Anambra River Basin Research Articles

Dynamics of land cover change in the Anambra River Basin of Nigeria and implications for sustainable land management

Land cover change and its consequences such as environmental degradation and biodiversity loss pose significant global challenges, including in Nigeria’s Anambra River Basin. This study focuses on monitoring, predicting and understanding land cover changes in the basin from 1987 to 2018, with projections up to 2030. It explores the intricate relationship between population growth and land cover dynamics, aiming to contribute to sustainable land management practices and align with the Sustainable Development Goals (SDGs) for 2030. Using a combination of neural network classification and the CA-Markov model, the study analyses historical land cover data to identify significant transformations. Between 1987 and 2018, bare lands increased by 29%, vegetation increased by 14%, built-up areas increased by 128% and waterbodies increased by 10%, whereas there was a 58% decline in the extent of wetlands. The most significant transformation occurred in the wetlands, with a total of 1819.46 km2 being converted to various land cover types. The results demonstrate remarkable shifts characterised by rapid urbanisation, substantial wetland loss and a decline in vegetation cover. Expectedly, population growth is found to be closely linked to the expansion of built-up areas while negatively impacting other land cover types. These findings underscore the urgent need for sustainable land management strategies that balance the demands of growing populations with the preservation of natural ecosystems and biodiversity. Furthermore, the study provides future projections that offer crucial insights for decision-makers involved in land use planning, biodiversity conservation and sustainable development.

Evaluation of heavy metal pollution status of Anambra River basin using different indices

Evaluation of heavy metal pollution status of Anambra River basin using different indices

Optimization of a multipurpose river basin in anambra state, Nigeria

In this study, the multipurpose objective of development in the Anambra River basin was examined. The study's goals are to determine the net benefits of the various objectives under each purpose currently carried out by the Anambra River Basin, to identify the best way to achieve the goals, and to show, through logical and mathematical reasoning, how money could be allocated to the various goals of a dam project in Anambra State effectively. Economic Efficiency (EE), Regional Economic Redistribution (RER), Social Well-Being (SW), Youth Empowerment (YE), and Environmental Quality Improvement are the objectives taken into account in the study (EQI). The optimization problem in the multi-purpose-objective development of the Anambra State river basin was solved utilizing the multi-start optimization method. The study showed that the basin would achieve enormous financial benefits if it used its N15.0 billion strategic development budget over four years for various purposes as illustrated. The results showed that the following allocation of the five purposes should be optimized simultaneously for an N15.0 billion four-year strategic development fund: EE should receive N0.762 billion, RER should receive N0.594 billion, SW should receive N0.649 billion, YE should receive N0.683 billion, and environmental quality improvement should receive N4.768 billion. It was found that Environmental Quality Improvement was allocated the higher amount while Regional Economic Redistribution was allocated the least amount for the development. The study's findings recommended that the management of the basin stop the practice of allocating funds to various uses at their discretion, which has led to significant oversight and the improper distribution of scarce resources. As a result, every fund distribution must be justified using logic and mathematics. To increase the accuracy of the data, the Anambra State River Basin Development Authorities must intensify record-keeping activities.

Assessing the potential of a surface water body for multiple uses. Case study: the Anambra River Basin, south-eastern Nigeria

Anthropogenic activities causing deterioration in water quality and a decrease in meeting the ecosystem service potentials of surface water are considered one of the major basic environmental challenges. Water samples were collected from three sampling stations (Ogurugu, Otuocha, and Otu- Nsugbe) in the Anambra River Basin and analyzed following standard protocols and procedures for nine months. The cosystem services potentials of the Anambra River Basin were evaluated using physico-chemical parameters and some indices: Comprehensive pollution index (CPI), nutrient pollution index (NPI), salinity potential, and soluble sodium percentage (SSP). All the water quality parameters were within the standard level for drinking water, aquaculture practice, recreation (swimming/bathing) and agricultural purposes, with the exception of pH and phosphate, whereas dissolved oxygen met aquaculture criteria only in station II. Comprehensive pollution index (0.150 – 0.449), nutrient pollution index (0.07 – 0.46), and soluble sodium percentage (6.0% -26.92%) were within the category of non-polluted or excellent to sub-clean. Potential salinity (39.39 - 97.19) was high, indicating water from the Anambra River Basin contained crystallized solutes. Conclusion: the Anambra River Basin is not at risk of eutrophication but may not support irrigation program due to the high potential salinity. However, the river needs to be monitored, and anthropogenic activities need to be regulated.

Socio – Economic Impacts of Prolonged Little Dry Season (August Break) in a Climatic Changed Era in Agrarian Communities of Anambra River Basin, Anambra State, Nigeria

The food supply and demand situation for the 2020 fiscal year concerning the main seasonal crops in Nigeria was unpredictable due to the effect of Covid-19 pandemic. Federal and state governments laid much emphasis as a result on agriculture, especially crop production in order to produce food enough to ameliorate hunger, which is one of the negative effects of Covid-19. Nigeria been a rain fed dependent agricultural nation, follows the dictate of weather and other weather elements in her agricultural activities. With climate change and the effect of Little Dry Season, there was a reduction in rainfall in mid-July through August 2020. Rice and Maize which are among the staple foods in Nigeria requires about 750mm to 1200mm of rainfall to thrive. The mean monthly rainfall recorded in our study area (part of Anambra River Basin) consisting of Ayamelum, Anambra West, Anambra East, Oyi and Dunukofia local government areas are 21.15mm and 3.25mm for July, 2020 and August, 2020 respectively. As a result of the shortage of rainfall in these two months, the farmers and the authors observed these negative outcomes which are early maturity of crops; early harvesting of crops as well as poor yields for early season crops. While during the late season planting, farming was affected by the hardening of the ground as a result of absence of rainfall; undissolved fertilizers in farm lands; partial germination of scattered seedlings; Ant, Birds and Rodent infestation and stunted growth. Base on our observation, it was concluded that yields and harvest would be poor and subsequently there would be shortage of food and price hike in food items. The paper recommends for the revitalization of the moribund irrigation facility in Omor, Ayamelum local government area to provide for the shortfall in moisture that is likely to occur in the absence of rainfall.

Communication and Resource Conflict Resolution: The Case of Aguleri-Kogi Feud Over Ownership of Crude Oil Finds

Conflict is inevitable among communities especially where there are vested interests or contentious boundaries. This paper analyzed the role and effect of communication in conflict resolution within community setting. The controversy investigated was Aguleri-Kogi Crude Oil ownership feud otherwise known as “Crude oil War”, which had led to loss of many lives and property in both communities. Using literature review methodology, which borders on conflict and conflict resolution; effects of communication in conflict prevention and resolution; historical account of Anambra River Basin Communities; and, efforts of stakeholders in the various communities towards resolution of the resource conflict, it was observed that conflict can be either good or bad, depending on the way it is handled; that poor communication escalates conflict; and, that effective communication, anchored on dialogue and negotiation, is the key to conflict resolution. We observed that both parties in Aguleri-Kogi feud relied more on litigations in settling their resource dispute which has lingered for a long time. This paper, therefore, suggested among other things, the need for the stakeholders in conflicts to embrace negotiation and dialogue in the resolution of differences. Keywords: Aguleri-Kogi feud, Anambra River Basin, Crude oil ownership, Resource conflict DOI : 10.7176/JRDM/56-06 Publication date :June 30 th 2019

A morphological and molecular study of Clinostomid metacercariae from African fish with a redescription of Clinostomum tilapiae.

The genus Clinostomum Leidy, 1856 (Digenea: Clinostomidae) has been reported in all ecozones of the world and a clear separation between the species of the 'Old World' and 'New World' has been recognized based on molecular studies. Recent works on Afrotropical species include redescriptions of C. cutaneum and C. phalacrocoracis, while C. tilapiae has yet to be studied using modern taxonomic approaches. In the present research, morphological redescription of C. tilapiae metacercariae from a new host, Synodontis batensoda sampled at Anambra River Basin, Nigeria, together with molecular analysis of nuclear internal transcribed spacer rDNA and cytochrome c oxidase 1 mtDNA are reported. We also provide morphological and molecular data from four further putative species of Clinostomum (morphotypes 1-4) from different areas of Africa, as well as the first report of C. phalacrocoracis in South Africa.

Differences in host-infection patterns of clinostomatids (Clinostomatidae) in human disturbed aquatic ecosystems against undisturbed lake

Scarcely use of Opi Lake for many years (1995-2007) due to road cut to its site by erosion during which parasite survey of its major fish composition was carried out established host specificity disparity especially when compared with entirely human disturbed Oguta Lake and Anambra River Basin in Southeast, Nigeria. The infection prevalence had dispersed infection in mainly skin musculature micro-habitat in encysted forms in the later reservoirs. Conversely, the parasites occupied more host micro-habitats of eye, skin and buccal cavity with high rate of excysted forms in the former reservoir. The record of mainly encysted forms in the latter reservoirs is indicative of immune resistance host-parasite relationship. Also, human disturbance which has complimentary environmental influence on both parasite and host upsets parasite-host location strategies in aquatic communities within human vicinities where the reservoirs are used for numerous domestic chores. To the best of our knowledge, hitherto the latter had little or no clinostomatids parasites report.

Potentials of <i>Bambusa vulgaris</i> Grown in Southeast Nigeria for the Manufacture of Wood-Cement Composite Panels

In this work, the potentials of Bambusa vulgaris grown in southeast Nigeria for the manufacture of wood-cement composite panels were studied. Representative culms of Bambusa vulgaris were collected from a 4-year-old stand at lower Anambra river basin, southeast, Nigeria. Fiber morphological properties and proximate chemical analysis were determined in accordance with the provisions of the Technical Association of the Pulp and Paper Industries (TAPPI, 1998). Fiber slenderness ratio was 160.95:1, component solubility of 3.09, 5.60, and 19.8 percent for cold water soak for 24 hrs; hot water soak at 80°C for 1 hr, and 1% NaOH soak for 24 hrs respectively. Composite panels were made at 1200 kg/m3 and 800 kg/m3 density levels with flakes of different soak treatments (untreated/control; cold water soak for 24 hrs; water at 80°C soak for 1 hr and 1% NaOH soak for 24 hrs) at variable cement/B. vulgaris mix ratios (1:1, 1.5:1, 2:1, 2.5:1 and 3:1 wt/wt) with 3% CaCl2 as accelerator applied to the wood furnish before cement mixing. Prepared furnish was subjected to initial pre-pressing of 0.5 N/mm2 and final consolidation of 1.4 N/mm2 retained for 24 hrs. Panels were sampled and tested after 28 days for Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) in bending and for water absorption (WA) and thickness swelling (TS) due to a 24-hr water soak. Test was in accordance with provisions of American Standard for Testing of Materials (ASTM-1998). Properties ranged from a low of 25.00 to 75.45 N/mm2 for MOR; 4128 to 15,065 N/mm2 for MOE; 15.01 to 36.11 percent for WA and 3.04 to 12.72 percent for TA. Effect of production mix on properties was determined using factorial analysis. Except for composite density whose effect was not significant at 0.05% level, all production mix was found significant at 0.01% level at the second order level of interactions. All panels met minimum property requirements of American National Standard Institute 208-2-1994 and 208-1-1993, British Standard (BS 5669, 1979) and Malaysian Standard (MS 934, 1984).

The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50 mm, 75 mm, and 100 mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5%, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300 mm, standard length 231 mm, head length 69 mm, body length 101 mm, body girth 176 mm, body weight 900 mg. Alestes nurse total length 200, standard length 140 mm, head length 60 mm, body length 80 mm, body girth 120 mm, body weight 400 mg. The most abundant animal utilizing the basin was Ardea cinerea (D3) with 22.2% occurrence (D4) and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence.

Length-Weight relationships and condition factor of <i>Citharinus citharus</i> and <i>Alestes baremoze</i> from Anambra river basin, Nigeria

The length-weight relationships and conditions of Citharinus citharus and Alestes baremoze from Anambra River were investgated from September 2007- March 2008. Analyss of the size ranges ofthe two fshes showed that C. citharinus was heavier than A. baremoze but A. baremoze was long than C. citharus. Both fishes showed only one peak each in their size disribution indicating that they belonged to the same size or year cass. There was highly significant relationship between the body weights and standard lengths of C. citharinus and A. baremoze (P < 0.001). The Kn vaues for the two fishes were fairly equal but the mean K. values showed that C. citharinus was more robustand in a better state of “well being” than A. baremoze. The results were discussed of similar studies, particularly the importance of the condition factor in the study of the biology of the fsh population.Keywords: Citharinus citharus, Alestes baremoze, Anambra River, Length-weight, Condition factor

The prevalence of helminthofauna and fecundity studies in west African lungfish, &lt;i&gt;Protepterus annectens&lt;/i&gt; Owen, 1839 (Dipteriformes: Lepidoserinidae) in river Anambra, Nigeria

An investigation was conducted on the helminthofauna and some aspects of reproductive biology of the West African lungfish, Protopterus annectens in River Anambra, Nigeria, between May and July, 2008. The sample comprised forty two fishes purchased from fishermen and fish mongers at Otuocha fish market, a major fish landing location in the Anambra River Basin. The sex composition of the sample which was 1:41 (male: female) is thought to reflect a preponderance of female fish in the natural population of P. annectens in the river system. Heterorchis protopteri, a digenean, was the only helminth parasite recovered, infesting 6 (six) out of the 42 fish.33 worms were recovered, giving a prevalence of 14.29 %, mean intensity of infection of 5.5 and mean abundance of 0.8 for the parasite in the fish population. The infection parameters increased with size of fish (weight and length). No parasite was recovered from the lone male fish examined, and this could be attributed to sample size. H. protopteri is reported from P. annectens in Nigeria for the first time. All the female fish examined were gravid while the lone male fish had ripe testes which indicate that P.annectens spawns in the river system in the wet season. Fecundity of the species was estimated to be about 1423 eggs per female and P. annectens is categorized as a mesofecund species. It is suggested that some form of regulation of cropping of P. annectens in the river system should be put in place pending a clearer understanding of its ecology, in order to reduce the chances of harming the recovery capacity of the species.Keywords: Protopterus annectens, River Anambra, Heterorchis protopteri, fecundity, spawning.

The Biology Of The West African Clariid, Clarias macromystax Gunther, 1864 (Osteichthyes: Clariidae) In A Nigerian River Basin

The biology of the West African clariid, Clarias macromystax, was studied in Anambra river basin, Nigeria. The clariid occurred more abundantly and frequently in forest floodplain ponds than in other habitats, and was totally absent in the river systems. Length ranged from 9.7 to 30.2 cm TL and weight from 9 to 168 g; females were heavier, but not longer, than males. The b-values (2.4190-2.5209) of the total length-weight relationships exhibited negative allometric function. Mean relative condition, Kn, was better in females than males but showed a definite cycle in both sexes. Over 50% of both sexes were mature at 15.1-20.0 cm TL in their first year of life. Fecundity ranged from 2.136 x 103 to 37.250 x 103 (mean 14.942 x 103± 11.248 x 103) and correlated highly and positively with length, body weight and ovary weight. Ovary weight was the best predictor of fecundity. Communal spawning involving C. macromystax and C. agboyiensis occurred. Feeding was carried out throughout the day with higher feeding intensity at night. Food of primary importance were Caridina niloticus, Sudanonautes africanus, Odonata naiad, terrestrial Orthoptera, formicoid Hymenoptera, Dytiscidae, Oreochromis niloticus, Parachanna obscura, fruits and seeds, plant detritus and mud. Diet breadth was season-dependent. The clariid fed by foraging, shoveling and surfacefeeding. E. clarias, Procamallanus laevichonchus and a larval spiruroid parasitized various organs. C. macromystax is a new host record for these helminth parasites. Keywords: Clarias macromystax, Abundance, Reproduction, Food, Parasites, Anambra river basin, Nigeria. Animal Research International Vol. 1 (3) 2004 pp. 190-199

Host-Vector-Parasite Relationship Among Inhabitants Of The Anambra River Basin Irrigation Project Area

A questionnaire survey was employed to identify the sources of contact with parasites and disease vectors among people living in the Anambra River Basin Irrigation Project Area. The survey indicated that more than half of the inhabitants of this area go to farm. While in the farm disease vectors such as mosquitoes, biting midges, snails and tsetse flies are usually encountered. In addition, the lack of proper sewage disposal common among the communities exacerbates the situation. Water from various sources such as rivers, ponds, streams, as well as rainwater are used for many purposes. Common disease symptoms such as diarrhoea, abdominal pain, blood in sputum, body nodules, blood in stool, coughing, itching, headache, fever, haematuria were commonly recorded. Positive relationships were observed between the presence of some vectors and the corresponding disease symptoms.

Harnessing Aquatic Physicochemical Parameters Influencing Macroinvertebrate Fauna In Anambra River Basin For Sustainable Fish Productivity

The management-oriented background for harnessing aquatic physicochemical parameters influencing macro invertebrate fauna of Anambra River basin for sustainable fish productivity was studied. The intra seasonal variability in the water quality of the river revealed mean transparency of 1.79 cm, Conductivity of 28.81 &#956;scm-1, nitrate-nitrogen of 3.23 mgl-1, total hardness of 6.43 mgcaco3L-1, biological Oxygen Demand (BOD) of 3.62 mgl-1, No3-N/Po4-P 0.54 ratio and Co2/DO o0.81 were significantly higher in the dry season than all other parameters which were signicantly higher in he wet season. A toal of 1808 individuals (mosty adults) belongng to 97 species of macro-invertebrate fauna were collected. The overall composition of the fauna in the river basin was dominated by coleopterans and the hemipterans. The estimated annual fish yield of the river basin was 72.91 kg/ha based on a morphoedaphic index. The water quality of the River can be harnessed by controlling and/or prohibiting the discharge of municipal effluents and domestic garbage into the river as well as the continuous use of the riparian zone for agronomy. The maintenance of periphera 50/60 m of thick riparian vegetation can act as buffer strp to check bank erosion is suggested. Keywords: Macro invertebrates, Physicochemical Parameters, Harnessing, Fish yield Animal Research International Vol. 4 (2) 2007 pp. 705-712

Helminth parasitic diseases status of school children within the Anambra River Basin irrigation project area

The incidence of the parasitic disease, especially infection with helminths, among school children within Anambra River Basin Irrigation Project Area in Ayamelum Local Government Area of Anambra State is reported. A cross section survey revealed the prevalence of hookworms, ascariasis, trichuriasis, trichuriasis, enterobiasis and taeniasis in school children. Analysis of the prevalence data showed that Ascaris lumbricoids (24%) is the dominant helminth parsite in the area while Taenia infection (6.7%) is the least prevalent helminth infection. Symptoms of many other parasitic diseases abound in the form of skin nodules (Onchocerciasis), itching, rashes, abdominal problems and elephantiasis. Age of children affected the level of prevalence of the parasitic diseases e.g. younger children were more infected that the older children in many cases (except hookworm disease and filariasis). Poor sanitary conditions emanating from poor sewage disposal facilitates, poor potable water supply, full participation in irrigated rice farming and poor housing are factors affecting the parasitic disease status of the school children and possibly the whole communities.Bio-Research Vol. 3(1) 2005: 93-98

Malacological Survey Of The Freshwater Systems Of Anambra River Basin Area In Anambra State, Nigeria

A malacological survey was undertaken in the freshwater systems within Anambra River basin from July 2000 to June 2001. Three stations were selected within which 13 sites were studied. The survey revealed the presence of a rich molluscan fauna including those endemic in the basin alone. The species collected included 5 pulmonates and 12 prosobranchs (all gastropods). Otu Idoko was identified as the habitat having the richest snail fauna while the burrow pits at Mmiata had the lowest snail population. Habitat type, rainfall and desiccation had tremendous effects on the population dynamics of snails. Thus the highest density in flowing water habitats was recorded between July and September, whereas the highest density in stagnant pools was recorded in May to June. Other factors found to impact severely on the populations of snails causing visible fluctuation in their density include: electrical conductivity, dissolved oxygen, calcium ions and pH. Three genera: Pila, Lanistes and Bulinus were found to contain infected species. The dominant snails found in this basin were Pila and Potadoma species. The finding of Gabiella sp was the most exciting find as it is very rare in Nigerian waters. The findings were used to discuss the health implications for the people living and working in the basin area. Key Words: Malacological Survey, Freshwater Systems, Anambra State Bio-Research Vol.2(1) 2004: 29-38

The biology of Clarias ebriensis Pellegrin, 1920 (Osteichthyes: Clariidae) in an African rainforest river basin

The West African catfish, Clarias ebriensis, is commercially important and cultured in floodplain ponds. This paper describes the abundance, condition, reproduction, food and parasites of C. ebriensis in the Anambra river basin, Nigeria. This clariid occurred more abundantly and frequently in forest floodplain ponds than in other habitats. Weight ranged from 4 to 240 g and TL from 54 to 437 mm, males being heavier and longer than females. Mean relative condition was not sex-dependent and showed a definite cycle with the highest value in March/April or June and the lowest in September. Maturity was not sex-dependent. Fecundity ranged from 2.746×10 3 to 54.216×10 3 oocytes (mean 14.730×10 3±10.799×10 3 oocytes). Ovary weight was the best predictor of fecundity and GSI. First communal spawning, along with Clarias agboyiensis, C. buthupogon, C. albopunctatus and C. anguillaris, occurred in the first year of life. Feeding was mainly at night and stomach fullness index was higher in the rainy than dry season. The index of food significance (IFS) showed that fish and insects were equally important, followed by molluscs and crustaceans. Qualitative food composition and food richness were size- and sex-dependent but not season-dependent. Observed feeding behaviors were foraging, shoveling and surface feeding. Euclinostomum clarias, Procamallanus laevichonchus and a larval spiruroid (f. Physalopteridae) parasitized various organs. C. ebriensis is a new host record for these helminth parasites. The presence of high numbers of larval spiruroid in the muscles resulted in consumer resistance.

Efficacy of human chorionic gonadotropin (hCG) and crude pituitary extract of fish and frog in oocyte maturation and ovulation in African catfish, Clarias gariepinus Burchell, 1822 and Clarias anguillaris L., 1762

Abstract. The African catfish, Clarias gariepinus Burchell and Clarias anguillaris L., were induced to ovulate in aquaria by the administration of human chorionic gonadotropin (hCG) and pituitary extracts of Clarias albopunctatus (Nichols & Lamonte) and frog, Rana elegans. For final maturation and ovulation in both species of Clarias, the total dosage of each hormone was inversely proportional to the initial oocyte diameters of the recipient females. The time of ovulation after the last injection (latent period) was significantly shorter (11–13h) in females with large oocyte diameters (>920μm) than in those whose mean oocyte diameters were less than 920 μm (13–16h) (P < 0·05). The mean dosage of each test hormone required to induce ovulation was lower in females with large oocyte diameters than in those with smaller oocyte diameters (<920μm). The mean percentage hatch did not depend significantly on the nature of the treatment (P > 0μ05) and was about 86%. Clarias albopunclatus and R. elegans, which are economically unimportant and abundant in Anambra River basin, Nigeria, could be used as effective sources of hypophyseal factors in Clarias breeding programmes.

The reproductive biology of four African catfishes (Osteichthyes: Clariidae) in Anambra River basin, Nigeria

The reproductive biology of Clarias ebriensis, C. agboyiensis, C. macromystax and C. buthupogon was investigated over a period of 32 months in Anambra River basin, Nigeria. Immature (stage I) C. ebriensis and C. agboyiensis were recruited into the fishery in October, and in September in C. macromystax and C. buthupogon. The occurrence of mature (stage III) fish all the year round indicated the potential of the Clarias species to breed at any time of the year. C. ebriensis bred from April–September while breeding occurred from May–September in the other species. The clariids matured between their first and second year of life. C. ebriensis females matured earlier than males but the reserve was the case in C. agboyiensis, C. macromystax and C. buthupogon. Ovary weight was a better indicator of egg number than either total length or body weight in all species. Communal spawning is reported for the first time in Clarias species and its significance to survival discussed.