Oreochromis Urolepis Hornorum Research Articles

Effect of Microplastic Exposure to the Reproductive Energy and Fecundity of Female Wami Tilapia (Oreochromis urolepis, Norman 1922) Fish

ABSTRACTThere is mounting evidence indicating that microplastics (MPs, < 5 mm) cause reproductive dysfunction in fish, yet information on the long‐term effects of MP exposure remains scarce. In this study, Wami tilapia fries were exposed to 38–45 µm polyethylene (PE) MPs for their first 2 months in treatment groups of control (0 PE MPs/mL), 1, 10, and 100 PE MPs/mL (with 60 individuals per group in triplicates), and subsequently maintained in a ratio of 3 females to 1 male for an additional 5 months. Reproductive proxies and parameters of female fish health were calculated, and models were developed according to the Akaike information criterion (AIC) and no significant differences in fecundity, relative fecundity, hepatosomatic index (HSI), weight, length, gonadosomatic index, and oocyte packing density were found between treatment groups (one‐Way ANOVA, p > 0.05). However, condition factors varied significantly between treatment groups (Kruskal–Wallis Test, p = 0.006), with the control group differing significantly from the groups exposed to 1 PE MPs/mL (p = 0.007), 10 PE MPs/mL (p = 0.03), and 100 PE MPs/mL (p = 0.001). Fecundity showed strong correlations with weight and length in all treatment groups except the group exposed to 10 PE MPs/mL (weight: r = 0.471, p = 0.346; length: r = 0.688, p = 0.131) and showed insignificant correlations with condition factors and HSI. Multiple regression models revealed that weight significantly contributed to fecundity in all treatment groups except the group exposed to 10 PE MPs/mL. Histopathological analysis indicated damage to livers and small intestines proportional to the dose of PE MPs. This study demonstrates that long‐term exposure of fish to MPs has no significant effect on fecundity but impairs fish health, which could potentially jeopardize the quality of fish eggs and recruitment.

Status of conventional and molecular breeding of salinity‐tolerant tilapia

AbstractAquaculture is an important sector for ensuring global food security. Due to the scarcity of freshwater available for expanding aquaculture, the development of omnivorous fish species and varieties that can tolerate high salinity will enhance fish production. Some tilapia species are good candidates for aquaculture in brackish and seawater because they can grow in high salinity. Among tilapia species, Oreochromis mossambicus, Oreochromis aureus, Oreochromis spilurus, Oreochromis urolepis hornorum, Sarotherodon galilaeus and Coptodon zillii are the most salinity‐tolerant. Hybrids derived from salinity‐tolerant tilapia species are tolerant to a certain level of salinity. They have been used in aquaculture production in brackish water and full seawater. Conventional selective breeding has been applied to increase the growth rate of salinity‐tolerant tilapias. However, their growth rate is lower than that of the freshwater Oreochromis niloticus. Recently, many genomic resources and tools have been developed for salinity‐tolerant tilapia. Quantitative trait locus (QTL) mapping and genome‐wide association studies (GWAS) for important economic traits, including salinity tolerance and other desired traits, have been carried out and applied in molecular breeding for superior salinity‐tolerant tilapia lines. In this review, we systematically analysed tilapia species that can be cultured in brackish and saltwater. We summarized previous works in conventional breeding and molecular breeding for salinity‐tolerant tilapia. We pointed out a few known and potential challenges in the selective breeding and culture of salinity‐tolerant tilapia. Due to the rapid advances in molecular and other disruptive technologies, we are optimistic that novel breeding approaches will significantly increase the production salinity‐tolerant tilapia.

Histomorphological Damage in the Small Intestine of Wami Tilapia (Oreochromis urolepis) (Norman, 1922) Exposed to Microplastics Remain Long after Depuration

The histopathological effects of microplastics (MPs) in the gastrointestinal tracts of fish following long-term exposure and depuration are relatively understudied. This study investigated histomorphological damage in the small intestine of Oreochromis urolepis larvae following 65 d exposure to 38–45 μm of polyethylene microspheres (PE MPs) and after a recovery period of 60 d. Larval fish were assigned to each treatment group (control, 1, 10 and 100 PE MPs), where ingestion and degenerative changes in the small intestine were examined using a routine hematoxylin and eosin staining technique. The results highlighted significant PE MPs ingestion and retention proportional to exposure dose (χ2 = 49.54; df = 2). Villi height and width and epithelial cell height were significantly affected and differed between treatment groups. Indices of damage to the small intestine organ (χ2 = 47.37; df = 2; p < 0.05) and reaction patterns of villi, epithelial, goblet and cryptic glandular cells, leucocytic infiltration and blood congestion revealed significant occurrence of alteration as PE MPs exposure dose increased. After the recovery period, no PE MPs were observed, and villi height, width and epithelial cells showed recovery with no significant difference between treatment groups. Organ indices declined (χ2 = 12; df = 2; p < 0.05) but remained significantly different between treatment groups, largely due to leucocytic infiltration (χ2 = 9.08; df = 2; p < 0.05). The study demonstrated that microplastics induced small intestinal wall degeneration, but recovery in young fish occurred slowly. The damage likely compromised its digestive function, which may affect growth and reproduction. This requires further research.

Effects of High Salinity on Survival, Growth, and Reproductive performance of Red Tilapia (Oreochromis urolepis hornorum ♀× Oreochromis mossambicus ♂)

This study estimated the survival, growth, and fry production of red tilapia (Oreochromis urolepis hornorum ♀× Oreochromis mossambicus ♂) broodstock in outdoors farming conditions at various salinity levels (1‰, 25‰, 33‰, 39‰, and 42‰) at 25.3°C–39.0°C. The experiments were conducted in triplicates in 2020 using 300 broodstock per group. The survival rate, growth performance, and fry production were monitored. Our results showed that red tilapia fry production and grow-out farming were feasible under high salinity conditions; however, the various levels of salinity condition exhibited significant differences in terms of survival rate, growth performance, fry production. The results suggest that red tilapia broodstock was maintained under salinity as high as 33‰ without impairing fry production; above 33‰ was feasible for the grow-out stage, implying that the fry production in euryhaline tilapia farming would be practical in regions where freshwater acclimation is limited.

Identification and Characterization of Osmoregulation Related MicroRNAs in Gills of Hybrid Tilapia Under Three Types of Osmotic Stress.

Researchers have increasingly suggested that microRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression and protein translation in organs and respond to abiotic and biotic stressors. To understand the function of miRNAs in osmotic stress regulation of the gills of hybrid tilapia (Oreochromis mossambicus ♀ × Oreochromis urolepis hornorum ♂), high-throughput Illumina deep sequencing technology was used to investigate the expression profiles of miRNAs under salinity stress (S, 25‰), alkalinity stress (A, 4‰) and salinity–alkalinity stress (SA, S: 15‰, A: 4‰) challenges. The results showed that 31, 41, and 27 upregulated and 33, 42, and 40 downregulated miRNAs (P < 0.05) were identified in the salt stress, alkali stress, and saline–alkali stress group, respectively, which were compared with those in the control group (C). Fourteen significantly differently expressed miRNAs were selected randomly and then validated by a quantitative polymerase chain reaction. On the basis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, genes related to osmoregulation and biosynthesis were enriched in the three types of osmotic stress. In addition, three miRNAs and three predicted target genes were chosen to conduct a quantitative polymerase chain reaction in the hybrid tilapia and its parents during 96-h osmotic stress. Differential expression patterns of miRNAs provided the basis for research data to further investigate the miRNA-modulating networks in osmoregulation of teleost.

Losing cichlid fish biodiversity: genetic and morphological homogenization of tilapia following colonization by introduced species

Among the many negative impacts of invasive species, hybridization with indigenous species has increasingly become recognized as a major issue. However, relatively few studies have characterized the phenotypic outcomes of hybridization following biological invasions. Here we investigate the genetic and morphological consequences of stocking invasive tilapia species in two water bodies in central Tanzania. We sampled individuals from the Mindu Reservoir on the Ruvu river system, and at Kidatu on the Great Ruaha–Rufiji river system. We screened individuals at 16 microsatellite loci, and quantified morphology using geometric morphometrics and linear measurements. In both the Mindu and Kidatu systems, we identified evidence of hybridization between indigenous Wami tilapia (Oreochromis urolepis) and the introduced Nile tilapia (Oreochromis niloticus) or blue-spotted tilapia (Oreochromis leucostictus). At both sites, purebred individuals could largely be separated using geometric morphometric variables, with hybrids occupying a broad morphospace among the parental species. Our data demonstrate that the gene pools and phenotypic identity of the indigenous O. urolepis have been severely impacted by the stocking of the invasive species. Given the lack of evidence for clear commercial benefits from stocking invasive tilapia species in waters already populated by indigenous congenerics, we suggest further spread of introduced species should be undertaken with considerable caution.

Characterization and expression of Na+/K+-ATPase in gills and kidneys of the Teleost fish Oreochromis mossambicus, Oreochromis urolepis hornorum and their hybrids in response to salinity challenge

Tilapia (Oreochromis mossambicus, O. urolepis hornorum, their hybrids O. mossambicus♀ × O. hornorum♂ and O. hornorum♀ × O. mossambicus♂) were exposed to a high salinity environment to evaluate their osmoregulatory responses. The plasma osmolality of all the tilapia species were elevated with the salinity challenge. The activities of Na+/K+-ATPase (NKA) in both the gill and kidney showed a similar increased change tendency compared with the control. The distribution of NKA α1 mRNA in all the examined tissues suggested that NKA α1 has a possible housekeeping role for this isoform. The amount of NKA α1 mRNA in the gill and kidney was elevated in the four fishes with similar expression patterns after transfer from freshwater to seawater. The NKAα1 mRNA expression levels in the gill reached their peak level at 24 h after transfer (P < 0.01) compared to the freshwater group, following decreases in the pretreatment level at 48 h (P > 0.05). However, the NKAα1 mRNA expression levels in the kidney were not significantly affected with increasing environmental salinity (P > 0.05). The differences in the responses to saltwater challenge may be associated with differences in saltwater tolerance between the four tilapia. The drastic increase in the plasma osmolality, NKA activities and mRNA expression suggested that the hybrids (O. mossambicus♀ × O. hornorum♂) possess heterosis in salinity responsiveness compared to that of both the parents, indicating a maternal effect on the salinity tolerance of the tilapia hybrids. This study provides a theoretical basis to further study the mechanism of fish osmoregulation response to salinity challenge.

Community Based Milkfish Farming in Tanzania

In the 1990s experimental integrated mariculture of finfish, shellfish and seaweeds in a flow through system was developed to investigate bio-filtration in the ponds. The project supported mainly by WIOMSA culminated in a stakeholders’ workshop in 2004 translating the results of the experiment to community based projects. The finfish tested were milkfish ( Chanos chanos ), rabbit fish ( Siganus canaliculatus and S. sutor ), mullet ( Mugil cephalus ) and Zanzibar tilapia ( Oreochromis urolepis hornorum ). Before the workshop there were 3 milkfish mariculture ponds in Tanzania one of which was established by IMS. Following the workshop, pond finfish mariculture took off in the coastal Tanzania. In 2006, the first commercial type farm at Bagamoyo produced 1 MT/ha/yr, earning the group 2000 USD. Ever since, finfish farming has spread to all coastal districts with the highest production of 7.5 MT/ha/yr at Ndumbwe Mtwara in 2011. In 2011, trials of tilapia acclimatization and farming in estuarine and full strength sea water were started where survival and growth rates of fry and fingerlings of 4 species of tilapia were tested.

Oviposition of Culex tarsalis (Diptera: Culicidae) Differs on Water Conditioned by Potential Fish and Insect Predators.

The response of egg-laying Culex tarsalis Coquillett (Diptera: Culicidae) to water conditioned by three fish species used for mosquito control and three predatory aquatic insect species was examined in laboratory binary choice experiments. Oviposition by Cx. tarsalis was 72% less on water conditioned with the arroyo chub, Gila orcutti (Eigenmann & Eigenmann) (Cypriniformes: Cyprinidae) relative to control cups containing aged tap water, but no significant difference was found in the numbers of egg rafts laid on water conditioned with the fathead minnow (Pimephales promelas (Rafinesque), Cypriniformes: Cyprinidae) and the control treatment (water aged 24 h). Mosquito oviposition on water conditioned with the predominantly herbivorous/algivorous California Mozambique tilapia hybrid (Oreochromis mossambicus (Peters) × Oreochromis urolepis hornorum L. (Perciformes: Cichlidae)) or predatory insects (nymphs: Sympetrum corruptum (Hagen) (Odonata: Libellulidae); adults: Thermonectus basillaris (Harris) or Cybister fimbriolatus (Say) (Coleoptera: Dytiscidae)) did not differ significantly relative to that onto water aged for 24 h. As compared with water aged 24 h and water conditioned with diving beetles, oviposition by Cx. tarsalis was significantly lower (≥53%) when live predatory diving beetles were present in oviposition cups. Gravid Cx. tarsalis females do not respond equally to putative semiochemicals in water conditioned with the piscine or aquatic insect predators of immature mosquitoes tested here.

Screening and identification of a microsatellite marker associated with sex in Wami tilapia, Oreochromis urolepis hornorum.

In this study, primer pairs of 15 microsatellite markers associated with sex determination of tilapia were selected and amplified in Wami tilapia, Oreochromis urolepis hornorum. While one marker, UNH168, on linkage group 3 (LG3) was associated (P <0.001) with the phenotypic sex in the experimental population, nine genotypes were detected in both sexes. Only 99-bp allele was detected in the female samples, while 141, 149 and 157-bp alleles were present in both male and female samples. UNH168 was localized by fluorescence in situ hybridization (FISH) on the long arm of the largest tilapia chromosome pair (chromosome 1, equivalent to LG3). This sex-linked microsatellite marker could potentially be used for marker-assisted selection in tilapia breeding programmes to produce monosex male tilapia.

Impacts of Combined Salinity and Temperature Extremes on Different Strains and Species of Tilapia Inhabiting the Watershed of the Salton Sea

AbstractTilapia have relatively rapid osmoregulatory abilities, but the combined stress due to extreme temperature and salinity can negatively affect the survival of the fish. This study compared the tolerance of the California Mozambique Tilapia hybrid (Mozambique Tilapia Oreochromis mossambicus × Wami Tilapia O. urolepis; CA hybrid) from aquaculture and three species of tilapia that currently live in the Salton Sea area: Blue Tilapia O. aureus, Redbelly Tilapia Tilapia zillii, and CA hybrid collected from the sea. The CA hybrid tilapia (both cultured and feral) was the most resistant species across all treatments and could survive salinities up to 60 g/L (‰). The CA hybrid from aquaculture was the most tolerant to higher temperatures (33–38°C), while the one from the Salton Sea was the most tolerant to colder temperatures (11–16°C). In terms of salinity regimes, the aquaculture CA hybrid and Blue Tilapia survived better at 20‰, while the CA hybrid from the sea did best at 45‰. The different stocks of tilapia showed very different tolerances, and these results provide valuable information for the future management of the Salton Sea.

Yield, viscosity, and gel strength of wami tilapia (Oreochromis urolepis hornorum) skin gelatin: Optimization of the extraction process

A factorial design and response surface methodology were used to optimize the extraction process of tilapia skin gelatin (Oreochromis urolepis hornorum). The concentrations of NaOH (0.15%–0.35%) and H2SO4 (0.15%–0.35%), the extraction temperature (40°C–60°C), and the extraction time (3–15 h) were independent variables. Response variables were yield (%), viscosity (mPa·s), and gel strength (g). The NaOH (%) and H2SO4 (%) concentrations had significant influences (p<0.05) on viscosity and gel strength, while the extraction temperature (°C) and the extraction time (h) showed significant influences (p<0.05) on all dependent variables. Increasing the temperature and extraction time provided higher yields with a reduction in the gelatin viscosity and gel strength. Tilapia fish skin can be used as a source for production of gelatin.

Effect of Feeding Levels and Feeding Frequency on Growth Performance and Feed Utilization of Red Tilapia Fingerlings (Tilapia hornorum X Tilapia mossambicus) .

The present study was carried out at the Mariculture research center (M.R.C.) of the Suez Canal University, EL-Arish, North Sinai, Egypt. It aims to evaluate the feasibility of Red Tilapia culture in salt water. Effect of feeding levels and feeding regimes on growth performance and feed utilization of Red Tilapia fingerlings. Three feeding levels (2, 3 and 4% of total fish biomass) and within each feeding level two feeding frequency (4 times/day and 6 times/day). The fish had an average initial weight of 5.50 g and 32% crude protein were tested .The results showed that: The fish fed on 4% feeding levels from total fish biomass and 4 times /day have the heaviest final body weight (29.68+4.35 g) and have a daily weight gain and specific growth rate of 0.28+0.05 (g/fish/day) and 1.98+0.16 (%/day) , respectively.

Physical and chemical properties of wami tilapia skin gelatin

Gelatin was extracted from the skin of tilapia (Oreochromis urolepis hornorum) and characterized according to its physical and chemical properties. It had pH 4.66, which is slightly higher than the values reported for gelatins processed by acid solubilization. In general, the ionic content was low, and the average yield of the process was 5.10 g/100 g. The proximal composition of the gelatin was similar to that of the commercial gelatins, with slightly higher moisture content. The tilapia skin gelatin had whitish-yellow color and average turbidity of 67 NTU.

Characterization of wami tilapia (Oreochromis urolepis hornorum) skin gelatin: microbiological, rheological and structural properties

Gelatin was extracted from the skin of tilapia (Oreochromis urolepis hornorum) and its microbiological, rheological and structural properties were characterized. The tilapia skin gelatin presented typical molecular weight distribution of type I collagen with contents of imino acids (proline + hydroxyproline) of 21.67%. Gel strength and viscosity values were 221 ± 5.68 g and 5.98 ± 0.34 cP, respectively, with the maturation time of 18 ± 1 h, and both parameters increased with the maturation time. Melting and gelling points of 25 degrees C and 21 degrees C, respectively, were obtained for tilapia skin gelatin. The gelatin presented microbiological standards in accordance with the Brazilian Legislation.

Prevalence of Francisella noatunensis subsp. orientalis in Cultured Tilapia on the Island of Oahu, Hawaii

Francisellosis is an emergent disease in cultured and wild aquatic animals. The causative agent, Francisella noatunensis subsp. orientalis (Fno), is a gram-negative bacterium recognized as one of the most virulent pathogens of warmwater fish. The main objective of this project was to investigate the prevalence of Fno in cultured tilapia (specifically, Mozambique Tilapia Oreochromis mossambicus, Koilapia [also known as Wami Tilapia] O. hornorum, Blue Tilapia O. aureus, and Nile Tilapia O. niloticus hybrids) on the island of Oahu, Hawaii, using conventional and real-time PCR assays followed by statistical modeling to compare the different diagnostic methods and identify potential risk factors. During 2010 and 2012, 827 fish were collected from different geographical locations throughout the island of Oahu. Upon collection of fish, the water temperature in the rearing system and the length of individual fish were measured. Extraction of DNA from different tissues collected aseptically during necropsy served as a template for molecular diagnosis. High correlation between both molecular methods was observed. Moreover, the bacterium was isolated from infected tilapia on selective media and confirmed to be Fno utilizing a species-specific Taqman-based real-time PCR assay. Although a direct comparison of the prevalence of Fno between the different geographical areas was not possible, the results indicate a high prevalence of Fno DNA in cultured tilapia throughout the farm sites located on Oahu. Of the different tilapia species and hybrids currently cultured in Hawaii, Mozambique Tilapia were more susceptible to infection than Koilapia. Water temperature in the rearing systems and fish size also had a strong effect on the predicted level of infection, with fish held at lower temperatures and smaller fish being more susceptible to piscine francisellosis.

Enhancement of Functional Properties of Wami Tilapia (Oreochromis urolepis hornorum) Skin Gelatin at Different pH Values

The effects of several agents in two different concentrations and pH values (5.0 and 8.0) on the functional properties of tilapia (Oreochromis urolepis hornorum) skin gelatin were evaluated and compared using a control tilapia skin gelatin and a commercial mammalian gelatin. The addition of the agents (sucrose 4 % and 8 % (w/v), glycerol 5 % and 10 % (v/v), NaCl 0.3 and 0.8 mol/L, MgCl2 0.3 and 0.8 mol/L, MgSO4 0.3 and 0.8 mol/L, KCl 0.3 and 0.8 mol/L, and transglutaminase 10 and 15 mg/mL) slightly increased the turbidity. There were different ratios of rheological properties depending on the agent, concentration, and pH. The addition of all agents increased the viscosity of the gelatin solution, mainly at pH 5.0. The addition of glycerol (10 % (v/v)) raised viscosity up to 7.45 cP. The setting time was prolonged by incorporating the agents. The gelatin samples with the addition of MgSO4 0.8 mol/L showed higher gel strength than the mammalian gelatin, exhibiting values of 298 and 295gf at pH 5.0 and 8.0, respectively.

Heavy Metals and Organochlorine Residues in Water, Sediments, and Fish in Aquatic Ecosystems in Urban and Peri-Urban Areas in Tanzania

Heavy metals and organochlorine residues were determined in water, sediment, fish muscle, and freshwater shrimps from aquatic environments in urban and peri-urban areas in Morogoro, Tanzania. Most of the water samples had heavy metal concentrations below WHO acceptable water quality guidelines. All sediment samples had comparable heavy metal concentrations that suggest natural rather than anthropogenic origin. Hexachlorobenzene, α-hexachlocychlohexane, cis-chlordane, trans-nonachlordane, cis-nonachlordane, pp′-DDE, op′-DDD, pp′-DDD, op′-DDT, and pp′-DDT in hairy river prawn (Macrobrachium rude), African sharptooth catfish (Clarias gariepinus), and Wami tilapia (Oreochromis urolepis) were detected at significant concentrations above the methods’ detection limits. The ratio of pp′-DDT to ∑DDTs was 0.4 in O. urolepis and 0.3 in C. gariepinus, which indicated previous rather than current use of DDT. In M. rude, only pp′-DDE was detected and in O. urolepis and C. gariepinus there were higher levels of pp′-DDE than pp′-DDT, which demonstrate uptake of pp′-DDE, rather than pp′-DDT, from the environment. Bioaccumulation of organochlorines and mercury was the highest in C. gariepinus, cadmium in M. rude, and lead in both M. rude and O. urolepis. Maximum detected levels of organochlorine pesticides and heavy metals in M. rude, O. urolepis, and C. gariepinus were below the maximum permissible concentrations recommended by FAO/WHO. It is concluded that, at present, the contribution of anthropogenic sources in pollution of aquatic environments in Morogoro urban and peri-urban areas are low and that the concentrations of heavy metals and organochlorine pesticides in water and fish do not indicate a risk to the consumers.

Polyculture of green mussels, brown mussels and oysters with shrimp control luminous bacterial disease in a simulated culture system

Shrimp mortality due to luminous bacteria has been a problem of the shrimp industry worldwide. Polyculture of shrimp with finfish, such as grouper, seabass, snapper, siganid, Tilapia hornorum, and the Genetically Improved Farmed Tilapia (GIFT), could control the growth of luminous bacteria. One way to reduce adverse environmental impact and to reduce bacterial count is through the use of bivalves to filter pond effluents.This study investigated the effect of several bivalves on the growth of luminous bacteria in a simulated shrimp culture environment using concrete tanks. Tanks were stocked with shrimp at a biomass of 100 g/m3 and with brown mussel (158 pcs/m3), green mussel (137 pcs/m3), or oyster (376 pcs/m3). Growth of luminous bacteria decreased to below 101 cfu/ml in tanks with green mussel after 5 d, brown mussel after 16 d, and oyster after 17 d. Bivalves, such as green and brown mussels, and oyster, could be used as an alternative species for polyculture with shrimp to control disease due to luminous bacteria.

Efficiency of Chlorella sp. and Tilapia hornorum in controlling the growth of luminous bacteria in a simulated shrimp culture environment

This study clarifies the effect of green water from Chlorella sp., Tilapia hornorum and the combination of the two organisms on the growth of luminous bacteria in a simulated shrimp culture environment. Results showed that the presence of Chlorella sp. (10 5 cells/ml) alone was not effective in the control of luminous bacteria in shrimp (biomass=80 g/m 3) rearing water. The presence of T. hornorum alone (biomass=500 g/m 3) was more efficient in controlling the growth of luminous bacteria than the co-existence of tilapia and Chlorella sp. Nevertheless, the presumptive Vibrio count was lowest in control tanks that had the highest shrimp survival rate, which was attributed to the presence of other micro-algae such as Chaetoceros, Thalassiosira, Navicula, Nitszchia, Melosira, and Fragilaria.