Okomoda Victor Tosin | University Of Agriculture, Makurdi (original) (raw)

Papers by Okomoda Victor Tosin

Comparative study on the hematological parameters of pure and reciprocal crosses of the African a... more Comparative study on the hematological parameters of pure and reciprocal crosses of the African and Asian catfish was done to establish a reference range for fingerlings of the novel fish. Blood was collected from Clarias gariepinus (CG), Pangasianodon hypophthalmus (PH), Pangapinus (♀PH × ♂CG), and the two observed morphotypes (Clarias-like and Panga-like) of Clariothalmus (♀CG × ♂PH) obtained from similar breeding history. Result obtained revealed that red blood cell counts and white blood cell counts were significantly lower in Panga-like Clariothalmus (1.08 × 10 6 /mm 3 and 6.99 × 10 3 /mm 3 , respectively) compare to other groups with similar higher counts (between 2.09 × 10 6 /mm 3 and 2.65 × 10 6 /mm 3 ; 13.60 × 10 3 /mm 3 and 17.27 × 10 3 /mm 3 , respectively). However, Pangapinus and pure P. hypophthalmus had significantly higher values of packed cell volume (33.10 and 32.50%, respectively) and hemoglobin content (12.63 and 11.72 g/dL, respectively); similar values were recorded in those fish with Clarias maternal origin (between 25.00–27.80% and 6.67–8.03 g/dL, respectively for PCV and Hb). Calculated values for mean corpuscular volume was higher in Panga-like Clariothalmus (198.8 fL and 80.26 pg, respectively) while mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values were higher in the Pangapinus and pure P. hypophthalmus (between 48.10–56.98 pg and 38.28–35.96 g/dL, respectively). This result obtained is suggestive that the Panga-like Clariothalmus may have reduced fitness as compared to the other progenies. The baseline values established in this study could serve as a standard for physiological, pathological, and toxicological references in future studies.

Background and Objective: Erythrocyte shape determination has largely been through visual observa... more Background and Objective: Erythrocyte shape determination has largely been through visual observation only; this study describes for the very first time a standardized method for normal erythrocyte shape determination in fishes using the values of the cell axis ratio.
Materials and Methods: Blood smear was made from two important freshwater species namely Pangasianodon hypophthalmus and Clarias gariepinus. Erythrocyte measurement of the cell and nuclear axis were done under the microscope, while the cell axis ratio was calculated (as minor axis/major axis). Visual assessment was done to categorize the erythrocyte into two (rounded and oval) or three (strongly rounded, slightly oval and strongly oval) groups. This was then matched with its corresponding cell axis ratio to formulate two standardized decision rules for shape determination.
Results: Decision rule Type A; rounded erythrocyte have cell axis ratio between 1.0 and 0.75, while the oval cell is below 0.75. Decision rule Type B; strongly rounded erythrocyte have cell axis ratio between 1.0 and 0.90, slightly oval cell is between 0.89 and 0.75, and strongly oval cell below 0.75.
Conclusion: This novel approach to shape determination of normal fish erythrocyte proposed in this study have been shown to be easier, simpler and accurate than visual observation alone, hence, preventing false generalization.

This study investigated the catch per unit effort and water quality of Lake Kalgwai Jigawa state,... more This study investigated the catch per unit effort and water quality of Lake Kalgwai Jigawa state, Nigeria for the period of 10 month (July 2012-June 2013). The man hours, gears used, and fish catches of the Lake was determined by assessing the fisher-men operating on three major landing sites of the Lake, namely Marke (Site I), Dingare (Site II), and Kalgwai (Site III). Water samples from the landing sites were collected and analyzed. Concentration of fishers ranged from 41 (April) to 51 (September). The highest number of fishing hour was observed in August (64 hr), whereas the lowest was in March (49 hr). The average catch per fisher per day ranged from 107 kg/day (December) to 144 kg/day (August) during the study period. An average of 25 days was spent fishing in each month. The result also indicated similarities in the water qualities of all the three sampling sites per months. Based on the result gotten it was concluded that lake Kalgwa is not over fished and water quality are within recommended ranges for fish production.

This research investigated the effect of Pawpaw (Carica papaya) seed meal (PSM) on haematological... more This research investigated the effect of Pawpaw (Carica papaya) seed meal (PSM)
on haematological parameters and gonad histology of Oreochromis niloticus (Linnaeus, 1758). Freshly hatched fry of O.
niloticus were fed blended commercial diet (35%CP) mixed with varying levels of PSM (0, 2, 4, 6 and 8gkg-1) for 28days
in fifteen aquarium tanks (30×30×20cm3). Resultant fingerlings were maintained in outdoor concrete tanks (1×1×1m3) for
140days till they gained an average weight of 30g. Haematological analysis and gonad histology was done to determent
the effect of the PSM on the fish. Haematological changes observed in this study did not revealed detrimental effect of
feeding of PSM. However, histological evaluation of the gonads showed various degrees of deformities and tends to increase
in severity as the levels of PMS increased. It was concluded that PSM might not affect the health status of the Nile
tilapia but lead to sterility of the fish.

In this study, erythrocyte characteristic of pure and reciprocal crosses of African catfish Clari... more In this study, erythrocyte characteristic of pure and reciprocal crosses of African catfish Clarias gariepinus (Burchell, 1822) and Asian catfish Pangasianodon hypophthalmus (Sauvage, 1878) were evaluated. Blood smear was made from the progenies of C. gariepinus (CG), P. hypophthalmus (PH), Pangapinus (♀PH × ♂CG) and in two morphotypes (Clarias-like and Panga-like) of Clariothalmus (♀CG × ♂PH) obtained from similar breeding history. Erythrocyte measurement of the cell and nuclear axis was done under the microscope, while many other parameters were calculated. Result obtained suggests a preponderant maternal influence on the erythrocytes shape and size characteristics of the reciprocal crosses. Erythrocytes from progenies with C. gariepinus maternal origin was rounded in shape (not less than 90%) while those with P. hypophthalmus maternal origin had relatively high oval shaped erythrocytes (between 76 and 64%). Also, significant size variations were recorded for the different group. Principal component analysis and biplot of component loading of the trio comparison of hybrid progenies and the pure crosses suggest the possibility of discriminating the direction of hybridization of the reciprocal crosses. However, it was impossible to describe the hybridization status of the progenies assessed in this study. This approach may be a simple and viable alternative to molecular markers which characterizes maternal inheritance in hybrid crosses provided that there is significant shape difference between the fishes. Erythrocyte characterization coupled with morphological and cytogenetic studies is recommended for clearer understanding of the nature of hybrid progenies.

This study was conducted to determine the efficacy of preserved and fresh pituitary extract of Cl... more This study was conducted to determine the efficacy of preserved and fresh pituitary extract of Clarias gariepinus (Burchell, 1822) to induced spawning in the same species. Growth performance of fry was also monitored for 15 days to determine the possible effect of natural hormone treatment on the fry. Pituitary glands (PG) were obtained from 12 male broodstocks, six extracted PG were preserved in 96% ethanol 24 h before injection, while the other were extracted and used in their fresh state. The PG solutions (1 g ml −1 of saline water) were injected at 1 ml kg −1 of the female broodstock. Ovaprim R (a synthetic hormone) was used as the control and administered at a rate of 0.5 ml kg −1 of fish. After a uniform latency period of 9 h 30 min, fish were striped, fertilized, incubated and the performance evaluated. Results obtained revealed better hatching performance using Ovaprim R synthetic hormone (64.52%), however, preserved PG gave better hatchability (59.74%) than fresh PG extract (51.39%). After 15 days of feeding ad libitum with shell-free Artemia cysts, the growth of fry spawn with preserved PG was comparable with that of the control, while least performance was observed using the fresh PG. It was concluded that preservation of PG in ethanol 24 h before injection had a positive effect on breeding performance and could be exploited in the commercial production of C. gariepinus fingerlings.

The nutritional value of raw Jack bean meal (Canavalia ensiformis) as a partial substitute for so... more The nutritional value of raw Jack bean meal (Canavalia ensiformis) as a partial substitute for soybeans meal was investigated in this study. Preliminary investigation on nutrient composition revealed that lysine, histidine, and phenylalanine were significantly higher in C. ensiformis seed meal compared to soybean meal. However, crude protein and other essential amino acids were significantly lower. Feeding trial was then conducted to investigate the effect of replacing about 40% soybeans meal (at 58.8% inclusion) with C. ensiformis in the diet of Clarias gariepinus. The result obtained after 56 days revealed that fingerlings could tolerate up to 20% replacement without significant effect on growth and nutrient utilization. Beyond this, growth was significantly reduced. Survivals of the fish also follow a similar trend as stated above. It was concluded that dietary inclusion of raw C. ensiform meal should not be beyond 11% (or 20% replacement for soybeans meal included at 58.8%) in the diet of C. gariepinus.

The egg and larval development of reciprocal crosses of Pangasianodon hypophthalmus (Sauvage, 187... more The egg and larval development of reciprocal crosses of Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell, 1822) were studied under laboratory conditions. Crosses between ♀C. gariepinus × ♂P. hypophthalmus (Clariothalmus) and ♀P. hypophthalmus × ♂C. gariepinus (Pangapinus) had embryonic stages similar to those of the pure sib, however, unequal cell cleavages were notable in the early development of both crosses, hence, leading to different forms of deformities. The critical stage where highest mortality occurred during the embryogenesis was the somite (21.68%) and hatching (48.1%) stages (respectively for the Clariothalmus and Pangapinus). However, both crosses produced viable larvae (60.21 vs 13.20% hatchability respectively), which survived (30.3 vs 2.1% respectively) until the end of the study (2 weeks). The external morphological features of the larvae were completely formed by the 14th day after hatching. The body forms of the crosses at this time were either phenotypic intermediary of the parent species (92% of Clariothalmus) or indistinguishable from the female parent (all Pangapinus and 8% of the Clariothalmus). This study thus laid the groundwork for further comparative studies on hybrid performance and characterization.

This study investigates gonado somatic index, food and feeding habit of selected fish species of ... more This study investigates gonado somatic index, food and feeding habit of selected fish species of Lake Kalgwai Jigawa State, Nigeria. Samples of fish were collected every fortnight (July 2012-June 2013) at three major landing sites of the lake. The weight of each fish was recorded, gonads were removed, weighed and the gonadosomatic index (GSI) calculated. Stomach was also removed and the content analyzed using frequency of occurrence and point method. Result obtained reveals GSI to range from 2.39±0.08% in Nile perch Latesniloticus [1] to 5.92±0.29% in Nile tilapia Oreochromisniloticus [1]. The stomach content analysis in this study distinguished the fish species into two major groups; Latesniloticus, Mormyrusmacrophthalmus Günther, 1866 and Bayad bagrus bayad Forsskål [2] were observed to exhibit carnivorous feeding habits and feed predominantly on crustacean, fish, fish parts, mollusks, insects and insect larvae, Oreochromisniloticus, African bony tongue Heterotisniloticus [3], Electric catfish Malapteruruselectricus, Synodotisnigrita and North African catfish Clarias gariepinus on the other hand were observed to have an omnivorous feeding pattern with plant parts, insect parts, detritus, crustaceans, snails, worms, fish parts, insects larvae, sand/mud, and algae dominating their diet. Many of the omnivores encountered in this study have good potential as future aquaculture candidate hence the need to further study their biology and their performance under captivity.

The nutritional value of toasted pigeon pea Cajanus cajan seed in the diet of African catfish Cla... more The nutritional value of toasted pigeon pea Cajanus cajan seed in the diet of African catfish Clarias gariepinus (Burchell, 1822) was investigated in this study by progressively increasing its inclusion level (100, 200, 300 and 400 g kg −1) in isonitrogenous (35% crude protein) and isoenergetic (17.7 kJ g −1) diets. Toasting of the C. cajan seed significantly reduced the anti-nutrients and increased most essential amino acid, protein, and fibre in the seeds. The growth of C. gariepinus (1.36 ± 0.05 g) fingerlings fed in triplicate 1 × 1 × 1m 3 hapa pond system (n = 40 in triplicates) was significantly improved by the different inclusion levels of toasted C. cajan in the diets after 56 days. Comparing the performance of the fish fed 400 g kg −1 of toasted C. cajan with that fed raw seed (400 g kg −1) reveal the efficacy of this processing method in improving the utilization of the feedstuff. Mortality was significantly higher (32%) in fish fed the diet containing raw inclusion compared to that fed the control diet or inclusion of toasted C. cajan (< 5%). Cost analysis revealed that it was economically cheaper to raise the African catfish using toasted C. cajan at 400 g kg −1. It was therefore concluded that toasting improves the nutritional quality of C. cajan, resulting in better performance at higher inclusion levels, hence, can possibly reduce the cost of catfish production.

This study investigates the performance of all male and mixed sex tilapia (Oreochromis niloticus)... more This study investigates the performance of all male and mixed sex tilapia (Oreochromis niloticus) raised in outdoor
rearing conditions. All male tilapia were obtained by hormonal administration of 17 α-methyltestosterone (30 μg) into the diet of
hatchlings of O. niloticus and fed them for 28 days. Both sex-reversed male and mixed sex O. niloticus were fed with coppens®
commercial diet and replicated thrice at 45% crude protein for 24 weeks Biological evaluation such as Mean Weight Gain (MWG),
Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR) were determined. Temperature, pH, conductivity and total dissolved
solids were measured using standard methods. Data were analyzed using descriptive statistics and ANOVA at P=0.05. Result
revealed that all male tilapia had significant weight gain (p<0.05) (5.93 ± 0.13 g) compared to the mixed sexes (2.19 ± 0.09 g).
However, breeding activity was not noticed within the mixed sex tilapia population after a culture period of six months. Hence, poor
performance could not be directly linked to spawning activity. The value of temperature, pH, conductivity and total dissolved solids
were closely related and were within recommended range for the culture of tropical fishes. It was therefore hypothesized that 17
α-methyltestosterone besides achieving masculation, may have growth promoting characteristic. The detail mechanism responsible
for this better performance could be the focus of future research.

Several scientific methods have been described in the identification of triploid fish. However, m... more Several scientific methods have been described in the identification of triploid fish. However, many of these methods are not applicable for routine management purposes due to their complexity and cost. In this study, the possibility of using morphological variation as a least cost and less complex method of distinguishing triploid and diploid African catfish Clarias gariepinus (Burchell, 1822) was examined. Triploid catfish were produced by cold shock of fertilized eggs in 5°C for 20 mins (at approximately 3 mins after fertilization). The fish were incubated, hatched and raised for 3 months. Ploidy levels of the fish were then ascertained by observing the erythrocyte shape. Triploid erythrocyte was ellipsoidal in shape while diploid was round. Morphological characterization was then carried out on 100 samples each of triploid and diploid African catfish. Although significant differences were observed in many parameters, the principal morphometric difference between triploid and diploid African catfish could not be clearly distinguished. It was therefore concluded that morphological characteristics is not ideal for discriminating triploids and diploids of African catfish. The used of erythrocyte characteristics still remains the cheapest and relatively effective method for triploid and diploid determination in African catfish.

The production of fish in captivity necessitates the use of artificial means for its propagation.... more The production of fish in captivity necessitates the use of artificial means for its propagation. This process involves the collection and mixing of both male and female gametes to form a developing embryo (Ataguba, Okomoda & Onwuka, 2013). However, this is not 100% successful hence, the need to estimate the percentage of the egg fertilized during the process of artificial spawning. This is also one of the ways of measuring gamete quality of brood-stocks and their progenies (Carrillo et al., 2000). The most widely used method to estimate fertilization rate in previous studies is that described by Ella (1987). This involves monitoring a small portion of the unfertilized egg from the time of stripping until the eggs become completely opaque (dead). Then, a subsample of the fertilized egg is taken through capillary action with the aid of a glass tube (300 mm length and 2.5 mm diameter), and the total numbers of the good (live) and bad (dead) eggs are counted. The percentage of the good eggs is then estimated as the fertilization rate. This method assumes that all good eggs at this point are fertilized while the white/opaque (bad) eggs are unfertilized (Ataguba, Annune & Ogbe, 2010). However, the above method is flawed due to several reasons; it takes several hours for the referenced standard of unfertilized eggs to become opaque hence, making the estimation of fertilization a time-consuming process. Values gotten from this method are also inaccurate due to the fact that some fertilized eggs die during the process of embryogenesis and add up to the percentage of bad eggs (dead egg) which is erroneously thought to be 100% unfertilized eggs. More so, the unfertilized eggs amidst the fertilized eggs are usually hydrated with water while the reference standard of unfertilized eggs is not. Hence, the biological response of the hydrated eggs and the time taken to become opaque differ significantly compared with the standards (which is non-hydrated and unfertilized). There is, therefore, a need to develop a more suitable method which could distinguish " hydrated " and " fertilized " eggs earlier in the embryogenesis process hence, the aim of this research. The working hypothesis for this study, therefore, is to discriminate " fertilized " and " hydrated " eggs using the shape of the animal pole during different stages of embryogenic development. The stages which gave the highest possibility for easy discrimination were identified and suggested as the best stages for accurate estimation of fertilization rate.

Breeding and larval performance of novel hybrids from reciprocal crosses of Asian catfish Pangasi... more Breeding and larval performance of novel hybrids from reciprocal crosses of Asian catfish Pangasianodon hypophthalmus (Sauvage, 1878) and African catfish Clarias gariepinus (Burchell, 1822) were investigated in this study. Spawning was by hormonal injection of brood fish, artificial fertilization, and incubation in triplicate aquarium tanks (0.5 × 0.5 × 0.5 m 3) with continuous aeration. Reciprocal crosses (♀C. gariepinus × ♂P. hypophthalmus and ♀P. hypophthalmus × ♂C. gariepinus) had lower hatchability (50%) than their pure siblings (75%). Fish from all crosses survived until the juvenile stage but survival at 35 days post hatching (dph) was higher for pure C. gariepinus sib. ♀C. gariepinus × ♂P. hypophthalmus was observed to be less resistant to degradation of water quality than the other crosses, however it had higher body weight compared with the other crosses that showed similar performance. Morphological comparison of surviving juvenile at 35 dph, showed that all ♀P. hypophthalmus × ♂C. gariepinus and 13% of the ♀C. gariepinus × ♂P. hypophthalmus exhibited the very same morphology as that of their maternal parent species, while the other portion of the ♀C. gariepinus × ♂P. hypophthalmus cross exhibited morphological traits that were intermediate between those of both parent species. This study been the first successful attempt to hybridize both species and therefore, laid the groundwork for further studies on the aquaculture potentials of the novel hybrids.

This study was conducted to determine fish composition and diversity Index in Lake Kalgwai Jigawa... more This study was conducted to determine fish composition and diversity Index in Lake Kalgwai Jigawa State, Nigeria
between July 2012 and April 2013. The ichthyofauna of Lake Kalgwai was assessed using catches statistics at
three major landing sites of the Lake, namely Marke, Dingare and Kalgwai. Twenty-seven fish species belonging
to sixteen families were encountered during the study period. Fish species of Cichlidae, Bagridae, and Mormyridae
were found dominant representing 13.8%, 13.4% and 12.6% of the total catch, respectively. Citharinidae was the
least abundant (0.53%). Eight species were found numerically dominant in the catch based on the monthly
generated data. It include Lates niloticus (11.1%), Oreochromis niloticus (11.1%), Mormyrus macrophthalmus
(9.8%), Synodontis nigrita (8.4%), Bagrus bayad (8.4%), Heterotis niloticus (7.6%), Malapterurus electricus
(7.5%%), and Clarias gariepinus (7.0%). Fish diversity indices estimated included species richness (d) which
ranged from 0.94 (March) to 1.93 (October), Shannon – Wiener index (H’) between 0.22 (January) to 1.60 (July),
Equitability Index (J) ranging from 0.10 in January to 0.89 in July, Simpson’s Index (D) from 0.14 (October) to
0.23 (July) and Species Heterogeneity (1 – D) from 0.77 (September) to 0.86 (October). It was concluded that
there was high fish species richness in the Lake. Also, species equitability index of fishes across all the landing
sites reveals that the distribution of species or fish population is nearly even.

Thisstudyaimedtoinvestigatetheefficacyofsoakingasacheapprocessingmethod inimprovingthenutritional... more Thisstudyaimedtoinvestigatetheefficacyofsoakingasacheapprocessingmethod inimprovingthenutritionalutilizationofCajanus cajanforpartialreplacementofsoy-beanmealinformulateddietsoftheAfricancatfishClarias gariepinus(Burchell,1822). ThenutrientprofileofsoakedC. cajanrevealedasignificantreduction(≤50%)inall anti-nutritionalfactors.Proximateandaminoacidswerealsoaffectedbythisprocessingmethod.Sixpracticaldiets(35g/kgcrudeprotein,19.1KJ/gdiet)containingsub-stitutionlevelsof0,10,20,30,40and50%C. cajanforsoybeanprotein(includedat 578g/kg)werethenformulatedandfedtotriplicategroups(n=50ineachgroup)of C. gariepinus fingerlings (1.41±0.06g) in a hapa pond system (1×1×1m 3 ) for 56days(meantemperature25.3±0.6).Theresultsrevealedthatfishsurvivalwasnot significantlyaffecteduntila40%substitutionofsoybeanwasreached.However,be-yond20%soybeansubstitution,growthwassignificantlyreduced(≥7%;p≤.05).Fish fedthehighestsubstitutionofsoakedC. cajanmeal(50%soybeanreplacement)had thepoorestperformance.Thecostofthecompounddietswassubstantiallyreduced withtheinclusionofsoakedC. cajan.Productioncostsof1kgfishusingthedietwith aninclusionofupto20%soakedC. cajanmealreplacementwerecomparabletousing thecontroldiet.ItwasconcludedthatsoakingC. cajanseedfor24hrimprovedthe nutritionalprofileoftheingredientstoreplace20%ofthesoybean(includedat57.8%) protein in the diet of C. gariepinus with no negative effect on growth and nutrient utilization.

This study investigated the length-weight relationship as well as feeding habit of two important ... more This study investigated the length-weight relationship as well as feeding habit of two important commercial fish species from lower River Benue namely Heterotis niloticus and Labeo coubie. Fish samples were collected between November 2014 and January 2015 every fortnight for the recording of relevant data (length, weight and stomach content). The result obtained reveals significantly higher biometric parameters in H. niloticus compared to L. coubie. Many biometric parameters measured correlated significantly with the gut characteristics. The length-weight relationship revealed negative allometric growth for both species. However, sampled fishes were in good condition at the time of the study. Food item isolated in both species revealed an omnivorous feeding habit, hence these fish species may be considered as potential candidates for aquaculture.

The value of toasted Mucuna utilis seed meals was investigated in this study by evaluating the nu... more The value of toasted Mucuna utilis seed meals was investigated in this study by evaluating the nutritional profile and the utilization of the processed seeds in isonitrogenous (35% CP) and isocaloric diets (17 kJ g−1) for African catfish Clarias gariepinus (Burchell 1822). Toasting the M. utilis seed significantly reduced the levels of tannins, phytate, trypsin, and hemagglutinin in the seeds. However, protein, gross energy, arginine, histidine, and valine were increased (P ≤ 0.05). The processed seed was then used to formulate five experimental diets by progressively increasing its inclusion (by 50 g kg−1) from zero up to 200 g kg−1. A sixth diet was also formulated with raw M. utilis included at 200 g kg−1 to determine the efficacy of the processing method applied in this study. Fifty fingerlings of C. gariepinus (2.02 g ± 0.08) stocked in 18 hapas measuring 1 × 1 × 1 m 3 were then fed the diets for 56 days. The growth of C. gariepinus fingerlings was significantly improved by the addition of the toasted M. utilis seed meal. However, fish fed the diet containing 200 g kg−1 of raw M. utilis had poor growth with higher mortality (35%). Estimation of the feeding cost using the diets revealed reduction in production cost of fish with the inclusion of toasted M. utilis seed meal. It was concluded that toasting significantly improved the nutritional quality of this unconventional feedstuff, allowing better utilization at up to 200 g kg−1 inclusion level in the diet of African catfish C. gariepinus.

The effect of varying levels of groundnut oil was assessed on growth of African catfish. Fingerli... more The effect of varying levels of groundnut oil was assessed on growth of African catfish. Fingerlings with mean weight 1.87g were stocked at 20 fish per hapa (measuring 1m x 1m x 1m) and fed five 35% Crude protein diets formulated with groundnut oil (GO) included at 0.00%, 2.50%, 5.00%, 7.50% and 10.00%. After eight weeks of feeding, result shows evidence of the fact that increasing lipid level spared dietary protein conversion into energy as GO inclusion significantly performed better than the control without GO, however, performance was optimized at 2.50% GO inclusion in the diet, beyond this growth significantly reduced.