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Effects of dilution ratio on the potency and viability of the spermatozoa of African Catfish (Clarias gariepinus Burchell, 1822) using normal saline solution.Journal of Agriculture and EnvironmentNormal saline solution is one of the most common diluents in artificial breeding and to dilute the milt of C. gariepinus, however the most desirable quantity or volume to be used is still a problem leading to several failures in artificial propagation of fish. The study determined the effects of dilution ratio on the potency of the spermatozoa, fertilization and hatchability rate of the eggs and survival rate of the hatchlings. The dilution ratio used included milt to saline solution ratio of: 1:10 (T2), 1:50 (T3), 1:100 (T4), and zero saline inclusion (T1), as the control. The experiment was laid out in a complete randomized design (CRD) with 3 replications each for the treatments. The result showed that there was significant difference (P<0.05) in percentage motility of the milt, egg fertilization and hatchability rate, and survival rate of the larvae across the treatments. The highest percentage motility (87.67%), fertilization (97.55%), hatchability (87.78%) and survival rate (I83.53%) occurred at T2 (1:10), while the least percentage motility (49%), fertilization (75.89%), hatchability (40.73%) and survival rate (45.43%) occurred at T1 (zero saline inclusion). It can be concluded that normal saline improves artificial propagation of C. gariepinus and with further increase of normal saline solution there is a negative effect on the potency of the milt, fertilization and hatchability of the eggs and survival rate of the hatchlings. A dilution ratio of 1:10 is therefore recommended to fertilize eggs of C. gariepinus for improving artificial propagation of fish
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Heavy metal concentrations in the West African clam, Egeria radiata (Lammark, 1804) from McIver market, Warri, Nigeria.International Journal of Science and NatureSamples of Egeria radiata were purchased from local dealers in McIver mar et, Warri, Nigeria, to investigate the presence and concentrations of some heavy metals in order to ascertain the suitability of the clam for human consumption. Analyses using Atomic Absorption Spectrophotometer (AAS) show that E. radiata accumulated some heavy metals with the following sequence of concentration: Iron> Nic el> Lead> Copper> Arsenic> Manganese> Chromium> Cadmium> Mercury. The variability of heavy metals concentration observed in E. radiata during the period of study was affected by rainfall amount. A negative relationship between changes in rainfall and body weight of clams show that the higher the rainfall the lower the mean dry weight. Individual heavy metal differed significantly (P< 0.05) in concentration. However, heavy metal concentrations did not vary significantly (P> 0.05) by months. Out of the nine heavy metals found in E. radiata tissues, lead and cadmium were higher than the WHO/FAO set limit. E. radiata sold in McIver mar et during this period of study were contaminated with lead and cadmium and therefore not fit for consumption.
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Gynogenesis: An effective way of controlling fish population and increasing profit in aquacultureGynogenesis is a gene manipulation technology to produce all female fish. Brood stock of Clarias gariepinus were obtained from a fish farm in Mosogar, Delta State, Nigeria. The milt was irradiated with Ultra Violet (UV) light to inactivate the male chromosomes. The fertilized eggs were then cold shocked. One way analysis of variance was use to analyze the data on the haploids, triploids and diploids. Hatchability of fertilized eggs indicated lower hatchability and survival rates in the diploids and the triploids. Analysis of variance showed significant difference in the growth of the diploid and triploid. There were also higher growth rates in the triploid than the diploids.
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Fish diversity of the wild and aquaculture water bodies in Singida RegionTanzania Fisheries Research Institute being currently the only fisheries research institute in Tanzania has sole responsibility of marking the presence and distribution of fish species in the country. This work is expected to be completed by the year 2005. In order that this work can be accomplished, both published works and field observations(including geographical location using GPS) have to be compiled. Since the institute has centers in all the Great Lakes and one along the Indian Ocean coast, it is expected that field observations and identifications will be obtained and incorporated into the document to be produced by 2005. (PDF contains 15 pages)
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National report of IFMP catch assessment survey (CAS) for August 2005The first comprehensive CAS was carried out during the month of July 2005 This is the second report of CAS for the month of August 2005 following the July report. The design and methodology followed was the same as in July. This report highlights the results obtained in August catch assessment survey. The report gives estimates of mean catch rates in Kgs./boat/day, total catches in M.tons and values of the catch by species. The total catch for August was 31,633.0 M. tons. This is lower when compared with the July catch which was 39,745.1 M. tons. In August the catch composed of Dagaa (45%), Nile perch (33%), Haplochromines (16%), Tilapiines (5%) and all other species combined (1%). (PDF contains 14 pages)
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New record of giant devil ray (Chondrichthyes: Myliobatidae) from Oran Bay (Western Meditteranean Sea)Indonesian Fisheries Research JournalThe present paper reports a new record of Giant devil ray Mobula mobular (Bonnaterre, 1788)from western Algerian waters that is encountered for the first time in that coast since its firstdescription in 1901 and last observation in late 80’s. This elasmobranch is categorized asendangered on the IUCN Red List (Endangered A2d ver 3.1) and is likely to be the rarest of the ninespecies of Mobula genus. Occasionally it is captured in Mediterranean Sea by purse seines,bottom and pelagic trawls, pelagic nets, bottom longlines, drifters and harpoons. The specimenstranded in “la Madrague Beach” in Western Algerian coasts. Its disc length was measuring108.96 cm and disc width was 226.02 cm. This Myliobatidae is rarely seen with daily landed fish atOran fishery. Up to date no explicit reason can be given for the strand of M. mobular but ghostfishing and important maritime traffic stay the most plausible cause of this incident.
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Reproductive biology of Pagellus acarne (Risso, 1927) (Teleostei: Sparidae) off western Algerian waters (Western Mediterranean)Cahiers de Biologie MarineThe reproduction of Pagellus acarne caught in Oran Bay was studied. The samples used were sorted monthlyfrom commercial catches of coastal trawlers operating in this area from April 2008 to July 2009. The overall sex ratio wasin favor of females 1:1.27 and length frequency distribution according to sex revealed that the females were highlyrepresentative beyond 20.5 cm of total length presuming a sexual inversion already described for this sparidae. Theestimated lengths at maturity (Lm) were 12.8 cm for females and 16.0 cm for males. Two spawning periods were made outby the follow-up of the gonado and hepato somatic indexes: a spring period from April to June with a peak in May and anautumnal period, between November and January with a peak in December. The closed season in Oran Bay extends from 1stMay to 31th August, which is to our opinion insufficient to safeguard the renewal of the resource and its spawning stock.
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On the fecundity of the seabream, Pagellus acarne (Risso, 1827) of the western Mediterranean Sea, Algerian coastsThalassasThe fecundity of the Seabream from the western Mediterranean (Algerian coast) was assessed by the volumetric methodusing 22 ovaries from females between 169 and 263 mm total length (206.62 ± 19.93). Estimates of total potential annualfecundity varied between 19875 and 49125 oocytes per female (29448.86 ± 8198.12). Relationships between total potentialfecundity (F) and total length (Lt), total weight (Wt), gonad weight (Wg) were established using the multiplicative regressionmodel and a significant correlation was found (ANOVA: P‹0.01).
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Weight-length relationships of seven fish species (Teleostei: Sparidae, Mullidae, Carangidae) of Western Mediterranean Sea (Oran Bay, Algeria)Journal of King Abdul Aziz University, Marine SciencesNo information currently exists on the weight-length relationships of Sparidae:Axillary seabream Pagellus acarne (Risso, 1827), bogue Boops boops (Linnaeus, 1758);Mullidae: Red mullet Mullus barbatus (Linnaeus, 1758), surmulet Mullus surmuletus (Linnaeus,1758) and Carangidae: Atlantic horse mackerel Trachurus trachurus (Linnaeus,1758),Mediterranean horse mackerel Trachurus mediterraneus (Steindachner 1863), Blue jackmackerel Trachurus picturatus (Bowdich 1825), seven commercial fish species of Oran Bay inWestern Mediterranean Sea. Data are presented for the first time for that region of theMediterranean Sea to contribute and help comparative growth studies. Samples were collectedfrom commercial catches at Oran Bay fisheries in Algeria. The values of the slope b in the lengthweightrelationship, W=aLb ranged from 2.841 to 3.296. The coefficients of correlation r2 werecomprised between 0.85 and 0.97. “a” and “b” parameters were compared with other fishing sitesfor the same fish species with Froese plot [Log a=ƒ(b)].
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First record of invasive green algae Caulerpa racemosa var. cylindracea in Oran Bay (Western Algeria)Indian Journal of Geo Marine SciencesCaulerpa racemosa var. cylindracea (hereafter Caulerpa cylindracea) was first reported in the Mediterranean Sea in1926 1 in Tunisian waters and then in Tripoli harbor in Libya, in 1990. In late 90s it invaded the southern shore of Europe. InAlgeria, this invasive species was reported for the first time in 20072, five years after it appeared about 450 km from the firstsite in the eastern part of the Oranian littoral. This situation required widespread monitoring of this invasive species all along124 km of the coastline. More than 10 stations were patrolled and monitored since then, studied by scuba diving between thesurface and 30 m depth.The observations devoted to the distribution of Caulerpa cylindracea in Oran showed that specimens presented the sameappearance with irregularly entangled branched stolons attached to the substrate by colorless rhizoids from which the nameof the variety cylindracea was derived. Chronologically, the invasion direction seems to move from the bottom to the surfacewith an orientation from east to west, in the Oranian coastline. In situ observations confirmed high propagation speed ofCaulerpe in the Oranian coastline where invasions were signaled in several stations. The seaweed was observed for the firsttime in late 2011 and early 2012 (pers.obs) in Arzew Gulf (Cap Carbon) at the extreme east of the littoral, where the firstfronds were noticed. Then it extended geographically to the center of the coastline, in Kristel, early 2013. In 2014, it wasobserved in Ain Turc and Cap Falcon. In 2015, it was observed in the western shoreline near Bousfer beach and in 2016 itreached the “Plane” island (Paloma).This alien species was encountered at depths ranging from a few centimeters in microcuvettes up to 37 m, on varioussubstrates (hard, sandy, muddy) between marine phanerogams rhizomes and, also between the lower mid-littoral and infralittoralssuperior algae, with Posidonia oceanica herbarium. The study suggested a strong need for scientific monitoring andmanagement program, using optimized methodslike biological control or manual eradication for controlling the invasion.
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Age, growth and mortality of the common carp (Cyprinus carpio) population in Merdja Sidi Abed Dam, AlgeriaOmni-AkuatikaWe tried to estimate age, growth parameters, condition factor, length-weight relationship and mortality rates (Z, M, and F) of the common carp in Merdja Sidi Abed dam. Cyprinus carpio specimens were captured by long line between April and June 2013 in Merdjea Sidi abed. 220 individuals were collected and weights ranged between 265.5 and 620.3 g while the total length ranged between 26.3 and 35.6 cm. Length-converted catch curve was used to estimate total annual instantaneous mortality rates (Z), natural mortality was calculated using Pauly formula [ln(M) = -0.0152 - 0.279 ln(L∞) + 0.6543 ln(K) + 0.463 ln(T)]. Recruitment patterns were determined from the routine implemented in FISAT II. For all individuals (n = 220) of the common carp, the relationship between total length and body weight was: W = 0.0384 L2.70 (r2 = 0.906) for females and W = 0.0467 L2.653 (r2 = 0.976) for males a minor allometry was found for this species, mean condition factor K was estimated at 1.41. The maximum value of recruitment was recorded in March-April period with 19.56 and 15.20% respectively. The Battacharya method was used to estimate age of individuals that was comprised between 1 and years 3. The equation of Von Bertalanffy growth was: L = 36.75 [1-e-0.46 (t + 0.33)] for all the population. Total mortality (Z), natural mortality (M) and fishing mortality (F) were as follows: Z = 1.08, M = 0.82, F = 0.26 yr-1 while exploitation ratio (E) was evaluated at 0.24 indicating an under exploitation of this local resource.
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Some population characteristics of the pink spiny lobster Palinurus mauritanicus (Gruvel, 1911) caught in the Béni-Saf Bay (Western Algeria)Ege Journal of Fisheries and Aquatic Sciences
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A preliminary inventory of biodiversity and benthic habitats of “Plane” Island (Paloma) in Oran Bay, north western Algeria (western Mediterranean)Journal of the Black Sea / Mediterranean Environment
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Population dynamic parameters of the red mullet Mullus barbatus (Mullidae) in the Arzew Gulf, AlgeriaInternational Journal of Aquatic Biology
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Reproductive biology of the common pandora Pagellus erythrinus (Linnaeus, 1758) of Oran Bay (Algerian west coasts)Turkish Journal of Fisheries and Aquatic Sciences
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Fecundity of the blotched picarel, Spicara maena (Linnaeus, 1758) from Oran Bay (Western Mediterranean Sea)Journal of FisheriesThe fecundity of the blotched picarel Spicara maena from the western Mediterranean (Oran Bay) was assessed by the volumetric method. Total length (TL) of studied females varied between 91 and 140 mm (mean ± SD: 111.9 ± 10.6 mm). Estimates of total potential annual fecundity varied from 16,750 to 28,125 oocytes per individual (mean ± SD: 21,404.7± 2,698.8). Relationships between total potential fecundity (F) and TL, total weight, gonad weight were established using the multiplicative regression model and a high significant correlation was found in all the cases.
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Acrosymphyton purpuriferum (J. Agardh) Sjostedt et Balliella cladoderma (Zanardini) Athanasiadis, deux nouvelles espèces d’algues benthiques de la Méditerranée marocaineBulletin de l'Institut Scientifique, Rabat, Section Sciences de la VieThe authors report two new species of benthic algae from the Mediterranean sea of Morocco : Acrosymphyton purpuriferum (J. Agardh) Sjostedt (Acrosymphytaceae, Rhodophyta) and Balliella cladoderma (Zanardini) Athanasiadis. The geographical distribution,description and illustration of macroscopic and microscopic characters and ecological characteristics of these species are presented.
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Fisheries annual report for the year ending 1966The Chief Fisheries Officer's Annual Report of 1965 showed then that there had been an increase in the volume of work of the Fisheries Department. This increase continued and accelerated during 1966. The Transitional Development Plan was successfully completed on schedule, with the exception of two items which had been almost finished by the end of the year, and the Four Year Development Plan was introduced; by the end of the year all officers of the Department were fully engaged in its implementation.
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The phytoplankton species composition and abundance of Ogun River, Abeokuta, southwestern NigeriaInternational Journal of AquacultureThe phytoplankton species composition and abundance in Ogun River, Ogun state, Southwest Nigeria was studied for a period of seven months (December, 2011 - June, 2012), a total of forty-one genera belonging to five taxonomic groups were recorded from Ogun River. The phytoplankton species composition was surpassed by Chrysophyta with 15 species consisting of 36.6% followed by Chlorophyta with 14 consisting of 34.1%. This was followed by Cyanophyta (7 species) consisting of 17.1%, Euglenophyta with 3 species consisting of 7.3% and Pyrrophyta with 2 species consisting 4.92%. Cyanophyta was the highest in abundance consisting of 41% while the lowest in abundance was Pyrrophyta consisting of 1.5%. The low nature of phytoplankton abundance and diversity observed in this study must have been caused by the polluted nature of the water due to the anthropogenic activities carried out around its shores The dominance of Cyanophyta in this river is similar to findings from Lake Victoria, Lake Bishoftu, Lake Chaohu and the temple pond of Thirupour.
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Assessment of some physico-chemical parameters of River Ogun (Abeokuta, Ogun State, southwestern Nigeria) in comparison with national and international standardsInternational Journal of AquacultureThis study assessed the physico-chemical quality of River Ogun, Abeokuta, Ogun state, Southwestern Nigeria. Four locations were chosen spatially along the water course to reflect a consideration of all possible human activities that are capable of changing the quality of river water. The water samples were collected monthly for seven consecutive months (December 2011 – June 2012) at the four sampling stations. pH, air temperature (℃), water temperature (℃), conductivity (µs/cm) and total dissolved solids (mg/L) were conducted in-situ with the use of HANNA Combo pH and EC multi meter Hi 98129 and Mercury-in-glass thermometer while dissolved oxygen (mg/L), nitrate (mg/L), phosphate (mg/L), alkalinity (mg/L) and hardness (mg/L) were determined ex-situ using standard methods. Results showed that dissolved oxygen, hydrogen ion concentration, total hardness and nitrate were above the maximum permissible limit of National Administration for Food, Drugs and Control (NAFDAC), Standard Organization of Nigeria (SON), Federal Environmental Protection Agency (FEPA), United States Environmental Protection Agency (USEPA), European Union (EU) and World Health Organization (WHO) for drinking water during certain months of the study period. Results also showed that water temperature and conductivity were within the permissible limits of all the standards excluding FEPA. However, total dissolved solids and alkalinity were within the permissible limits of all the standards. Adejuwon and Adelakun, (2012) also reported similar findings on Rivers Lala, Yobo and Agodo in Ewekoro local government area of Ogun state, Nigeria. Since most of the parameters measured were above the maximum permissible limits of the national and international standards, it can be concluded that the water is unfit for domestic uses, drinking and aquacultural purposes and therefore needs to be treated if it is to be used at all. The low dissolved oxygen values for the first four months was too low i.e. < 5 mg/L. This is most likely as a result of the amount of effluents discharged into the river. To prevent mass extinction of aquatic organisms due to anoxic conditions, proper regulations should be implemented to reduce the organic load the river receives.
