I, Lobster: A Crustacean Odyssey

Chapter 3 | “Natural” History

In book 9 of Pliny the Elder’s Natural History is a brief statement of inquiry as conceptually sweeping as his encyclopedic masterpiece as a whole: “Why the Sea should breed the greatest living Creatures.”1 This statement compels us to consider an idea that we might not ordinarily think about, let alone question. Yet before we have time to do either, Pliny follows his statement with explanations:“The Waters bring forth greater Abundance of living Creatures, and these also of a larger size, than the Land. The Cause is evident, in the excessive Abundance of Moisture . . . [I]n the Sea, which is so widely spread abroad, so soft and proper to yield Nourishment and increase,and receiveth the Causes of Propagation from on high, Nature is always framing some new Creatures .”2 Pliny elaborates. Not only is there more water than dry land on the surface of the earth, but life that might barely survive on solid ground flourishes and multiplies in number,size,and kind in the embrace of the sea because that is where“Seeds and universal Elements” are propelled by wind and the tumble of waves. In retrospect, his imagery suggests natural selection theory—evolutionary Darwinism almost two thousand years before the fact. “It may truly be said,” Pliny adds,“that whatever is bred in any Part of Nature is to be found also in the Sea.” Examples are things that resemble bunches of grapes,or that look,smell,and even taste like cucumbers, and some things standing out like“horse-heads.”3 As the sea cucumber is named after the vegetable it reminds us of, and the sea horse miniaturizes one of our most familiar domesticated animals so, in the first century ce, the lobster reminded Pliny of a locust. Thus he named lobsters locusta, locusts of the sea, and his naming influenced what we call them today: lobster is from the Old English for locust, which was spelled lopustre, or lopystre, or loppestre. “Natural”History 44 , i , l o b s t e r Part of Pliny’s legacy is the intensely satisfying hypothesis that things that look alike are alike. Appealing as it is, this premise doesn’t work. In the universe of understanding initiated by Carolus Linnaeus with the publication of Systema Naturae in 1758, the land cucumber is in the plant kingdom and the sea cucumber is in the animal kingdom, so they are not even distantly related. Early classification of the horse’s genus was Equus, and its species ca‑ ballus. When sea horses were assigned a genus later, in 1816, it was Hippocampus, and there are more than thirty species of this fish whose only relationship to Black Beauty or Mr. Ed, apart from the vague though enticing similarity in the shape of their heads, is that they are all in the animal kingdom. The connection between locusts and lobsters is only a rank closer—both are animals, and both are arthropods—but, Pliny and popular names aside, that is the extent of their relationship. Linnaeus devised a hierarchical system of five orders for naming , ranking, and classifying groups of organisms that takes into account how they look in very specific ways. Lobsters in general fall in the phylum Arthropoda, which consists of invertebrates with jointed appendages and an external skeleton that the creature must molt in order to grow. The lobster’s class, Malacostraca, refers to the form of a animal’s shell, which is soft and flexible (compared , say, to that of an oyster or a scallop). The order, Decapoda, counts the lobster’s ten legs; and the family name, Nephropidae, refers to the lobster’s possession of claws. Thus, the Linnaean classification of the American lobster, in the kingdom Animalia, looks like this: Phylum Arthropoda Class Malacostraca Order Decapoda Family Nephropidae Genus Homarus Species americanus The two last classifications finalize the distinctions with the most significant contribution of the Linnaean system: binominal nomenclature. The combination of generic name with species name effectively consummates what is unique about particular “Natural” History , 45 kinds of animals. There are both American and European lobsters in the genus Homarus, but they are distinguished by their species names: European lobsters are Homarus gammarus (sometimes called vulgaris). The species’ geographical range (the western versus the eastern Atlantic) and size (americanus runs slightly larger) are the main differentials. As neatly arranged as the Linnaean system might seem to be, there are...