scholarly journals Abundance, Distribution, Morphometric, Feeding Evaluation and the Reproductive Strategies of Gymnarchus niloticus in the Lower River Niger at Agenebode, Edo State Nigeria

2021 ◽  
Vol 25 (8) ◽  
pp. 1371-1377
Author(s):  
M.O. Agbugui ◽  
F.E. Abhulimen ◽  
A.O. Adeniyi
Keyword(s):  
Fish Species ◽  
Standard Length ◽  
Relevant Information ◽  
Breeding Strategy ◽  
Reproductive Pattern ◽  
Maturity Stage ◽  
Major Food ◽  
Gymnarchus Niloticus ◽  
Small Brood ◽  
River Niger

The study of the numerous areas of biology of fish produces ample and relevant information that aids scientist to explore, know and maintain the survival, growth, continuity and sustainability of life of various fish species. A total of 94 specimens of Gymnarchus niloticus were collected from River Niger at Agenebode during the sample period that ranged from 14 – 94 cm total length (54.88± 17.92); weighed 424 - 2281g (1569.61 ± 422.85). The length weight relationship (LWR) of G. niloticus in this study showed a negative (b<3) allometric growth pattern. Out of the 94 specimens analysed 54 males and 40 females were examined with a ratio of 1:1.4. Insects and decapods were the major food of the juveniles of Gymnarchus niloticus while the major food of preference of the sub adults and adults were Fish and insects with 27.12%, and 27.97% by FO. Gymnarchus niloticus possesses a single ovary in the female and single testis in the male which is often referred to as unpaired gonad. Fecundity ranged between 620 to 1378 eggs with a mean of 957.69 ± 112.31 eggs in females. The relationship between fecundity (F) and weight (W) and fecundity and standard length (SL) showed that fecundity is more related to weight than length of fish. Log F = 820.66 + 0.11 W and Log F = 151.23 + 5.31 SL. Fecundity had a positive significant correlation (P<0.05) with both somatic weight (r = 0.714) and standard length (r = 0.657) of fish. Ova diameter showed a ranged between 3.5 and 7.9 mm with a mean of 4.72 ± SD1.69 mm and it had significant relationship (P<0.05) with total weight, gonad weight and maturity stage. Gymnarchus niloticus in the Lower River Niger at Agenebode showed that G. niloticus has an unpaired gonad in both sexes, a gonochoristic reproductive pattern. Fecundity is low and the ova are large. They are small brood spawners with asynchronous breeding strategy. The attributes of G. niloticus obtained from this study reveals that the fish species is a good candidate for fish culture.

Seasonal reproductive patterns and recommended sampling times for sentinel fish species used in environmental effects monitoring programs in Canada

2010 ◽  
Vol 18 (NA) ◽  
pp. 115-135 ◽  
Author(s):  
Timothy J. Barrett ◽  
Kelly R. Munkittrick
Keyword(s):  
Fish Species ◽  
Environmental Effects ◽  
Reproductive Strategy ◽  
Mining Industry ◽  
Pulp And Paper ◽  
Reproductive Pattern ◽  
Metal Mining ◽  
Reproductive Patterns ◽  
Sampling Times ◽  
Environmental Effects Monitoring

Canada’s environmental effects monitoring (EEM) program is currently in its fifth cycle of monitoring for the pulp and paper industry and second cycle of monitoring for the metal mining industry. More than 60 different sentinel fish species have been used in the EEM fish population surveys and reproductive impacts have been identified as an issue of concern in the pulp and paper program. A review of the literature was conducted to obtain details of the reproductive biology of each fish species that has been used in EEM studies in Canada. Using available data on seasonal changes in gonadosomatic indices, the seasonal reproductive patterns of Canadian fish species were divided into categories based on reproductive strategy and the timing of initiation of gonadal recrudescence. Recommended sampling times were developed for each reproductive pattern based on periods of temporal stability, minimum variability, and maximum value in gonadosomatic indices within a reproductive cycle. The reproductive strategy, spawning time, spawning temperature, and recommended sampling time were provided for the each sentinel fish species as well as life history characteristics including longevity, age and size at maturity, and mobility. Examination of the fish surveys using small bodied forage species from the EEM pulp and paper program revealed that approximately 72% of these studies were not conducted at the developed recommended sampling times and the magnitude of impacts may be underestimated by failing to sample at the recommended time.

scholarly journals Population structure and reproduction of a migratory fish Leporinus piau (Characiformes: Anostomidae) in a semiarid tropical reservoir, Brazil

2016 ◽  
Vol 64 (4) ◽  
Author(s):  
Darlan Dantas Alves de Araújo ◽  
Jônnata Fernandes de Oliveira ◽  
Rodrigo Silva da Costa ◽  
José Luís Costa Novaes
Keyword(s):  
Population Structure ◽  
Standard Length ◽  
Water Levels ◽  
Maturity Stage ◽  
Migratory Fish ◽  
Initial Development ◽  
Relationship Length ◽  
Length Relationship ◽  
First Maturity ◽  
Migratory Fishes

Migratory fishes have been seriously impacted by the building of reservoirs and because of the negative effects of these projects such as the interruption of migratory routes, reduction or elimination of spawning/feeding areas, and initial development can influence the population structure the migratory fishes, resulting in reduction in abundance. Leporinus piau is migratory fish widely distributed in the watersheds of the Brazilian semiarid             and it is of importance for artisanal and sport fishing. The goal of the study was to evaluate the population structure and reproductive dynamics of the migratory species Leporinus piau in the Pau dos Ferros Reservoir, which is located in the semiarid region of Brazil. The CPUE, length structure, length-weight relationship, length at first maturity, sex ratio, gonad development and IGS were analyzed. Collections were performed quarterly between February 2011 and November 2012 using gillnets. The captured fish were counted; the standard length (cm) and total weight (g) were measured, and dissected to determine the sex and gonad maturity stage. The rainfall and reservoir water levels were recorded, and their correlations with the reproductive period and CPUE were analyzed. A total 549 individuals were captured. The average CPUE varied between 0.0259 individuals/m2*h (May/2011) and 0.0008 individuals/m2*h (August/2012), and significant differences were observed; however, significant correlations were not observed between rainfall and reservoir levels. The standard length varied between 5.9 cm and 20.7 cm, and the weight varied between 4.16 g and 271.5 g. A histogram analysis revealed that the 5-10 cm standard length class was the most abundant for juveniles and that the 10-15 cm class was the most abundant for adult females and males. The weight-length relationship was best fit by the equation log10Wt = -1.57711 + 3.00707 Log10 Ls, and the species presented isometric growth. The estimated length at first maturity was 12.76 cm. A total of 148 males and 82 females were collected (1.81:1, M:F), and these values were significantly different. The highest GSI was observed in February 2011 for both females (10.69) and males (5.72), and the GSI was significantly and positively correlated with rainfall. We concluded that the L. piau population is established in the reservoir and found that its reproduction period occurred during the rainy season between February and May.

Observations on the Diet of Red Morwong, Cheilodactylus fuscus Castelnau (Pisces : Cheilodactylidae)

1979 ◽  
Vol 30 (1) ◽  
pp. 129 ◽  
Author(s):  
JD Bell
Keyword(s):  
Standard Length ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Major Food ◽  
Seasonal Basis

Stomach contents of 104 C. fuscus (of 275-415 mm standard length) from rocky reef habitats in the Sydney region were analysed. This species was found to be entirely carnivorous, polychaetes, brachyurans, amphipods, gastropods and bivalves comprising the major food types and dominating the diet throughout the year. However, the relative proportions of these food types in the diet were found to vary considerably on a seasonal basis.

scholarly journals Reproductive indicators of the endemic species Astyanax bifasciatus (Teleostei: Characidae) in a tributary of the Lower Iguaçu River Basin, Brazil

2019 ◽  
Vol 41 ◽  
pp. e47720
Author(s):  
Elton Celton de Oliveira ◽  
Alexandre Augusto Auache-Filho ◽  
Denis Damasio ◽  
Nédia de Castilhos Ghisi ◽  
Maria Antônia Michels-Souza
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Maturity Stage ◽  
Reproductive Process ◽  
Maturation Stages ◽  
High Degree ◽  
Iguaçu River

The reproductive process promotes morphophysiological and behavioral changes in fish species throughout their life cycle. Its success is vital to define their resilience in the environment. This study aimed to evaluate the reproductive biology of the endemic fish species Astyanax bifasciatus in a tributary of the Lower Iguaçu River Basin, Paraná, Brazil. Fish were collected monthly at four sites along the Jirau Alto River in the city of Dois Vizinhos from October 2015 to September 2016. A standardized catch effort with gill nets and fish traps was used. In the laboratory, standard length and total weight were recorded. After anesthesia, the animals were sectioned to macroscopically determine the sex, sexual maturity stage, and presence of celomatic fat. The gonads and liver were removed to determine the gonadosomatic and hepatosomatic indexes, respectively. A total of 160 individuals (104 females and 56 males) were used. The gonadosomatic index, frequency of the gonadal maturation stages, and condition factor showed a long reproductive period with two investment cycles for both sex. Length at first sexual maturity was 4.57 cm for females and 3.56 cm for males. The reproductive data corroborate the generalist profile of the species and demonstrate a high degree of adaptive capacity, even in smaller tributaries.

Concentrations and Profiles of Polycyclic Aromatic Hydrocarbons in Some Popular Fish Species in Nigeria

2015 ◽  
Vol 78 (3) ◽  
pp. 554-560 ◽  
Author(s):  
CHUKWUJINDU M. A. IWEGBUE ◽  
GODSWILL O. TESI ◽  
LORETTA C. OVERAH ◽  
FRANCISCA I. BASSEY ◽  
FRANK O. NWADUKWE ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Fish Species ◽  
Aromatic Hydrocarbons ◽  
Gadus Morhua ◽  
Gas Chromatography Mass Spectrometry ◽  
The European Union ◽  
Trachurus Trachurus ◽  
Gymnarchus Niloticus ◽  
Fish Samples ◽  
Polycyclic Aromatic

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in 10 popular fish species in the Nigerian market were determined with a view to providing information on the health hazards associated with the consumption of these fish species. The concentrations of PAHs were measured by gas chromatography–mass spectrometry after extraction by ultrasonication with acetone-dichloromethane and clean up. The concentration ranges of the Σ16 PAHs were 20 to 39.6 μg kg−1 for Parachanna obscura (African snake head), 6.8 to 532.3 μg kg−1 for Oreochromis niloticus (tilapia), 7.4 to 91.1 μg kg−1 for Gymnarchus niloticus (Asa), 13.1 to 34.1 μg kg−1 for Sebastes fasciatus (red fish), 11.2 to 80.0 μg kg−1 for Gadus morhua (cod), 23.9 to 34.6 μg kg−1 for Chrysicthys nigrodigitatus (silver cat fish), 63.4 to 131.4 μg kg−1 for Sardinella aurita (sardine), 22 to 52.9 μg kg−1 for Trachurus trachurus (Atlantic horse mackerel), 21.0 to 63.7 μg kg−1 for Scomber scombrus (mackerel), and 27.7 to 44.5 μg kg−1 for Pseudotolithus senegalensis (croaker). Benzo[a]pyrene occurred in 23% of these fish samples at concentrations above the European Union permissible limit of 2.0 μg kg−1. The calculated margins of exposure based on the indicators for occurrence and effects of PAHs were greater than 10,000 indicating no potential risk for the consumers of the species evaluated in this study.

scholarly journals The use of premaxillary bones of six fish species in giant otter (Pteronura brasiliensis) diet analysis

2015 ◽  
Vol 10 (2) ◽  
pp. 131-142
Author(s):  
Maria del Pilar Becerra Cardona ◽  
Heiddy Asunción Mallea Cardenas ◽  
Paul André Van Damme
Keyword(s):  
Fish Species ◽  
Standard Length ◽  
Prey Size ◽  
Morphological Characteristics ◽  
Diet Analysis ◽  
Regression Equations ◽  
Fish Prey ◽  
Important Prey ◽  
Bolivian Amazon ◽  
Pteronura Brasiliensis

The premaxillary bones of fish are considered key bones due to their highly differentiated features, allowing the identification to species level. When these bones are present in the latrines of giant otter (Pteronura brasiliensis), they can be used to identify fish species and estimate the size of prey consumed. We briefly describe the differentiable morphological characteristics of premaxillary bones,useful for the successful identification of six fish species which are important prey for giant otter in the Paraguá river (Bolivian Amazon): Hoplias malabaricus (family Erithrynidae), Serrasalmus rhombeus, Pygocentrus nattereri (family Characidae), Chaetobranchus flavescens, Satanoperca pappaterra and Astronotus crassipinnis (family Cichlidae). We also present the linear regression equations which can be used to estimate the standard length ofthese fish species based on their bone measurements. Overall, 19 latrine samples were analyzed, which contained 109 premaxillarybones of these six species. Of the bones collected, 53% allowed successful estimation of the standard length of the fish consumed. The use of premaxillary bones in diet studies has a high potential as it permits the identification and estimation of prey size for the majority of species consumed. This method is important for studying the size of the giant otter’s fish prey.

scholarly journals MODERN BIOLOGICAL CHARACTERISTICS OF WHITEFISH COREGONUS LAVARETUS, EUROPEAN VENDACE C. ALBULA AND EUROPEAN SMELT OSMERUS EPERLANUS FROM THE IMANDRA LAKE

2020 ◽  
pp. 210-226
Author(s):  
E. M. Zubova ◽  
◽  
N. A. Kashulin ◽  
P. M. Terentyev ◽  
◽  
...  
Keyword(s):  
Fish Species ◽  
Breeding Strategy ◽  
Biological Characteristics ◽  
Coregonus Lavaretus ◽  
Short Cycle ◽  
The Past ◽  
Negative Change ◽  
Osmerus Eperlanus ◽  
Imandra Lake

The modern biological characteristics of numerous fish species from the Imandra Lake reaches – white-fish, european vendace and european smelt was investigated. It was shown that under the conditions of the ongoing negative change in the hydrological and hydrochemical regimes of the lake over the past 20 years, there have been multidirectional changes in the population’s structures of these species. If in short-cycle species (smelt, vendace) there is a positive dynamics of a number of indicators, then in whitefish these changes are negative. Euryphagia of smelt from the Imandra Lake, including the transition to preda-tion when reaching a length of 150 mm, combined with an effective breeding strategy and the virtual ab-sence of a predator press, provide him high numbers and successful competition with other species.

scholarly journals Reproductive biology of Moenkhausia intermedia (Eigenmann) (Pisces, Characiformes) in Itumbiara Reservoir, Goiás, Brazil

2004 ◽  
Vol 21 (3) ◽  
pp. 519-524 ◽  
Author(s):  
Renê Eiji Souza Hojo ◽  
Gilmar Bastos Santos ◽  
Nilo Bazzoli
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Standard Length ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Female Predominance

To study the reproductive biology of Moenkhausia intermedia (Eigenmann, 1908) in Itumbiara reservoir, Paranaíba river, Goiás, Brazil, a total of 301 specimens (237 females and 64 males) were captured quaterly from January to December 1993. The gonadosomatic index of females and males were related to morphologic variations of the gonads in different reproductive cycle stages (RCS). Analysis of RCS frequency and variations in the gonadosomatic index showed that M. intermedia reproduces during the whole year with fractional spawning. The smallest standard length at advanced maturity stage was estimated as 6.6 cm for females and 6.0 cm for males. The stomach repletion and coelomic fat indexes of both sexes reached peak values in the rest stage, suggesting that this species probably store energy in this phase and consume its fat reserve during reproduction. In the Itumbiara reservoir there was female predominance (4:1). Males were smaller than females, indicating sexual dimorphism in M. intermedia.

scholarly journals Defining the reproductive period of freshwater fish species using the Gonadosomatic Index: a proposed protocol applied to ten species of the Patos Lagoon basin

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Nelson Ferreira Fontoura ◽  
Gianfranco Ceni ◽  
Aloisio Sirangelo Braun ◽  
Camilla da Silva Marques
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Gonadosomatic Index ◽  
Cooling Water ◽  
Late Summer ◽  
Reproductive Period ◽  
Warm Water ◽  
Reproductive Pattern ◽  
Patos Lagoon ◽  
Freshwater Fish Species

ABSTRACT This contribution records the reproductive periods of ten dominant freshwater fish species from the Patos Lagoon and Guaíba Lake (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Data were derived from monthly samples in Casamento Lake (northern Patos Lagoon; Nov. 2002 to Apr. 2004) and Guaíba Lake (Jun. 2005 to May 2006). The reproductive period was determined according to the monthly variation of the gonadosomatic index (GSI). Fish reproduction was identified during all months of the year. Oligosarcus jenynsii started reproduction in winter, but extended spawning to spring (early warming-water reproduction). Three species also presented reproduction during warming water months, but beginning in spring and finishing in summer (late warm-water reproduction): P. nigribarbis, T. lucenai and P. bonariensis. Three species presented relatively short reproduction periods on summer (spotted warm-water reproduction): H. malabaricus, H. littorale and L. anus, and only one species reproduces almost continuously during warmer waters (long-season warm-water reproduction): A. fasciatus. Finally, two other species presented a very distinct reproductive pattern, starting reproduction on late summer but increasing GSI values along autumn and winter (long-season cooling-water reproducers): C. voga and O. robustus.

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