Freeze‐dried forms of mosquito larvae for feeding of Siamese fighting fish (Betta splendensRegan, 1910)

Abstract

Live diets are preferably used for rearing Siamese fighting fish (Betta splendens Regan, 1910) since they provide superior growth over the dry feed. In the current study, three different preparations of mosquito larvae were prepared (frozen at −20°C, F-20; freeze-dried and kept at 4°C, FD4; freeze-dried and kept at ambient temperature, FDAT) and were individually fed to 1-month-old red male fighting fish (1.18 ± 0.01 g initial body weight) over 6 weeks duration. At the end of experiment, there were no significant differences in growth performance and feed utilization across three dietary treatments (p ˃ 0.05). Specific activity of lipase was significantly lower in fish fed FD4 and FDAT than with the F-20 diet, while no differences in other enzymes were observed. The fish fed with FDAT diet significantly increased in viscerosomatic index relative to F-20 and FD4 treatments. Significant improvements in skin redness and flesh quality (RNA and RNA/protein ratio) were observed in the fish fed with FDAT diet relative to the other treatments. This preferred FDAT treatment also maintained the carcass composition. Analysis of digestive enzymes in FDAT mosquito larvae demonstrated the presence of protein-, carbohydrate-, and lipid-digesting enzymes after 1 month of storage. The findings from our experiments indicate that the freeze-dried form (FDAT) of mosquito larvae is suitable for rearing Siamese fighting fish. However, effective preparation protocol and appropriate storage times should be further studied. K E Y W O R D S colour, digestive enzyme, flesh quality, freeze, freeze-dry, live diet

Polyculture of tilapia (Oreochromis niloticus) and lemeduk (Barbonymus schwanenfeldii) in floating net cages as a strategy for utilizing natural food

“…The parameters of growth performance were obtained by according to study Thongprajukaew [11] and Ferosekhan [12] using the following equations:…”

Performance of Co-Housed Neon Tetras (Paracheirodon innesi) and Glowlight Rasboras (Trigonostigma hengeli) Fed Commercial Flakes and Lyophilized Natural Food

“…In comparison, the majority of scientifically verified reports about aquarium fish nutrition also concern the application of natural food for larval stages [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ], but there are mostly vague reports about diets for fish which already underwent larval metamorphosis [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. More attention has thus far been paid only to the Siamese fighting fish, Betta splendens [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ], commonly known as the “betta”. For this species, natural food in the form of mosquito larvae ( Culex sp.)…”

“…For this species, natural food in the form of mosquito larvae ( Culex sp.) apparently improves its coloration [ 39 , 43 ]. Furthermore, best fecundity was attained when using at least 50% of Tubifex sp.…”

“…All in all, these results generally point toward a presumption that natural food is highly desirable in the nutrition of aquarium fish, especially when used in addition to formulated feed. Unfortunately, apart from some of the aforementioned studies on the betta [ 40 , 41 , 42 , 43 ] and zebrafish [ 45 , 47 , 48 , 51 ], most of the scientists cited above [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 46 , 49 , 50 ] did not use almost any analytical methodology other than standard growth parameters. Thus, they did not take into account that there are distinct internal biological features which distinguish the studied species, which may be of consequence during their co-housing in community tanks.…”

“…When assessing the effects of feeding in aquaculture studies, the histology of the digestive organs is naturally one of the major features which is being looked at [ 70 , 71 , 72 ]; however, skeletal performance (mineralization) and feeding-induced deformities are also often described in various farmed fish [ 73 , 74 ]. While some of the aforementioned papers included relatively advanced analytical methods, such as digestive enzyme activity [ 41 , 42 , 43 ], histology has never been used before in feeding-related studies on ornamentals, with the exception of the zebrafish [ 45 , 51 ]. Skeletal development of aquarium fish is also a sparsely discussed topic.…”