Secondary Lamellae Research Articles

Effect of Impregnation with a Low-Concentration Furfuryl Alcohol Aqueous Solution on Hygroscopic Properties of Chinese Fir and Poplar Wood

Furfurylation with a low concentration of furfuryl alcohol (FA) promotes the improvement of the properties and the effectiveness of FA on cell–wall action without darkening the furfurylated wood to the point that it affects its applications. In this paper, the effects of furfurylation on the hygroscopicity and water uptake dimensional stability of poplar (Populus sp.) and Chinese fir (Cunninghamia lanceolata) were analyzed. Meanwhile, the distribution of FA resin, the relationship between wood and water, the change in pore size distribution, and the weight percentage gain and cell wall bulking coefficient of wood were also investigated. The results were as follows: (1) A low concentration of FA could better enter the cell walls of the Chinese fir than the poplar, as FA resin was almost cured in the secondary walls, cell corners, and compound middle lamellae when a 10% concentration of FA was applied to the Chinese fir and poplar. When the FA concentration was increased to 30%, there were no significant increases in the amount of FA entering the cell walls and the amounts of FA cured in the cell lumen of the poplar were greater than those of the Chinese fir. Meanwhile, the modification of cell walls was more suitable in poplar than in Chinese fir. (2) The pointed ends of the pit chambers and the pit apertures (800–1000 nm) in the poplar and the small pores of the pit membranes and the pit apertures (1–6 μm) in the Chinese fir were partially deposited by the FA resin, which formed new pores in the size ranges of 80–600 nm and 15–100 nm, respectively. The porosity of the poplar was greater than that of the Chinese fir, and the bulk density of the poplar was less than that of the Chinese fir before and after modification. (3) Furfurylation with a low concentration of FA was able to better reduce the equilibrium moisture content, improve the anti-swelling efficiency, and enhance the dimensional stability of the poplar wood compared to the Chinese fir. Furfurylation effectively reduced water uptake due to the hydrophobic property of the FA resin. The water uptake of the Chinese fir increased by 17%–19% in second cyclic water soaking when treated with FA with various concentrations, which indicated the loss and leaching of FA resin during the test. Low-field NMR was used to demonstrate that the furfurylation not only reduced the amount of water but also affected the combination state of bound and free water with wood. Thus, furfurylation at a low concentration is a feasible method by which to extend applications of furfurylated wood.

The Differences in Histoarchitecture of Hoof Lamellae between Obese and Lean Draft Horses.

Obesity is a common problem in horses. The associations between obesity and equine metabolic syndrome (EMS) and between EMS and laminitis are known. However, there is a lack of data on whether obesity itself can affect hoof lamellae. Forelimbs and blood from 12 draft horses (six obese and six lean) from a slaughterhouse were acquired. To exclude laminitis and EMS horses, insulin concentration was measured, and hooves were radiographed. Histological evaluation was performed. The shape of the primary and secondary epidermal lamellae (PEL and SEL) was evaluated, and the length of the keratinized and total primary epidermal lamellae was measured (KPEL and TEL). All horses showed pathological changes in lamellae. In the lean group, the changes were longer SELs, more proliferated and separated PDLs, and less standard PDLs. In the obese group, the changes were a lower number of club-shaped and standard SELs and significantly more tapered SELs. No difference in the shape of PELs and the length of KPELs was noticed. The research did not confirm the effects of obesity on lamellar failure. The measurements taken indicate that the lamellae are much longer compared to other research studies; this could indicate that the length of the PEL depends on the hoof size.

Histopathological evaluation of Wallago attu (Bloch & Schneider, 1801) infested by ectoparasites

BackgroundHost-parasite interaction studies represent the dependency of the parasites on the host through various models. Gill infesting copepods, monogeneans and isopods served as excellent models to study the details of host-parasite interaction. In the present investigation, Wallago attu (Bloch & Schneider, 1801) was extensively studied for histopathological damage caused by ectoparasites like monogeneans (Thaparocleidus indicus, Thaparocleidus wallagonius and Mizelleus indicus), copepod (Ergasilus malnadensis) and an isopod (Alitropus typus) during August 2017 to February 2018. Both the control (least infested) and severely infested gills were examined through light microscope to approximate the intensity of damage caused by above ectoparasites.ResultsPathological effects of ectoparasites displayed a fusion of secondary lamella, hyperplasia of the gill filaments and the epithelial cells, propagation of bronchial tips, thinning of the central axis, deshaping, shortening and fusion of secondary gill lamellae epithelium, severe degenerative and necrotic changes in gill filaments and secondary lamellae, curling of secondary lamellae and mucous cells proliferation.ConclusionsEctoparasites cause severe damage to gills of W. attu, thereby diminishing the gill breathing capacity of the fish. Timely pathological studies can reveal the extent of damage caused by the parasites and thus various diagnostic programs and best management practices can be implemented in aquaculture for the better yield.

Comparative histopathological studies of selected organs of Oreochromis niloticus (Linnaeus, 1758) from Igun and Opa Reservoirs, Southwestern Nigeria

Heavy metals have been reported to have negative impacts on the histology of fishes. In this study, the impact of heavy metal bioaccumulation on the gills, muscle and liver of Oreochromis niloticus from Opa and Igun reservoirs was determined by histological methods. This was with a view to checking for possible alterations on fish organs. Live fish samples were collected from Opa and Igun reservoirs and identified in the laboratory. Histological analyses were carried out on the organs and their photomicrographs taken using digital binocular compound LED microscope. The gills of O. niloticus from Opa and Igun reservoirs showed hyperplasia of secondary lamellae and hypertrophy of primary lamellae while shortening and edema of secondary lamellae were observed in O. niloticus from Opa reservoir only. Muscular atrophy and degeneration were revealed in the muscle of fish from the two reservoirs with muscular splitting in O. niloticus from Igun reservoir. The liver of O. niloticus from Opa reservoir showed vascular congestion in the bile duct compared to O. niloticus from Igun reservoir which showed hepatopancreas degeneration, melanomacrophages aggregates, nucleus and hepatocytes hypertrophy. In conclusion, histopathological alterations were more severe in the organs of O. niloticus from Igun reservoir compared to that from Opa reservoir.

Anesthetics efficacy and physiological response of MS222 and clove oil in spotted knifejaw Oplegnathus punctatus

Anesthesia prevents mechanical injuries and manipulation stress during fish farming. The efficacy of the clove oil and tricaine methanesulfonate (MS222) and their effects on respiratory frequency, the proportion of the secondary lamellae available for gas exchange (PAGE), gill histological alteration, biochemical (cortisol, glucose, lactate, aspartate aminotransferase [AST], alanine aminotransferase [ALT]), hematological (white blood cells [WBC], red blood cells [RBC], hemoglobin [Hb], hematocrit [Hct]) and hepatic antioxidative parameters (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], malondialdehyde [MDA]) during anesthesia and recovery were determined to illustrate their underlying physiological response mechanisms in spotted knifejaw. Results showed that the anesthetic induction and recovery under clove oil (10, 20, 30, 35, 40 mg/L) and MS222 (50, 60, 70, 80, 90, 100 mg/L) treatment exhibited time-dose dependent manner for fish (206 g). The minimum concentrations of clove oil and MS222 producing desirable anesthetic properties were 35 mg/L and 80 mg/L, respectively. Rapid induction and recovery were observed in the fish with 16–839 g average body weight (BW) upon exposure to 35 mg/L clove oil and 80 mg/L MS222, while 30 min exposure cause the death of fish with 16 g average BW. The survival rate of the fish with the average BW of 102–839 g was more than 90 % after expose to 80 mg/L MS222 for 30 min. However, 35 mg/L clove oil treatment for 30 min induced significantly lower survival rate than 80 mg/L MS222. Meanwhile, 35 mg/L clove oil significantly increased PAGE, caused higher percentage of lamellar clubbing and hypertrophy compared with 80 mg/L MS222. Plasma glucose, lactate contents, AST and ALT activities, WBC and RBC counts, Hb and Hct levels exhibited similar results. These parameters recovered to nearly normal levels after the fish returned to normal active swimming for 6 h. Hepatic SOD, GSH-Px, and CAT activities and MDA levels were significantly stimulated by 35 mg/L clove oil but were not affected by 80 mg/L MS222 during anesthesia and recovery. These results suggest that compared with clove oil, MS222 exhibits advantages in different scenarios and its dose of 80 mg/L is recommended for use in spotted knifejaw.

Anthelmintic efficacy of Copaifera reticulata oleoresin in the control of monogeneans and haematological and histopathological effects on Colossoma macropomum

This study investigated for the first time the anthelmintic efficacy of therapeutic baths with Copaifera reticulata oleoresin and nanoemulsion with this oleoresin against monogeneans of Colossoma macropomum, as well as the haematological and histological effects in this fish. In the therapeutic baths of three consecutives were used 100 mg/L of C. reticulata oleoresin or 250 mg/L of nanoemulsion containing C. reticulata oleoresin. Therapeutic baths with 100 mg/L of C. reticulata oleoresin had anthelmintic an efficacy of 48.5% against monogeneans (Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri), while baths with nanoemulsion of C. reticulata oleoresin had not anthelmintic efficacy, which was discussed. Baths for 1 h with 100 mg/L of C. reticulata oleoresin or 2 h with 250 mg/L of C. reticulata nanoemulsion increased levels of plasma total protein and glucose, mean corpuscular volume (MCV) and neutrophils number in C. macropomum and decreased in the number of total leucocytes and lymphocytes. In the gills of fish exposed and controls occurred detachment of the epithelium, hyperplasia and hypertrophy, resulting in moderate fusion of the secondary lamellae. Therefore, therapeutic baths with C. reticulata oleoresin and nanoemulsion of C. reticulata oleoresin have a low toxicity to C. macropomum, as there were few changes to the blood parameters.

Eradication of Livoneca redmanii infestation in cultured Argyrosomus regius

Two Argyrosomus regius nursery ponds suffered from high mortality during the summer season of 2020. Diseased fish showed signs of respiratory distress, mainly during hot days. Physiochemical pond water parameters were normal, except dissolved oxygen was lower than the optimum level. Livoneca redmanii (Cymotidae, Isopoda) was isolated from the gill chamber of infested fish. The infestation percent was 41 and 33%, and the intensity was 1.146 and 1.06 in the first and second ponds, respectively. The diseased fingerlings were infested in the natural habitat (Mediterranean Sea) before collection for culture. L. redmanii infestation was associated with high economic losses due to direct fish mortality, reduced growth rates and lower condition factor. The molecular study confirmed the presence of L. redmanii based on the phylogenetic analysis of 16S rRNA and COI gene sequences. Infested fish gills showed massive destruction in gill filaments, sloughing and curling of secondary gill lamellae with the detachment of the cartilaginous core supporting the primary gill filaments. Deltamethrin and trichlorfon effectively eradicated L. redmanii at concentrations of 12.5 μg.l−1 and 0.5 mg.l−1, respectively. The lowest detectable deltamethrin residue in treated pond water was 2.18 μg.l−1 at 120 h, with a half-life of 47.63 h.

Clinicohematological, Mutagenic, and Oxidative Stress Induced by Pendimethalin in Freshwater Fish Bighead Carp (Hypophthalmichthys nobilis).

Currently, aquatic and terrestrial ecosystems are continuously and chronically polluted by cocktails of countless chemical compounds. The susceptibility to infections is tremendously increasing in a variety of organisms due to exposure to environmental pollutants. Pendimethalin, an herbicide, is continuously used in agriculture to remove unwanted broadleaf weeds across the globe. Therefore, this study investigates the mechanisms of toxicity of pendimethalin in freshwater fish bighead carp upon exposure to low and environmentally relevant concentrations. For this purpose, 48 fish without any clinical abnormalities were kept in a glass aquarium in different experimental groups (T0, T1, T2, and T3). These groups were treated with pendimethalin at 0.00, 0.25, 0.50, and 0.75 mg/L, respectively. Four fish were randomly picked from each experimental group and killed at 72, 96, and 120 hours of the trial to study hematobiochemical parameters and visceral tissues including the brain, liver, heart, gills, and kidneys for histopathology. Herbicide-treated fish indicated various physical and behavioral abnormalities including hypersecretion of mucus, erratic swimming, operculum movement, air gulping, tremors of fins, loss of equilibrium, and increased surface breathing. Histopathologically, gills tissues of treated fish indicated atrophied lamellae, uplifting of secondary lamellae, necrosis of primary and secondary lamellar epithelial cells, telogenesis, congestion, and lamellar fusion. Histopathological examination of liver tissues of treated fish showed mild to moderate congestion, necrosis of hepatocytes, and atrophy of hepatocytes while kidneys revealed degeneration of renal tubules, glomerular atrophy, ceroid, and necrosis of renal tubules. The erythrocyte counts, monocyte and lymphocyte counts, and hemoglobin values were significantly (P < 0.05) reduced in pendimethalin-treated fish. Results on serum biochemistry showed that the biomarkers of kidneys, heart, and liver were significantly higher in fish of treated groups. In addition, values of different biochemical reactions like reactive oxygen species (ROS), thiobarbituric acid reactive species (TBARS), total proteins, and quantity of different antioxidant enzymes including reduced glutathione (GSH), catalase, and superoxide dismutase (SOD) were significantly different when compared to untreated fish. Moreover, the percentile of different nuclear abnormalities in red blood cells and frequency of DNA damage increased significantly in treated fish. It can be concluded from the findings that pendimethalin causes its toxic effects via disruption of physiological and hematobiochemical reactions of fish.

The effect of copper and cadmium on oxygen consumption of the juvenile common carp, Cyprinus carpio (L.)

This study was carried out on juvenile Cyprinus carpio (L.) to investigate the effects of sub-lethal concentrations of copper and cadmium (0.1, 0.25, 0.4 ppm) on the survival rate, oxygen consumption and histopathological changes in the gills of exposed fish. The results showed a decrease in survival rate with increasing concentration of each metal. Copper has the most toxic effect compared with cadmium, the survival rate has decreased from 50% to 10% for copper and from 70% to 20% for cadmium with increasing concentration for 15 days. The half lethal time (LT50) was (14 and &gt;15) days for copper and cadmium, respectively. Oxygen consumption rate decreased with increasing concentration and there was a negative correlation between oxygen consumption and metal concentration. The exposure to each metal caused histopathological changes in the gill and resulted in separation of epithelial secondary gill lamellae, hyperplasia, fusion of secondary lamellae and necrosis.

Assessment of the ameliorative roles of vitamin e on the histopathology of Clarias Gariepinus (Burchell, 1822) fingerlings exposed to lead nitrate

Pollution of aquatic ecosystems is constantly increasing with the increase in anthropogenic activities all over the world with negative effects on the constituent biota. The current study addressed the possibility of remedying the effects posed to the tissues of Clarias gariepinus fingerlings (3-11g initial weight) exposed to lead nitrate over a 12 week period. The treatment groups were Pb only and PbVE (Pb+vitamin E) with T1-T4 and replicate in each case. The sub-lethal treatments of lead nitrate concentrations are as follow: 00 (control), 26mg/L (T1), 44mg/L (T2), 61mg/L (T3) and 79mg/L (T4). 26mg/L concentration of the vitamin was applied to every treatment and replicate of the PbVE group. At the end of the exposure period, gills, liver, and kidneys were excised from the samples and preserved in 10% formalin for histopathological analyses. From the results; the livers of the samples of C. gariepinus exposed to sub-lethal concentration of Pb only group displayed aggregation and lumping together of the hepatocytes, massive necrosis and shattering of the hepatocytes, vacoulation with greater severity as the concentration increased. The samples of PbVE treatment group showed preserved hepatocytes, reduced aggregation and vacoulation of the cells, gradual recovery of the cell nucleus and cytoplasm, normal tissue architecture, and hepatocytes similar to control samples in T1-T3. In the kidneys of Pb only group, there were massive necrosis and vacoulation, shattering of cells, tissue edema, and massive lumping of cells together, especially in higher concentrations. The PbVE treatments displayed reduced necrosis and cells aggregating together coupled with reduced vacoulation, preserved cells, and cells with cytoplasm returning to normal. But these were not sustained in the highest concentration. In the gills of the Pb only group, there was rarefied gill filament with ruptured lamellae, shattered gill arch, and filaments ruptured primary and secondary lamellae with greater severity in higher concentrations. The PbVE group displayed how the gill arch and filaments with the primary and secondary lamellae were gradually restored to a certain extent similar to the control. In all the organs the alteration and amelioration of the architecture were concentration-dependent. Therefore, a proportionate concentration of the vitamin can facilitate faster tissue damage recovery in heavy metal exposure.

Potential mechanisms of Na+/K+-ATPase attenuation by heat and pesticides co-exposure in goldfish: role of cellular apoptosis, oxidative/nitrative stress, and antioxidants in gills.

In this study, we examined the dose-dependent effects of an environmentally relevant pesticide cocktail (metalachlor, linuron, isoproturon, tebucanazole, aclonifen, atrazine, pendimethalin, and azinphos-methyl) and temperature change (22 vs. 32°C for 4-week exposure) on Na+/K+-ATPase, 3-nitrotyrosine protein (NTP), dinitrophenyl protein (DNP), catalase (CAT), and superoxide dismutase (SOD) expressions in gills of goldfish (Carassius auratus). Histopathological analysis showed widespread damage to gill in elevated temperature (32°C) and pesticide co-exposure groups, including fusion of secondary lamellae, club-shaped primary lamellae, rupture of epithelial layer, loss of normal architecture, and hemorrhaging. Immunohistochemical and qRT-PCR analyses showed significant decreases in Na+/K+-ATPase protein and mRNA expressions in gills exposed to higher temperature and pesticides; however, combined exposure to heat and pesticides significantly increases NTP, DNP, CAT, and SOD expressions. In situ TUNEL assay revealed elevated levels of apoptotic cells in response to combined exposure. Collectively, our results suggest the combined effects of heat and pesticide stress cause cellular damage, upregulate oxidative/nitrative stress biomarkers, and increase apoptotic cells, downregulate Na+/K+-ATPase expression in gills. This provides new evidence for oxidant/antioxidant-dependent mechanisms for downregulation of Na+/K+-ATPase expression in gills during combined exposure.

Study of Histopathological change in gills of Coptodon zillii as a bioindicator of pollution in Sarragy River In Abu Alkhasiib region

In the present study the fish Coptodon zillii are collectedfrom Sarragy River in Abu Alkhasiib region through two season that the first is expansion from 7\2013 to 11\2013 and the second season is expansion from 12\2013 to 6\2014,and bringing it to the laboratory for dissection and ablation the gills for studied the histopathological change that appear on it, that included change of the form of some secondary lamellae, adherence in other secondary lamella ,cellular hyperplasia , hypertrophy , swelling in the epithelial layer of secondary lamellae, epithelial lifting ,and hyperplasia in cartilage skeletal of primary filaments.

Behavioural and Histological Abnormalities Observed in Heteroclarias Juveniles Exposed to Aqueous Extract of Ricinus communis Leaf Meal

The study evaluated the toxicity of aqueous extracts of Ricinus communis leaf on the juveniles of Heteroclarias, with mean weight 24.00 ± 0.25 g. Fish were exposed to varying concentrations of C (0.0, 2.0, 3.0, 4.0., 5.0 and 6.0 g/l), in a static bio-assay procedure for 96 hours. The 96 hours LC50 values were calculated at 4.37 g/l. Results indicated varying concentrations of R. communis resulted in different pathological alterations in the juveniles of Heteroclarias. Behavioural responses observed in experimental fish includes; erratic swimming, twitching, gaping, mucous discharge, skin discoloration and death. These responses and mortalities were significantly different (P˂0.05) in treatments with increasing concentration of R. communis when compared with the control. Experimental water showed increase in temperature (°C), pH and conductivity (µS/cm) with increase in test ingredient concentration while reverse was the case with dissolved oxygen (mg/l). Histolopathological assay of gills, liver and kidney, revealed different alterations in architecture, fragmentation and haemorrhage of gill filaments, fusion of the primary and secondary lamellae. Liver showed congestion of hepatic veins and foci hepatocellular degeneration while kidney revealed congestion of the renal artery, inflammation of the renal tubules, haematopoietic cells and nephrons, hyperplasia of the glomerular vessels, pyknotic nephrons and degenerated renal corpuscle.

Analyses of the health status, risk assessment and recovery response of the nutritionally important catfish Clarias batrachus reared in coal mine effluent-fed pond water: a biochemical, haematological and histopathological investigation.

The present field study evaluates the health status of the catfish Clarias batrachus reared in coal mine effluent (CME)-fed pond water at Rajrappa mining complex using biochemical, haematological and histopathological parameters. Simultaneously, risk assessment along with recovery response of the CME intoxicated fish following their treatment with CME-free freshwater was also studied. The CME-fed pond water fish revealed significant decrease in biomolecules concentrations and considerable increase in activities of several enzymes along with metallothionein level as compared to control. The impaired regulation of metabolic function was also revealed by blood parameters showing significant decrease in haemoglobin content (8.78 ± 0.344g/100mL) and red blood cells count (1.77 ± 0.12 × 106 mm3) while substantial elevation in white blood cells (187.13 ± 9.78 × 103 mm3). The histopathological study also confirmed the changes including hypertrophy of club cells of skin, swelling of secondary lamella of gills, extensive fibrosis in liver and glomerular shrinkage with increased Bowman's space in kidney. Potential health risk assessments based on estimated daily intake and target hazard quotient indicated health risks associated with the consumption of such fishes. The CME-contaminated fish when transferred to CME-free freshwater exhibited decreased metal content accompanied by eventual recovery response as evident by retrieval in biochemical and haematological parameters. Withdrawal study also revealed restoration in the activity of different marker enzymes in fish tissues including blood as well as recovery in their cellular architecture. The results of the present study validate the depuration process as an effective practice for detoxification of fish contaminated with effluent.

Air sac and gill vasotocin receptor gene expression in the air-breathing catfish Heteropneustes fossilis exposed to water and air deprivation conditions.

Heteropneustes fossilis is a facultative air-breathing freshwater catfish and inhabits ponds, ditches, swamps, marshes and rivers that dry up in summers. It possesses a pair of unique tubular accessory respiratory organ (air sac), which is a modification of the gill chamber and enables it to live in water-air transition zones. In the catfish, three vasotocin (Vt) receptor gene paralogs viz., v1a1, v1a2 and v2a were identified for Vt actions. In the present study, the receptor gene transcripts were localized in the gill and air sac by in situ hybridization, and their expression levels in relation to water and air deprivation conditions were investigated by quantitative RT-PCR. The catfish were exposed to 1h and 2h in gonad inactive (resting) and gonad active (prespawning) phases. The gene paralogs showed overlapping distribution in the respiratory epithelium of primary and secondary lamellae of gills and reduced lamellae of the air sacs. In water deprivation (forced aerial mode of respiration) experiment, v2a expression showed a high fold increase in the air sac, which was unchanged or inhibited in the gill. Both v1a1 and v1a2 expression was significantly upregulated in the air sac but showed varied responses in the gill. The gill v1a1 expression was unchanged in the resting phase and modestly upregulated in the prespawning phase. The gill v1a2 expression was modestly upregulated at 1h in both phases but unchanged at 2h. In the air deprivation experiment (forced aquatic respiration), the v2a expression in the air sac was inhibited except for a mild stimulation at 1h in the prespawning phase. In the gill, the v2a expression was stimulated with a steep upregulation at 2h in the prespawning phase. Both v1a1 and v1a2 expression was significantly high in the gill but only modestly increased or unchanged in the air sac. The expression patterns point to a functional distinction; the V2 type receptor expression was higher in the air sac during forced aerial respiration, and the V1 type receptor expression was highly prominent in the gill during forced aquatic respiration. Water and air deprivation treatments caused a significant increase in plasma cortisol level, and the stimulation was higher in the water deprivation fish in the resting phase but equally prominent in the water and air deprivation groups in the prespawning phase. The results indicate that the changes in the expression patterns of Vt receptor genes may be a sequel to stress (hypoxic, metabolic and osmotic), and both Vt and cortisol may interact to counter the stress responses. This study shows that Vt has a new role in the control of air sac functions.

Stress, growth, cytokines and histopathological effects of permethrin in common carp (Cyprinus carpio)

ABSTRACT Although permethrin has low toxicity in mammals, it affects many aquatic organisms directly or indirectly due to its high insecticide potential. In this study, changes in the levels of some hormones, cytokines and histopathological effects in the gill and liver were studied in common carp (Cyprinus carpio) exposed to permethrin at different doses (0, 10 and 20 ppm) and durations (4 days and 21 days). Permethrin exposure showed significant (P < 0.05) elevation in the serum levels of adrenocorticotropic hormone (ACTH), cortisol (CORT), tumor necrosis factor-α (TNF-α), interleukin 1β (IL- 1β) and interleukin 6 (IL-6) while decrease in growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in duration- and concentration dependent-manner compared to the control group. Histopathological findings such as reduction in secondary interlamellar space in the gill tissue, shortening of secondary lamellae, merging, fusion, oedema and telangiectasia were obtained. In the liver tissue, histopathological symptoms such as vacuolization of hepatocytes, passive hyperaemia, mononuclear cell infiltration and hepatocellular degeneration were observed. As a result, it was determined that permethrin had a toxic effect on common carp depending on the dose and duration exposure.

Behavioral and histo-pathological indices of striped catfish (Pangasionodon hypophthalmus) exposed to different salinities

Salinity intrusion due to climate changes in the coastal area is substantially jeopardized for sustainable aquaculture. This study was focused on behavioral and histo-pathological changes (gills, liver and kidney) of striped catfish (Pangasionodon hypopththalmas) exposed to four salinities (0, 4, 8 and 12 ppt), each with three replications for 56 days. Both behavioral and histological analyses were carried out for durations of 7, 14, 28 and 56 days of exposure. Mild to moderate behavioral abnormalities such as rate of swimming, food intake, gill motion and convulsions were observed in 8 ppt, but pronounced alterations were detected at higher salinity (12 ppt), increasing with longer exposures. Similarly, mild to moderate histological anomalies in gills (hypertrophy of the chloride cell, telangiectasia at the tips of secondary lamellae, epithelial necrosis, fusion of some secondary lamellae and lifting of the lamellar epithelium), liver (vacuolation, blood congestion, melanomacrophage centers, patchy degeneration, necrosis and hypertrophy nucleus) and kidney (degeneration of renal tubule, enlarged Bowman's capsule, increased space in between glomerulus center, melanomacrophage centers, vacuolation and necrotic cell in the hematopoetic tissue) were detected in 8 ppt but pronounced alterations were detected at higher salinity (12 ppt) with increasing the days of exposure. This preliminary study revealed more profound responses to higher salinity exposure in the striped catfish, and this species could serve as a model bio-indicator in costal aquaculture.

Aquaporin (AQP) channels in the spiny dogfish, Squalus acanthias I: Characterization of AQP3 and AQP15 function and expression, and localization of the proteins in gill and spiral valve intestine.

Complementary DNAs (cDNAs) for two aquaporin water channel genes (AQP3 and AQP15) were amplified cloned and sequenced to initiate this study. Northern blot analysis was carried out to confirm the mRNA sizes of these AQP genes with AQP3 mRNA bands exhibiting sizes of 1.2 and 1.6k bases and AQP15 had a mRNA band of 2.1k bases. Northern blot analysis was also performed on kidney and esophagus total RNA samples from fish acclimated to 75%, 100% or 120% seawater (SW). The level of AQP15 mRNA expression was shown to significantly decrease following salinity acclimation from 100 to 120% SW. An opposite but non-significantly different trend was observed for AQP3 mRNA levels. Full length cDNAs were then used to generate AQP3 and AQP15 mRNAs for microinjection into Xenopus oocytes. Both AQP3- and AQP15- microinjected oocytes exhibited significantly elevated apparent water permeability compared to control oocytes at neutral pH. The apparent water permeability was mercury-inhibitable, significantly so in the case of AQP3. AQP3 microinjected oocytes showed pH sensitivity in their apparent water permeability, showing a lack of permeability at acidic pH values. The Carboxyl-terminal derived amino acid sequences of AQP3 and AQP15 were used to generate rabbit affinity-purified polyclonal antibodies. Western blots with the antibodies showed a band of 31.3kDa for AQP3 in the kidney, with minor bands at 26, 24 and 21kDa. For AQP15 a band of 26kDa was seen in gill and kidney. Fainter bands at 28 and 24kDa were also seen in the kidney. There was also some higher molecular weight banding. None of the bands were seen when the antibodies were pre- blocked with their peptide antigens. Immunohistochemical localization studies were also performed in the gill and spiral valve intestine. In the gill, AQP15 antibody staining was seen sporadically in the membranes of surface epithelial cells of the secondary lamellae. Tyramide amplification of signals was employed in the spiral valve intestine. Tyramide-amplified AQP3 antibody staining was observed in the basal membrane of the invaginated epithelial cell layer of secondary intestinal folds in luminal surface of either the side wall of the spiral valve intestine or in internal valve tissue 'flaps'. For the AQP15 antibody, tyramide-amplified staining was instead found on the apical and to a lesser extent the lateral membranes of the same invaginated epithelial cell layer. The localization of AQP3 and AQP15 in the spiral valve intestine suggests that a trans-cellular water absorption pathway may exist in this tissue.

Histology, physiology, and glucose and lipid metabolism of Lateolabrax maculatus under low temperature stress.

Spotted sea bass (Lateolabrax maculatus) is a popular and important commercial fish throughout the world, but it is unknown whether introducing domesticated fish to locations that experience cold weather might alter physiological performance. In this study, we evaluated the behavior, fatty acid content, histological analysis of liver and gills, liver enzymatic activity in carbohydrate and lipid metabolism, and gene expression in liver related to carbohydrate and lipid metabolism of spotted sea bass acclimatized at 22°C (control), 16°C, 10°C, 8°C, and 4°C for 24h, and 8°C for 4 days. When L. maculatus was exposed to acute cold stress for 24h, the gill showed curling, lamellar disorganization, lamellar epithelium hyperplasia, and formed aneurysms inside of the secondary lamellae. Long term stress over four days resulted in severe lamellar epithelium hyperplasia and curling. Continued extreme cold exposure (4°C) in L. maculatus caused liver HK, PK levels and LDH activities to achieve a peak value at 0h, and decreased over time. These indicated that glucose metabolism might play critical roles in the initial time of stress. Results of carbohydrate and lipid metabolism showed that lipids appear to play roles in prolonged cold stress. The constitutive transcriptional levels of six genes related to glucose (G6Pase) and lipid metabolism (PPAR-α, PPAR-γ) and mTOR signal pathway (eif4ebp1, eif4ebp2, mlst8) genes increased significantly in most groups during cold stress.

Histopathology and Morphometric Characters of Tilapia guineensis as Biomarker to Evaluate Level of Environmental Stress in Badagry and Ojo Creeks, Lagos, Nigeria

Forty wild adult Tilapia guineensis were sourced from Ojo and Badagry creeks between January and March 2021, to investigate its morphometric character (total length, body weight, standard length, and head depth) and tissues structure (gill, muscle and small intestine) differences. Samples were collected and analysed using standard methods. The results showed no significant difference (P&lt;0.05) between the mean total length, body weight, standard length, and head depth of Tilapia guineensis recorded from both creeks. Length-weight relationships of T. guineensis obtained from both creeks showed negative allometry(b&lt;3) growth pattern while its condition factor (k) value was more significant than one, which indicated that the fishes are in good condition. Muscle of T.guineensis from Ojo creek showed a severe lesion of muscle bundle, degeneration of muscular bundle and shortening of bundles. Similarly, the gills structure of T. guineensis from Ojo creek showed severe degeneration, hyperplasia of secondary gill lamellae, and curling of secondary lamellae with unclear water channels. It is also characterized by hypertrophy of lamellae, and there is evidence of partial fusion of lamellae and dilation of gill filament. The observation of none lesion or degenerated tissues of T. guineensis in Badagry creek could suggest that Ojo creek is more subjected to effluents or other environmental stressors than Badagry creek. In conclusion, T. guineensis from Badagry creek is less affected by any environmental contaminants than T. guineensis from Ojo creek. Therefore, a collective effort towards ensuring reduction in direct discharge of untreated effluent or avoidance of another unhygienic usage of the creeks is very pertinent.