There may be some restaurants or markets selling pond fish and loach fish in Guangning area. You can try the following methods to find suppliers:

1. Ask others if there is a market or restaurant selling pond fish and mud squid in Guangning local catering group or forum.

2. Ask the salesperson about pond fish and loach fish by calling or visiting the local fish market.

3. If there is an aquaculture base nearby, you can directly contact the person in charge of the base and ask if these fish are available.

Please note that the supply situation of fish market will be affected by factors such as seasons, so it is best to confirm whether the supplier has inventory in advance. In addition, it is recommended to choose fresh and healthy fish when purchasing, and pay attention to the purchasing environment that meets the hygienic requirements.