SpiderSpotter.com isn't a shop or a financial service; it's a research-driven citizen science project. That changes what you should care about. When you're contributing observations to a study, the main question is whether the people behind it are who they say they are and whether they'll handle your data reasonably.
On identity, this site scores well. It has an about page, legal entity disclosure, and contact info. The domain is over seven years old, which is a good sign of longevity. There's no history of malware or blacklisting, and the site uses modern security measures like HTTPS.
The main gap is the missing privacy policy. For a project that likely collects location data with spider sightings, that's a legitimate concern. But it's not a red flag on its own, and for this kind of non-commercial work, it's not unusual. If you're happy to contribute sightings without reading a detailed privacy statement, that's fine. If you're privacy-sensitive, you might want to contact them first and ask how your data is used. Overall, this is a trustworthy-looking project with a minor administrative gap, not a scam.