The Differences In Shape And Related Physiological Characteristics Between Different Escaping Performances Of Juvenile Black Seabream In The Same Growth Group

The 1800 black seabream of the same group with body length?99.843±2.071mm?and body mass?17.779±0.467g?was used as the experimental object.The self-made height was60cm,the width was 180cm,and the total length was 540cm.The fish pass is used as a grouping device for experimental fish escape ability,and A?0-90 cm?,B?90-180 cm?,C?180-270 cm?,D?270-360 cm?,and E?360-540 cm?are set according to their lengths.In the5 sections,chilled fish were used as bait,and the escape abilities of the experimental fish were grouped simultaneously with 6 fish passes.when finally a fish pass experiment fish escaped to the E zone to reach 5%of the total fish test fish?15 tails?,immediately terminate all fish pass experiments and use framed polyethylene mesh The plates were divided into sections,and the experimental fish retained in the A?B?C?D,and E sections were collected as different escape performance groups,and they were respectively defined as A?B?C?D,and E experimental groups.In order to find the cause of the difference in escape performance between the experimental groups A?B?C?D and E,the sputum traits,the color difference of the lateral lines,the texture of the back muscles and the enzymes related to the organs were developed.Differences in the shape and related physiological characteristics between different escape performance groups in juvenile fish.The results show:?1?The different escape movement abilities of this experiment were analyzed with 28morphological phenotypes of juvenile black mullet,and 7 of them?A13,A16,A17,A23,A25,A27,A28?were not significantly different?P>0.05?;the other indicators showed significant differences in different degrees,and some indicators were positively correlated with the escape performance of juvenile black carp,mainly as follows:A10,A11,A15 and C There are differences between A?B?D and E,which are C<A?B?D?E;B<D?A<E in A20;B<C<D<E in A21;B?C<E in A26?All of the above P<0.05?;In addition,there are significant differences between the morphological scale characteristics,mainly in the indicators X1?X2?X4?X5?X7?X8?X11?X13,the ratio of the ratio traits of the E group and the difference group is significantly biased.Big.Where in E>C>D in X1;E>C?B>A in X2;E>C in X4;E>A in X5,X7 and X8;E>A>C in X11;E>B?in X13C?P<0.05?;the final variance cumulative contribution rate of the five principal components shown in the table is 81.128%,and the Fisher discriminant function is established,and the discriminant accuracy is 77.33%.?2?The five groups A?B?C?D,and E showed no significant difference at locus 1,locus 2,and locus 3;there were significant differences in locus 4 and locus 5 near the tail.Studies have shown that fish tails play a vital role in fish motility.Among them,the E group had the strongest escape ability,and the RG value at the 4th point showed significant difference with the A?C,and D groups?P<0.05?:Group D and Groups A?B?C,and E were in RG.The difference in value was significant?P<0.05?;the D and E groups showed a significant difference in the YB value compared with the A?B and C groups in the relatively strong escape ability?P<0.05?.?3?On the parameters of the back muscle hardness index,the hardness indexes of the two groups with weak escape ability of A and B were significantly larger than those with strong escape ability such as group C?D and E?P<0.05?;the index of muscle adhesion was from large to small.The descending structure,A>C>D>E,better reflects the relationship between the structure of the back muscles and the ability of the black carp to escape.The elasticity index of the back muscles generally increases with the ability of escape movement.Group A<C group<D group<E group,and the E group with the strongest escape ability also showed the highest value in the back muscle elasticity index?P<0.05?.?4?Groups D and E with strong escape ability showed strong oxygen consumption rate at 22:00-02:00?P<0.05?;02:00-6:00 D group had strong oxygen consumption rate in escape ability.Therefore,the highest level was observed in the group?P<0.05?;the gradient relationship between A<B?C?D<E and respiratory abilities was shown from 14:00-18:00with weak escape to strong?P<0.05?.The oxygen consumption rate and the oxygen consumption rate during the day were not significantly different,and the oxygen consumption rate at night was significantly different.The D group showed the strongest respiratory metabolism at night?P<0.05?;the oxygen content in the water at the asphyxiation point The rate of A?B?C>D>E?P<0.05?;the ammonia excretion rate at 02:00-6:00 is A<B<C<E<D?P<0.05?;14:00-18:00 The ammonia metabolism ability also showed a gradient trend from weak to strong A<B?C<D?E?P<0.05?;there was significant difference between the whole day ammonia excretion rate and the daytime ammonia excretion rate?P<0.05?.,all are D?E>A?B?C.?5?Compared with the B?C?D?E group,the group A with the weakest escape ability had lower liver lipase activity,almost one third of the other 4 groups?P<0.05?;the liver trypsin activity,group A?B,There was no significant difference between C?D and E?P>0.05?.The pepsin activity of the D and E groups was relatively high?P<0.05?,and the intestinal enzyme activity level was B?C<A<D?E?P<0.05?.?6?The activity of CAT enzyme in the liver of juveniles in different escape ability groups was from A to B<C<D<E?P<0.05?,which showed a positive correlation with the escape ability of juveniles.The most powerful group E showed the strongest SOD activity of liver?P<0.05?;The Na+/K+ATPase activity in the liver of the strong D group was the highest?P<0.05?.There was no significant difference in the activity of Ca²⁺/Mg²⁺ATPase in the liver of the five groups A?B?C?D and E?P>0.05?.In group D,the activity of SOD in the scorpion larvae of the second group was significantly higher than that of the other four groups,and there was a significant difference?P<0.05?.In conclusion,there are significant differences in morphological traits,lateral chromatic aberration,back muscle texture,and organ-related functional enzyme activities in the different escape performance groups of the juveniles of the black carp,and the juveniles with strong escape ability have superiority in these aspects.