Fin Erosion Research Articles

Not too slow, not too fast: water currents affect group structure, aggression and welfare in post-smolt Atlantic salmon Salmo salar

Increased swimming speed of Atlantic salmon is generally considered an improvement to welfare under aquaculture settings, as group structure is improved and agonistic behaviour re- duced. As such, establishing fish farms in exposed areas with fast water current velocities should be favourable. However, at some locations, velocities exceed what is known as preferable for salmonids, and this may compromise fish welfare. In this study, behaviour and fin erosion were observed on post-smolt salmon stocked at 39 kg m �3 in raceways at 3 water current velocities: fast (1.5 body lengths (BL) s �1 ), moderate (0.8 BL s �1 ) and slow (0.2 BL s �1 ). Movements that affect group structure and interactions between individuals varied by up to 20-fold between velocities. A behavioural change occurred directly after velocities were set. Severe fin erosion decreased over time in all groups, but new injuries increased almost 3-fold in the faster-velocity group. Our results suggest that moderate velocity is ideal from a welfare perspective. At slow velocity, higher frequency of structural movements and between-individual interactions could be stressful for the fish. At faster velocity, the fish have to focus on swimming, which could increase unintentional collisions with obstacles and other individuals and result in new fin erosion. Our results suggest that management of water currents may be an effective way of controlling behaviour and may thereby improve welfare.

The Morphological Deformations and Discrepancy in Sex Ratio in Goldfish (Carassius Auratus) As Biomarker for Pollution in Al- Hammar Marshes – South Iraq

The present study include determine the morphological anomalies and sex ratio disruption for gold fish Carassiusauratus that captured from Al-Hammar marshes during study period that prolonged from October 2013 to May 2014 . the number of captured fish were 106. Morphological anomalies were represent ell by deformity of vertebral column (curved and fusion of vertebrae ) ,face and upper jaws , fin erosion , popeye and eye bleeding . Sex ratio tend strongly towed females (1;25.5).

Effects of Familiarity and Population Density on Competitive Interactions and Growth: An Experimental Study on a Territorial Salmonid Fish

AbstractThe deleterious effect of competition for space and food in animals increases with increasing population density. In contrast, familiarity towards conspecifics can relax the intensity of interference competition. Here, we hypothesized that familiarity towards conspecifics mitigates the effect of density‐dependent growth and dispersal behaviour in territorial animals. To test this, wild‐captured juvenile brown trout were subjected to two consecutive laboratory experiments. First, growth and fin erosion were measured for 40 d in a 2 × 2 factorial design manipulating density and familiarity. The density was manipulated via size of experimental tanks, while per capita food abundance and fish number was constant. All fish were subsequently exposed to an emergence test, giving them the option to leave their group and disperse to a novel unoccupied environment. The results show that familiarity increases growth and decreases the level of fin erosion (i.e. proxy of intensity of aggressive interactions). We found no significant effect of population density on growth rate. However, there was a tendency towards higher fin erosion in fish kept under high density. The growth of individuals was also affected by their size rank within the group, with the largest individuals in each group growing disproportionally faster than the rest of the group, probably due to their high social rank. However, the second and third fish in the size rank did not grow significantly faster and tended to suffer higher mortality than the rest of the group. During the emergence test, the largest individuals in the familiar groups left the shelter either as the first (six of 12 groups) or last (five of 12 groups) individual in the group, while no such pattern was observed in unfamiliar groups. Our results suggest that individuals in familiar groups receive less aggression and stress (i.e. fin damage) and grow faster than fish in unfamiliar groups. The mechanisms indicated in this laboratory study may be especially important in highly fecund organisms like fish which undergo density‐dependent bottlenecks during early life.

Changes in migratory fish communities and their health, hydrology, and water chemistry in rivers of the Athabasca oil sands region: a review of historical and current data

The long-lived migratory fish in the lower Athabasca region (including the Athabasca oil sands region) are valued ecosystem components and good bio-indicators of changes in habitat condition, water quality and quantity over the entire stream network. Changes in this region may have been caused by a variety of human activities including oil sands development, forestry, urban development, and recreational activities. We reviewed existing data to examine whether community composition and health of migratory fish (such as northern pike, walleye, and suckers) in the lower Athabasca region have changed over the past 40 years and whether these could be explained by changes in hydrology or water chemistry. Declines of 53%–100% in the abundance of three migratory fish species were detected in the Muskeg watershed (15% land change). Significant changes in fish health were detected. The largest decreases in body condition of fish in the region occurred in the late 1990s and coincided with elevated levels of fin erosion, the most frequently occurring external abnormality, and with extreme discharge conditions. Fish habitat can be affected by both increases and decreases in discharge, and the most pronounced changes were increases in some watersheds of up to 20% of average discharge post-development. In contrast, decreases in discharge post-development in the Muskeg and Steepbank rivers correlated with a decrease in precipitation. Our results show that climatic events and landscape features such as wetlands are important for understanding changes in the system. Further research is needed to examine potential ecological consequences of the observed changes in hydrology for fish and to explore what caused the changes in migratory fish communities and fish health. This will require a better understanding of the trophic structure of the system and a better monitoring program for migratory fish.

Repeatability of fin length measurements using digital image analysis and studies of fin erosion as indicator of social interactions in Atlantic cod (Gadus morhua)

The aims of this study were to examine fin erosion caused by social interactions between Atlantic cod (Gadus morhua) juveniles, and to evaluate the repeatability of recorded fin length using digital image analysis (DIA). Fin length of 2100 juvenile Atlantic cod was analysed using DIA, during a 6 weeks experiment. The lengths of the three dorsal fins and the caudal fin were measured by three different assessors (M, K, B) three times during the experiment. Repeatability was based on a sub set of data from 42 randomly chosen fish. Assessor M measured the length of the fins of the 42 fish three times (M1, M2, M3). M1 and M2 were done on the same day, while M3 was conducted 2 weeks later. Assessor K measured two times with a 2-year interval, and assessor B measured the fin length only once. The correlations between replicated measurements within assessor were highest for assessor M measured on the same day indicating an effect of memory. Repeatability of fin length ranged from 0.57 to 0.73 for the four fins. Social interaction with respect to fin erosion was studied using data on the four fins from all 2100 fish. ‘Relative fin length’ (fin length/total body length × 100) was calculated to assess fin erosion. Results indicated that all four fins were eroded due to social interactions, but the caudal fin was most severely eroded. In conclusion, DIA can be used to measured fin length but the method could be improved by using chromatic pictures.

Evidence of between-population variation in morphology and thermal plasticity of agonistic behavior in two genetically distinct populations of steelhead (Oncorhynchus mykiss)

Morphological and behavioral traits affect an individual’s fitness and can reflect both evolutionary adaptations and phenotypic responses to environmental conditions. We conducted a reciprocal transplant ‘common garden’ experiment at two temperature regimes to test for phenotypic plasticity in morphological and behavioral traits between and within two populations of steelhead Oncorhynchus mykiss from Hood Canal, WA, USA. The Dewatto River and Duckabush River populations exhibited asymmetric changes in body morphology in response to the two temperature regimes, suggesting both between- and within-population variation in morphological plasticity. In most cases, within population variation in body shapes was less than between temperature regimes. Most notably the populations differed in dorso-ventral and caudal regions, body depth, and head shape, with some differences on the anterior-posterior placement of the dorsal and ventral fins. The warm temperature regime caused more exploratory behavior, more charging behavior, and higher fin erosion, and population effects included slight differences in feeding aggression frequency. Morphology appeared to vary more between populations than between temperature regimes, and behavioral traits varied more between temperature regimes than between populations. Morphological variation may reflect adaptations to variation in freshwater habitat conditions, and both populations show behavioral plasticity in response to temperature. This study sheds new light on the role of genetic and environmental influence on morphology and behavior in juvenile steelhead.

Maladaptation and phenotypic mismatch in hatchery-reared Atlantic salmon Salmo salar released in the wild.

Changes in body shape, fluctuating asymmetry (FA) and crypsis were compared among Atlantic salmon Salmo salar fry kept as controls in captivity and those released and subsequently recaptured in the wild according to a before-after-control-impact (BACI) design. Hatchery fish that survived in the wild became more cryptic and displayed a much lower incidence of fin erosion and of asymmetric individuals than control fish kept in captivity. Significant differences in body shape were also apparent, and survivors had longer heads, thicker caudal peduncles and a more streamlined body shape than hatchery controls as early as 20 days following stocking, most likely as a result of phenotypic plasticity and non-random, selective mortality of maladapted phenotypes. Hatchery-reared fish typically perform poorly in the wild and the results of this study indicate that this may be due to phenotypic mismatch, i.e. because hatcheries generate fish that are phenotypically mismatched to the natural environment.

Effects of feed quality and quantity on growth, early maturation and smolt development in hatchery-reared landlocked Atlantic salmon Salmo salar.

The effects of feed quality and quantity on growth, early male parr maturation and development of smolt characteristics were studied in hatchery-reared landlocked Atlantic salmon Salmo salar. The fish were subjected to two levels of feed rations and two levels of lipid content from first feeding until release in May of their second year. Salmo salar fed high rations, regardless of lipid content, grew the most and those fed low lipid feed with low rations grew the least. In addition, fish fed low lipid feed had lower body lipid levels than fish fed high lipid feed. Salmo salar from all treatments showed some reduction in condition factor (K) and lipid levels during their second spring. Smolt status was evaluated using both physiological and morphological variables. These results, based on gill Na(+) , K(+) -ATPase (NKA) enzyme activity, saltwater tolerance challenges and visual assessments, were consistent with each other, showing that S. salar from all treatments, except the treatment in which the fish were fed low rations with low lipid content, exhibited characteristics associated with smolting at 2 years of age. Sexually mature male parr from the high ration, high lipid content treatment were also subjected to saltwater challenge tests, and were found to be unable to regulate plasma sodium levels. The proportion of sexually mature male parr was reduced when the fish were fed low feed rations, but was not affected by the lipid content of the feed. Salmo salar fed low rations with low lipid content exhibited the highest degree of severe fin erosion.

The Effects of Rearing Density on Growth, Fin Erosion, Survival, and Migration Behavior of Hatchery Winter Steelhead

AbstractJuvenile winter steelhead Oncorhynchus mykiss at Eagle Creek National Fish Hatchery in Estacada, Oregon, were reared for three brood years (2004–2006) at raceway densities of 7,500 (214 fish/m3), 15,000 (429 fish/m3), and 22,500 fish (643 fish/m3) to determine the effects of rearing density on growth, fin erosion, survival, adult yield, and migration behavior. Coded wire tags were used to evaluate adult survival, and fish were radio‐tagged to monitor migration times from the hatchery to the mouth of Eagle Creek following volitional release from the hatchery. We found rearing density had a significant effect (P < 0.05) on steelhead growth, fin erosion, and adult survival. Winter steelhead reared in low‐density raceways (13.6 kg/m3 at release) were significantly larger at release, larger at return, had significantly better dorsal fin condition, and had significantly greater smolt‐to‐adult survival rates than did those reared in medium (23.4 kg/m3) and high (35.2 kg/m3) density raceways. No significant relationship between smolt size at release and migration timing was detected; however, the effect of rearing density on fish migration was noticeable in brood year 2004. In that year (2004), smolts from the medium‐ and high‐density groups took from 6 to15 d longer to out‐migrate than those from the low‐density group.

Ascorbic acid requirement and histopathological changes due to its deficiency in juvenile spotted rose snapper Lutjanus guttatus (Steindachner, 1869)

A 13-week feeding trial was conducted to determine the optimal dietary ascorbic acid (AA) requirement of juvenile spotted rose snapper (Lutjanus guttatus). Six experimental diets containing 0, 7, 19, 29, 62 and 250 mg AA equivalent kg−1 diet, supplied as l-ascorbyl-2-polyphosphate designated as VC0, VC7, VC19, VC29, VC62 and VC250, were fed ad libitum to triplicate groups of 20 juveniles [initial weight (IW) of 8 ± 1.85 g]. Nutrient deficiency resulting in fin erosion, dark skin, desquamation and erratic swimming was observed after 8 weeks in fish fed diets from 0 to 29 mg AA kg−1. Fish that were fed all diets showed gill, kidney and brain alterations. The degree of tissue change values indicates that increasing vitamin C (VC) levels reduces these alterations. Fish fed diets VC29, VC62 and VC 250 showed a significantly higher growth rate in comparison with those fed the diets VC0, VC7 and VC17 (P > 0.05). The dietary requirement of VC in L. guttatus was estimated to be 29 mg kg−1 of AA based on weight gain and specific growth rate, but more than 250 mg kg−1 of AA is required to eliminate clinical signs and histopathological lesions.

Investigation of the effects of dietary protein source on copper and zinc bioavailability in fishmeal and plant-based diets for rainbow trout

Limited research has examined the effects that dietary protein sources have on copper (Cu) and zinc (Zn) absorption, interactions and utilization in rainbow trout. Therefore, the objective of the first trial was to determine what effect Cu source (complex vs. inorganic) and Cu concentration (0, 5, 10, 15, 20 ppm) had on rate and efficiency of gain and Cu tissue concentration in rainbow trout fed both plant-protein and animal-protein based diets. The second trial then examined if interactions occur due to increasing dietary content of Zn (0, 30, 300, 1500 ppm) in rainbow trout fed a plant-based diet. Results from the first trial demonstrated differences in growth and tissue mineral concentrations due to Cu concentration but not source. Trout fed plant-based diets had higher weight gain, improved feed conversion ratio and higher hepatic Cu concentration when compared to fishmeal-fed trout. Results from the second trial show that increasing dietary Zn supplementation increased whole body Zn and Cu at 12 weeks. No significant antagonism between Cu and Zn was observed in rainbow trout fed plant-based diets. Zn deficiency signs were observed at 12 weeks in trout fed a plant-based diet without Cu and Zn supplementation which included mortality, cataracts and caudal fin erosion. Results of these studies indicate that rainbow trout fed plant-based diets require both Cu and Zn supplementation at concentrations higher than those previously reported to maximize growth.

The Physical Condition and Welfare of Five Species of Wild‐caught Wrasse Stocked under Aquaculture Conditions and when Stocked in Atlantic Salmon, Salmo salar, Production Cages

AbstractSeveral indices were examined to assess the physical condition of wrasse stocked on Atlantic salmon, Salmo salar, farms as cleaner fish, and included examination of eye condition, snout erosion, skin hemorrhaging, and erosion and splitting of dorsal, pectoral, anal and caudal fins. Baseline values were determined for five wrasse species: goldsinny, Ctenolabrus rupestris; rock cook, Centrolabrus exoletus; corkwing, Crenilabrus melops; cuckoo, Labrus mixtus; and ballan, Labrus bergylta, held in a farm environment for 3 mo prior to transfer to salmon farms. The caudal fin was most affected by injury. The fin erosion index (FEI) was low in all species and below 0.6. The fin splitting index (FSI) was the most prominent index and was significantly higher in the caudal fin (FSI > 2) compared with other fins (FSI < 0.5), and also significantly higher in corkwing and rock cook compared with the other wrasse species. The FEI and FSI were also calculated for a group of ballan wrasse before stocking on a seawater farm, during the first winter and upon harvesting. There were no significant differences in the scores of fin erosion and fin splitting in any of the samples, although the indices were marginally poorer in winter.

Direct and social genetic parameters for growth and fin damage traits in Atlantic cod (Gadus morhua)

BackgroundThe aim of the study was to estimate genetic parameters for direct and social genetic effects (SGE) for growth and welfare traits in farmed Atlantic cod (Gadus morhua). A SGE refers to the effect of an individual’s genes on trait performance of its social partners. In total, 2100 individually tagged juveniles from 100 families at an average age of 222 days post-hatching were used. Each family was separated into three groups of seven fish, and were randomly assigned to 100 experimental tanks, together with fish from two other families. Body weight and length of the first, second and third dorsal fin and the caudal fin measured by digital image analysis were measured at the start of the experiment, after two weeks, and after six weeks. Fin erosion was scored subjectively after six weeks. Variance components estimated using a conventional animal model were compared to those of an animal model including a SGE.ResultsHeritabilities from the conventional animal model ranged from 0.24 to 0.34 for body weight and 0.05 to 0.80 for fin length. Heritabilities for fin erosion were highest for the first dorsal fin (0.83 ± 0.08, mean ± standard error) and lowest for the third dorsal fin (0.01 ± 0.04). No significant SGE were found for body weight, whereas SGE for fin lengths were significant after two and six weeks. Contributions to the total heritable variance were equal to 21.5% (6.1 ± 2.1) for the direct effect, 33.1% (9.4 ± 3.2) for the direct-social covariance, and 45.4% (12.9 ± 4.1) for the social variance for length of the first dorsal fin. For fin erosion, SGE were only significant for the second and third dorsal fin.ConclusionsIncluding SGE for fin length and fin erosion in the animal model increased the estimated heritable variation. However, estimates of total heritable variances were inaccurate and a larger experiment is needed to accurately quantify total heritable variance. Despite this, our results demonstrate that considering social breeding values for fin length or fin erosion when selecting fish will enable us to improve response to selection for welfare traits in Atlantic cod juveniles.

Rearing Velocity Impacts on Landlocked Fall Chinook Salmon (<i>Oncorhynchus tshawytscha</i>) Growth, Condition, and Survival

Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/s (BL/s)] for four weeks to determine possible effects of water velocity on growth, condition, and survival. Fish were sampled for weight, fork length, condition factor, hepatosomatic index (HSI), viscerosomatic index (VSI), and fin erosion after four weeks of feeding to satiation. At the end of the feeding trial, the fish were handled and transported to simulate stocking, with survival observed over the following 10 d. Following four weeks of feeding, fish reared in 0.5 and 1.5 BL/s had the same growth and food conversion ratio, but fish reared at 3.0 BL/s had a significant reduction in both metrics. Furthermore, fish reared at 1.5 BL/s had a significantly higher condition factor than fish reared in other treatments. No significant differences were found for HSI, VSI, fin erosion, or survival. The results from this study indicate that a moderate velocity (1.5 BL/s), which is necessary for circular tanks to be self-cleaning, is not detrimental to fish growth or condition, but a faster water velocity (3.0 BL/s) negatively affects fish growth and food utilization.

Effects of dietary levels of vitamin A on growth, hematology, immune response and resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

This study was conducted to evaluate the effect of supplemental levels of vitamin A (0, 2500, 5000, 10,000, and 20,000IU/kg diet) on the growth performance, hematology, immune response and resistance of Nile tilapia, Oreochromis niloticus to Streptococcus iniae challenge. Each diet was fed to Nile tilapia (initial weight, 5.26±0.10g) in quadruplicate aquaria to apparent satiation twice daily for 10 weeks. The results indicate that vitamin A is a dietary essential for Nile tilapia. After 2 weeks of feeding, fish fed the vitamin A unsupplemented diet exhibited significantly lowest weight gain, feed intake and feed efficiency ratio than those of other treatments. Dietary vitamin A levels had no effect on survival. Other gross deficiency signs observed during the 10-week trial were hemorrhages, operculum deformity, fin erosion, darker body coloration and lethargy. Significantly lower hepatosomatic index and hematological parameters (except white blood cell count) were also recorded in fish fed the vitamin A unsupplemented diet. The resistance of erythrocytes to hemolysis in hypotonic solutions was lowest in fish fed vitamin A unsupplemented diet and increased with increasing vitamin A supplementation. A supplemental level of vitamin A of 3910IU/kg diet was sufficient to prevent these deficiency signs in juvenile Nile tilapia. Serum protein, lysozyme activity and superoxide anion production were enhanced by supplementation of vitamin A, whilst serum total immunoglobulin and spontaneous complement activity were not affected by dietary treatments. Dietary supplementation of vitamin A had no effect on the resistance of Nile tilapia to S. iniae infection challenge and antibody production against the same bacterium.

Biomarker Investigations in Adult Female Perch (Perca fluviatilis) From Industrialised Areas in Northern Sweden in 2003

Since the new millennium, a notion has developed in certain parts of society that environmental pollutants and their associated effects are under control. The primary objective of this investigation, performed in 2003, was to test whether this was actually the case in an industrialised region in the County of Västernorrland in northern Sweden with well-documented environmental pollution from past and present activities. This was performed by measuring a moderate battery of simple biomarkers in adult female perch at several stations. The point sources included sewage-treatment plants, pulp and paper mills, as well as other industries. The biomarkers included growth, somatic indices, gonad maturation status, gonad pigmentation, fin erosion, skin ulcers, and ethoxyresorufin-O-deethylase (EROD) activity in the liver. The results showed that the environmental pollutants and their associated effects were not under control. In fact, the health of the perch was impaired at all of the polluted stations. Many responses were unspecific with respect to underlying cause, whereas some effects on EROD activity and gonad maturation status were attributed to historical creosote pollution and current kraft pulp mill effluents, respectively. The data presented may also be used as reference values for future investigations of health effects in perch.

High oxygen consumption rates and scale loss indicate elevated aggressive behaviour at low rearing density, while elevated brain serotonergic activity suggests chronic stress at high rearing densities in farmed rainbow trout

The effect of stocking density on indicators of welfare has been investigated by several studies on farmed rainbow trout Oncorhynchus mykiss. However, the densities at which welfare are compromised remain ambiguous. Here three different stocking density treatments were selected based on the results of a previous study, where levels of crowding where determined using the spatial distribution of fish in two-tank systems. An un-crowded low density of 25kgm−3, the highest density accepted by the fish without showing indications of crowding stress of 80kgm−3 as the intermediate density, and the highest density accepted by the fish showing indications of crowding stress of 140kgm−3 as the high density were investigated. The aim of the present study was to examine the effect of being held at these densities on indicators of welfare. This was achieved through oxygen consumption measurements using automated respirometry, recording fin erosion, determining scale loss and analysing plasma cortisol and brain serotonergic activity levels. The results obtained in the present study indicated that at the lowest density the fish had the space and opportunity to display their natural aggressive behaviour and that the fish held at the highest density were exposed to a situation of confinement.

Does the water reuse affect the fish growth, welfare quality?

The fish production in aquaculture is growing from year to year. However capacities of current aquaculture facilities are limited. So the need of intensification of old facilities and building new intensive facilities is obvious. The high intensity of fish culture generates some questions. Could water reuse affect fish growth, welfare, health or quality of final product? A lot of research was performed for this issue but just a few works compared water reuse systems (RAS) versus flow thru systems (FTS). A problem with CO2 oversaturation was solved by shallow diffusers. Fin erosion seems to be a problem of high stocking density and system hygienic but it is not related directly to water reuse. A few papers were written about biochemical blood stress markers but it was mostly aimed to acute crowding or changes were found at extreme stocking densities over 124 kg.m3 for rainbow trout and 70 kg.m3 for sea bass. The fish are able to accustom to increased noise produced by RAS equipment very fast so it don’t affect fish negatively. There wasn’t found any prove of main water reuse to fish influence in the available literature. All results indicates that if the ecological parameters are kept in natural range for the fish reared in RAS, there is no negative effect of water reuse on fish.

Fin erosion and injuries in relation to adult recapture rates in cultured smolts of Atlantic salmon and brown trout

The implications of fin erosion and other injuries that are directly or indirectly caused by the hatchery environment have long been debated. Fin condition has been regarded as an indicator of welfare in fish farms, but until now there has been little evidence that eroded fins have negative effects on survival after stocking in the wild. Based on over 40 years of tagging and recapture data, we show that Atlantic salmon (Salmo salar) with dorsal fin erosion and brown trout (Salmo trutta) with any kind of injuries had lower recapture rates than fish without injuries. In salmon, precocious mature males had a lower probability of being recaptured compared with immature fish. Data from a hatchery monitoring program indicated that the degree of fin erosion on the dorsal fin in salmon and on the caudal fin in trout was correlated with the number of other injuries. We conclude that fin erosion and other injuries may reduce the probability of survival after release. All actions in the hatcheries to reduce fin erosion and other injuries will most likely be positive for the long-term outcome of the stocking programs.

Effects of Cadmium on Embryo Hatchability, Larval Development and Survival of the Olive flounder, Paralichthys olivaceus

The cadmium (Cd) toxicological effects on the fertilized eggs, embryos and larvae were investigated in olive flounder, Paralichthys olivaceus water-borne exposed to Cd. The survival rate and hatching success of the embryos significantly diminished in treated groups in dependence of the Cd concentration. Significant differences were found at <TEX>${\geq}30{\mu}g\;L^{-1}$</TEX> exposed groups compared to the control group. A significant increase of malformation of the embryo was observed at <TEX>${\geq}20{\mu}g\;L^{-1}$</TEX> exposed groups. They usually include such symptoms as clouded yolk-sac abnormality, fin erosion and spinal curvature. A significant reduction in the survival rate of the larvae was observed in <TEX>${\geq}20{\mu}g\;L^{-1}$</TEX> exposed groups with accompanied by the disorder. Notably, in larvae, a concentration as low as <TEX>$10{\mu}g\;L^{-1}$</TEX> exposed groups caused significant elevated abnormalities that is incidences of spinal cord deformation, abnormal eyes, deformation of the head region and severe developmental delay.