## 3 Results  
### Short-Term Preservation of Celestial Goldfish Sperm  
(1) Microscopic Observation of the Optimal Dilution Ratio for Celestial Goldfish Sperm  
Experimental results indicated that when the sperm dilution ratio was 1:5, the survival rate of sperm decreased to 50% within 130 s. At this dilution concentration, the sperm exhibited the longest survival time, making it most suitable for microscopic observation. Detailed observation results are outlined in Table 1. Additionally, it was observed that sperm vitality decreased noticeably after approximately 1 min at all dilution ratios. (2) Microscopic Observation of Fresh Sperm from Celestial Goldfish  
Based on the optimal sperm dilution ratio determined in Result (1) as 1:5, microscopic observations were conducted on fresh sperm from celestial goldfish. The results indicated that the situation was the same as that with the 1:5 dilution with phenol red [PERSON]'s solution, as described in Table 1. Additionally, it was observed that the vitality of sperm significantly decreases after sperm activation at approximately 1 min. The above indirectly suggested that the short-term preservation effect of sperm with phenol red [PERSON]'s solution was comparable to that of fresh sperm. (3) Observation Results of Celestial Goldfish Sperm Preservation Time at Four Different Temperatures, and the Relationship between Solution Color and Sperm Viability  
Celestial Goldfish sperm preserved in phenol red [PERSON]'s solution at four different temperatures (16-22 \({}^{\circ}\)C, 4 \({}^{\circ}\)C, \(-20\)\({}^{\circ}\)C, and \(-25\)\({}^{\circ}\)C) yielded the following observations:  
* When the phenol red in the solution maintained a pink color, the sperm viability was consistently greater than 60%. As the phenol red began to change, transitioning from concentrated to diluted and gradually turning light yellow, the sperm viability decreased significantly until complete death. * At 18-22 \({}^{\circ}\)C, preservation of goldfish sperm in phenol red [PERSON]'s solution maintained viability greater than 60% for only 7 h. Afterward, the solution started to change color, accelerating sperm death. At 4 \({}^{\circ}\)C, the use of phenol red [PERSON]'s solution to preserve goldfish sperm resulted in maintained viability for at least 14 h, with viability greater than 60%. However, after 18 h, the solution began to change color, and sperm viability dropped to less than 20%. * At \(-20\)\({}^{\circ}\)C and \(-25\)\({}^{\circ}\)C, the solution froze within 1 h, turning both the solution and phenol red colorless. Upon thawing, the liquid gradually changed from colorless to pink, but sperm aggregated and precipitated at the bottom. Microscopic observation revealed that all sperm had died. Please refer to Table 2 for specific results. \begin{table}
\begin{tabular}{c c c c c} \hline \multicolumn{2}{c}{**Preservative Temperature**} & \multicolumn{2}{c}{**Semen Status**} \\ \hline
18–22 \({}^{\circ}\)C & 1–7 h: Pink, Sperm Viability \textgreater{}60\%; after 7 h: Gradual transition to Yellow, Sperm Viability \textgreater{}20\% \\
4 \({}^{\circ}\)C & 1–14 h: Pink, Sperm Viability \textgreater{}60\%; 18–20 h: Light Pink, Sperm Viability \textless{}20\% \\  & Within 1 h, gradually freezing from pink to colorless; after complete freezing, thawing for 2 min at room temperature, liquid changes from colorless to pink, and sperm aggregates into clusters, settling at the bottom of the tube, all dead. \\ \(-25\)\({}^{\circ}\)C & Same as preservation at above \(-20\)\({}^{\circ}\)C. \\ \hline \end{tabular}
\end{table} 
Table 2: The status for celestial gold fish sperm preserved with [PERSON]’s solution in 4 different temperatures. In summary, the preliminary results suggested that preserving celestial goldfish sperm with phenol red [PERSON]'s solution at 4 \({}^{\circ}\)C is the most suitable option. Furthermore, the color changes in the solution could serve as a visual indicator of sperm vitality, indicating the onset of significant sperm death.