Squid are a large, diverse group of marine cephalopods. Like all cephalopods, squid are distinguished by having a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms and two tentacles arranged in pairs. Many species of squid are popular as food in cuisines as diverse as Korean and Italian. In English-speaking countries, it is often known by the name calamari. Individual species of squid are found abundantly in certain areas and provide large catches for fisheries. The body can be stuffed whole, cut into flat pieces or sliced into rings. The arms, tentacles and ink are also edible; in fact, the only parts of the squid that are not eaten are its beak and gladius (pen). Source:http://en.wikipedia.org/wiki/Squid
High levels of glutamates are present in the ink of squid and in the squid itself. Glutamic acid content means it can cause side effects in some people, so avoid if you are sensitive to other glutamates such as MSG.