.