Pollution in marine, brackish and fresh water environments has become a major threat in recent times, causing a great damage to the aquatic ecosystems in a great magnitude [1]. In different parts of the world, industrial and domestic wastes will ultimately find their way into the aquatic environment. Most of the water bodies have become polluted due to indiscriminate and excessive pouring of wastes into them and making it unfavourable for aquatic organisms to thrive [2]. Globally, aquatic contaminations by industrial and domestic sewage outlets are constant sources of public health raising many issues of international concern. Conversely, the series of contamination in different water bodies may differ between inorganic toxicants such as polycyclic aromatic hydrocarbons from oil explorative activities, resin acids, and heavy metals from industries and also akylphenols deriving from domestic wastes [3]. The effluents from industries are a complex mixture of a number of chemical constituents [4] and have huge amount of oxidant potential [5]. According to Gabriel et al. [6], most of the wastes being discharge into different water bodies contain an extensive variety of anthropogenic substances such as toxic industrial chemicals and pharmaceutical residues. In recent years due to increase in human population and lack of proper waste disposal, wastes generated from domestic sources are on the increase and remain a potential source of pollution especially in developing countries around the globe [7]. In view of this Akinrotimi and Amachree [8], reported that detergents a cleaning materials utilized in most homes is one of the most common source of domestic wastes in both rural and urban areas across the globe.

Detergent can be described as a surfactant or a mixture of surfactants with “cleaning  properties in dilute solutions”. These substances are usually alkyl benzene sulfonates, a family of compounds that are similar to soap but are more soluble in hard water because the polar sulfonate (of detergents) is less likely than the polar carboxyl (of soap) to bind to Calcium and other ions found in hard water [9]. Detergents in the vein of soap, work because they are amphoteric (having the characteristics of both acid and base), partly hydrophilic (polar) and partly hydrophobic (non-polar) [10]. They are inorganic pollutants that accumulate in freshwater sediment, constituting pollutant mixtures [11]. They are also one of the most common domestic wastes that enter the aquatic ecosystem, which is a non-biodegradable chemical substance [12]. Generally detergents are xenobiotic components which are usually washed into water bodies and are made up of several compounds of which the active components are the surface-active agents or surfactants [13]. Surfactants are of various types which are used in the formulation of detergents; the LAS (Linear alkyl benzene sulphonate) are the most widely used anionic surfactant in household and cleaning products that lower the surface tension of water, enabling soils and stains to loosen and release from fabrics and surfaces. These anionic surfactants are reported to be acutely toxic to aquatic organisms [14]. 

Recently, haematological parameters have become promising biomarkers in the assessment of chemical contaminant in teleost fish. Blood samples can regularly be obtained from test organisms, thus allowing the use of non- destructive approach in   end product evaluation [15]. Characteristically, haematological parameters are non-specific in their responses towards chemical stressors. Nevertheless, they may provide important information in assessment studies, by providing an indication as to the general physiology and health status of the organism under investigation [16]. Several researcher have investigated the toxicity, uptake and tissues distribution and haematological changes of pollutants in fish [17-19], and the use of hematological techniques in fisheries research is growing rapidly, as it is very important in toxicological research which result in monitoring and predicting health conditions of the fish [20-21]. Since fish are so intimately associated with the aqueous environment, the blood will reveal measurable physiological changes in the fish more rapidly than any physiological assessment parameters [22]. Pollutants such as herbicides, pesticide and industrial effluent are known to alter the haematological indices of fish [23-25]. According to Svobodova et al. [26] study of haematological parameter is carried out on the fish to ascertain the normal range of blood parameter, find out the variation with age, sex, season, and determine the effects of disease condition on the fish. This study therefore aimed at assessing the haematological indices of black jaw Tilapia (Sarotherodon melanotheron) treated with various concentrations of detergents. 

One hundred and fifty (150) adult of S. melanotheron  (mean length 10cm + 1.99 SD and mean weight 105.11g+8.33 SD) were harvested from African regional Aquaculture Center, Buguma, Rivers State, Nigeria. They were transferred immediately in open, 50L tanks, half filled with water to the laboratory where they were acclimated to laboratory conditions for a period of seven day [27]. A locally made detergent, Quality was used for the study. 10mg were weighed using a sensitive weighing balance (Sartorius Balance, model H2013, Portugal). Stock solution of the detergents was then prepared by dissolving each 10mg in 1000ml of clean water. Appropriable graded concentrations were made by serial dilutions. The desired toxicant concentrations 0.5, 1.00, 1.50, 2.00 2.50 mg) and a control (0.00mg/l) with no toxicants prepared according to the method described by [28]. Each toxicant was replicated three times. The measured effluents were later introduced into 40L plastic tanks filled up to 30L mark.  Fish (10 per tank) were introduced into the 15 tanks (3 tanks per each concentration and control). The fish were exposed to the detergent for a period of 15 days. Water quality parameters in the experimental tanks during the study were evaluated: Water temperature was measured with mercury in glass thermometers, pH with pH meter (Model 3013, Jenway, China), and Salinity was determined with hand held refractometer (Atago products, Model H191, Japan). The values of dissolved oxygen, nitrite and ammonia were evaluated using the method described by APHA [29].

Haematological analysis procedures described by Blaxhall and Daisly [30] were used in the assessment of the various blood parameters or otherwise stated.  Red blood cell (RBC) was evaluated using haemocytometer; while the packed cell volume (PCV) was determined using micro haematocrit tubes after centrifuging for five minutes. The hemoglobin content of the blood was assessed by cyanomethaemoglobin method. The white blood cell (WBC) was done using improved Neubauer counter. The values of thrombocytes were determined using the Rees and Beeker method [31]. The differential counts (neutrophils, lymphocytes, eosinophils and monocytes) were evaluated by dropping thoroughly mixed blood film on clean microscope slides and allowed to dry. The slides were then fixed in methanol and stained with leishman stain. The counting was done based on different cell types and recorded. The values of haematological indices were calculated using the method of Rusia and Sood [32]. 

OCC = Hb x 1.34

MCV =

MCH =

MCHC =         

source: Miale [33]

Data obtained from the study were subjected to a one-way analysis of variance (ANOVA) test at 0.05% probability level, using statistical package for the social sciences (SPSS) version 17. Differences among means where existed was done using Tukey test.

The water quality parameters in the experimental tanks of S.melanotheron exposed to akyl benzene sulplonate indicated a concentration dependent change in the values of ammonia, dissolved oxygen and nitrites (Table 1). These values were distorted significantly (P < 0.05) when put side by side to the control values (Table 1). The haematological changes produced by the effects of akylbenzene in  S.melanotheron, showed a concentration dependent reduction in the values of Hb from 6.33 0.66 in the control, to 2.42 0.99 g/dl at 2.50mg/L concentration of the detergents. The values of RBC equally  reduced from 5.02 0.77 in the control, to 1.62 0.55 at 2.50mg/L concentration. In addition, similar trend was observed in PCV which reduced significantly (P<0.05) from 29.77 1.82% to 15.61 2.99% at 2.50mg/l of the detergent. Likewise significant reductions (P<0.05) comparable to the control values were similarly recorded in leucocrit, thrombocytes, and lymphocytes.  On the contrary, concentration dependent elevations were recorded in WBC, neutrophils and monocytes of the exposed fish.  (Table 2). The results of the red blood cell indices and oxygen carrying capacity were shown in Table 3. Consistent reductions relative to the concentrations of the chemical were recorded in the values of MCHC, and OCC, however, no definite trend was observed in the values of MCH and MCB across all the concentrations.

Key

MCHC – mean corpuscular Hoemoglobia concentration; MCH – mean corpuscular Haemoglobin; mean corpuscular volume, OCC – Oxygen carrying capacity.

Table 1: Physico-Chemical Parameters of Water in Experimental Tanks (Meant Sd) 

Note: Means within the row with different superscripts are significantly different (p<0.05)

Table 2: Haematological Parameters of S.Melanotheron Exposed to Different Concentrations of Akylbenzene Sulplonate (Mean Sd)

Note: Means within the row with different superscripts are significantly different (p<0.05).

Table 3: Red Blood Cell Indices of  S.melanotheron Exposed to Different Concentrations of Akylbenzene sulphonate (mean SD)

Note: Means within the same row with different superscripts are significantly different (p < 0.05). 

Haematological parameters of juveniles of S. melanotheron exposed to sub lethal concentration of detergents revealed a significant difference in all of the parameters across the concentrations. Blood is recognized as a potential index of fish response to water quality, and can be used to ascertain the effects of pollutants in the environment. This is because; haematological parameters are closely related to the response of the animal and to the environment, an indication that the environment where the fish lives exert some influence on the haematological characteristics [34]. There was a remarkable decrease in the values of haematological parameters in S.melanotheron exposed to various concentrations of detergent. This is in agreement with the reports of Akinrotimi et al. [35] that reported effect of toxicants on blood parameters in fresh water teleost fish Clarias gariepinus. The RBC count decreased considerably in the akyl benzene treated fish. This result agreed with the report of Akinrotimi [36] in Tilapia guineensis exposed to industrial effluents in the laboratory. Similarly, Nwankwo et al. [37] observed a significant reduction in the values of RBC in Tilapia guineensis treated with pesticides. This reduction in RBC count according to Vani et al. [38] may be due to inhibition of erythropoiesis, and destruction of erythrocyte in the haematopoietic organs of the fish. Conversely, the haemoglobin content of the fish decreased significantly in detergents exposed fish. This result is in line with that of Akinrotimi [39] in T.guineensis subjected to dichloride phosphate. The observed phenomenon may be as a result of rapid oxidation of haemoglobin content of the blood to methaemoglobin or release of O₂ radical brought about by the toxic stress of the toxicant [40]. The values of, PCV followed the same trend of reduction observed in the exposed T.guineensis.   PCV is an important tool for evaluating the amount of plasma and blood corpuscles in the blood.  Values of PCV in the exposed S.melanotheron in this study are an indicative anaemia and haemodilution consequent of gill damage in the exposed fish [41]. The toxic effect of the anionic detergent (surfactant) has been reported by [41], to cause reduction in blood parameters and weight loss. The reduction in the blood parameters was as a result of destruction of the cells of the fish by the surfactant and traces amount of heavy metals found in detergents.

Increase in total white blood cell (leucopomia) as observed in the fish exposed to detergents is attributed to increased production of leucocytes in the haematopoietic tissue of the kidney and perhaps the spleen. Lymphocytes are the most numerous cells comprising the leucocytes which function in the production of antibodies and chemical substances serving as defense against infection. The primary consequence of observed changes in leucocytes count in stressed fish is suppression of the immune system and increased susceptibility to disease [42]. The increase in WBC observed in this study can be related to a correspond increase in antibody production, which assists the fish to survive and recover from the effect of the toxicants, by producing more white blood cells to suppress the stress induced through exposure of the fish to detergents. Moreover, the reduction recorded in the leucocrit, which represents the leucocytes and thrombocytes   packed value expressed as a percentage of the blood, is an indication internally disturbed stressful condition of the fish [16]. Elevated levels of some differential counts namely neutrophils and monocytes were observed in the exposed fish. This indicated a state of pathological stress induced by contaminants, as Gabriel et al. [43] noted that exposure of fish to some toxicants may results in the increase of some differential counts which leads to stressful condition and ultimately results in their dysfunction in the blood stream.  In this study, the values of MCV, MCH and MCHC decreased in S. melanotheron treated with detergents with concomitant decline in oxygen carrying capacity of the fish. 

Exposure of S.melanotheron to sublethal levels of detergents in the laboratory altered some mechanisms of its haematological parameters which may lead to abnormal metabolism and ultimately results in the death of the fish. There is therefore the need to inform the public on proper disposal of domestic wastes containing detergent to the aquatic environment so as to minimize their effects on the aquatic ecosystem.

1. Chindah A.C. and Hart A.I. "Occurrence and distribution of epi fauna and in-fauna community in shallow mangrove wet land in the tropical West African region." Afri. J. Env. Stud., vol. 1-2, 2000, pp. 76–83.

2. Chindah A.C. "Toxicity of cypermethrin to Tilapia guineensis juveniles." Journal of Agric. Biotech Env., vol. 2, no. 2, 2004, pp. 60–66.

3. Chindah A.C. et al. "Response of Sarotherodon melanotheron in the Niger Delta wetland, Nigeria to changes in pH." Revista UDO Agricola, vol. 8, no. 1, 2008, pp. 143–153.

4. Nestmann E.R. et al. "Mutagenicity of constituents identified in pulp and paper mill effluents using salmonella." Mutat. Res., vol. 79, 1980, pp. 203–212.

5. Ellis R.J. et al. "In vivo and in vitro assessment of the androgenic potential of a pulp and paper mill effluent." Environ. Toxicol. Chem., vol. 22, 2003, pp. 1448–1456.

6. Gabriel U.U. et al. "Pollutant induced altered behaviours in fish: a review of selected literature." Journal of Technology and Education in Nigeria, vol. 16, no. 1, 2011, pp. 9–23.

7. Nwosu P.O. et al. "Toxic effect of dichlorvos pesticide on some antioxidants profiles in different life stages of Tilapia guineensis (Bleeker 1862)." In Lelei K.E. (ed.), 34rd Annual Conference of the Fisheries Society of Nigeria, 2019, pp. 420–423.

8. Akinrotimi O.A. and Amachree D. "Changes in haematological parameters of Tilapia guineensis exposed to different concentrations of detergent under laboratory conditions." Journal of Aquatic Sciences, vol. 31, no. 1, 2016, pp. 95–103.

9. Spirita S.V. et al. "Studies on the toxicity of akylbenzene sulphonate to zebra fish Danio rerio." Journal of Entomology and Zoology Studies, vol. 3, no. 1, 2015, pp. 204–207.

10. Roy D. "Toxicity of an endemic detergent dodecyl benzene sodium sulfonate to a freshwater fish Rita rita: determination of LC50 values by different methods." Ecotoxicol. Environ. Saf., vol. 15, 1988, pp. 186–194.

11. Omer S.A. et al. "Cadmium bioaccumulation and toxicity in tilapia fish (Oreochromis niloticus)." Journal of Animal and Veterinary Advances, vol. 11, no. 10, 2012, pp. 1601–1606.

12. Ogundiran M.A. et al. "Toxicological impact of detergent effluent on juveniles of African catfish (Clarias gariepinus)." Agriculture and Biology Journal of North America, vol. 1, no. 3, 2010, pp. 330–342.

13. Nte M.D. et al. "Effect of industrial effluents on haematological parameters of black jaw tilapia Sarotherodon melanotheron." Continental Journal of Environmental Science, vol. 5, no. 2, 2011, pp. 29–37.

14. Kumar M. et al. "Toxicity of detergent effluent to fish Pontius sophore." Journal of Tissue Research, vol. 1, no. 1–2, 2005, pp. 41–48.

15. Akinrotimi O.A. et al. "Effects of direct transfer to fresh water on the haematological parameters of Tilapia guineensis (Bleeker 1862)." Animal Research International, vol. 7, no. 2, 2010, pp. 1199–1205.

16. Adhikari S. et al. "Effects of cypermethrin and carbofuran on certain haematological parameters and prediction of their recovery in a fresh water teleost, Labeo rohita (Hamilton)." Ecotoxicol. Environ. Saf., vol. 58, 2004, pp. 220–226.

17. Akinrotimi O.A. et al. "Effects of acclimation on haematological parameters of Tilapia guineensis." Science World Journal, vol. 5, no. 4, 2010, pp. 1–4.

18. Akinrotimi O.A. et al. "Haematological responses of Tilapia guineensis to acute stress." International Journal of Natural and Applied Sciences, vol. 5, no. 3, 2009, pp. 338–343.

19. Akinrotimi O.A. et al. "Influence of sex, acclimation methods and period on haematology of Sarotherodon melanotheron (Cichilidae)." Research Journal of Biological Sciences, vol. 2, no. 3, 2007, pp. 348–352.

20. Akani N.P. and Gabriel U.U. "Haematological responses of the African catfish (Clarias gariepinus) exposed to sublethal concentrations of oil field waste water in Nigeria." Journal of Aquatic Sciences, vol. 30, no. 1B, 2015, pp. 207–210.

21. Akinrotimi O.A. et al. "Haematological characteristics of Tilapia guineensis from Buguma Creek, Niger Delta, Nigeria." Electronic Journal of Environmental Agricultural and Food Chemistry, vol. 9, no. 8, 2010, pp. 1415–1422.

22. Ezeri G.N.O. et al. "Haematological response of cultured and wild Clarias gariepinus to acclimation." Env. and Ecol., vol. 22, no. 3, 2004, pp. 628–632.

23. Houston A.H. "Components of the haematological response of fish to environmental changes: a review." In Ali M.A. (ed.), Environmental Physiology of Fishes, Nato Advances Study Inst. Series A Life Science, vol. 35, 1980, pp. 241–298.

24. Gabriel U.U. et al. "Haematological profile of black chinned tilapia Sarotherodon melanotheron from Buguma Creek, Niger Delta." Agric. J., vol. 2, no. 3, 2007, pp. 384–387.

25. Mankittrick K.R. and Leatherland J.F. "Haematocrit values in feral gold fish, Carassius auratus (L.) as indicators of the health of the population." J. Fish Biol., vol. 23, 1983, pp. 1553–1561.

26. Svobodova Z. et al. "The effect of selected negative factors on haematological parameters of common carp Cyprinus carpio." Review Zoology, vol. 31, 1996, pp. 112–116.

27. Akinrotimi O.A. et al. "Haematotoxicity of cypermethrin to African catfish, Clarias gariepinus under laboratory conditions." Journal of Environmental Engineering and Technology, vol. 1, no. 2, 2012, pp. 20–25.

28. Yaji A.J. and Auta J. "Sublethal effects of monocrotophos on some haematological indices of African catfish Clarias gariepinus." Int. Fish J., vol. 2, no. 1, 2007, pp. 115–117.

29. APHA. Standard methods for the examination of water and waste water. American Public Health Association, 1998, 874pp.

30. Blaxhall P.C. and Daisley K.W. "Routine haematological methods for use with fish blood." Journal of Fish Biology, vol. 5, 1973, pp. 771–781.

31. Seiverd C.E. Haematology for medical technologists. Lea and Febiger, Philadelphia, 1964, 946pp.

32. Rusia V. and Sood S.K. "Routine haematological test." In Mukerjee K.L. (ed.), Medical Laboratory Technology, Tata McGraw Hill Publishing Co. Ltd., 1992.

33. Miale J.B. Laboratory medicine haematology. 6th ed., The C.V. Mosby Publishing, London, 1982.

34. Wilson R.W. and Taylor E.W. "The physiological responses of freshwater rainbow trout, Onchorynches mykiss during acute exposure." Journal of Comparative Physiology, vol. 16, no. 3B, 1993, pp. 38–47.

35. Akinrotimi O.A. et al. "Haematological responses of Tilapia guineensis treated with industrial effluents." Applied Ecology and Environmental Sciences, vol. 1, no. 1, 2013, pp. 10–13.

36. Akinrotimi O.A. et al. "Changes in lymphocytes in three sizes of African catfish (Clarias gariepinus) exposed to different chemicals in the laboratory." International Journal for Research Under Literal Access, vol. 1, no. 4, 2018, pp. 1–6.

37. Nwankwo A.K. et al. "Enzymatic response activities in Tilapia guineensis exposed to dimethoate in the laboratory." In Lelei K.E. (ed.), 34rd Annual Conference of the Fisheries Society of Nigeria, 2019, pp. 305–307.

38. Vani T. et al. "Deltamethrin induced alterations of haematological and biochemical parameters in fingerlings of Catla catla (Ham) and their amelioration by dietary supplement of vitamin C." Pestic. Biochem. Physiol., vol. 101, 2011, pp. 16–20.

39. Akinrotimi O.A. et al. "Effects of 2,2-dichlorovinyl dimethyl phosphate (DDVP) on leukocyte profiles in juveniles and adult sizes of Tilapia guineensis." MOJ Immunology, vol. 6, no. 5, 2018, pp. 173–176.

40. Vutukuru S.S. "Acute effects of hexavalent chromium on survival, oxygen consumption, haematological parameters and some biochemical profiles of the Indian major carp, Labeo rohita." Int. J. Environ. Res. Public Health, vol. 2, no. 3, 2005, pp. 456–462.

41. Larsson A. et al. "Fish physiology and metal pollution: results and experiences from laboratory and field studies." Ecotoxicol. Environ. Saf., vol. 9, 1985, pp. 250–281.

42. Iteze P.N. et al. "Effects of paraquat dichloride on some metabolites in Tilapia guineensis." In Lelei K.E. (ed.), 34rd Annual Conference of the Fisheries Society of Nigeria, 2019, pp. 416–419.

43. Gabriel U.U. et al. "Haematological responses of wild Nile tilapia Oreochromis niloticus after acclimation to captivity." Jordan Journal of Biological Sciences, vol. 4, no. 4, 2011, pp. 223–230.