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The Morphology, Abundance, Condition Factor and Length-weight Relationship of Ethmalosa fimbriata (Bowdish 1825) from Nkoro River Niger Delta, Nigeria
Abstract
The morphology, abundance, condition factor and length-w eight relationship of Ethmalosa fimbriatafrom Nkoro River in the Niger Delta area of Nigeria was studied from January-December 2008. The bodydescription of E. fimbriata from Nkoro River was; Dorsal spine (total): 0, Dorsal soft rays(total): 16-19, Analspine: 0, Anal soft rays: 19-23. The m outh is sharply upw ard and V-shaped. Caudal fin is deep chrome withlong and pointed tips. The upper jaw contains distinct median notch, into which tip of lower jaw fits. Lowergill rakes are long, fine and numerous, often 3 times as long as gill filaments; upper gill rakes bent. There isa faint dark spot behind gill cover sometimes followed by others. The dorsal fin tip is black with golden tintson the body. The scute is 16-19, pre-pelvic, 10-13 post and scales in lateral series is 37-42. The highest catchwas recorded in January (8.16), followed by February (4.21), May (1.65), March (1.40), April (1.11) andOctober (1.10). June (0.87), December (0.32), November (0.20) and July (0.14) were less than 1. No catch wasrecorded for August and September during the study. T he highest catch per unit effort (5.62) w as recorded instation 2, followed by station 1 (5.04) and station 4. The least catch per unit effort (3.75) was recorded in station3 . From a sample size of 1200 specimens, K value was 0.946 and the exponential equation was Wt = 0.162(TL)3.199, indicating an isometric growth pattern. The highest condition factor value (1.00) was recorded in Mayand the lowest (0.6) in September. This was an indication that the beginning of rains favors E. fimbriata thanmid rains.
... E. fimbriata, commonly referred to as "bonga" or "West African shad" (Charles-dominique & Albaret, 2003;Döring et al., 2018) of the family Clupeidae (Abowei, 2009;Sobowale et al., 2017), is a clupeid found along the West African coast with many local names from this region (Charles-dominique & Albaret, 2003;Döring et al., 2018). It is a source of protein and essential nutrients (Abowei, 2009). ...
... E. fimbriata, commonly referred to as "bonga" or "West African shad" (Charles-dominique & Albaret, 2003;Döring et al., 2018) of the family Clupeidae (Abowei, 2009;Sobowale et al., 2017), is a clupeid found along the West African coast with many local names from this region (Charles-dominique & Albaret, 2003;Döring et al., 2018). It is a source of protein and essential nutrients (Abowei, 2009). The fish is marketed fresh, dried or smoked (Abowei, 2009) and subjected to processing techniques (including boiling) to enhance its palatability, consumption as well as acceptance (Sobowale et al., 2017). ...
... It is a source of protein and essential nutrients (Abowei, 2009). The fish is marketed fresh, dried or smoked (Abowei, 2009) and subjected to processing techniques (including boiling) to enhance its palatability, consumption as well as acceptance (Sobowale et al., 2017). ...
Changes in fish odour are attributed to volatile compounds’ generation. In this study,
the effect of three processing methods (boiling, sun-drying, and smoke-drying) on
the volatile compounds produced from Ethmalosa fimbriata was investigated using
two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF-MS). For complete cooking, appropriate fish samples were boiled
slowly in water, while sun-drying was achieved traditionally. An improved Altonatype smoking oven was utilized for the smoke-drying process. The experimental results revealed the production of alkene, alkyne, alcohol, ketone, acids, esters, amines,
sulfur-containing, and miscellaneous volatile compounds. Although the selected processing methods were effective for preserving E. fimbriata from the release of some
volatile compounds associated with fish spoilage, they also contributed to the release
of other volatile compounds and odour production. Boiling and smoke-drying were
specifically found to be efficient for the removal of the three amines detected in the
fresh fish sample, including carcinogenic N-nitrosodimethylamine.
... Ama-Abasi (2004) on the length weight relationship of bonga in Cross River estuary concluded that it exhibited an isometric growth since the growth was proportional in all directions. Abowei (2009) had a study on the morphology, abundance, length-weight relationship and condition factor of E.thmalosa fimbriata and reported an isometric growth with b value equal to 3.199 which agreed with that of Ama-Abasi (2004). Abowei, (2009) on Ilisha africana observed a negative allometric growth pattern. ...
... The mean condition factor for the males, females and juveniles showed that the fish was actually doing well. Even when the three groups were pooled together it still indicated that the species was doing very well unlike the values obtained for the weight-length relationship by Abowei (2009) and Ama-Abasi (2004) who both concluded that bonga exhibited an isometric growth pattern. Both isometric and allometric growth pattern have been reported by several other authors for different fresh water species in different locations. ...
... for Clarotes filamentosus in lake Oguta. Abowei (2009) Oni et al, (1983) pointed out that for a particular population over a specific period of time the physiological well-being of any species is never constant and this may be a resultant effect of biological and non-biological factors such as the frequency of feeding and the gonad maturity state (Saliu, 2001). The monthly abundance and sex ratio between the males and females showed that the males dominated in 5 months more than the females in 2 months. ...
IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB)
ISSN: 2455-264X, Volume 3, Issue 2 (Mar. – Apr. 2017), PP 46-55
www.iosrjournals.org
Sex Ratio, Length-Weight Relationship And Condition Factor Of
Ethmalosa Fimbriata In The Cross River Estuary, Nigeria.
1Ajah, P.O., 2Asuquo P. E
1 Faculty of Oceanography, University of Calabar, Nigeria
2 Departments of Zoology and Environmental Studies, University of Calabar, Nigeria.
Abstract:
A total of 855 samples of Ethmalosa fimbriata were collected from the Cross River Estuary between
January to August 2014 for length-weight, sex ratio and condition factor determinations. The males dominated
the populations with a total of 315 followed by 304 juveniles and 236 females with a corresponding sex ratio of
1:1:1.3. E. fimbriata exhibited negative allometric growth pattern with exponent b=2.303, a=0.086 indicating
that the growth was not proportional in all directions and that the species was slimmer as it grows. The mean
condition factor revealed that the species was in good condition with a corresponding values of 0.81± 0.147,
0.978 ± 0.745, 0.98 ± 0.121, 1.22 ± 1.38 and 1.06 ± 0.84, respectively, for the males, the females, the pooled
sex, juveniles and the three categories merged together. The variations in growth of E. fimbriata could be
attributed to climate change and prevailing ecological conditions of the environment.
Key Words: Ethmalosa fimbriata, sex ratio, length-weight, condition factor
... The condition factor of one or greater than one indicates the good condition of fish while the one less than 1 shows bad condition (Abobi, 2015). Condition factor can be influenced by season, sex, type of food organism consumed by fish, age of fish, amount of fat reserved and environmental conditions (Bagenal and Tesch, 1978;Anene, 2005;Abowei, 2009). ...
... Many studies on LWR and CF analyses have been conducted for these fish species in the Niger-Delta (King, 1996;Hart, 1997;Alfred-Ockiya and Njoku, 1995;Abowei, 2009;Ezekiel and Abowei, 2014). There is no published research conducted on the biology or ecology aspects of the fish species in the Okrika estuary. ...
... This finding agrees with Ezekiel and Abowei (2014) and Mohammed et al. (2016) for M. cephalus who reported isometric growth for this species in Amassoma flood plain (Niger-Delta) and Ain El-Ghzala Lagoon, Libya respectively but contrary to negative allometric growth pattern in Cross River estuary (Niger Delta) and Majidun creek (Lagos) reported by Asuquo et al. (2015) and Lawson and Doseku (2013) and positive allometric in Nun river (Niger Delta), Karachi and Balochistan coasts of Pakistan (Abowei and Hart, 2009;Zubia et al., 2014;Elahi et al., 2015). The isometric growth pattern obtained in this study for S. maderensis was contrary to the positive allometric growth reported for this species in Nkoro River (Niger-Delta) (Abowei, 2009;. The value of ''b'' may be different due to feeding, sex, state of maturity, metabolic activity and genetic nature (Wootton, 1990). ...
Assessment of length–weight relationships and condition factors of two commercially important fish species, Mullet, Mugil cephalus and Sardine, Sardinella maderensis, from Okrika estuary was conducted from October, 2015 to February, 2016. A total of 60 samples of the two fish species were caught by fishermen using various gears. The results obtained showed that the two fish species had isometric growth patterns with the growth exponents, b values of 2.86 and 2.91 for Mullet, Mugil cephalus and Sardine, Sardinella maderensis, respectively. These values were isometric because they were not significantly (p>0.05) different from 3 when t-test was carried out. The condition factors, K of both species were 1.2 and 1.3 which indicated that they were in good condition during the sampling period. This study was necessary to fill the new knowledge gap and provide baseline and first-hand information for management and conservation of the two investigated species in Okrika estuary.
This study recommended that further research needs to be conducted because the sample size of the two fish species collected and sampling duration (4 months) might be too small to make a valid, rigid and concrete conclusion.
... Fish weight was measured after drying its body with a piece of clean hand towel. The relationship between the total length (L) and total weight (W) of fish was expressed by the following equations: [14,15] W = aL b (non-linear relation) and ...
... [18,19] It was reported that the lengthweight relation gave information on the condition and growth patterns of fish. [15,20] Fish are said to exhibit isometric growth when length increases in equal proportions with body weight for constant specific gravity. The regression coefficient for isometric growth is '3' and values greater or lesser than this value indicate allometric growth. ...
... The regression coefficient for isometric growth is '3' and values greater or lesser than this value indicate allometric growth. [15,21] ...
The study was undertaken to assess the accumulation of some heavy metals (Cr, Co, Cu, Ni, Zn, Pb and Cd) in different tissues (muscle, gills, heart, liver, brain, bone and skin) of Tilapia nilotica. It is one of the most edible fish species in Egypt and was collected from a commercial fish farm in order to evaluate their potential risk to fishermen and consumers. This fish farm is fed with discharged water containing agricultural, industrial, sewage and domestic wastes. The length-weight relation and condition factor calculation of Tilapia nilotica samples showed a significant linear regression (r(2) = 0.920) and an average condition factor of 4.1 g/cm(3). This indicated that the health status for the studied fish samples was good. Metal pollution index (MPI) values for the determined heavy metals in the different tissues reflected that the muscle was the only tissue that had the lowest content. Provisional Tolerable Weekly Intake (PTWI) values for the investigated heavy metals were lower than those reported for the permissible limits. The data were evaluated by using ANOVA statistical analysis. For appraising the human health risk effects of heavy metals in fish muscle, estimated dietary intake (EDI) and hazard quotient (HQ) were determined. HQ levels indicated that Cr and Co were the only heavy metals among the determined ones that had values more than unity. Also, their relative contributions in fish consumptions were Cr> Co> Pb> Ni> Cu> Cd> Zn. The highest average HQ value of chromium determined in this study referred to the possible adverse effects of Cr on human health. Accordingly, the potential public health risks from dietary exposure to hazardous contaminants in fish species from fish farms must be continually subjected to research, regulation and debate.
... According to Le Cren (1951) when b is equal to 3 or close to 3, growth in the fish is said to be isometric, i.e. fish becomes more robust as they increase in length, but when 'b' is far less or greater than 3, growth in the fish is allometric, i.e. the fish becomes thinner with increasing length. As suggested by Abowei (2009) in the present study also the growth pattern for L.nebulosus and L.microdon were found to be isometric indicating that the fish increases in length and weight proportionately or at the same rate and this value correlates with Mohammed et al. (2016) and Vasantharajan et al. (2013). The higher b value observed post monsoon implies standardized growth pattern after the spawning period while decreased value of regression coefficient during pre-monsoon typically reflects change in body form when the weight of the fish is altered by environmental conditions, especially temperature, food supply, life stages, sex, fishing area, and sample size variations (Ricker, 1973). ...
... Moreover the mean values indicate healthy nature of fish population as the values are greater than 1. According to Maurya et al. (2018) if the K value is ≥ 0.5, the fish is said to be adequately fed; correspondingly in the present study Kc >1 was obtained for both species (Abowei, 2009;Eyo et al., 2015;Mohammed et al., 2016;Ogunola & Onada, 2017) throughout the four seasons. The relative condition factor Kn ranged between 0.99 and 1.0 similar to the observation made by Jisr et al. (2018) signifying the status of wellbeing of these fish species. ...
Estimation of length-weight relationship and condition factor of two commercially important Lethrinus species, Lethrinus nebulosus and Lethrinus microdon along Thoothukudi coast was studied from January 2019 to December 2019. A total of 736 samples of the two species were subjected to morphometric investigation for evaluating their total length and total body weight and analyzed season wise. The results indicate an isometric growth pattern with growth exponent, b values of 2.90 and 2.84 for L. nebulosus and L. microdon respectively. There was a strong positive correlation (r = 0.99-1.0) between the length and weight of fish samples examined while the coefficient of determination (R 2) varied between 0.97-1.0 during all four seasons. The relative condition factor (Kn) was 1.0 for both species while Fulton's condition factor (Kc) was observed to be 1.52 and 2.08 for L. nebulosus and L. microdon respectively.
... Condition factor can be used as an index of growth and feeding intensity (Fagade, 1979;, George et al., 2013, Omobepade & Ajibare, 2015. It was also linked with reproductive cycle of fishes (Fawole & Arawomo, 1998;Abowei, 2009;2010, Omobepade & Ajibare, 2015 and as indicator of environmental quality (Ajibare et al., 2017). ...
... The condition factor is however higher than the values reported by Meye and Arimoro (2005) for M. dux in Odogboro river, Nigeria and Olawusi-Peters et al. (2014) for Nematopalaemon hastatus and Parapenaeopsis atlantica in coastal waters of Ondo State, Nigeria. These discrepancies may be as a result of variations in environmental factors such as feeding activities, food availability, sex difference, change in season as well as gonad maturity level (Abowei, 2009), sampling size, habitat suitability and the length interval within different areas (Lawal-Are & Owolabi, 2012). Furthermore, David et al. (2010) pointed out that the value of 'K' of fish can be influenced by stomach fullness, length-weight relationship and decrease in water volume. ...
The condition factor and length-weight relationship of 209 berried Macrobrachium vollenhovenii from Asejire Reservoir was examined for a period of six months. Regression analysis was used to determine the length-weight relationship while the data were also subjected to Descriptive analysis, Standard deviations and frequency distribution to evaluate means. The relationship among parameters was determined by correlation. The mean total length was 13.45±1.41 cm while the mean total weight was 76.25±9.63 g. The mean length and mean weight of cephalothorax were 6.98±1.13 cm and 21.05±3.49 g respectively. The total weight had strong and positive correlation with weight of walking leg (0.93); Body weight (0.94) and length of walking leg (0.95). The condition factor which measures the general well-being of fish ranged from 2.79 to 3.33 (mean = 3.14) while the regression coefficient (b) of weight and length ranged from 1.98 to 2.33. The study revealed that berried M. vollenhovenii exhibited negative allometric growth while their condition factor showed that prawns from Asejire reservoir were healthy even in their reproductive stages. This showed that the study area is conducive for the development and sustenance of M. vollenhovenii despite the various human activities in the reservoir and its seed could be used for aquaculture industry.
... The caudal fin is deep chrome with long and pointed tips, and the dorsal fin has a golden tint and a black tip (Figure 1.1). There is also a apparent dark spot behind the operculum, which is in some individuals followed by additional smaller spots (Abowei 2009). The species' maximum total length was reported to be 30.4 ...
... Comparably low fecundities observed in Cape Coast females were explained with relatively poor feeding conditions (Blay Jr. & Eyeson 1982a, b). All mentioned studies on ABF confirmed the general trend, that fecundity is positively correlated with fish length and weight (Facade & Olaniyan 1972, Blay Jr. & Eyeson 1982a, Hunter et al. 1985, Abowei 2009). The Bonga Shad Ethmalosa fimbriata (Bowdich, 1825) 31 ...
Marine fishes employ specialized reproductive tactics in response to hydrographic fluctuations in their spawning habitats. Unprecedented environmental conditions induced by climate change will challenge these behavioral and physiological adaptations. Taking into account the key drivers of stock productivity, this work aimed at assessing the reproductive adaptations of a clupeid fish species, Ethmalosa fimbriata, towards hydrographic alterations in its spawning habitats: the upwelling area at the Senegalese South Coast and the inverse hypersaline Sine Saloum estuary. Obtained results show that E. fimbriata's is adapted towards increasing its reproductive investment at high water temperatures (26 - 30°C) and at salinities (42 - 51), which by far exceed marine conditions, in an effort to maximize recruitment success. Examination of oocyte fatty acid profiles revealed that oocytes spawned inside the estuary under these high temperature/high salinity conditions were likely to develop normally. Investigation of spawning energetics and otolith micro-chemistry evidenced distinct stock spawning components, which are characterized by delimited home ranges and specific productivity. Because of this complex stock structure and by employing auspicious reproductive tactics the species is so far likely to benefit from the severe impacts of climate change on its spawning habitat. The adaptations described herein potentially allow for out-competing other pelagic fish species with lower adaptive potential. All in all, high plasticity in reproductive traits combined with high fecundity and small generation times in clupeid fishes such as E. fimbriata may lead to an enhanced fitness during rapid environmental changes.
... E. fimbriata is a pelagic-neritic species belonging to the family clupeidae found in coastal and estuarine areas. It feeds by filtering phytoplankton, chiefly diatoms and breeds throughout the year in waters of salinities 3.5-38 ppt (Abowei, 2009). ...
... The two environmental parameters used most often in investigations about relationships between the environmental changes and fish abundance are sea surface temperature (SST) and chlorophyll-a (Chl-a) concentration (phytoplankton biomass). A change of 0.1 o C could be perceived by many fish species and temperature can impact fish in many different ways (Abowei, 2009). Temperature influences fish during spawning, and at the development and survival of the eggs and larvae, as well as influencing distribution, aggregation, migration and schooling behavior of juveniles and adults (Gordoa et al., 2000;Laevastu and Hayes, 1981;Sund et al., 1981).Chlorophyll-a concentration considered as the phytoplankton biomass is the primary food source of any small pelagic species (Zainudhin et al., 2004). ...
The seasonal variability of Ethmalosa fimbriata abundance off Senegal Coastal Waters was investigated using an observation sea surface temperature (SST) and chlorophyll-a (Chl-a) concentration from PATHFINDER and SeaWiFS satellites' data of 1999-2009. The results showed that the variability of E. fimbriata landings in Senegalese waters is related to environmental changes. The seasonal fluctuations of E. fimbriata landings off Senegal Coastal Waters seemed to be governed by the combined effect of SST and Chl-a. However, SST better explains the seasonal variations of E. fimbriata landings than Chl-a, when they are used separately. A variabilidade sazonal da abundância de Ethmalosa fimbriata na Zona Costeira do Senegal foi investigada através da observação da temperatura da superfície do mar (TSM) e da concentração de clorofila-a (Chl-a) a partir de dados dos anos de 1999-2009, provenientes dos satélites PATHFINDER e SeaWiFS. Os resultados observados mostraram que a variabilidade da pesca de E. fimbriata em águas senegalesas aparentemente está relacionada com as mudanças ambientais. As flutuações sazonais na pesca de E. fimbriata na Zona Costeira do Senegal parece ser controlada pelo efeito combinado da TSM e Chl-a. Porem, a TSM explica melhor as variações sazonais na pesca de E. fimbriata que a Chl-a, quando estas variáveis são utilizadas separadamente. Palavras-chave: Clorofila-a, Ethmalosa fimbriata, Temperatura da superfície do mar, Senegal.
... This is particularly so important on fishes which are widely consumed locally such as Bonga shad fish, popularly called Efolo among the Yoruba. Abowei [14] described Bonga shad fish as catadromous freshwater fish which belongs to the family clupeidae and other clupiformes which George et al. [15] identified among the commercially exploited fishes for human consumption especially in Africa due to its cheap price. FAO [16] confirmed inadequacy or non-existence of food-borne disease surveillance in Nigeria which usually hinders government's ability to truly assess the impact of food-borne diseases arising from the consumption of contaminated fishery products. ...
... (2005), Oscoz et.al., (2005, Rajsegar (2005), Froese (2006, Andreu-Soler et.al., (2006), Kumar et.al., (2006), Miranda et.al.,(2006, Laleye (2006), ), Hossain et.al., (2006, Ayoade and Ikulala (2007), Pervin and Mortuza (2008), Mohanraj ( 2008), Heydarnejad (2009), Abowei (2009), Bahuguna et.al., (2009, Muchlisin et.al., (2010), Imam et.al., (2010), Deekae et.al., (2010, Kar and Barbhuiya (2010), Gupta, et.al., (2011), Oribhabor et.al.,(2011, Pepple and Ofor (2011), Khan et.al., (2011), ...
Analysis of length-weight relationship and relative condition factor of the hillstream fish mastacembelus armatus (lacepede) from river nayar, garhwal, uttarakhand ARTICLE INFO ABSTRACT One of the important aspects of fish biology is the length weight relationship and relative condition factor. In the hillstream fish Mastacembelus armatus, a relationship between total length and body weight was studied sex wise and season wise. The length and body weight ranged from 10 to 59.2cm. and 7.0 to 250 gm. in males and 21.2 to 56.3 cm. and 37 to 229 gm. in females respectively. The regression coefficient for sex wise and pooled data varied from a maximum of 3.997 for male (r = 0.794) and minimum of 3.977 for female (r = 0.414) fishes. Sex wise seasonal data ranged from 1.811 (r = 0.207) during the autumn months to 5.658 (r = 0.820) during summer for the males. However, in female it ranged from 4.043 (r = 0.339) during autumn to 6.682 (r = 0.245) during summer seasons. The relative condition factor was maximum for males as 1.265 ± 0.199 and for females 1.339 ± 0.074 in the month of February. The lowest value was observed 0.779 ± 0.167 for males and 0.888 ± 0.058 for females in the month of July. Season wise the Kn values were observed high 1.016 ± 0.181 for males and 1.009 ± 0.229 for female fishes in spring. It is also observed that the second next peak values were found during winter for both sexes (For male: 1.003 ± 0.391 and female: 1.002 ± 0.411) which represent good condition of fish on the basis of active feeding and suitability of the environment.
... The weight-length relationships for bonga were isometric in Senegal. An isometric relationship was also reported for bonga in the Niger Delta [27] , and previously in Senegal [9,10] . However, these authors found highly significant differences between the populations off northern Senegal and those off southern Senegal, as well as highly significant differences between Gambia and mid-Senegal. ...
... The condition factor (K) of C. puncticeps and C. quardilineatus was 0.735 and 0.634 respectively (Table 3), showed the moderate favorable environmental condition in the area. Similar condition factor for these species were described from coastal waters of Nigeria from Nkoro River Niger Delta [38]. For the C. arel the K value (0.469) showed the poor conditions and similar condition factor was described from coastal waters of Tighra reservoir, Gwalior, throughout May 2012 to April 2013. ...
INVESTIGATION OF BIOCHEMICAL ASPECTS IN EDIBLE TISSUES OF
FLATFISHES ALONG THE COASTS OF BALUCHISTAN AND SINDH
Wajid Ali 1
, Noor us Sahar 2
, Faiz Muhammad2
, Muhammad Aslam 1
and Muhammad Shafi 1*
1
Lasbella University of Agriculture, Water and Marine Sciences, Uthal, Balochistan.
2Centre of Excellence in Marine Biology, University of Karachi, Karachi.
*Corresponding author: mshafi3333@yahoo.com
ABSTRACT
The current study was based on proximate composition of seven species of sole fishes belong to three different
families; Paralichthyidae, Cynoglossidae, and Soleidae. Biochemical analysis have been done on Cynoglossus
punticeps, Cynoglossus arel, Pseudorhombus javanicus, Pseudorhombus elevates, Cynoglossus quadrilineatus,
Brachirus orientalis, Dagetichthys commersonnii. Biochemical composition was analyzed and compared along five
landing sites from Balochistan and Sindh province. Current study revealed that the high Protein concentration was
estimated within species of from sole fishes, the highest reported value was 664.969mg/mL from Pseudorhombus
elevates and lower was reported 25.723 mg/mL from Dagetichthys commersonnii.
Lipid concentrations have been done within species whereas highest lipid was 36.198% in Cynoglossus puncticeps and
lowest found 7.613% in Dagetichthys commersonnii. While highest carbohydrate found 5.277% in pseudorhombus
javanicus and lowest was 3.8722% in p. elevatus. Highest moisture content was reported 75.433% in p. elevats and
lowermost was 70.839% in Brachirus orientalis.
Keywords: Biochemical analysis, Flatfishes, Carbohydrate, Lipid, Proteins, Moisture.
... The specimens analysed in this study belonged to a wide spectrum of sizes, ranging from small (from 2.7 cm L F ) to larger individuals (up to 30.4 cm L F ). Morphometric and ponderal measurements and their relationships (e.g. M -L F ) are important tools in fishery management (Abowei 2009) and stock assessment studies, because they allow either biomass or body length to be estimated when one of these values is lacking. The length-weight relationship is also used to assess the growth performance of cultured fish to determine whether the food intake is transformed into energy for growth (Philipose et al. 2013). ...
This is the first paper to provide detailed information on the age and growth of Trachinotus ovatus. The size of the 244 individuals collected in the Strait of Messina ranged from 2.7 to 30.4 cm in fork length (LF) and 0.31 to 508.6 g in body mass (M). The relationship between these parameters (M - LF) was investigated and showed a good fit. Age estimation based on vertebrae and otoliths yielded similar results, suggesting a maximum age of five years. However, the precision and accuracy tests, such as percentage of agreement (PA), mean coefficient of variation (ACV) and average percent error (APE) indicated that the otolith readings (97.83% PA, 0.54% ACV and 0.38% APE) were more reliable for age estimation than vertebrae readings (82.17% PA, 5.33% ACV and 3.77% APE). The multi-model inference approach allowed us to compare different non-linear growth models. The von Bertalanffy model (L∞=29.139, k=0.496 and t0=−0.347) fitted the length-at-age data best. This species has a relatively rapid growth and an estimated longevity of five to seven years. This information could be used for management and first stock assessment studies on T. ovatus in the Mediterranean Sea.
... This is particularly so important on fishes which are widely consumed locally such as Bonga shad fish, popularly called Efolo among the Yoruba. Abowei [14] described Bonga shad fish as catadromous freshwater fish which belongs to the family clupeidae and other clupiformes which George et al. [15] identified among the commercially exploited fishes for human consumption especially in Africa due to its cheap price. FAO [16] confirmed inadequacy or non-existence of food-borne disease surveillance in Nigeria which usually hinders government's ability to truly assess the impact of food-borne diseases arising from the consumption of contaminated fishery products. ...
This study was carried out to determine microbial load of fresh and smoked Bonga shad fish (Ethmalosa fimbriata) and hygiene practices among fishmongers in Epe town, Epe Local Government Area of Lagos State (Nigeria). Through a cross-sectional in design, a semi-structured questionnaire was administered on 44 consented fishmongers to collect data on their knowledge of fish contamination and spoilage, and their hygiene practices. Key informant interview guide also was used to collect data on fish preservation methods. In addition, 34 Bonga shad fish samples were collected for bacteriological analysis using standard methods. Quantitative data were analyzed using descriptive statistics and fisher’s exact Chi-square at p=0.05 while key informant interview responses were analyzed using thematic referent approach. Fishmongers’ age was 37.1±10.8 years; 90.9% were female while 45.5% had completed primary education. The major source of water supply reported by the fish mongers was stream (84.1%). Significantly high proportion (77.8%) of smoked fish sellers demonstrated good knowledge on fish contamination and spoilage. The major fish preservation methods identified in the study were smoking, salting, preservation with ice, and live fish preservation, using valium and paracetamol tablets. Predominantly identified microorganisms were fish spoilage micro-organisms. Education of fish mongers on the importance of maintaining good hygiene levels, and the use of treated water for fish processing are therefore recommended.
... Indian waters. Studies on the taxonomy and description (Whitehead, 1985;Fishbase, 2009), dynamics of the exploited population (Abasi et al., 2004), population structure (Durand et al., 2005), heavy metals accumulation in tissue (Monday and Benson, 2007), morphology and length-weight relationship (Abowei, 2009) and catch rate of juveniles (Sheriff et al., 2010). ...
This book describes you the taxonomical identification of Clupeiformes fishes of
Southeast coast of India. Nagapattinam, Puducherry fishing harbors and Parangipettai
fish landing centre, was the places mainly concentrated for the sample collcetion. A total
of 56 species of Clupeiformes fishes belonging to 19 genera and 4 families were
identified during January 2008 to December 2009. The order Clupeiformes comprised
four families namely Clupeidae, Engraulidae, Pristigasteridae and Chirocentridae. The
family Clupeidae was represented by 30 species belonging to twelve genera. The family
Engraulidae was represented by 17 species belonging to four genera. The family
Pristigasteridae was represented by 7 species belonging to two genera. The family
Chirocentridae was poorly represented at all the three stations by only 2 species
belonging to single genera.
A clear detailed study on the description of the order Clupeiformes and family
chirocentridae, key characters clupeoid families and clupeoid genera were given for
trouble-free identification.
Vivid pictographic representation with Classification, distribution and statistical
analysis (mean, median, mode, standard deviation, and standard error) were described
and demonstrated on the basis of adequate samples and morphometric and meristic
characters of all the 56 species were explained using the key of Whitehead (1985).
... Bonga shad, Ethmalosa fimbriata (Bowdich, 1825), is an estuarydependent tropical species, distributed from Mauritania to Angola (Lozano-Rey, 1950;Poll, 1953;Charles-Dominique, 1982;Lévêque et al., 1990) and is the most wide-spread clupeid inhabiting brackish waters of the West African coastal estuaries (Charles-Dominique, 1982). Ethmalosa fimbriata can live in a wide and varying range of salinity between 5 and 90 ppt (Charles-Dominique and Abowei, 2009). Although, the individuals of this species spend most of their life in estuaries and spawn in the open sea near the coast (Charles-Dominique, 1982). ...
Small pelagic fish occupy a significant component of the food supply in West Africa and are vitally important for the nutritional needs of local people. The bonga shad (Ethmalosa fimbriata Bowdich, 1825) is the third most-exploited of the small pelagic species fished from coastal waters of Senegal (after Sardinella aurita and S. maderensis) and is routinely consumed by Senegalese people. Bonga shad fishing is practised mainly by artisanal fishermen and of great importance to the Senegalese economy and food security in the region. Our study was designed to examine population dynamics of bonga shad to support the development of fishery management options that may improve the livelihoods of artisanal fishermen. The current rate of exploitation (E=0.8) suggests that the bonga shad in Senegal is over-fished. In addition, we describe seasonal variability in recruitment and biomass of bonga shad along the Senegal coast, its downward trend in landings over a 17-y study period, and its decline (18%) in maximum size over a 63-y period. We attribute the declines to an increase in fishing pressure and/or changes in local climate. To reverse the effects of overexploitation of the bonga shad stock, it will be necessary to drastically reduce fishing effort, apply and enforce regulatory restrictions on the capture, sale and processing of juveniles, and prohibit seiners and monofilament nets in the fishery.
... The high K value could also be explained probably because they were sampled when they were not breeding. This statement contradicts [43][44][45][46][47][48], who reported that their spawning, oviposition and early embryonic development are restricted to the beginning of the dry season months from November to January. During this period, their condition factor is expected to drop as they are spawning or breeding. ...
Assessment of length-weight relationship and condition factor of a commercially important mollusc species, Periwinkle, Tympanotonus fuscatus, from Okrika estuary was conducted from October, 2015 to February, 2016. A total of 120 samples of the species were hand-picked from the mangrove ecosystem of Okrika. The results obtained showed that the gastropod species had negative allometric growth patterns with a growth exponent, b value of 2.18. This value was confirmed as negative allometric, because it was significantly different (p<0.05) from 3 when a t-test was carried out. The mean condition factor, K of the species was 18.9, which indicated that they were in good condition during the sampling period.This study recommends that further research needs to be conducted because the sampling duration (4 months) might be too small to make a valid, rigid and concrete conclusion. Also efforts should be undertaken to reduce the pollution load in order to safe-guard this valuable resource for the local population.
... Factor of Periwinkle (Tympanotonus fuscatus, Linnaeus 1758) from Okrika Estuary Condition Factor (CF) is an estimation of general well-being of fish (Oribhabor et al., 2011) and is based on the hypothesis or assumption that heavier fish (at a given length) are in better condition than the lighter ones ( Bagenal and Tesch, 1978;Ogamba et al., 2014). The condition factor of 1.0 or greater indicates the good condition of fish while less than 1.0 shows bad condition (Abobi, 2015).The condition factor can be influenced by season, sex, type of food organism consumed by fish, age of fish, amount of fat reserved and environmental conditions ( Bagenal and Tesch, 1978;Anene, 2005;Abowei, 2009). ...
Assessment of length weight relationship and condition factor of a commercially important mollusc species, Periwinkle, Tympanotonus fuscatus, from Okrika estuary was conducted from October, 2015 to February, 2016. A total of 120 samples of the species were hand
picked from the mangrove ecosystem of Okrika. The results obtained showed that the gastropod species had negative allometric growth patterns with a growth exponent, b value of 2.18. This value was confirmed as negative allometric, because it was significantly different (p<0.05) from 3 when a t test was carried out. The mean condition factor, K of the species
was18.9, which indicated that they were in good condition during the sampling period.
... The high K value could also be explained probably because they were sampled when they were not breeding. This statement contradicts [43][44][45][46][47][48], who reported that their spawning, oviposition and early embryonic development are restricted to the beginning of the dry season months from November to January. During this period, their condition factor is expected to drop as they are spawning or breeding. ...
Assessment of length-weight relationship and condition factor of a commercially important mollusc species, Periwinkle, Tympanotonus fuscatus, from Okrika estuary was conducted from October, 2015 to February, 2016. A total of 120 samples of the species were hand-picked from the mangrove ecosystem of Okrika. The results obtained showed that the gastropod species had negative allometric growth patterns with a growth exponent, b value of 2.18. This value was confirmed as negative allometric, because it was significantly different (p<0.05) from 3 when a t-test was carried out. The mean condition factor, K of the species was 18.9, which indicated that they were in good condition during the sampling period.This study recommends that further research needs to be conducted because the sampling duration (4 months) might be too small to make a valid, rigid and concrete conclusion. Also efforts should be undertaken to reduce the pollution load in order to safe-guard this valuable resource for the local population.
... The cause of variation in the morphometric and meristic characters may range from variability to the intraspecific which is under the influence of environmental parameters [9]. The morphometric relationships between various body parts of fish can be used to assess the well being of individuals and to determine possible difference between separate unit stocks of the same species [10]. Fish are very sensitive to environmental changes and quickly adapt themselves by changing necessary morphometrics [11]. ...
... Bonga shad, Ethmalosa fimbriata (Bowdich, 1825), is an estuarydependent tropical species, distributed from Mauritania to Angola (Lozano-Rey, 1950;Poll, 1953;Charles-Dominique, 1982;Lévêque et al., 1990) and is the most wide-spread clupeid inhabiting brackish waters of the West African coastal estuaries (Charles-Dominique, 1982). Ethmalosa fimbriata can live in a wide and varying range of salinity between 5 and 90 ppt (Charles-Dominique and Abowei, 2009). Although, the individuals of this species spend most of their life in estuaries and spawn in the open sea near the coast (Charles-Dominique, 1982). ...
... Also similar work by King (1996) gave the condition factor of Periophthalamus barbarus in Iwo River for males and combined sexes as 1.19 and 1.01 respectively. This result also conforms to the value obtained by other researchers like Abowei (2009), with a value of 0.946 and monthly condition factor of 0.6-1.00; Ajayi (1982) reported a value between 0.77-0.81 ...
... It is supposed that heavier fish of a particular length are in better physiological condition [8] . Condition factor is also a constructive index for examining the feeding intensity of fish its growth rates and age [9] . Both biotic and abiotic environmental factors strongly influenced conditions factor of fish and also assess the status of the aquatic ecosystem [2] . ...
This study was the first effort to illustrate the length-weight relationship (LWR), condition factor and sex
ratio of an economically important Snow trout, Schizothorax plagiostomus collected from Neelum and
Jhelum Rivers, Muzaffarabad, Azad Kashmir. The LWR of S. plagiostomus was analyzed for both sexes
with formula Log W = Log a + b Log L. A total of 330 specimens were collected during January to
December, 2012 by using conventional fishing tools. The allometric coefficient b of LWR was found to
be negative (b<3) all over the year. A trend line graph disclosed the declination in growth condition. The
sex ratio of S. plagiostomus was calculated as 0.15: 6.4 (male: female) which strongly favors the
dominance of the female sex over male in the natural population throughout the year. It is concluded that
LWR, condition factor and sex ratio of S. plagiostomus demonstrated significant variation with
environmental and physiological factors. This study would be useful to handle the adequate regulations
and conservation of sustainable fishery management.
... It is supposed that heavier fish of a particular length are in better physiological condition [8] . Condition factor is also a constructive index for examining the feeding intensity of fish its growth rates and age [9] . Both biotic and abiotic environmental factors strongly influenced conditions factor of fish and also assess the status of the aquatic ecosystem [2] . ...
This study was the first effort to illustrate the length-weight relationship (LWR), condition factor and sex
ratio of an economically important Snow trout, Schizothorax plagiostomus collected from Neelum and
Jhelum Rivers, Muzaffarabad, Azad Kashmir. The LWR of S. plagiostomus was analyzed for both sexes
with formula Log W = Log a + b Log L. A total of 330 specimens were collected during January to
December, 2012 by using conventional fishing tools. The allometric coefficient b of LWR was found to
be negative (b<3) all over the year. A trend line graph disclosed the declination in growth condition. The
sex ratio of S. plagiostomus was calculated as 0.15: 6.4 (male: female) which strongly favors the
dominance of the female sex over male in the natural population throughout the year. It is concluded that
LWR, condition factor and sex ratio of S. plagiostomus demonstrated significant variation with
environmental and physiological factors. This study would be useful to handle the adequate regulations
and conservation of sustainable fishery management.
... Comparisons therefore could be meaningful if these factors are roughly equivalent among the samples to be compared (Abowei, 2009b). The condition factor of a fish decrease will increase in length (Bakare, 1970;Fagade, 1979) and also influences the reproduction cycle in fish (Abowei, 2009c). The length weight relationship of a fish is an important fishery management tool. ...
An estimation of the size composition and condition factor of Ophiocara porocephala from Amassoma flood plains, Niger Delta, Nigeria was carried out for a period of six months (April-June 2010 and November, 2011- January, 2012) to assess aspects of the fishery status. The flood plain of Amassoma is one of the low lands in Niger Delta providing nursery and breeding grounds for variety of both finfish and shell fish species. Fish plays on important role in the development of a nation. Apart from being a cheap source of highly nutritive protein, it also contains other essential nutrients required by the body. Therefore the study of condition factor and size composition of Ophiocara porocephala from Amassoma flood plains will provide information on the amount of stock available for the fishery, evaluation of production, information for stock sizes, an important information for the evaluation of mortalities and status of the fish population, estimating the average weight at a given length group and an index of growth and feeding intensity. Length measurement values ranged from 8.2-15.3 cm; while width, weight and condition factor measurement values ranged from 1.2-2.5 cm, 3.98 g-40.35 g and 0.29-1.78. The highest length frequency (26) was estimated for values ranging from 11.5-12.5 with class mark 12.0 mm. The lowest length frequency (1) was estimated for length range 14.8-15.8 mm with class mark 15.3 mm. The highest width frequency (27) was estimated for values ranging 1.8-1.9 mm with class mark 1.85 mm. The lowest width frequency (2) was estimated for values ranging from 2.2-2.4 and 2.5 -2.6 mm with class marks 2.45 and 2.65 mm, respectively. The highest weight frequency (31) was estimated for values ranging from 10.0-14.9 g with class mark 12.45 g. The lowest weight frequency (2) was estimated for values ranging 6. 0-10.9 g with class mark 8.45 g. The highest condition factor frequency (49) was estimated for values ranging from 0.9-1.1 with class mark 1.0. The lowest condition factor frequency (4) was estimated for values ranging from 0.3-0.5 with class mark 0.4. From a sample size of 81 specimens, K value was 0.999 and the exponential equation was Wt = = 0.05998 (TL) 2 719, indicating an isometric growth pattern. There was no temporal variation in the condition of the fish with condition index value 0.99- 1.00 and condition factor value of 0.999 is an indication of the fish species poor condition.
The growth and size at first sexual maturity of the species Ethmalosa fimbriata were studied in two sites in the Ebrié lagoon: Bietri, a highly anthropized environment and Vitré 2, a reference site. Growth parameters estimated from size frequencies showed that growth in both size and weight was faster in females than in males regardless of habitat. On the other hand, specimens from Biétri bay have a slower growth rate than those from Vitré 2. In Bietri bay, individuals are characterized by early sexual maturity. They reach sexual maturity at the age of 0.55 years (about 7 months), corresponding to a size of 6.13 cm for males and 8.42 cm for females; whereas in Vitré 2, they reach sexual maturity at the age of 0.82 years (about 10 months) corresponding to a size of 10.22 cm and 12.94 cm for males and females respectively. These results show that in a highly antropic environment, the growth of Ethmalosa fimbriata is affected and individuals reproduce earlier.
Successful recruitment of small pelagic fish populations into upwelling areas is subject to variations in fecundity and spatial and temporal fluctuations in environmental conditions such as temperature and food availability. In West Africa and Senegal in particular, the lack of adaptive responses to climate change can impact food security. Based on this observation, this work aims to evaluate the exploitation of small pelagic in Senegal in a variable environmental context and at a seasonal and annual basis. The results show that round sardinella (Sardinella aurita) and bonga shad (Ethmalosa fimbriata) are biologically overexploited. We postpone a decrease in growth performance for round sardinella and bonga shad, as well as a decrease in their maximum size over 60 years (between 1950 and 2013) of 20% and 18% for round sardinella and bonga shad, respectively. In addition, the seasonal variability in recruitment and biomass of round sardinella and bonga shad show upward and downward trends in landings between 1996 and 2013, respectively. In one hand, as round sardinella is a shared stock by several countries in the sub-region, intergovernmental management remains the best option for the sustainability of its exploitation. On the other hand, for bonga shad, which is more sedentary and distributed among several stocks and meta-population in the sub-regions, the usual indicators, such as biomass per recruit and yield per recruit, remain relevant in terms of support for their national management. This work highlights the importance of the impact of environmental variability on the growth and reproduction performance of small pelagic in an east border upwelling system. The phenotypic plasticity of round sardinella and bonga shad allows them efficient adaptation to their environment by synchronizing their reproduction during upwelling event combined at a relatively high sea surface temperature. Climate changes potentially have a major effect on the distribution and abundance of small pelagic fish because of their influence on their recruitment. As a result, small pelagic species living in upwelling regions appear to have developed mechanisms to cope with environmental variability, such as opportunistic breeding tactics, improving their growth performance or increasing their egg production by following the more predictable system attributes of seasonal cycles. For a better understanding of the processes underway in Senegalo-Mauritanian upwelling system, we are advocating for increased sub-regional scientific collaboration that is still struggling to put into practice and a reflection on agro-ecology concepts to apply to West African fisheries.
The effect of processing variables [blanching conditions (time and temperature) and frying temperature] of bonga fish (Ethmalosa fimbriata) on different responses were investigated, using response surface methodology to establish the optimum processing conditions. Six responses were evaluated and they include moisture content, oil content, breaking force, lightness, redness and yellowness. Sensory qualities of the samples were also determined. Using numerical optimization, the optimal conditions for the processing of fried bonga fish was estimated as 60 °C (blanching temperature), 1 min (blanching time), and frying temperature of 150 °C. Results from sensory evaluation also suggests that samples obtained at this condition were better in terms of taste, aroma, color and general acceptability to consumers. Observations from this study indicate the efficiency of the regression equations for predicting parameters for fried bonga fish. The blanching pretreatment also reduced oil uptake and positively influenced the characteristics of fried bonga fish. Such knowledge of the optimization of these conditions will further benefit processors of fish and other similar products. The optimized conditions could also be applied to successfully obtain fish of good quality, which can be further commercialized.
The aim of this study was to determine the prevalence of bacterial species associated with smoked and fresh Bonga (Ethmalosa fimbriata) sold at two different markets in Uyo using standard microbiological techniques and their susceptibility to antibiotics (cephalosporins) using Disc Diffusion Technique (DDT). The results of the bacteriological status of both fresh and smoked Bonga fish showed variations in the total bacterial and total conform counts in different anatomical parts (skins, gills and intestine). The highest total bacterial counts was recorded from gills (9.2×l05 cfug-1) and lowest in skin (4.3×l05 cfug-1) in fresh bonga fish, while the highest total bacterial counts was obtained in intestine (7.7×l04 cfug-1) and lowest in skin (3.1×l04 cfug-1) in smoked Bonga fish. The total conform counts of the fresh Bonga fish ranged from 3.3×l02 to 4.1×10s, 3.6×l02 to 3.1×10s and 4.3×l02 to 7.5×10s in skins, intestines and gills, respectively. In smoked fish, the skin had the lowest total coliform counts (1.5×l02), while the highest coliform counts was obtained in gills (3.5×10s). The prevalence of the Streptococcus spp., Escherichia coli, Yersinia sp., Enterobacter sp., Staphylococcus aureus, Enterococcus sp., Vibrio cholerae, Proteus sp., Shigella sp., Salmonella sp. and Campylobacter sp. isolated from both fresh and smoked fish samples varied depending on the anatomical parts. The results of antibiotic susceptibility showed that the bacteria isolated from both fresh and smoked fish were more sensitive to ceftazidime, cefoxitin and cefoperazone than cephalothin. However, both fresh and smoked Bonga fish could be carriers of pathogenic bacteria and a vehicle of transferring bacterial food borne infections and intoxication and cephalosporins may be the drugs of choice for the treatment.
A survey of the studies published in two leading fisheries journals revealed that the analysis and measurement of condition, based on length-weight data, has been performed using a wide variety of indices and statistical procedures. Eight forms of index were identified which can be categorized into those which measure the condition of individual fish, i.e. condition factors‘, and those which measure the condition of subpopulations as a whole, i.e. regressions of log, 10 weight on log, 10 length and the parameters of such regressions. Analysis of a test data set indicated that both the form of index and properties of the data set size can dictate the patterns of condition observed. The various indices were reviewed in terms of appropriateness, simplicity and statistical correctness. It was concluded that an index should be selected only after a detailed examination of both the underlying assumptions of the index and the properties of the data set.
The length-weight relationships by sexes, combined and condition factor of the snake head, Channa channa from the freshwater swamps of Niger Delta were studied. Two hundred and sixty-four samples ranging from 11.0 cm to 22.0 cm (TL) and weighing between 10.0 g and 140 g collected between June and December 1996 were analyzed. Results show that the male fish were longer than female hence more anguilliform whereas female fish are heavier with higher condition factor than male. Cube law analysis gave an exponent of 3 indicative of an allometric growth. Furthermore, female ovaries show a state of recrudescence indicating that spawning is during the rainy seasons.
Journal of Aquatic Sciences Volume 15, April 2000, pp. 12-14
KEY WORDS: Length-weight relationship, Channa channa, Niger Delta, Nigeria.
In Lake Naivasha Tilapia leucosticta (Trewavas) spawns throughout the year. Males attain maturity at 180 mm and females at 160 mm total length. Males predominate over females in the catches (sex ratio 1-00 : 0-51). Fecundity ranged from 320 to 1328 eggs with an average of 751. The relationship between fecundity (F) and total length (L), body weight (W) and gonad weight (GW) is:
The length-weight regression coefficient is near to the cube. There is little seasonal fluctuation in relative condition of the fishes.
There are species differences in the physiological robustness of Alestes nurse, Synodontis schall and Tilapia zillii. The values of coefficient of condition in the Alestes sp., Synodontis sp. and Tilapia sp. were 1·74,2·48 and 3·6 respectively. Tilapia zillii was significantly more robust than any of the other two species (P<0–02).
In ‘runted’ populations of Tilapia zilli positive correlations were found between maturation stages and the following: gonadosomatic index, gonad weight, fish weight and fish length. The minimum size at maturity was 9·0 cm in males and 11·0 cm in females. The mean fecundity in the ‘stunted’ females was 2359 eggs and it increased with length (L) weight (HO and depth (D) of the fish. There was, however, no correlation between fecundity and egg size. The results indicated that growth in this ‘stunted’T. zilli population was not isometric. The relative condition factor (Kn) which approached one indicates good condition.
The distribution of fish in the three major habitats (inshore, surface and bottom) in Kainji Lake was studied using gill-nets
in graded fleets each consisting of seven nets with mesh sizes ranging from 5 cm to 18 cm. No significant difference was observed
in the annual yields of fish in the three habitats. Three of the nine major families, however, gave higher yields in selected
habitats. Characidae and Cichlidae were most abundant in the shore and surface and Bagridae in the shore and bottom. Catches
of the Cichlidae in the surface were limited to areas where the mean depth was below 7 meters.
Analysis of variance showed no significant difference in the overall yields of fish among sampling areas located within the
major strata of the lake. Although a general trend was observed in the seasonal yields of fish, with higher yields during
low water, the variations were not significant either for the overall annual yields or among sets. The implications of these
findings in relation to the mode of life of the major fish species and the stability of the fish population are discussed.
A frame survey of fishing communities was carried out, employing the complete census technique, to assess the artisanal fisheries characteristics of the fresh water reaches of lower nun river for a period of two year, Eleven Community lie along the stretch of the study area. The total number of 4718 fishers with 1645 canoe units employing various fishing gear resulted to a fishers density of 3 fishers per canoe unit. A total of 29 fin fish families were recorded. Seasonally occurring fresh water crustacean. Attaya gaboneensis and palacemon paucidens were present. Etheria elliptica , an oyster was also present. A specie of fresh water clam, Galacea Paradoxa from the family Donacidae was present. Trichechus senegelensis (Manattee) was occasionally captured by local hunter during the flood period. Hippopotamus amphibious (Hippopotamus) was reported from isolated places but they were rare. A specie of Otta, Lutra macullicolis was present. Three species of crocodiles, Crococdylus niloticus Crocodylus cataphractus (Alligator) and Osteolaemus tetraspsis were also present. The Nile monitor, Veramus niloticus and the aquatic snake, Anoscopus sp. And three species of water turtle, Kimxy erosa , Pelumedusa sp and Peliosus sp were also present. The commonest fishing method employed was local fishponds (50.8%) and the least was gill nets (1.6%). Drift net caught the highest fish (8.01kg) per gear, while local fishponds was the least 0.25 kg. The annual catch per canoe was recorded for local fishponds (167. 84kg), while the lowest was assorted traps (14.7kg). Drift not recorded the highest annual for local fishponds. The mean biomass of 25.04 of fish catch of 20.2kg per fisher and the lowest value (4.53kg) was recorded per boat, total catch of 37903. 6kg, annual producing estimate of 434.81 tonnes, standing struck of 2.27 km-2 and of twenty two million, seven hundred and forty two thousand one hundred and sixty naira (N22742160) was estimated. The reduced annual income per fisher in the study was four thousand, eight hundred and twenty naira, thirty kobo. There is therefore the, urgent need for effective management of the Nun river fisheries, to improve on the living standard of the people.
National review for aquaculture development in Africa
- B P Satia
Satia, B.P., 1990: National review for aquaculture development in Africa. Nigeria. FAO Fish Girel, 770(29): 191
Conditions and Growth Patterns in Fresh Water Habitats Bottom Deposits as Food of Inland Fresh Water Fish In: Kainsi, A Nigerian Man Made Lake
- T B Bagenal
- A T Tesch
- Oxford Bakare
Bagenal, T.B. and A.T. Tesch, 1978. Conditions and Growth Patterns in Fresh Water Habitats. Blackwell Scientific Publications, Oxford. Bakare, O., 1970. Bottom Deposits as Food of Inland Fresh Water Fish. In: Kainsi, A Nigerian Man Made Lake. Kanyi Lake Studies. Visser, S.A. (Ed.). Vol. 1. Ecology Published for the Nigerian Institute
Estudo entre o factor de condição e relação peso/comprimento para alguns peixes marinhos
- F M S Braga
Braga, F.M.S., 1986. Estudo entre o factor de condição e relação peso/comprimento para alguns peixes marinhos. Rev. Brasil. Biol., 46(2): 339-346
Studies on the fish and fisheries of the Brass river system and adjoining coastal waters in Bayelsa State Nigeria
- F D Sikoki
- S A Hart
Sikoki, F. D. and S.A. Hart., 1999. Studies on the fish and fisheries of the Brass river system and adjoining coastal waters in Bayelsa State Nigeria. J. Appl. Sci. Environ Manag., (2): 63-67
Age determination of Tilapia melanotheron (Ruppel) in the Lagos lagoon
- S O Fagade
Fagade, S.O., 1978. Age determination of Tilapia melanotheron (Ruppel) in the Lagos lagoon, Nigeria. Int. Symp. Ageing Fish, pp: 71-77
Length-weight and diet composition of Ethinalose fimbriata (Bowchch) Pliscea: clupeidae in Cross River estuary
- E O Ekeng
Ekeng, E.O., 1990. Length-weight and diet composition of Ethinalose fimbriata (Bowchch). Pliscea: clupeidae in Cross River estuary, Nigeria. B.Sc. Project University of Calabar. Cross River State, Nigeria, pp: 36
The fish species assemblage of Odhioku-Ekpeye flood plains, Niger Delta
- E N Ezekiel
- J F N Abowei
- A I Hart
Ezekiel, E.N., J.F.N. Abowei and A.I. Hart, 2002. The fish species assemblage of Odhioku-Ekpeye flood plains, Niger Delta. Nigeria. Int. J. Sci. Technol., 1(1): 54-59
Size, Composition, age, growth, mortality and exploitation rate of Chysichthys nigrodigitatus from Nun River, Niger Delta
- J F N Abowei
- A I Hart
Abowei, J.F.N. and A.I. Hart, 2007. Size, Composition, age, growth, mortality and exploitation rate of Chysichthys nigrodigitatus from Nun River, Niger Delta, Nigeria. Afr. J. Appl. Zool. Environ. Biol., 9: 44-50
Aspects of some physicochemical parameters of the fresh water reaches of the lower Num River, Niger Delta
- J F N Abowei
- E N Ezekiel
Abowei, J.F.N. and E.N. Ezekiel, 2003. Aspects of some physicochemical parameters of the fresh water reaches of the lower Num River, Niger Delta. Int. J. Sci. Technol., 1(2): 5-9
Some population parameters of Clarotes laticeps (Rupell, 1829) from the fresh water reaches of the lower river, Niger Delta, Nigeria
- J F N Abowei
- A O Davies
Abowei, J.F.N. and A.O. Davies, 2009. Some population parameters of Clarotes laticeps (Rupell, 1829) from the fresh water reaches of the lower river, Niger Delta, Nigeria. Am. J. Sci. Res., (2): 15-19
A detail study on age and growth for Chrysichthys auratus and Chrysichthys rueppelli from the southern most part of the River Nile (Egypt)
- T S Shenouda
- F A Faten
- M R Mahmoud
- M M Ray
Shenouda, T.S., F.A. Faten, M.R. Mahmoud and M.M. Ray, 1994. A detail study on age and growth for Chrysichthys auratus and Chrysichthys rueppelli from the southern most part of the River Nile (Egypt). J Egypt Ger. Soc., 200(1412): 73-101
The Biology of Mugil cephalus in Bonny River estuary
- S A Hart
Hart, S.A., 1997. The Biology of Mugil cephalus in Bonny River estuary. M.Sc. Thesis, University of port Harcourt, Nigeria, pp: 42
Ichthyology John Wiley and Sons Inc., pp: 506. rAdv The length-weight relationship and seasonal cycle in gonad weight and condition in the perch Perca fluviatilis
- K F Lagler
- J E Bardach
- R R Litter
- D R M Passimo
Lagler, K.F., J.E. Bardach, R.R. litter and D.R.M. Passimo, 1977. Ichthyology. John Wiley and Sons Inc., pp: 506. rAdv. J. Food Sci. Technol., 1(1): 51-56, 2009 56 Le Cren, E.D., 1951. The length-weight relationship and seasonal cycle in gonad weight and condition in the perch Perca fluviatilis. J. Anim. Ecol., 20(2): 201-219
The biology of chromido Tilapia guntheri from a small lake
- S Fagade
Fagade, S., 1983. The biology of chromido Tilapia guntheri from a small lake. Arch. Hydobil., 97: 60-72
Population dynamics of the mud skipper Periophthalmus barbarus (Gobidae) in the estuarine swamps of Cross River Nigeria
- R P King
King, R.P., 1996. Population dynamics of the mud skipper Periophthalmus barbarus (Gobidae) in the estuarine swamps of Cross River Nigeria. J. Aquat. Sci., 11: 31-34
Fin and shell fish of conservation interest in Nigeria
- J G Tobor
Tobor, J.G., 1992. Fin and shell fish of conservation interest in Nigeria. NIOMR Tech Paper No 79: 1-23
Catch composition and seasonality of Fin fish in the fresh water reaches of the lower Nun River, Niger Delta
- J F N Abowei
- F D Sikoki
- A I Hart
- M E Allison
Abowei, J.F.N., F.D. Sikoki, A.I. Hart and M.E. Allison, 2007. Catch composition and seasonality of Fin fish in the fresh water reaches of the lower Nun River, Niger Delta. J. Field Aquat. Stud., 3: 8-21
West African Fresh water Fishes
- M Holden
- W Reed
Holden, M. and W. Reed, 1972. West African Fresh water Fishes. Longmans Ltd., London. pp: 33
Biometric characteristics: length weight relationships and condition factors in Chrychthys filamentosus, Pisces, Bagandae from Oguta lake Nigeria
- C S Nwadiaro
- P U Okorie
Nwadiaro, C.S. and P.U. Okorie, 1985. Biometric characteristics: length weight relationships and condition factors in Chrychthys filamentosus, Pisces, Bagandae from Oguta lake Nigeria. Biol. Afr., 2: 48-56
Length-weight relationship of Sarotheredon melanotheron and Tilapia guineensis in Elechi creek Niger Delta
- M S Diri
Diri, M.S., 2002. Length-weight relationship of Sarotheredon melanotheron and Tilapia guineensis in Elechi creek Niger Delta, Nigeria. B.Sc. Project Rivers State University of Science and Technology Port Harcourt. pp: 33
Fisheries. In: The land people of Bayelsa State Central Niger Delta
- F D Sikoki
- A J T Otobotekere
Sikoki, F.D. and A.J.T. Otobotekere., 1999. Fisheries. In:
The land people of Bayelsa State Central Niger
Delta. E.C. Alagoa, (Ed.). Port Harcourt, pp:
301-319.
The current status of fish stock and fisheries in Kainji Lake; consultancy report on fish stock assessment in Kainji Lake. The Nigerian-German (Gtz) Kainji Lake Fisheries Promotion Project
- E O Ita
- I Maelahili
Ita, E.O. and I. Maelahili, 1997. The current status of fish
stock and fisheries in Kainji Lake; consultancy report
on fish stock assessment in Kainji Lake. The
Nigerian-German (Gtz) Kainji Lake Fisheries
Promotion Project, New Bussa. pp: 128.
Preminary estimates of potential yield of Cross River State inland fresh waster fisheries
- B S Moses
Moses, B.S., 1981. Preminary estimates of potential yield
of Cross River State inland fresh waster fisheries. In:
Pro. First CR. Fish Cont. MFN Calabar. pp: 41-46.
The ecology and fishery of the Pygmy Herring Sierrathensa Leonensis (Thysvan Den Audenaerde, 1969) in the Nun River and Taylor Creek of the Niger Delta
- A J T Otobo
Otobo, A.J.T., 1993. The ecology and fishery of the
Pygmy Herring. Sierrathensa Leonensis (Thysvan
Den Audenaerde, 1969) in the Nun River and Taylor
Creek of the Niger Delta. Ph.D. Thesis. University of
Port Harcourt, pp: 298.
Fish and fisheries of Northern Nigeria. Ministry of Agriculture, Northern Nigeria
- W Reed
- T A J Burchad
- J Hopson
- J Jenness
- I Yaro
Reed, W., T.A.J. Burchad, J. Hopson, J. Jenness and I.
Yaro, 1967. Fish and fisheries of Northern Nigeria.
Ministry of Agriculture, Northern Nigeria. pp: 226.
The fresh and brackish Water fishes of W est Africa
- C O Loveque
- G G Pyugy
- Teugels
Loveque, C.O. Pyugy and G.G. Teugels, 1991. The fresh
and brackish Water fishes of W est Africa. Vol. 1
Conditions and Growth Patterns in Fresh Water Habitats
- T B Bagenal
- A T Tesch
Bagenal, T.B. and A.T. Tesch, 1978. Conditions and
Growth Patterns in Fresh Water Habitats. Blackwell
Scientific Publications, Oxford.
Report on the fisheries of the Niger Delta Special Area
- J S Scott
Scott, J. S., 1966: Report on the fisheries of the Niger
Delta Special Area. NDDB, pp: 109.
Biology of bonga fish; Ethmalosa fimbriata (Bowdich): in the Nigeria Coastal and brackish waters project (NF) 1,2. Annual Report, Nigeria Institute for Oceanography and Marine Research Lagos
- C Marcus
Marcus, C., 1984. Biology of bonga fish; Ethmalosa
fimbriata (Bowdich): in the Nigeria Coastal and
brackish waters project (NF) 1,2. Annual Report,
Nigeria Institute for Oceanography and Marine
Research Lagos. pp: 232.