Yes.
Observant Jews do not eat crayfish.
Fish that have fins and scales
Jews who keep kosher don't eat fish wihout scales (Deuteronomy ch.14).
yes they can
Yes because ice cream is made up of milk, so it is harmful to eat fish after eating ice cream.
No, monk fish has been determined to be non-kosher.
They Mostly Eat Fish, Bread, And Ice Cream
At the time of the Mishna (200 CE), rabbis deemed it meritorious to eat fish on the Sabbath and Jews became accustomed to eating fish at festive meals. Gefilte fish, which has been called the quintessential Jewish food, is an especially popular fish to serve at the Passover Seder meal.
The flavors of ice cream and fish do not really go together well, they do not complement each other. But if you enjoy that combination, go ahead and eat it.
Beef, chicken, fish, lamb, venison. It is worth noting that there is no magical food that Jews replace pork with, it's just that they do not eat dishes made with pork and therefore will eat different dishes than non-Jews who do eat pork.
Steelheads (rainbow trout, Oncorhynchus mykiss) have a diet of smaller fish, fish eggs, insects, and crayfish.
It doesn't matter what kind of restaurant it is. That's not relevant to what Jews eat. Consider this:Orthodox Jews will not eat in unkosher restaurants at all, unless they find themselves in a place where that is the only choice. In that case, they would typically only eat vegetarian cold food on clean cold plates, such as plain salads without dressing, raw vegetables, fruits and nuts. Some may eat kosher fish, if it is unseasoned. Kosher fish are fish with fins and scales.Non-Orthodox Jews who keep kosher will often eat dairy, vegetarian, and kosher fish even with seasoning. (Kosher fish have fins and scales).Non-Orthodox Jews who don't keep kosher will eat whatever they want.