FACT : You don’t want to read a book about the zoology and comparative anatomy of rare Italian sea planariums. Not when you can look at these pictures from Arnold Lang’s 1884’s “The polyclades of the Gulf of Naples” instead.
Arnold Lang (1855 – 1914) was a Swiss naturalist, a comparative anatomist and student of the German biologist, Ernst Haeckel. From 1878 to 1885 he was stationed at the Zoological Station in Naples, where he conducted research on marine wildlife native to the Gulf of Naples.
The illustrations are from the book that Lang produced as a result of his research, 1884’s “The polyclades (sea planariums) of the Gulf of Naples and the adjacent sea sections. A monograph. Fauna and flora of the Gulf of Naples and the adjacent sea sections, published by the Zoological Station in Naples”.
WHAT ARE THEY?
The Polycladida represents a highly diverse clade of free-living marine flatworms. They are known from the littoral to the sublittoral zone (extending to the deep hot vents), and many species are common from coral reefs. Only a few species are found in freshwater habitats.
Polyclads range from 3 millimetres (0.12 in) to 10 centimetres (3.9 in) in length with a flattened, roughly oval, body shape and, in many cases, a pair of short tentacles on the head. They are distinguished from other related animals by the presence of a folded pharynx, an elongated intestine with numerous complex diverticula, and multiple ocelli. The etymology of the order name Polycladida corresponds to the two Ancient Greek words πολλός (polús), meaning “numerous”, and kládos, meaning “branch”. It refers to the ramified shape of the intestine in these flatworms. Most polyclads hide away from direct light. However, some of the brightly colored species often are active during the day. With their flamboyant coloring they advertise their potential toxicity to visual predators such as fish.
– POLYCLADIDA of the GULF OF NAPLES : PLATES ONE TO NINE –