The Influence Of Starvation On Fast-Start Performance Of Spinibarhus Sinensis

The Spinibarhus sinensis is distributed in fresh water in China and a warmwater fish species. The fast-start performance of 48 juvenile Spinibarhus sinensis (body length,5.86±0.10cm) after 0,0.5,1,2,4 and 6 weeks starvation were recorded by employing high-speed cinematography and the locomotive kinematics were analyzed. The morphological parameters including tail height (H2), tail length (L2), lateral body area (S1), median fins area (S2), dorsal cross section area (S3) and tail cross section area (S4) were measured by TpsDig and Photoshop correspondingly. The experimental water temperature was maintained at (25.0±0.5)℃.The aim of my study was to reveal the influence of starvation on fast-start performance and discuss the accommodation strategy for starvation in juvenile Spinibarhus sinensis.The results showed that all escape responses observed were C-type fast-starts with either a right or left turning direction, and there were no significant differences in kinematics of fast-starts performance with different directions (p>0.05).The distance (d) of the center of mass in control group (0 week) increased significantly (p <0.05) during the whole escape response process while the liner velocity (V) increased significantly (p<0.05) in the beginning but leveled at its maximum value at the end of stage 2 (36 ms). The liner acceleration (a) presented the maximum value at the end of stage 2 (p<0.05) while it presented the lowest value in stage 3. The angular velocity (w) presented the maximum value at the beginning of fast-start response and then decreased significantly (p<0.05) during the first and second stages and then remained unchanged at a lower level in whole stage 3.There is no significant relationship between liner velocity (V) and relative turning radius (RTr) in stage 1 in control group (0 week)The escape distance (d), maximum linear velocity (Vmax) and maximum linear acceleration (amax) of center of mass in Stage 1 and Stage 2 of fast-start process decreased significantly after 6 weeks of starvation (p<0.05), but there were two relatively stable phases in the Vmax and d, i.e. during 1 to 2 week and 4 to 6 week, their values were 0.67±0.06mm/ms,8.86±073mm and 0.31±0.04mm/ms,3.70±0.56mm(p<0.05).The turning angle (Ta(1+2)) were 188.2±13.3deg showed no significant differences (p>0.05) among all experimental groups. When compared with the control group (0 week starvation group), only the 6 week starvation group showed the significantly different response time (t). The response time (t) in 0 to 4 week were 9.20±0.37ms.The areas of dorsal body cross section (45.4%) decreased more acutely than caudal body cross section (38.0%,p<0.05)during starvation while no significant differences were found in both the tail height and tail length among all treatment groups (p>0.05).The results indicated that juvenile Spinibarhus sinensis in control group (0 week) favors higher velocity linear escape strategy in fast-start process. This may be due to its streamline shape and quickwater habitat.The fast-start performance of juvenile Spinibarhus sinensis can be influenced by the starvation, both the maximum linear velocity and maximum linear acceleration which were closely related to energy metabolism decreased significantly after starvation whereas both the response time and turning angle which have no direct relationship with energy metabolism remained unchanged during starvation. No change in maneuverability after food deprivation suggests that the escape strategy of juvenile Spinibarhus sinensis is relatively conservative.