accumulate protein-digesting enzymes in their muscle and literally transform their own flesh into the next generation Then and afterward, their muscle is meager and spent, and makes a spongy, mushy dish Because different fish have different cycles, and can be in different phases depending on the part of the world in which they’ve been caught, it’s often hard to know whether a given wild fish in the market is at its prime The Anatomy and Qualities of Fish Fish and shellfish have many things in common, but anatomy is not one of them Fish are vertebrates, animals with backbones; shellfish are boneless invertebrates Their muscles and organs are organized differently, and as a result they can have very different textures The anatomy and special qualities of shellfish are described separately, beginning on p 218 Fish Anatomy For about 400 million years, beginning well before reptiles or birds or mammals had even made an appearance, fish have had the same basic body plan: a streamlined bullet shape that minimizes the water’s resistance to their movement There are exceptions, but most fish can be thought of as sheets of muscle tissue anchored with connective tissue and the backbone to a propulsive tail The animals push water behind them, developing thrust by undulations of the whole body and flexing of the tail Skin and Scales Fish skin consists of two layers, a thin outer epidermis and a thicker underlying dermis A variety of gland cells in the epidermis secrete protective chemicals, ... backbone to a propulsive tail The animals push water behind them, developing thrust by undulations of the whole body and flexing of the tail Skin and Scales Fish skin consists of two layers, a thin outer epidermis and. .. that minimizes the water’s resistance to their movement There are exceptions, but most fish can be thought of as sheets of muscle tissue anchored with connective tissue and the backbone to a propulsive tail...shellfish are described separately, beginning on p 218 Fish Anatomy For about 400 million years, beginning well before reptiles or birds or mammals had even made an appearance, fish have had the same basic body plan: a streamlined bullet shape