Comparative transcriptomic analysis of ovary and testis reveals sex-related genes in roughskin sculpin Trachidermus fasciatus

The mechanisms underlying sex determination and differentiation have long intrigued researchers in the fields of development and evolutionary biology.The roughskin sculpin(Trachidermus fasciatus Heckel),displaying sexual dimorphism,provides an ideal model for studying the mechanisms.However,both genetic and genomic information concerning sex determination and differentiation,such as gonadal transcriptome data in roughskin sculpin,are lacking.Here,we present the first gonadal transcriptomes of roughskin sculpin and identify sex-related genes.We identified 8531 differentially expressed genes(DEGs),among them 4065 were upregulated in the ovary and 4466 upregulated in the testis.Several sex-related gene ontology(GO)terms were enriched in ovary-biased genes,including“binding of sperm to zona pellucida”,“egg coat formation”,“positive regulation of acrosome reaction”,“cell division”,and“cell cycle”,while the GO terms such as“spermatogenesis”,“sperm axoneme assembly”,“cilium assembly”,“cilium movement”,and“cilium movement involved in cell motility”were enriched in testis-biased genes.Moreover,six KEGG pathways were significantly enriched in the ovary,whereas only one was enriched in the testis.Of these DEGs,40 sex-related genes were identified,which including 26 testis-biased genes(such as Dmrtb 1,Gsdf,Sox 9 b,Wnt 4 b,Tcp 11 l 2,and Efhb),and 14 ovary-biased genes(such as Cyp 19 a 1 a,Foxh 1,Foxr 1,Gdf 3,Hsd 17 b 12,and Igf 2 bp 3).This gonadal transcript dataset would broaden our understanding of sex determination and differentiation mechanisms in roughskin sculpin,expand the genomic database,support future studies on sex-related gene functions,and facilitate molecular biology research into roughskin sculpin.

Fruit Powder of Tetrapleura tetraptera in Local Feed on Some Zootechnical Performances of Juveniles of Clarias gariepinus in Concrete Tank

This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T0+ (imported feed), T0-, T0.3, T0.4, and T0.5 respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m2 each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T0+ treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T0+). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).

Ingestion of Brachionus plicatilis under different microalgae conditions

The effects of four microalgae, Chlorella vulgaris, Platymonas helgolandicavar, Isochrysis galbana, and Nitzschia closterium on the grazing and filtering rates of the marine rotifer, Brachionus plicatilis, were evaluated under laboratory conditions. The grazing rates in separate cultures of the four microalga were as follows： C. vulgaris 〉 P. helgolandicavar 〉 L galbana 〉 N. closterium. However, the filtering rates occurred in the following order： P. helgolandicavar 〉 N. closterium 〉 C. vulgaris 〉 L galbana. A mixed diets experiment revealed that P. helgolandicavar was the preferred diet of B. plicatilis. In addition, the grazing rate of B. plicatilis increased gradually as the density of the microalgae increased, until concentrations of 2.5×10^6 cells mL^-1 for C. vulgaris and 1.5×10^6 cells mL^-1 for I. galbana were obtained. Furthermore, the filtering rate increased slightly when the density of the microalgae was low, after which it declined as the microalgal density increased. The grazing rates of B. plicatilis were as follows during the different growth phases： stationary phase 〉 exponential phase 〉 lag phase 〉 decline phase. Additionally, the filtering rates during the growth phases were： exponential phase 〉 lag phase 〉 stationary phase 〉 decline phase. The results of this study provide foundational information that can be used to explore the optimal culture conditions for rotifers and to promote the development of aquaculture.

Mass Selection for Fast Growth in the Third Generation of the Orange Line of the Manila Clam Ruditapes philippinarum

The Manila clam Ruditapes philippinarum is natively distributed along the Pacific coast of Asia,where it is one of the most important bivalve species for local fisheries.This species has been intentionally introduced due to its high adaptability to various coastal environments and is currently widely cultivated in Europe and North America.We have initiated a selective breeding program to improve the growth rate of the Manila clam since 2007,and a full-sib family with orange shell color was selected.This family features high survival but slow growth.Thereafter,two generations of mass selection were conducted in this family by 10% upward selection for faster growth.In 2011,three types of lines were produced by selecting the breeder from the second-generation of selected lines.These lines are SS(subject to three generations of selection for growth in shell length),SC(selected for the second but not the third generation),and C(randomly sampled individuals from the national population).The genetic parameters of the shell length including hR^2(realized heritability),SR(selection response),and GG(genetic gain)were analyzed.Results showed that the shell length of the SS line was significantly larger than those of the SC and C lines at all developmental stages(P<0.05).For the larval stage,the values of hR^2,SR,and GG were 0.42,0.73,and 6.66,respectively.For the juvenile stage,the values of hR^2,SR,and GG were 0.40,0.69,21.76,respectively.For grow-out stage,the values of hR^2,SR,and GG were 0.48,0.83,and 18.22,respectively.The results of hR^2 indicated the good potential of the SS line in selective breeding.The level of GG improvement was encouraging and consistent with the previous expectations.No inbreeding depressions in the shell length were observed in the SS and SC lines at all sampling days.All of the results indicate that maintaining selection pressure in successive generations may be effective in the selective breeding program of this family.

Effects of Using Exogenous Digestive Enzymes or Natural Enhancer Mixture on Growth, Feed Utilization, and Body Composition of Rabbitfish, Siganus rivulatus

This study was conducted to study the effects of a commercial exogenous digestive enzymes （EDE） containing cellulases, xylanases, u-amylase and proteases from anaerobic bacterium and natural enhancer mixture （NEM） containing allicin, high unit hydrolytic enzyme, Bacillus subtilis spores and ginseng extracts on survival, growth, carcass composition and feed cost/benefit in rabbitfish, Siganus rivulatus. Nine net cages （100 cm × 100 cm × 40 cm; L ×W ×H） were stocked with 10 juvenile rabbitfish （1.1 g per fish） each and placed in a large rectangular tank and offered feed at 4% body weight daily. Three replicates per treatment were offered three isonitrogenous and isocaloric diets, control and two supplemented diets with EDE or NEM at 2 g/kg diet for 74 days. Fish in all cages were weighed at two-week intervals and feed regimen was adjusted accordingly. Rabbitfish offered the control diet exhibited lower growth significantly （P 〈 0.05） and feed utilization than the other two experimental treatments. Experimental diet supplemented with NEM recorded the highest growth performance, feed conversion ratio, protein efficiency ratio, net protein utilization and energy retention significantly （P 〈 0.05） than the other two tested groups. Carcass composition and somatic parameters index was not affected by dietary EDE or NEM inclusion. Ultimately, when all variables are considered, EDE and NEM inclusion to diets appears to reduce feed cost per unit growth of rabbitfish.

Floc meal as potential substitute for soybean meal in tilapia diets under biofloc system conditions

This study was conducted to evaluate the ef fect of replacing soybean meal(SBM) by low protein ?oc meal(LPFM; 24% CP) in tilapia diets on growth performance, feed utilization and ?sh chemical composition. Three isonitrogenous and isocaloric diets were formulated; control diet(C; without LPFM),FM 25(25% of SBM protein was substituted by LPFM) and FM 50(50% of SBM protein was substituted by LPFM). Nine 55 l circular plastic tanks were stocked by 12 ?sh to form three experimental groups.No dif ferences in tilapia performance were observed between the control and the FM 25 diet. Chemical composition of ?sh did not dif fer signi?cantly among treatments except for protein and selenium contents where the highest values were recorded in the control treatment. The highest mineral content was recorded in ?oc collected from the control tanks, while calcium content showed its highest value in ?oc collected from FM 50 e ? uent. These data indicate that replacing soybean meal with LPFM up to 25%, had no negative ef fect on growth performance and potentially may improve the system sustainability. Meanwhile, the adverse ef fect of more inclusion of LPFM in tilapia diet may be attributed to the higher content of ash. In other word,minerals seem to cause more energy utilization in ?sh fed ?oc meal since it is needed to maintain osmotic homeostasis.

Tilapia： From the Nile to the World

This study addressed the potential oftilapia aquaculture as a major contributor to food production and poverty alleviation all over the world. To encompass this subject, tilapia history, origin, aquaculture potential, constraints, current and future production levels were reviewed. Tilapias are native to the River Nile and Africa in general then they were introduced and disseminated worldwide. Positive aquacultural characteristics of tilapia made tilapias the most cultured species worldwide now and in the near future. Tilapia world production is expected to reach 3 million tons this year 2010. Thus, tilapias could make a significant contribution to the livelihoods support especially in the tropical and subtropical countries.

Food Behavior Correlated with Lifestyle Pattern and Societal Influences in a Romanian Students Population. Part I: Eating General Habits

Input data from Students Food Behavior, Preference and Lifestyle Questionnaire conducted with 376 students from University “Dunarea de Jos” Galati (UDJG) were analyzed from socio-demographic criteria. The sample socio-demoraphic characteristics of the student population were investigated beside the general food & eating habits by gender. In the current study, most than three quart of students (76.06%) was of correct (normal) weight. Nearly 65.15% of the students reported having regular daily breakfast. The strongest correlation of having breakfast habit is show with the regular meal behaviour [r(3, 4) = 0.242] and regular meals were associated with reduced trends for BMI [r(4, 2) =-0.055].

Effect of salinity on the growth, and agar yield and composition of Gracilaria tenuistipitata var liui Zhang et Xia

Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar composition are analyzed. Results show that algae grow faster in low salinity. The total agar yield is higher under high salinity conditions than under low salinity conditions. Among the eight fractions extracted, the yields of cold water extract and 40% ethanol extract are about the highest In low salinities the yields of autoclaved extract and 60% ethanol extract are higher, while the yield of cold water extract is lower relative to high salinities.

Growth Rate of Kappaphycus striatum var cottonii at Different Positions of the Cultivation Lines to the Direction of Water Current

The study was conducted to determine the effects of different positions in cultivation lines towards the direction of water current on growth rate of Kappaphycus striatum var. cottonii for a duration of 45 d at 4°30′9.36″ N and 119°22′6.8″ E of Bungin Pondohan, Sitangkai, Tawi-Tawi. The experiment has three treatments;the parallel (T1), perpendicular (T2) and diagonal (T3) positions towards the direction of water current with five replicates in each treatment following the randomized complete block design (RCBD). Results showed that higher mean weight of 473 g and growth increment of 8.3 g/d were obtained from T3, although not significantly different from T1 and T2 with 431 g and 7.4 g/d, and 408 g and 6.8 g/d, respectively (p>0.05). However, results showed statistically similar growth rates of K. striatum var cottonii among all treatments. Thus, the positions of cultivation lines with respect to the direction of the current have no significant effect on the growth of the said seaweed species. Hence, the treatments used are viable in growing K. striatum var. cottonii in the selected study site.

Characteristics of dehalogenase from bacteria isolated from the Gut of Pond-reared Rohu (<i>Labeo rohita</i>) Juveniles in Myanmar

Unwarranted accumulation of halogenated compounds in the rivers and streams has in recent years emerged due to the widespread use agricultural pesticides. The presence of these halogenated compounds in the water does not only suppress the immune system of fish but adversely induce serious morbidity and mortality among cultured stocks. Importantly, gradual accumulation of these compounds in the system of cultured and wild freshwater fish species cultured in ponds and floating net-cages in dams and rivers, respectively, poses some risks to humans, the end users. In this study, we attempted to isolate bacteria from the gut of pond-reared rohu (Labeo rohita) in Myanmar, screened the isolated bacteria for dehalogenase gene using molecular technique and tested the ability of these bacteria to degrade halogenated compounds in vitro. The eight bacterial strains studied were identified as Enterobacter mori strain MK- 121001, Enterobacter cloacae strains MK121003, MK-121004, MK121010, Ralstonia solanacearum strain 121002, Acinetobacter baumannii strain MK121007, Chromobacterium violaceum strain MK121009 and Pantoea vagans strain 121011. Only three bacterial strains (MK121002, MK121007 and MK121009) were capable of degrading 2,2-dichloropropionic acid (2,2-DCP) as the sole carbon source up to a final substrate concentration of 20 mM. Their mean growth doubling time ranging from 6-23 hours with the maximum of chloride ion released of 85%. PCR amplifica- tion with oligonucleotide primers designed from group I dehalogenase revealed the presence of deha- logenase genes in all isolates suggesting dehalogenase gene in strains 121001, 121003, 121004, 121010 and 121011 were silenced. In contrast, group II dehalogenase primers did not show any PCR amplification. These results suggest that MK121002, MK121007 and MK121009 only encode a group I dehalogenase and its non-stereoselectivity is in agreement with previoulsly described group I haloacid dehalogenase. The partial gene sequences were blasted but no significant sequence identity was observed. Therefore, it suggest the 2-haloacid dehalogenase of MK121002, MK12-1007 and MK121009 might be a novel group I 2-haloacid dehalogenase. The results indicated a broad distribution of dehalogenation genes in many micro- bial genomes that harbor dehalogenase(s) due to the exposure of the microorganisms to the naturally occurring or man-made halogenated compounds in the environmental systems. So far, microorganisms capable of producing dehalogenases were mainly isolated from soil and scarcely from aquatic animals and their environments. To the authors’ knowledge, this is the first report on the isolation of dehalogenase-producing bacteria from the gut of pond-reared freshwater fish, Labeo rohita, in Myanmar.

Growth Performance of Muscovy Ducks (<i>Cairina moschata</i>) Fed Palm Kernel Meal Based Diets

From a total of 80 fertile eggs incubated naturally by female ducks, healthy sexed ducklings (n = 64, 32 males and 32 females ducklings) were randomly selected and allotted to four dietary treatments with four replicates, in a completely randomized design in order to evaluate the effect of varying levels of palm kernel meal (PKM) on performance of ducklings. The dietary treatments comprised R0-control ration, R50-50% PKM replacement, R75-75% PKM re-placement and R100-100% PKM replacement of soyabean meal. The main results revealed that the apparent digestive coefficients of dry matter (81.12%), organic matter (83.98%) and NDF (81.10%) were higher with the ration in which 50% (R50-50% PKM replacement of soyabean meal) of soybean was replaced by palm kernel meal. The highest feed intake in male was recorded with the ration containing 75% (R75-75% PKM replacement of soyabean meal) of palm kernel. This same ration (R75-75% PKM replacement of soyabean meal) equally induced the highest live weight and weight gain in females. The experimental design and arrangement is a 2 × 4 factorial arrangement with two sexes and four levels of PKM. In males, the control ration without palm kernel meal induced the highest live weight and highest cumulative weight gain. The lowest feed conversion ratio (p < 0.05) was recorded with the control ration regardless of the sex considered. The lowest cost of feed in-take and cost of production of a kg of body weight were obtained respectively in females and males fed on control ration. With the 50% (R50-50% PKM re-placement of soyabean meal) substitution of soybean meal, the carcass yield was the highest regardless of the sex. Serum content in ALAT, ASAT, creatinine, total cholesterol and total protein were not significantly (p > 0.05) affected by the incorporation of palm kernel meal into the diet. Urea serum content tends to decrease with the increasing level of palm kernel meal in feed. In conclusion, soybean meal can advantageously be replaced by palm kernel meal at the level of 75% (R75-75% PKM replacement of soyabean meal) in Muscovy duck feed.

Effects of Replacing Maize with Dioscarea bulbifera Flour on Growth Performance of Broiler Chickens

The present study was designed to evaluate Dioscarea bulbifera flour as potential feed ingredient in broilers diets. For this purpose, 256-day-old Cobb 500 broiler chicks, were divided into 4 groups replicated 4 times in a completely randomized design. A control ration (R0) containing maize as the main energy source was compared to three other rations in which 50%, 75% and 100% maize were substituted with Dioscarea bulbifera flour. The main results showed that, the increasing rate of Dioscarea bulbifera flour had no significant (p > 0.05) effect on the digestibility of feed components. Feed intake was higher with 50% and 75% Dioscarea bulbifera flour inclusion levels. As compared to the control ration, a significant (p < 0.05) drop in live weight and weight gain was recorded with 50% substitution while feed conversion ratio increased significantly with increasing level of Dioscarea bulbifera flour in the ration. Dioscarea bulbifera flour induced a linear and significant (p < 0.05) increase in the relative weight of the gizzard, liver and production cost. It was concluded that, substituting 50% maize with Dioscarea bulbifera flour could be a sustainable solution to palliate the growing inflation of maize as animal feed ingredient. However, the incorporation level of Dioscarea bulbifera as feed ingredient in substitution of maize must not exceed 50% at the risk of depreciating growth performance of broilers.

Waste production in aquaculture:Sources,components and managements in different culture systems

The intensification of aquaculture has emerged as a viable alternative for increasing aquaculture production due to competition that arose from the use of natural resources,such as land and water,by other production and developmental sectors.However,intensification demands increased inputs,such as fish and feed per unit culture area and,therefore,increased waste generation from the aquaculture production systems.The impact of waste products from aquaculture has increased public concern and threatens the sustainability of aquaculture practices.The need for increasing the production of aquaculture products cannot be overemphasized and,therefore,there is a need to develop culture systems that will increase fish production with efficient waste management in order to limit environmental degradation resulting from aquaculture wastes and ensure its sustainability.This paper reviewed various aspects of waste production from aquaculture,their sources,components,and methods of management,in different culture systems,primarily discussing waste production from feed,chemicals,and pathogens.We aimed to establish the sources of wastes,their contents,and potential harms to both the fish culture and the environment.Suggestions for managing wastes in different culture systems were made to ensure an improved and sustainable aquaculture production.

Available for millions of years but discovered through the last decade:Insects as a source of nutrients and energy in animal diets

The aim of this review is to present and discuss the most recent literature about the processing of insect biomass and its impact on nutritive value,further implementation of meals and fats derived from invertebrates to livestock(poultry and swine),aquaculture(salmonids),and companion animal diets and their impact on growth performance,metabolic response,and gastrointestinal microbiota shifts.Additionally,the most important barriers to obtaining unified products in terms of their nutritive value are considered,i.e.,to define insects'nutrient requirements,including various technological groups and further biomass processing(slaughtering,drying,and storage).Due to the current limitation in the insect production process consisting of the lack of infrastructure,there is stress on the relatively small amount of insect products added to the animal diets as a functional feed additive.Currently,only in the case of pet nutrition may insects be considered a full replacement for commonly used environmentally harmful and allergenic products.Simultaneously,the least information has been published on this topic.Thus,more scientific data are needed,particularly when the pet food branch and insect-based diets are rapidly growing.

Chronic effect of waterborne colloidal silver nanoparticles on plasma biochemistry and hematology of rainbow trout(Oncorhynchus mykiss)

Objective:To investigate the possible effects of silver nanoparticles(AgNPs)on some blood and plasma indices of rainbow trout(Oncorhynchus mykiss).Methods:Hence,fish were exposed for 21 days to sub-lethal concentrations of colloidal AgNPs and blood parameters including erythrocyte size and hematocrit,plasma parameters including cholinesterase,cortisol,sodium,chloride,and potassium,and also silver concentration in plasma were measured following the 11th and 21st days of exposure.Results:According to the results of present study,higher concentrations of AgNPs had more significant effects on plasma biochemistry and hematology of trout.The greatest impacts were decline of chloride ions and increase of cortisol and cholinesterase.Also fish exposed to AgNPs significantly increased silver concentration in the plasma.Conclusions:Further studies are needed to identify appropriate blood biomarkers following fish exposed to nanomaterials,especially AgNPs.

Biofloc technology (BFT): Adjusting the levels of digestible protein and digestible energy in diets of Nile tilapia juveniles raised in brackish water

Several studies have been performed adjusting the levels of dietary digestible protein and digestible energy for tilapia,but none of them was performed in biofloc technology(BFT)system,especially in brackish(10)water.In this sense,three levels of digestible protein(22,26 and 30%DP)and three levels of digestible energy(3000,3150 and 3300 kcal DE/kg)were evaluated on growth performance,body composition,hematological parameters and planktonic community in juveniles of Nile tilapia(O.niloticus)raised under BFT conditions.A total of 540 tilapia fingerlings(GIFT strain with 1.25±0.15 g initial weight)were reared during 42 days in thirty-six plastic tanks(75 L),fed three times a day.No interaction was detected in the parameters evaluated.The fish fed with feed containing 26%and 30%of DP obtained higher final weight,specific growth rate and condition factor as compared to those fed with 22%of DP(P<0.05).Body protein on tilapia carcass increased proportionally according to dietary protein.The higher dietary energy level promoted a higher body lipid deposition.According to hematological parameters fish from all treatments presented a satisfactory immunological status.The monitoring of planktonic community indicated a variation over time,specially on the number of dinoflagellates,rotifers and microalgae.The results indicated that diets containing 26%of DP and 3150 kcal/kg of DE for Nile tilapia juveniles promoted suitable growth performance and health conditions when reared in biofloc brackish water,and enabled savings in regards to dietary protein once the energy levels were adjusted.

Assessing potential protection effects on commercial fish species in a Cuban MPA

Cuba has been leading marine protected area(MPA)designation in the Caribbean region to ensure conservation of its valuable marine ecosystems.Yet,an efficient monitoring program for MPAs is still to be implemented and will benefit from pre-existing information.The highly regulated MPA of Punta Francés National Park is one of the first Cuban MPAs and was established mainly to protect species and ecosystems for tourism purposes.Monitoring of protection effects on commercial fish species was lacking in this MPA.This study aimed at increasing local scientific knowledge by providing a baseline study about the most commercially fished families(Haemulidae,Lutjanidae and Serranidae)around Punta Francés MPA.Data collected represent only a limited period but can be used as a base point to support future monitoring.Fish abundance in number and biomass,and size were collected to test for differences between inside and adjacent areas outside the Punta Francés MPA,in different coral reef types.The main result of this study was the significantly larger size and biomass of snappers and groupers outside the MPA where intense fisheries occur.An observation consistent with a large spawning aggregation was also recorded outside the MPA.Even with a limited set of data,these results suggest that,at least temporarily,the most targeted species[and sizes]are still highly vulnerable to fisheries.Relevant habitats in the adjacent area,that are apparently missing within the MPA,may support some of the results found.Extending the limits of the Punta Francés MPA to include those habitats outside may be critical to ensure the effectiveness of this MPA in contributing to protect the most commercial species of the region.This should be done together with efficient fisheries management measures in the region,such as the significantly increase of minimum legal sizes and temporal closures during spawning migrations.