Zooplankton play an important role in the faunal biodiversity of aquatic ecosystems as they assist in transferring algal energy to higher trophic levels through grazing and also eliminate harmful algae from water. The zooplankton and environmental characteristics of Yardantsi Reservoir were studied in order to provide essential information on this important ecosystem that serves as domestic and irrigation water supply, and fishing ground. Samples for water quality and zooplankton analyses were collected from the reservoir from May, 2015 to April, 2017 using standard methods. Three groups of zooplankton (Copepoda, Cladocera and Rotifera) comprising of thirteen genera were encountered. Rotifera (36.69%) and Cladocera (34.44%) were numerically dominant during the rainy and dry seasons, respectively. The highest zooplankton abundance (5646), species richness (11), Shannon-Weiner index (2.25) and Margalef's index (1.16) were observed during the rainy season. Axes 1 and 2 of the principal component analysis (PCA) explained 74.82% and 11.89% of the zooplankton-environmental variable relationship. Diaphanosoma sp, Eubranchipus sp, Kellicottia sp and Macrothrix sp were mostly influenced by NO3, BOD, depth, pH and dissolved oxygen while Cyclops sp and Daphnia were mostly influenced by changes in alkalinity, hardness and chloride. Brachionus patulus, the dominant species in the reservoir was mostly influenced by PO4-P. The study shows that the reservoir is slightly polluted and it is essential to adopt effective management strategies such as reduced agricultural run-offs and riparian animal grazing to prevent further deterioration of water quality.
{"title":"The zooplankton and environmental characteristics of Yardantsi Reservoir, Gusau, Nigeria","authors":"A. M. Jabbi, B. Isah","doi":"10.4314/tzool.v21i1.1","DOIUrl":"https://doi.org/10.4314/tzool.v21i1.1","url":null,"abstract":"Zooplankton play an important role in the faunal biodiversity of aquatic ecosystems as they assist in transferring algal energy to higher trophic levels through grazing and also eliminate harmful algae from water. The zooplankton and environmental characteristics of Yardantsi Reservoir were studied in order to provide essential information on this important ecosystem that serves as domestic and irrigation water supply, and fishing ground. Samples for water quality and zooplankton analyses were collected from the reservoir from May, 2015 to April, 2017 using standard methods. Three groups of zooplankton (Copepoda, Cladocera and Rotifera) comprising of thirteen genera were encountered. Rotifera (36.69%) and Cladocera (34.44%) were numerically dominant during the rainy and dry seasons, respectively. The highest zooplankton abundance (5646), species richness (11), Shannon-Weiner index (2.25) and Margalef's index (1.16) were observed during the rainy season. Axes 1 and 2 of the principal component analysis (PCA) explained 74.82% and 11.89% of the zooplankton-environmental variable relationship. Diaphanosoma sp, Eubranchipus sp, Kellicottia sp and Macrothrix sp were mostly influenced by NO3, BOD, depth, pH and dissolved oxygen while Cyclops sp and Daphnia were mostly influenced by changes in alkalinity, hardness and chloride. Brachionus patulus, the dominant species in the reservoir was mostly influenced by PO4-P. The study shows that the reservoir is slightly polluted and it is essential to adopt effective management strategies such as reduced agricultural run-offs and riparian animal grazing to prevent further deterioration of water quality.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125256115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The COVID-19 pandemic resulted in unprecedented awareness and use of hand sanitizer among the populace than seen before. This study used dermal sub-acute toxicity to assess the effect of triclosan-containing hand sanitizer on Rattus norvegicus skin. The research was conducted due to the toxicological and biochemical claims on the effect of triclosan. The study was a 14-day sub-acute dermal toxicity test following the Organization for Economic Cooperation and Development (OECD) guideline on animal testing with preferred test strategy by rubbing to emulate normal hand sanitizer use. The result revealed that triclosan-containing hand sanitizer induced no observable effect on the skin of rats, there was no induced liver dysfunctions, Oestrogen (E2) and Luteinizing hormone levels were normal as in the control. Based on the parameters studied, the hand sanitizers tested is considered safe on skin for consumer use in hand hygiene. It is recommended that more toxicological researches should be carried out on chronic exposures to hand sanitizers, to ensure safety of the populace in compliance with the Sustainable Development Goals
{"title":"Sub-acute toxicity of hand sanitizer dermal exposure on albino rat (Rattus norvegicus)","authors":"P. N. Inno-Anaemeje, C. Dike, B. B. Babatunde","doi":"10.4314/tzool.v20i1.12","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.12","url":null,"abstract":"The COVID-19 pandemic resulted in unprecedented awareness and use of hand sanitizer among the populace than seen before. This study used dermal sub-acute toxicity to assess the effect of triclosan-containing hand sanitizer on Rattus norvegicus skin. The research was conducted due to the toxicological and biochemical claims on the effect of triclosan. The study was a 14-day sub-acute dermal toxicity test following the Organization for Economic Cooperation and Development (OECD) guideline on animal testing with preferred test strategy by rubbing to emulate normal hand sanitizer use. The result revealed that triclosan-containing hand sanitizer induced no observable effect on the skin of rats, there was no induced liver dysfunctions, Oestrogen (E2) and Luteinizing hormone levels were normal as in the control. Based on the parameters studied, the hand sanitizers tested is considered safe on skin for consumer use in hand hygiene. It is recommended that more toxicological researches should be carried out on chronic exposures to hand sanitizers, to ensure safety of the populace in compliance with the Sustainable Development Goals","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124120812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The need to boost food productivity to meet the demands of the ever-increasing human population necessitates the frequent use of agrochemicals. Primextra Gold containing atrazine (329g/l) and S-metolachlor (400g/l) is commonly used in agriculture to control weeds, especially in rice paddies. Given that herbicides could harm non-target species like fish, this study examined the effects of Primextra Gold on the behaviour, haematology, blood biochemistry and kidney of Clarias gariepinus. Juvenile C. gariepinus mean weight (11.05±5.43g) and length (11.95±6.13cm) were exposed to lethal and sublethal concentrations of the herbicide. The toxicity assay showed that the median lethal concentration (LC50) was 3.63µg/l. The fish exposed to sublethal concentrations exhibited signs of asphyxiation. The white blood cell (9.4- 10.8×106), aspartate aminotransferase (40.01-60.01IU/l) and alanine aminotransferase (68.02-90.12IU/l) levels increased significantly (p<0.05) in the test group compared to the control. Contrarily, glucose (53.14-82.25mg/dl) and protein (3.12- 9.38mg/dl) were lower in the herbicide exposed group compared to the control (p <0.05). Kidney histopathology revealed focal loss of the renal tissue, mild intra renal haemorrhage, moderate focal loss of renal tissue and severe focal loss of renal tissue in the herbicide exposed fish. The findings of this study suggest that this herbicide is hazardous to aquatic life and has negative consequences for non-target species when used indiscriminately. It is recommended that the herbicide should be used with caution, especially near aquatic habitat to maintain good water quality and ensure sustenance of aquatic biodiversity.
{"title":"Acute toxicity of Primextra Gold on freshwater fish, Clarias gariepinus (Burchell 1822)","authors":"F. A. Elebe","doi":"10.4314/tzool.v20i1.13","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.13","url":null,"abstract":"The need to boost food productivity to meet the demands of the ever-increasing human population necessitates the frequent use of agrochemicals. Primextra Gold containing atrazine (329g/l) and S-metolachlor (400g/l) is commonly used in agriculture to control weeds, especially in rice paddies. Given that herbicides could harm non-target species like fish, this study examined the effects of Primextra Gold on the behaviour, haematology, blood biochemistry and kidney of Clarias gariepinus. Juvenile C. gariepinus mean weight (11.05±5.43g) and length (11.95±6.13cm) were exposed to lethal and sublethal concentrations of the herbicide. The toxicity assay showed that the median lethal concentration (LC50) was 3.63µg/l. The fish exposed to sublethal concentrations exhibited signs of asphyxiation. The white blood cell (9.4- 10.8×106), aspartate aminotransferase (40.01-60.01IU/l) and alanine aminotransferase (68.02-90.12IU/l) levels increased significantly (p<0.05) in the test group compared to the control. Contrarily, glucose (53.14-82.25mg/dl) and protein (3.12- 9.38mg/dl) were lower in the herbicide exposed group compared to the control (p <0.05). Kidney histopathology revealed focal loss of the renal tissue, mild intra renal haemorrhage, moderate focal loss of renal tissue and severe focal loss of renal tissue in the herbicide exposed fish. The findings of this study suggest that this herbicide is hazardous to aquatic life and has negative consequences for non-target species when used indiscriminately. It is recommended that the herbicide should be used with caution, especially near aquatic habitat to maintain good water quality and ensure sustenance of aquatic biodiversity.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128015737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of myths and taboos in species conservation represent a sustainable in situ means to wildlife protection. This study examined the role of taboos (traditional laws) in wildlife conservation within Bayelsa-East Senatorial District. Data were collected using a combination of semi-structured open-ended questionnaire guide and field observations, as well as species-evidence left behind. Informants for the study were selected from fifteen communities across the Local Government Areas (LGAs) that constitute the district. Local abundance status of the species implicated in the myths and taboos was determined within the various ecological settings, and likert scale was used to evaluate the informants’ perceptions on the taboos in relation to their effectiveness at protecting the identified species. The punishments for non-compliance with the taboos, as well as hypothetical inferences for the species conservation were documented. Ten (10) animal species in nine families were implicated in Bayelsa-East myths and taboos. The taboo animals were in 5 classes within Kingdom Animalia; members of the Class Reptilia (Crocodylus niloticus, Python regius, Python sebae and Varanus niloticus) were the most implicated; followed by Aves (Haliaetus vocifer, Macropygia doreya, Strix nebulosa). Abundance scale revealed that periwinkle (Gastropoda) was very abundant in Nembe and Brass. The informants’ perception on the effectiveness of the taboos (e.g. forbidding of hunting or killing Ekekoru, Python regius) in relation to the species protection revealed that the taboos were strongly effective in protecting the species in Nembe. The taboos in the study area were species specific, hence animals forbidden in Nembe and Brass LGA were not exclusively forbidden in Ogbia communities, and vice versa. The informants confirmed their beliefs and awe in the taboos and forbade abusive use, thus substantiating the taboos’ potential as sustainable tool for wildlife conservation.
{"title":"The use of myths and taboos in wildlife conservation: The case of Bayelsa-East Senatorial District of Nigeria","authors":"S. O. Ihinmikaiye, E. Ochekwu, V. Ojo","doi":"10.4314/tzool.v20i1.18","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.18","url":null,"abstract":"The use of myths and taboos in species conservation represent a sustainable in situ means to wildlife protection. This study examined the role of taboos (traditional laws) in wildlife conservation within Bayelsa-East Senatorial District. Data were collected using a combination of semi-structured open-ended questionnaire guide and field observations, as well as species-evidence left behind. Informants for the study were selected from fifteen communities across the Local Government Areas (LGAs) that constitute the district. Local abundance status of the species implicated in the myths and taboos was determined within the various ecological settings, and likert scale was used to evaluate the informants’ perceptions on the taboos in relation to their effectiveness at protecting the identified species. The punishments for non-compliance with the taboos, as well as hypothetical inferences for the species conservation were documented. Ten (10) animal species in nine families were implicated in Bayelsa-East myths and taboos. The taboo animals were in 5 classes within Kingdom Animalia; members of the Class Reptilia (Crocodylus niloticus, Python regius, Python sebae and Varanus niloticus) were the most implicated; followed by Aves (Haliaetus vocifer, Macropygia doreya, Strix nebulosa). Abundance scale revealed that periwinkle (Gastropoda) was very abundant in Nembe and Brass. The informants’ perception on the effectiveness of the taboos (e.g. forbidding of hunting or killing Ekekoru, Python regius) in relation to the species protection revealed that the taboos were strongly effective in protecting the species in Nembe. The taboos in the study area were species specific, hence animals forbidden in Nembe and Brass LGA were not exclusively forbidden in Ogbia communities, and vice versa. The informants confirmed their beliefs and awe in the taboos and forbade abusive use, thus substantiating the taboos’ potential as sustainable tool for wildlife conservation.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"290 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132617364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent decrease in global malaria burden was achieved through vector control interventions with pyrethroid insecticides. This study was carried out to determine the influence of lambdacyhalothrin on the physiology and activities of some detoxifying enzymes and to establish the systemic effects on Anopheles gambiae. The life cycle stages of the vector were exposed to six different concentrations of lambdacyhalothrin, in an insectary. After the toxicity tests, 325 each, of the dead eggs, larvae and pupae, and 175 of the dead adults from the toxicity test, were carefully selected and further used for enzyme study. Fifty (50) individuals were used for experimental study and 25 as control, for each of egg, larvae and pupae; 25 were used for experimental study and 25 as control for the adult. Each sample was homogenized in 10ml 0.1M phosphate buffer of pH 7.4, filtered and the filtrate used for enzymes study. Determination of the enzymes: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) was done using standard biochemical methods. The results showed that 97% mortality of the life cycle stages was achieved following exposure to six concentrations of lambdacyhalothrin. Some concentrations (1 and 05µg/l) induced stimulatory effect on the enzyme activities while others (15 and 25µg/l) elicited inhibitory effect and some (10µg/l and 20µg/l) had no significant effect (p>0.05) on the enzyme activities. Alkaline phosphatase (ALP) was the most active in all the life cycle stages. Nevertheless, in older stages (pupae and adults), AST and ALT activities were significantly (p<0.05) elevated. This suggests that lambdacyhalothrin is promising in providing effective mosquito control. The results also suggest that the enzymes play a part in detoxification of lambdacyhalothrin and hence could be correlated with the pyrethroid tolerance status of A. gambiae.
{"title":"Biochemical effects of lambdacyhalothrin on activities of some detoxifying enzymes of Anopheles gambiae life cycle stages","authors":"F. Okoh","doi":"10.4314/tzool.v20i1.15","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.15","url":null,"abstract":"Recent decrease in global malaria burden was achieved through vector control interventions with pyrethroid insecticides. This study was carried out to determine the influence of lambdacyhalothrin on the physiology and activities of some detoxifying enzymes and to establish the systemic effects on Anopheles gambiae. The life cycle stages of the vector were exposed to six different concentrations of lambdacyhalothrin, in an insectary. After the toxicity tests, 325 each, of the dead eggs, larvae and pupae, and 175 of the dead adults from the toxicity test, were carefully selected and further used for enzyme study. Fifty (50) individuals were used for experimental study and 25 as control, for each of egg, larvae and pupae; 25 were used for experimental study and 25 as control for the adult. Each sample was homogenized in 10ml 0.1M phosphate buffer of pH 7.4, filtered and the filtrate used for enzymes study. Determination of the enzymes: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) was done using standard biochemical methods. The results showed that 97% mortality of the life cycle stages was achieved following exposure to six concentrations of lambdacyhalothrin. Some concentrations (1 and 05µg/l) induced stimulatory effect on the enzyme activities while others (15 and 25µg/l) elicited inhibitory effect and some (10µg/l and 20µg/l) had no significant effect (p>0.05) on the enzyme activities. Alkaline phosphatase (ALP) was the most active in all the life cycle stages. Nevertheless, in older stages (pupae and adults), AST and ALT activities were significantly (p<0.05) elevated. This suggests that lambdacyhalothrin is promising in providing effective mosquito control. The results also suggest that the enzymes play a part in detoxification of lambdacyhalothrin and hence could be correlated with the pyrethroid tolerance status of A. gambiae.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127448219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Streams are often recipients of pollution from agricultural, domestic and industrial sources though they are important sources of water supply and habitats of several aquatic species. Regular monitoring is required to protect this fragile but important ecosystem. Therefore, some physico-chemical parameters and macroinvertebrate assemblages of Temidire Stream, a perennial stream that flows through the Nigeria National Petroleum Corporation (NNPC) depot and Temidire community in Apata, Ibadan metropolis were investigated in order to determine the pollution status of the water and sediment and its impact on the biological community. Water and sediment samples were collected from five stations in the stream and from an adjacent stream monthly between August, 2019 and January, 2020 for physico-chemical parameter and benthic macroinvertebrate analyses. Dissolved oxygen, conductivity and total dissolved solids (TDS), and pH were determined in situ using EXTECH EC400 and C933 pH meters, respectively. Heavy metals were determined by atomic absorption spectrophotometry. Benthic macroinvertebrates were collected by kick sampling method. The results showed that TDS and conductivity of station 1 differed significantly from the other stations (p< 0.05). The concentrations of Pb, Ni and Cd exceeded the recommended levels for surface water and Pb and Cd in water and sediment correlated mostly with PC 1. The average Igeo class for the heavy metals in all the stations was >2 indicating uncontaminated to moderately/heavily contaminated sediment. Ninety-six (96) individuals of macroinvertebrates from seven families and six orders were encountered and aquatic insects were dominant (75%). Taxa richness (0-0.82) and diversity (0-0.59) were lower in all the stations compared to the control site. Exceedance of WHO limits by some heavy metals and paucity of macroinvertebrates, especially pollution-sensitive species in the stream suggests that it is polluted. Regular monitoring of the stream is advocated to minimize pollution.
{"title":"Environmental variables and benthic macroinvertebrates of Temidire Stream associated with an oil depot, Ibadan, southwest Nigeria","authors":"A. Ayoade, D. S. Adoh","doi":"10.4314/tzool.v20i1.8","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.8","url":null,"abstract":"Streams are often recipients of pollution from agricultural, domestic and industrial sources though they are important sources of water supply and habitats of several aquatic species. Regular monitoring is required to protect this fragile but important ecosystem. Therefore, some physico-chemical parameters and macroinvertebrate assemblages of Temidire Stream, a perennial stream that flows through the Nigeria National Petroleum Corporation (NNPC) depot and Temidire community in Apata, Ibadan metropolis were investigated in order to determine the pollution status of the water and sediment and its impact on the biological community. Water and sediment samples were collected from five stations in the stream and from an adjacent stream monthly between August, 2019 and January, 2020 for physico-chemical parameter and benthic macroinvertebrate analyses. Dissolved oxygen, conductivity and total dissolved solids (TDS), and pH were determined in situ using EXTECH EC400 and C933 pH meters, respectively. Heavy metals were determined by atomic absorption spectrophotometry. Benthic macroinvertebrates were collected by kick sampling method. The results showed that TDS and conductivity of station 1 differed significantly from the other stations (p< 0.05). The concentrations of Pb, Ni and Cd exceeded the recommended levels for surface water and Pb and Cd in water and sediment correlated mostly with PC 1. The average Igeo class for the heavy metals in all the stations was >2 indicating uncontaminated to moderately/heavily contaminated sediment. Ninety-six (96) individuals of macroinvertebrates from seven families and six orders were encountered and aquatic insects were dominant (75%). Taxa richness (0-0.82) and diversity (0-0.59) were lower in all the stations compared to the control site. Exceedance of WHO limits by some heavy metals and paucity of macroinvertebrates, especially pollution-sensitive species in the stream suggests that it is polluted. Regular monitoring of the stream is advocated to minimize pollution.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114157873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iyieke Lake is one of the floodplain lakes within the middle reaches of the Cross River, it is a major foraging and breeding site of several fish species. It is not directly connected to any river, so the water level depends on seasonal inundation by the Cross River. With gradual changes in precipitation and consequent alteration in flooding pattern, and increased agricultural activities around the lake, there are indications of steady annual decline in water level and quality, and lake area. In order to understand the effect of these changes on the aquatic biota, the morphology and some limnological parameters of the lake were studied during low water period (March-May) in 2005, 2011 and 2019 at interval of 6.5 years. Water samples were collected from the lake and the limno-morphological parameters measured at the littoral and limnetic zones of the lake following standard procedures. The results showed that monthly rainfall was significantly (p<0.05) lower in 2019 compared to 2005 and 2011, while minimum and maximum temperature trended conversely (p<0.05). The mean total dissolved solids (TDS) increased from 13.00mg/l in 2005 to 39.33mg/l in 2019 and conductivity trended the same. Mean nitrate (0.92mg/l) and phosphate (1.78mg/l) were higher in 2019 compared to 2005 and 2011. Contrarily, transparency decreased from 0.45m in 2005 to 0.19m in 2019. Similarly, mean dissolved oxygen (3.80mg/l), maximum length (443.20m) and width (314.50m) declined significantly toward 2019 (p<0.05). Lake length, transparency, conductivity and TDS that were seemingly good predictors of water deterioration could be useful in modelling, which is vital in conserving the biodiversity of the Cross River floodplain ecosystem.
{"title":"Temporal changes in limno-morphometric characteristics in a floodplain lake within Cross River ecosystem during low water period","authors":"G. Nwonumara, O. I. Okogwu","doi":"10.4314/tzool.v20i1.11","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.11","url":null,"abstract":"Iyieke Lake is one of the floodplain lakes within the middle reaches of the Cross River, it is a major foraging and breeding site of several fish species. It is not directly connected to any river, so the water level depends on seasonal inundation by the Cross River. With gradual changes in precipitation and consequent alteration in flooding pattern, and increased agricultural activities around the lake, there are indications of steady annual decline in water level and quality, and lake area. In order to understand the effect of these changes on the aquatic biota, the morphology and some limnological parameters of the lake were studied during low water period (March-May) in 2005, 2011 and 2019 at interval of 6.5 years. Water samples were collected from the lake and the limno-morphological parameters measured at the littoral and limnetic zones of the lake following standard procedures. The results showed that monthly rainfall was significantly (p<0.05) lower in 2019 compared to 2005 and 2011, while minimum and maximum temperature trended conversely (p<0.05). The mean total dissolved solids (TDS) increased from 13.00mg/l in 2005 to 39.33mg/l in 2019 and conductivity trended the same. Mean nitrate (0.92mg/l) and phosphate (1.78mg/l) were higher in 2019 compared to 2005 and 2011. Contrarily, transparency decreased from 0.45m in 2005 to 0.19m in 2019. Similarly, mean dissolved oxygen (3.80mg/l), maximum length (443.20m) and width (314.50m) declined significantly toward 2019 (p<0.05). Lake length, transparency, conductivity and TDS that were seemingly good predictors of water deterioration could be useful in modelling, which is vital in conserving the biodiversity of the Cross River floodplain ecosystem.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"117 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129150697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. E. Akeredolu, S. Ekele, F. Olaleru, R. Egonmwan
Pesticides from agricultural run-off pose a severe threat to non-target organisms, such as fishes. This study was carried out to evaluate acute toxicity and histological and genotoxic effects (erythrocytic nuclear abnormalities) of lethal and sub-lethal concentrations of three commonly used pesticides: Atrazine, Butachlor and Glyphosate on the African mud catfish (Clarias gariepinus). Fishes were exposed to the pesticides for 96h periods to determine their LC50 and the sub-lethal effect at various concentrations (1/10th, 1/100th , 1/1000th 96h LC50) over 28 days. The 96h LC50 values were 7.63mg/l, 0.7mg/l and 15.97mg/l for atrazine, butachlor and glyphosate, respectively. Histological sections of the liver of C. gariepinus exposed to the three pesticides showed mild vascular congestion but no necrosis in the tissue. There was a significant (p<0.5) dose-dependent increase in micronuclei and nuclear abnormalities in the erythrocytes of exposed C. gariepinus compared to the control by 28 days. The study confirmed that C. gariepinus are at risk of adverse effects from exposure to pesticides. Discharge of agricultural run-off around water bodies should be prevented or prohibited to avoid adverse effects on aquatic life.
{"title":"Acute and sub-lethal toxicity in African mud catfish (Clarias gariepinus, Burchell, 1822) exposed to some pesticides","authors":"O. E. Akeredolu, S. Ekele, F. Olaleru, R. Egonmwan","doi":"10.4314/tzool.v20i1.7","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.7","url":null,"abstract":"Pesticides from agricultural run-off pose a severe threat to non-target organisms, such as fishes. This study was carried out to evaluate acute toxicity and histological and genotoxic effects (erythrocytic nuclear abnormalities) of lethal and sub-lethal concentrations of three commonly used pesticides: Atrazine, Butachlor and Glyphosate on the African mud catfish (Clarias gariepinus). Fishes were exposed to the pesticides for 96h periods to determine their LC50 and the sub-lethal effect at various concentrations (1/10th, 1/100th , 1/1000th 96h LC50) over 28 days. The 96h LC50 values were 7.63mg/l, 0.7mg/l and 15.97mg/l for atrazine, butachlor and glyphosate, respectively. Histological sections of the liver of C. gariepinus exposed to the three pesticides showed mild vascular congestion but no necrosis in the tissue. There was a significant (p<0.5) dose-dependent increase in micronuclei and nuclear abnormalities in the erythrocytes of exposed C. gariepinus compared to the control by 28 days. The study confirmed that C. gariepinus are at risk of adverse effects from exposure to pesticides. Discharge of agricultural run-off around water bodies should be prevented or prohibited to avoid adverse effects on aquatic life.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116285329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plastic pollution is ubiquitous throughout the world’s ecosystem. Increase in the world’s plastic production and use, inefficient recycling, indiscriminate disposal, synthetic nature and non-biodegradability of plastics have made it a considerable threat to biodiversity. The impact of plastic wastes on humans and the environment is becoming apparent. However, information on the impacts of plastic wastes on biodiversity is mostly directed towards marine environment with scarce information on land biodiversity although terrestrial environment is the major source of marine contamination. Terrestrial plastic waste contaminants are derived from long term used plastic containers and single-use plastic products, which are introduced by anthropological means, flood water, sewage and wind dispersal. Gradual breakdown of large plastic wastes give rise to microplastics, which increase its abundance in the environment. Plastics threaten wildlife in terms of entanglements, ingestion and chocking, which often results in loss of body parts or mortality. Plastics as vectors of invasive species in marine ecosystem have been widely established. Although not much is known on the importation of invasive species on terrestrial ecosystem by plastic wastes, there is possibility that plastic waste can be a potential vector of terrestrial alien species. Contamination of soil with microplastics alters soil habitats and disturbs the natural biophysical properties of the soil environment that leaves a negative impact on soil biota by reducing their activities and indirectly affecting food production. Accumulation of plastic wastes provides breeding ground for disease vectors, which has contributed to increased prevalence of emerging infectious diseases. This review examines the impact of plastic wastes on terrestrial biodiversity as it affects soil organisms, land animals and breeding of disease vectors.
{"title":"Hazardous effects of plastic wastes on land biodiversity: A review","authors":"T. J. Anunobi","doi":"10.4314/tzool.v20i1.10","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.10","url":null,"abstract":"Plastic pollution is ubiquitous throughout the world’s ecosystem. Increase in the world’s plastic production and use, inefficient recycling, indiscriminate disposal, synthetic nature and non-biodegradability of plastics have made it a considerable threat to biodiversity. The impact of plastic wastes on humans and the environment is becoming apparent. However, information on the impacts of plastic wastes on biodiversity is mostly directed towards marine environment with scarce information on land biodiversity although terrestrial environment is the major source of marine contamination. Terrestrial plastic waste contaminants are derived from long term used plastic containers and single-use plastic products, which are introduced by anthropological means, flood water, sewage and wind dispersal. Gradual breakdown of large plastic wastes give rise to microplastics, which increase its abundance in the environment. Plastics threaten wildlife in terms of entanglements, ingestion and chocking, which often results in loss of body parts or mortality. Plastics as vectors of invasive species in marine ecosystem have been widely established. Although not much is known on the importation of invasive species on terrestrial ecosystem by plastic wastes, there is possibility that plastic waste can be a potential vector of terrestrial alien species. Contamination of soil with microplastics alters soil habitats and disturbs the natural biophysical properties of the soil environment that leaves a negative impact on soil biota by reducing their activities and indirectly affecting food production. Accumulation of plastic wastes provides breeding ground for disease vectors, which has contributed to increased prevalence of emerging infectious diseases. This review examines the impact of plastic wastes on terrestrial biodiversity as it affects soil organisms, land animals and breeding of disease vectors.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125928061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Adamu, Y. M. Mohammed, U. F. Ibrahim, I. Abdullahi, Y. O. Jimoh
Ecological systems change over time due to anthropogenic and natural activities, regular monitoring is therefore necessary for identifying malignant changes and conservation of biodiversity. This study was undertaken to ascertain the health and biological diversity of Lake Dangana using both biotic and abiotic indicators. Samples for physico-chemical and biological analyses were collected monthly from four sampling stations in Lake Dangana from January to August, 2020 using standard methods. The results of physico-chemical variables were: temperature (23.5-26.5ºC), dissolved oxygen (3.96-4.13mg/l), biochemical oxygen demand (3.00-.12mg/l), pH (6.88-7.11), conductivity (86.43-94.80µS/cm), nitrate (0.67-0.76mg/l) and phosphate (0.85-1.04mg/l). Conductivity, nitrate and phosphate varied significantly (p<0.05) between stations. A total of 318 individuals from 13 species and 10 families of macroinvertebrates were encountered during the study period. Hemiptera (35.52%), Coleopterans (34.59%), Odonata (22.95%), Dipterans (5.03%) and Oligochaetes (1.87%) were the dominant groups. The first two Canonical Correspondence Analysis (CCA) axes explained 87.33% of macroinvertebrate-environment relationship and pH (-0.99), BOD5 (-0.62), nitrate (-0.61), conductivity (-0.59) and phosphate (-0.57) were the dominant structuring factors. Six bacteria species; Bacillus sp, Escherichia coli, Micrococcus sp., Staphylococcus aureus, Klebsiella sp and Pseudomonas sp. and five fungi species; Aspergillus fumigatus, A. niger, A. flavus, Penicillium sp and Mucor sp. were encountered. The presence of some of these microorganisms such as E. coli in the lake is an indication of faecal contamination and this could endanger public health.
{"title":"Assessment of some physical, chemical and biological parameters of Lake Dangana, Niger State, Nigeria","authors":"K. Adamu, Y. M. Mohammed, U. F. Ibrahim, I. Abdullahi, Y. O. Jimoh","doi":"10.4314/tzool.v20i1.17","DOIUrl":"https://doi.org/10.4314/tzool.v20i1.17","url":null,"abstract":"Ecological systems change over time due to anthropogenic and natural activities, regular monitoring is therefore necessary for identifying malignant changes and conservation of biodiversity. This study was undertaken to ascertain the health and biological diversity of Lake Dangana using both biotic and abiotic indicators. Samples for physico-chemical and biological analyses were collected monthly from four sampling stations in Lake Dangana from January to August, 2020 using standard methods. The results of physico-chemical variables were: temperature (23.5-26.5ºC), dissolved oxygen (3.96-4.13mg/l), biochemical oxygen demand (3.00-.12mg/l), pH (6.88-7.11), conductivity (86.43-94.80µS/cm), nitrate (0.67-0.76mg/l) and phosphate (0.85-1.04mg/l). Conductivity, nitrate and phosphate varied significantly (p<0.05) between stations. A total of 318 individuals from 13 species and 10 families of macroinvertebrates were encountered during the study period. Hemiptera (35.52%), Coleopterans (34.59%), Odonata (22.95%), Dipterans (5.03%) and Oligochaetes (1.87%) were the dominant groups. The first two Canonical Correspondence Analysis (CCA) axes explained 87.33% of macroinvertebrate-environment relationship and pH (-0.99), BOD5 (-0.62), nitrate (-0.61), conductivity (-0.59) and phosphate (-0.57) were the dominant structuring factors. Six bacteria species; Bacillus sp, Escherichia coli, Micrococcus sp., Staphylococcus aureus, Klebsiella sp and Pseudomonas sp. and five fungi species; Aspergillus fumigatus, A. niger, A. flavus, Penicillium sp and Mucor sp. were encountered. The presence of some of these microorganisms such as E. coli in the lake is an indication of faecal contamination and this could endanger public health.","PeriodicalId":426223,"journal":{"name":"Zoologist (The)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125572988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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