Iranian Journal of Aquatic Animal Health 5(2) 37-53 2019 Health assessment of Silver catfish (Chrysichthys nigrodigitatus): hydrodynamic and growth performance in Lagos Lagoon, Nigeria A. O Abidemi-Iromini 1*, A. O Bello-Olusoji 1, I. A Adebayo 2 1 Department of Fisheries and Aquaculture Technology, The Federal University of Technology, Akure, Ondo State, Nigeria 2 Department of Animal Production and Health, The Federal University of Technology, Akure, Ondo State, Nigeria Received: April 2019 Accepted: October 2019 Abstract Status of Chrysichthys nigrodigitatus, an Sex ratio indicated higher male to female economic important fish of the Gulf of Guinea (40:32) which is nature specific. Morphometric was investigated over 24 months in Lagos measurement indicated female samples Lagoon to know the state of well-being of the revealed negative allometric, but better fish; for fisheries management, public health condition factor (K) (2.86); while male revealed and food security. Ecological tools employed to positive allometric and lower condition factor determine some hydrodynamic status. Water (K) (0.44) which is sex, reproduction and food analysis: temperature (°C), pH, dissolved availability specific; as robustness indicate state oxygen (mg l-1), conductivity (μЅcm), depth of well-being of the fish. Heavy metal values (m), turbidity (m), and salinity (%0) were revealed slight accumulations. Results determined. Fish with mean standard length connoted fish species is relatively safe and of 18.90 ± 1.35 (cm) and mean weight range public health value. (201.59 ± 38.29) (g) were randomly collected and separated into sexes. Condition factor and Keywords: Condition status, Water parameters, regression analysis determined. Some heavy Estuary, Heavy metals, Chrysichthys Downloaded from ijaah.ir at 20:46 +0330 on Thursday September 23rd 2021 [ DOI: 10.29252/ijaah.5.2.37 ] metal concentrations (Lead, Iron, Zinc Copper, nigrodigitatus and Chromium) levels were determined in fish Introduction tissues. No significant difference (P ≥ 0.05) occurred in water parameters from normal Chrysichthys nigrodigitatus (Lacepede 1803) is range using ANOVA. a Bagridae mud silver catfish (Table 1), which occurs in most of the major rivers in Africa Correspondence A. O Abidemi-Iromini, Department of including Nigeria; the catfish is endemic to Fisheries and Aquaculture Technology, The Federal University of Technology, Akure, Ondo State, Nigeria (e- inland and coastal waters of Africa: Western, mail: [email protected]). Southern and Central Africa, (Emmanuel & 37 Abidemi-Iromini et al., Health assessment of Silver catfish hydrodynamic and growth performance … Osibona 2013). It is demersal, potamodromous specie that occurs in shallow waters of lakes (less than 4 m), over mud and fine sand bottom, in rivers and in swamps. A benthic omnivorous feeder, with significant ontogenetic shifts in diet composition subsisting and feeding on a variety of benthic food items (seeds, insects, bivalves and detritus), and specializes on its feeding Figure 1. Chrysichthys nigrodigitatus, Source: (Azeroual habits with age and size. While newly hatched et al. 2010). fries to young adult stages had preference for Challenge with uncontrolled fishing, and plankton, matured adults and larger fish may human influence on aquatic environment prefer or/ and feed on decapods and fish usage is important to the stress experienced by (Asuquo, Enin & Job 2010; Uneke, Uhuo & the ecosystem. Anthropogenic influence Nwangbo 2015). through aquatic ecosystem degrading In Nigeria, C. nigrodigitatus (Figure 1) is including oil spillage, sand milling, pollution highly desired, valued food-fish of commercial and destruction of mangrove swamps have had importance; hence, optimum production of the a considerable impact on the breeding and stock endeared Fisheries management to adopt nursery coastal habitat of C. nigrodigitatus; the fish for aquaculture, (Ezenwa, Kusemiju & particularly in Nigeria (Anyanwu 1991; Olaniyan 1986; Ezenwa, Alegbeleye, Anyanwu Ekanem 1996). Since the complex dynamics & Uzukwu 1990); as well as engage in of ecosystem relationships with stressors parameters such as length-weight relationship, influence the state of well-being as well as condition factor and sex composition to predict production of fish; the aquatic ecosystem mis- potential yield and size at capture for obtaining use impacts on the health status of C. optimum yield for rational exploitation nigrodigitatus in Lagos Lagoon ecosystem. (Ugwumba & Ugwumba 2007; Obeten Offem, Therefore, environments functions in relation Akegbejo-Samsons & Tunde Omoniyi 2008). to environmental contaminant through Downloaded from ijaah.ir at 20:46 +0330 on Thursday September 23rd 2021 [ DOI: 10.29252/ijaah.5.2.37 ] Table 1. Scientific classification of Chrysichthys deliberate and un-intentional deeds from nigrodigitatus varying pollution sources (coastal line near Classification Name Kingdom Animalia byers or sourced afar finding its way into the Phylum Chordata environment; through surface runoffs, Class Actinopterygii drainages, into the lagoon system); could Order Siluriformes Family Claroteidae result in depleted state of the desired Genus Chrysichthys economically important fish stock. Specie Nigrodigitatus Scientific name Chrysichthys nigrodigitatus Therefore, as environmental management Common name Silver catfish towards healthy functioning, survival and 38 Iranian Journal of Aquatic Animal Health production of fish is important to provide fish- reported that Lagos Lagoon stretches for about food that is of public health importance for the 257 km from Cotonuon in the Republic of Benin ever-increasing demands of man as well as for to the Western edge of the Niger-Delta. The economic importance; hence, health status of C. lagoon boarders the forest belt and receives input nigrodigitatus in Lagos Lagoon was determined. from a number of important large rivers draining more than 103,626 km of the country. However, Materials and Methods Ajao et al. (1996), estimated that the area of the 2 The experiment was carried out in Lagos Lagoon lagoon is 150.56 Km . It cuts across the Southern in Lagos State, Nigeria, West Africa. The Lagos part of the metropolis, linking the Atlantic Ocean Lagoon (Figure 2) is part of the continuous (in the West and South) and Lekki lagoon (in the system of lagoons and creeks that are found East). It is tidal and shallow with an average along coast of Nigeria from border with depth of 1.5 m except at channels that are Republic of Benin to Niger-Delta. This lagoon continually dredged to accommodate heavy bordering Lagos Island is located between water traffic (Adejare, Nwilo, Olusina & longitude 30° 10' and 30° 4' SE and latitude 60° 5' Opaluwa 2011). The Lagos Lagoon consists of and 60° 36' N. According to Onyema and three main segments: Lagos Harbour, the Popoola (2013), the Lagos Lagoon with a Metropolitan end and Epe division segments. surface area of 208 km2, is an open, tidal and The lagoon receives water influx from a number brackish lagoon which is the largest among the of important large rivers namely Yewa, Ogun, other lagoon systems of the Gulf of Guinea. It is Osun and Om; and empties into the Atlantic connected and non-parallel to Gulf of Guinea Ocean at Lagos harbor (Ajao, Okoye & coastline over a distance of 237 km. Ajao (1996) Adekanmbi 1996). o o 20 30 NIGERIA Lagos State Ikorodu o Ijede Egbin 30 Downloaded from ijaah.ir at 20:46 +0330 on Thursday September 23rd 2021 [ DOI: 10.29252/ijaah.5.2.37 ] Oworonsoki LAGOS LAGOON o 20 Ikoyi Mushin Figure 2. Map of Lagos Lagoon. Table 2 shows the notable attributes of the sampling points on Lagos Lagoon. 39 Abidemi-Iromini et al., Health assessment of Silver catfish hydrodynamic and growth performance … Table 2. Notable attributes of Sampling Points within fisherman using traps and set nets and were Lagos Lagoon immediately transported to laboratory where Sampling Bottom Type Tide/wave standard length (SL) (cm) to nearest 0.01 cm Locations Action Oworonshoki Silt soil Low/Minimal were determined using graduated board; and (LLOW) weight (W) (g) of fish samples were measured Lagoon centre: Brownish High/ Extreme Off third loamy soil to nearest 0.01 (g) using Mettle Toledo mainland bridge electronic weighing balance (Model; PB8001). (LLCE) Okobaba Black loamy Low/ minimal Length and frequency of occurrence of fish (LLOK) clay that ooze were recorded, and growth rate was determined offensive odor. 1.) Oworoshoki sampling point: notable with using Length-Weight Relationship (LWR) of human influence through solid waste fish regardless of sex and year class using the dumps, and sand mining activities. equation: 2.) Lagoon Centre sampling point: Exposed W = a Lb (Pauly 1984) to human interference causing Where W = weight (g) of fish anthropogenic pollution. L = length (cm) of fish 3.) Okobaba sampling point: Exposed to 'a' = regression constant wood logs, saw milling, burning, and anthropogenic pollutants. 'b' = regression coefficient which lies between 2 and 4; while isometric (symmetric) growth is Field work duration indicated at 3, and values other than 3 will Monthly study was carried out on Lagos indicate allometric growth i.e values greater Lagoon over 24 months and random collections than 3 = positive allometric growth, and values of samples were made for health determination. less than 3 = negative allometric growth); and Physico – chemical analysis Condition factor of fish collected were Some water analysis at point locations in determined using formula: