Cadmium (Cd) influences calcium (Ca) levels in the skeleton of a freshwater fish Channa gachua

Abstract Environmental contamination with heavy metals is a threat to the organisms due to their toxicity, persistence and bioaccumulation in food chains. The study was aimed to assess cadmium (Cd) effect on calcium (Ca) level in bones of a freshwater fish Channa gachua. 42 fish individuals were kept into six (6) aquaria; labelled aq.0, 1, 2, 3,4 and 5 in the laboratory for treatment. Aq.0 was control group and aq.1, 2,3,4,5 were experimental with treatment solution of Cd 0, 0.1ppm, 0.5ppm, 1ppm, 2.5ppm and 5ppm respectively for three months. After exposure, bones tissue were examined for Cd accumulation and Ca concentration. Highest accumulation of Cd were recorded in aq.5 mean 46.86 ± 0.46 mgkg-1 .and lowest in the control group with mean 0.61 ± 0.06 mgkg-1. The order of Cd bioaccumulation in bones were aq.5 > aq.4 >aq.3 > aq.2 > aq.1 > aq.0. Highest concentration of Ca were noted in aq.0 (Control group) mean 7888.06 ± 4827.22 mgkg-1 and lowest were 1132.36 ± 203.73 mgkg-1 in aq.5 (at 5.0 ppm). Generally a pattern of decreasing Ca level were observed with each rise of Cd bioaccumulation aq.0 > aq.1 > aq.2 > aq.3 > aq.4 > aq.5. Current study indicated that Cd accumulation have substantial effect on Ca level in bones and hence on skeleton system. Strict rules must be implemented by government to control metals pollution and exploitations of biota.

Effects of replacement of dietary fish oil with plant oil on growth performance and fatty acid composition of spinefoot rabbitfish, Siganus rivulatus

Abstract A 95-day feeding study was carried out to evaluate the impact of complete replacement of fish oil by plant oils in the growth performance, feed consumption fatty acid and body composition of juvenile rabbitfish, Siganus rivulatus. There were four treatments i.e., A (fish oil diet), (linseed oil diet), C (soybean meal oil diet) and D (sunflower oil diet). The experimental trial was conducted in twelve 1.5-m3 fiber glass tanks (n=3). Spinefoot rabbitfish juveniles had an average initial weight of 0.948 g ± 0.124 g and they were stocked at 50 fish per tank. Fish fed diet A showed significantly better growth rate, final body weight, and total body weight than fish fed on the other diets. Moreover, the best FCR was observed for diet A followed by diet C and diets B and D had the worst FCR. Fish body composition for crude protein, dry matter, ashes and gross energy at the end of the trial had not differed between the treatments. The highest polyunsaturated fatty acids (PUFA) was found in fish fed diet A followed in decreasing order by diets D, B, and C. Fish oil is a better dietary lipid source for Spinefoot rabbitfish juveniles, Siganus rivulatus, than plant oils. Among plant oils, soybean oil was better than linseed oil and sunflower oil as the main dietary fat source.

Size at sexual maturity estimation for 36 species captured by bottom and mid-water trawls from the marine habitat of Balochistan and Sindh in the Arabian Sea, Pakistan, using maximum length (Lmax) and logistic (L50) models

Abstract The aim of this study was to estimate the size at first sexual maturity (Lm) for 36 species belonging to 24 families from the marine habitat of Balochistan and Sindh in Arabian Sea, Pakistan through maximum length based an empirical and logistic model using commercial catch during June 2020 to May 2021. Individual total length (TL) was noted up to 0.1 cm using measuring broad. The Lm was calculated using two formulae; (i) log (Lm) = - 0.1246 + 0.9924 * log (Lmax) for Elasmobranchs and (ii) log (Lm) = -0.1189 + 0.9157* log (Lmax) for ray-finned fishes. The minimum Lm was recorded as 10.27 cm TL for Caranx malabaricus and 108.38 cm TL for Isurus oxyrinchus, respectively. Around Lm with 58.33% species were ranges from 19.00 cm to 25.00 cm TL. This study was estimated 16 newly Lm which is globally absent and rest 20 Lm are absent in the Arabian Sea (Pakistan coastal habitats). Therefore, the results will be helpful for the sustainable management and conservation of these marine fishes through the establishment of mesh size of trawl nets based on the size at sexual maturity (Lm).

Putting CRISPR-Cas system in action: a golden window for efficient and precise genome editing for crop improvement

The daunting task of feeding an ever-growing population is an immense challenge for the contemporary scientific community, especially in view of the rapidly changing climate throughout the world. Amidst these threatening crises, we witness rapid development in genome editing (GE) technologies, revolutionizing the field of applied genomics and molecular breeding. Various GE tools have been developed during the last two decades, but the CRISPR/Cas system has most recently made a significant impact on crop improvement. The major breakthroughs of this versatile toolbox are genomic modifications like single base-substitutions, multiplex GE, gene regulation, screening mutagenesis, and enhancing the breeding of wild crop plants. Previously, this toolbox was used to modify genes related to significant traits such as biotic/abiotic resistance/tolerance, post-harvest traits, nutritional regulation, and to address self-incompatibility analysis-related challenges. In the present review, we have demonstrated the functional dynamics of CRISPR-based GE and its applicability in targeting genes to accomplish novel editing of crops. The compiled knowledge will provide a solid foundation for highlighting the primary source for applying CRISPR/Cas as a toolbox for enhancing crops, to achieve food and nutritional security.

Integrating genomics and genome editing for orphan crop improvement: a bridge between orphan crops and modern agriculture system

Domestication of orphan crops could be explored by editing their genomes. Genome editing has a lot of promise for enhancing agricultural output, and there is a lot of interest in furthering breeding in orphan crops, which are sometimes plagued with unwanted traits that resemble wild cousins. Consequently, applying model crop knowledge to orphan crops allows for the rapid generation of targeted allelic diversity and innovative breeding germplasm. We explain how plant breeders could employ genome editing as a novel platform to accelerate the domestication of semi-domesticated or wild plants, resulting in a more diversified base for future food and fodder supplies. This review emphasizes both the practicality of the strategy and the need to invest in research that advances our understanding of plant genomes, genes, and cellular systems. Planting more of these abandoned orphan crops could help alleviate food scarcities in the challenge of future climate crises.