Which fish species has no fishing permitted at all?

Sturgeon is the correct answer because this species is highly endangered and has been subject to strict protections under both state and federal laws. Due to significant declines in their populations, particularly from overfishing, habitat loss, and pollution, all fishing for sturgeon is prohibited to aid in their recovery. This complete ban is designed to prevent further decline and encourage population restoration efforts.

In contrast, the other species mentioned have certain regulations in place but are not completely off-limits. For instance, striped bass may be fished with specific size and bag limits, American eel can be caught but is also regulated, and shad has designated seasons and limits for fishing. Each of these species, while regulated to promote sustainability, does not have a total prohibition on fishing like sturgeon does.