Aquaculture

In Tilapia aquaculture, it is more desirable to culture all male (monosex) population because they grow bigger and faster. The synthetic steroid hormones such as 17-?-methyl testosterone are commonly used to reverse sex in tilapia. Due to its latent health and environmental hazards, attention is presently being focused on the use of alternatives, such as plant extracts called phytochemicals. This study investigated the phytochemical “genistein” as a possible enzymatic aromatase inhibitor that could modulate the sex differential response in the gonad of sexually undifferentiated tilapia. Experimental diet supplemented with genistein (500mg/kg) along with a control diet were evaluated in the feeding of three days old tilapia fry (6mg-8mg) for eight weeks. Result shows that the presence of dietary genistein did not have any significance positive effect on the weight gain, SGR (%) and survival (%), although higher number of males were produced in the genistein fed fish but the phenotypic sex ratio was not significantly different (p>0.05) from the control.

The physicochemical characteristics of water in the Lower Litani River Basin (LLRB) were evaluated. It concerns with analyzing six representatives sites which are investigated over three seasons of the year 2011. The principal component analysis (PCA) method was used to interpret the elemental concentrations in the river water. Many variables were evaluated, especially the components or metals Fe, NO₂^-, CaCO₃, Cu. Three groups were identified and differentiated by PCA according to the seasons. The first group is rich in Fe and NO₂, and low in NH₄ and EC (in the mid rainy season). The second group formed in dry season and the third group with low concentration of K⁺, PO₄^3- and Cl^- (in mid rainy). However, no critical pollution has been reported in this part of the river; except the high concentration of Fe and NO₂ ^- in all investigated sites due to the reject of wastewater and touristic activities.

The present article test to analyze the present state of the fishing in the Ndjale lake in order to take out again the positive and negative points capable to allow the different actors intervening in this sector to get the necessary information capable to serve to a possible improvement of this economic circuit. While referring to the code of fishing and the aquaculture in RD - Congo, the document achieved by the FAO and to the practices of fishing that achieve themselves in the Ndjale lake by the fishers of this entity and the contraptions of fishing used, he/it observes himself/itself on the subject a deficiency of the state of fishing on land; the management of the lake is opaque and is held by the customary power where only the natives can reach there and especially fish captured at the time of the fishing are not weighed, and without any surveillance, the price of fish varies according to customer's type in presence and no regulation is to return it - you. The fishing is artisanal of subsistence and at a time commercial, the men are the main actors; the various nets, the cannons and the palangres are the materials the more used by the fishers, the transportation often gets used at bicycle and by motorcycles; dragging a lot of mediators between the fishers and the consumers, from where him ya place to organize this circuit in order to make this activity more profitable.

The objective of this work was to make an agronomic evaluation and morphological characterization of 4 varieties of upland rice (Lioto, Liboga, Lienge and Nerica7) and 1 traditional variety (Kitombe) in the ecological conditions of Kisangani.To achieve this objective, two trials were conducted at Kisangani in a randomized complete block device with 4 repetions and 5 treatments (varieties). The Qualitative traits were evaluated by using the Standard Evaluation System for Rice (SES). Quantitative trait analysis showed the statistical difference between varieties (p<0.05), ranging from 145±10 to 119±13 for total spikelets/panicle, from 215±6.5 to 318±31.5 for panicle/m2 and 112±5 to 143±6 for spikelets filled/panicle. Among the qualitative points common to all 5 varieties we found the ligule shape, shape and panicle habit. All varieties have a pointed ligule with two slits, panicle with secondary branches and drooping port.We had identified the proportion of teeth on the leaf Leaf blade as a new distinguishing feature of rice varieties. The variety Kitombe and Nerica7 have a denticulation on 2/3 of the Leaf blade length against 1/3 for the other varieties 

In the setting of this article on the inventory of the Ichtyofaune of the Ndjale lake that pulls his/her/its specificity of the surge of the Kasuku river in territory from kibombo in the Maniema;, the investigatings have been led during the artisanal fishing while using the nets, the cannons and the palangres as contraptions of fishing in two stations: Dongo and Gabon during one year of April 2018 to March 2019. Them TO the descended of our investigatings on the Ichtyofaune of the Ndjale lake in the Maniema; he/it clears himself/itself that this lake contains 4 orders, 15 families, 20 kinds and 20 species of which most abundant in term of strength by decreasing order are: the Mormyridaes represented by (Marcusenius morii; and Gnatonemus sp); the Mockokidaes represented by (Synodontis sp), lesClaroteidae (Chrysichtys nigodigitatus), the Clariidaes (Clarias Cichlidae gariepinus),les (Hemichromus elongatus and Tilapia sp) and the Channidaes (Parachanna obscura). The specific wealth is of 20 recorded species, the équitabilité inter station is of 0 ,69 for Dongo against 0,74 to Gabon. These results on the whole, confirm that the biodiversity of the Ndjale lake is raised and rich of the species. To the total 41825 individuals have been captured in the two retained stations, of which 41,9% to Dongos and 58 ,1% in Gabon; - The season of rainy appears more favorable to the capture and present more of strength of fish captured that the dry season for all disconcerted species 63% against 37% of the total strength; - The weights vary from a species to the other of Heterotis niloticus 5grs to 1950grs, but the average is in the interval of 7 to 1650 grs, - The species having presented the most elevated weights are in the decreasing order: the Chrysichthyses nigrodigitatus (1650 grs), Citharinus gibbosus(900grs), (890 grs), Mormyrops deliciosus (640grs), Parachanna obscura (600grs), Polypterus spp and Malapterirus bennenensis (460grs) each and the Distichodus fasciolatus (415grs). All other present the weakest weights lower to 200 gr in spite of their important strengths in the two stations and in all season. - The size: the variation goes from 35 to 670 mm and the middle values of the size are understood on the whole between 46mm and 435mm. The Chrysichthys presents the most elevated size (435mm); follow-up of Polypterus sp (360mm), Malapterirus bennenensis (345mm), Parachanna obscura (260mm), Mormyrops deliciosus (232mm), Hepsetus adoe (210 mm) and Citharinus gibbosus (206mm). The other also presented some sizes in spite of their strengths very important. While comparing the weight and the sizes, he/it notices himself/itself that these two factors are not proportional for all captured species. - Concerning the spatio-temporal distribution, he/it clears himself/itself that the species are present all 'year in all two stations, but to very different frequencies following the months of the year; and the rarest species are: Mormyrops deliciousus, during every month of the year, and absent in December; The Auchenoglamus punctatus: especially appears as rare during several months of the year in the Dongo station; - The Heterotis niloticus, is all year round less present to the Gabon station that in the Dongo station; - The Polypterus sp: is rare and sometimes absent during some months of the year (January, fervier and March) especially to the Gabon station; - The Malapterirus very rare bennenensis in Dongo but more frequent to the Gabon station; - The Distichodus fasciolatus, present all year round but, less represented in term of strength; and the Schilbe sp: absent all year round in Dongo but rarely present to the Gabon station and represent the weakest efficient of the all species counted in the Ndjale lake.

The study was conducted in Denu, Keta and Sogakope towns all in the lower Volta Region of Ghana to elicit information on the socio-economic status and constrains of fisherwomen involved in the Volta Clam, fishery. Majority of the respondents aged between 30 to 35 years. 26% had Junior School and 2% have had Tertiary education. Majority of the women in the clam business do not have access to credit facilities. Fisherwomen had difficulty in harvesting and processing because they use crude methods. Extension services should target women to help equip them with new knowledge and technologies in Clam trade.

The quality of three marine fish species smoked with a gas smoker (Abuesi Gas Fish Smoker) and a fuelwood smoker (Chorkor Smoker) were analyzed. The aim was to evaluate the nutritional profile and Polycyclic Aromatic Hydrocarbon (PAH) levels in smoked fish from these smokers. The three fish species were the yellowfin tuna Thunnus albacares, the common white grouper Epinephelus aeneus and barracuda Sphyraena sphyraena. The Abuesi Gas Fish Smoker produced significantly better quality-smoked fish than the Chorkor smoker. The protein, moisture, fat, total carbohydrate and ash contents of the gas smoked fish were in the range of 54.23 - 70.32%, 13.69 - 24.73%, 5.28 - 8.76%, 2.97 - 13.21% and 2.77 - 4.27% respectively, whilst that of the fuelwood-smoked fish were 43.38 - 43.75%, 22.00 - 46.5%, 2.00%, 5.26 - 25.78% and 2.85 - 6.50% respectively. Total PAH concentration ranged between 321.7 – 514.41 ?g/kg for gas-smoked fish and 1038.8 – 1550 ?g/kg for fuelwood-smoked fish. PAH concentrations per fish species in the two different fish smokers were significantly different. The EU maximum residue limits (MRLs) for PAH4 and BAP were met in the Gas Fish Smoker but not in the Chorkor Smoker. It is concluded that the gas fish smoker is a better choice, in terms of fish quality, than the fuelwood smoker.

This experiment was done for investigate the histopathological effects of bisphenol A exposure on testis tissue of guppy fish. In this study 90 guppies were examined in 2 experimental groups. In experiment groups, guppies exposed 4 mg/L and 8 mg/L BPA doses and after 96 hours fishes were sacrified. Tissues were dissected out, fixed in Bouin’s fixative, stained with Hematoksilen & Eosin, and examined using light microscopy. It is observed that deterioration, atresia and decreased in the number of seminiferous tubules in experiment groups.. In addition, openings between seminiferous tubules, increase in distance between tubules and decrease in the number of spermatogonium were detected.

The effect of feeding Telfairiaoccidentalis based diets was investigated on the blood of African catfish (Clarias gariepinus). 150 African catfish were randomly allotted to five experimental diets (CP 40%) in which ugu leaf replaced soybean at 0%, 10%, 20%, 30% and 40% respectively and fed at 3% body weight daily for the period of 9weeks. At the end of the feeding period, the blood samples were collected from the caudal peduncle of the fish samples in replicates and analyzed for both haematological parameters such as packed cell volume (PCV), haemoglobin (HB), red blood cell (RBC), white blood cell (WBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) and serum parameters such as Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) Alkaline phosphatase (ALP), Urea, Creatine (CRE), Total protein, Albumin(ALB), and Globulin(GLO). The highest PCV (40.1%) was recorded in fish fed 0% and the lowest PCV (11.5%) was recorded in fish fed 40%; while the highest RBC (3.14ul) was also recorded in the same treatment, fish fed 0% and lowest RBC (0.96ul) was recorded in fish fed 40%. The highest HB content (14.2g/dl) was recorded in fish fed 0% and the lowest HB (7.2g/dl) was obtained in fish fed 40%, the highest WBC count (152.5ul) was recorded in fish fed 0% and the lowest was recorded in fish fed 40% ugu leaf meal while the highest lymphocyte count (62.5) was recorded in fish fed 30%. But the highest MCV (132.3fl) value was recorded in fish fed 10%. The highest MCH (50.3) value was recorded in fish fed 40%. The serum indices increase significantly as the replacement level of Telfairia occidentaIis increases. In contrast, TP and Glo has its highest value in T1 (control) 4.805 and 3.13 respectively. In ALP, Urea and ALB, the highest value was observed in T3 (20%). However, in T1 and T4 of ALP there is no significant difference (p>0.05) in the diets, likewise in T2 and T5 of ALP, there is no significant difference (p>0.05). The chemical compositions of the Telfairia occidentalis used are as follows; crude protein (35.70%), crude fiber (23.52%), ether extract (2.38%), ash (12.60%), dry matter (92.10%).were recorded and there was significant difference (p<0.05).This trial indicates that Telfairia occidentalis meal can replace soybean at 20% in the diets of African catfish without any deleterious effect on the physiology and or health status of the fish.

This survey was conducted to quantify the effect of addition of Avizyme® multi enzyme to the body composition of western white shrimp (Litopenaeus vannamei)carrying the experiment based on initial average weight of 2.5±0.5 (gr). The experiment was conducted based on absolute casual program including 7 and 3 repetition for each attendants including a control attendants (free- canola, free Avizyme® -multi enzyme and 30% of fish meal) and six attendants at the level of 15,30,45 percent plant protein along with 0.5% Avizyme® multi enzyme and free-Avizyme® multi enzyme In the begging of the period, 525 shrimps were casually introduced in 21 plastic tanks of 50 liter each (25 shrimp in each tank). Shrimps were fed three times a day at 8, 14, 20 o'clock for about 8 weeks in a water with average temperature of 31.60 ± 0.60C0and water salinity of 41 ± 0.8 (ppm).In the begging of culturing process, 40 Shrimps were randomly selected and also at the end, from each repeat 10 shrimps were captured and after de-skinning and freezing they transferred to the laboratory for analyses of body. The results at the end 60 days of period showed that from humidity characteristic point of view and the shrimp body protein, no meaningful statistical differences were observed between the Control and testing attendants (P>0.05). But, From the protein characteristic aspect, fiber and body ash there were meaningful differences based on this, the lipid characteristic in testing attendants 1,2,3 with enzyme and similar attendants without enzyme and the control attendant, there were meaningful differences (P<0.05). The body ash characteristic between attendants 2 with 5 and 3with 6 in relation to control attendant was meaningful statistic differences.