Maggot meal was used to replace 0, 20% , 40% , 60% , 80% , 100% of the fish meal in the hasal feed, getting 6 kinds of feed with the same nitrogen content and equal energy (marked as group H0, H20, H40, H60, H80, H10...Maggot meal was used to replace 0, 20% , 40% , 60% , 80% , 100% of the fish meal in the hasal feed, getting 6 kinds of feed with the same nitrogen content and equal energy (marked as group H0, H20, H40, H60, H80, H100), which were used to feed the Misgurnus anguillicaudatus (loach) for60 d. The effects of the fish meal replacement by maggot meal on the growth performance of M. anguiUicaudatus were studied by comparing the growth performances and body indica- tors of M. anguillicaudatus fed with different feed groups. The results showed that the final weight, weight gain rate, specific growth rate of the M. anguillicaudatus in group H40 showed no significant difference with the control P 〉0.05 ), but was significantly higher than that of other groups P 〈0.05 ). Moreover, except group H40, the feed coefficients of all other groups were significantly higher than that in control group (P 〈0.05 ). The M. anguillicaudatus in group 1-140 had the highest condition factor and COR and the lowest viscera index, all of which showed significant differences with the other replacement groups (P 〈0.05) but the difference with the control group was not significant (P 〉 0.05). Thus, a proportion of 40% of the fish meal replaced with maggot meal in the mixed feed for the M. anguilli- caudatus could improve the growth performance and physique indexes of M. anguillicaudatus.展开更多
Loach(Misgurnus anguillicaudatus) is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insigh...Loach(Misgurnus anguillicaudatus) is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksac larvae ranged from 2.8 to 4.0 mm body length(BL) between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and postflexion larvae ranged from 7.1 to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics(e.g., external gill filament and ventral mouth opening) and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production.展开更多
基金Supported by the College Project of Xuzhou Vocational College of Bioengineering(2014B07)
文摘Maggot meal was used to replace 0, 20% , 40% , 60% , 80% , 100% of the fish meal in the hasal feed, getting 6 kinds of feed with the same nitrogen content and equal energy (marked as group H0, H20, H40, H60, H80, H100), which were used to feed the Misgurnus anguillicaudatus (loach) for60 d. The effects of the fish meal replacement by maggot meal on the growth performance of M. anguiUicaudatus were studied by comparing the growth performances and body indica- tors of M. anguillicaudatus fed with different feed groups. The results showed that the final weight, weight gain rate, specific growth rate of the M. anguillicaudatus in group H40 showed no significant difference with the control P 〉0.05 ), but was significantly higher than that of other groups P 〈0.05 ). Moreover, except group H40, the feed coefficients of all other groups were significantly higher than that in control group (P 〈0.05 ). The M. anguillicaudatus in group 1-140 had the highest condition factor and COR and the lowest viscera index, all of which showed significant differences with the other replacement groups (P 〈0.05) but the difference with the control group was not significant (P 〉 0.05). Thus, a proportion of 40% of the fish meal replaced with maggot meal in the mixed feed for the M. anguilli- caudatus could improve the growth performance and physique indexes of M. anguillicaudatus.
基金Supported by the Key Technology Research and Development Program of Huai’an(Nos.SN12100 and SN12101)the Construction of Innovation Carrier and Platform Project of Huai’an for the Key Laboratory of Sustainable Fisheries and Environmental Protection for Lakes of Northern Jiangsu(No.HAP201204)the Special Research Fund for Public Interest of MWR of China(No.201201028-02)
文摘Loach(Misgurnus anguillicaudatus) is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksac larvae ranged from 2.8 to 4.0 mm body length(BL) between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and postflexion larvae ranged from 7.1 to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics(e.g., external gill filament and ventral mouth opening) and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production.