Polychaetes - Detailed illustration of nature - Ernst Haeckel, Kunstformen der Natur

Reproduction engraving of: Polychaetes

Original title Chaetopoda - Borstenreichen

Sabella Poster - Arthropods of the main class Annelida (Annelida), Class Polychaeta (Chaetopoda)

Illustration from the book Kunstformen der Natur, which is a collection of artistic lithographs of natural sciences published by the German biologist Ernst Haeckel between 1899 and 1904.

This naturalistic illustration is part of an overall style inspired by Ernst Haeckel, which greatly influenced the emerging Art Nouveau movement at the beginning of the ^20th century. This work, illustrating the impressive beauty and great diversity of the biological world, was complemented by a certain amount of scientific information, some excerpts of which are reproduced below.

This information is over 120 years old and some of it may be outdated!

Scientific classification:

 Phylum of Arthropods (Articulata)
Main class of Ringed Worms (Annelida)
Class Chetopods (Chaetopoda)
Subclass of Polychaeta.

Scientific notice (extract) accompanying the poster print of Chaetopoda - Polychaetes :

The ringed worms, or Annelida, are generally considered a class of "worms," but they are clearly distinguished from the true unsegmented worms (Vermes, see Tables 23, 32, 33, 97) by their metamerism, that is, by the external and internal segmentation of their elongated bodies. In this respect, they are more similar to the higher "arthropods" (Arthropoda), the two form-rich groups of crustaceans (Crustacea, see Tables 56, 76) and tracheates (Tracheata, see Tables 58, 66). What is common to all these arthropods (Articulata) is not only the external segmentation of the cuticle, but also the internal organization of the central nervous system (medullary), myointestinal, vascular, etc. The ancient annelates are distinguished from the two more recent groups of arthropods mainly by the fact that the meromeres or individual body segments (segmenta, somita, metameres) in the former are often very uniform (homonomous), while in the latter they are more or less heterogeneous (heteronomous) due to the division of labor. Similarly, in annelates the legs (originally one pair per segment) are short and unjointed, while in most arthropods they are long and jointed. The main class of annelates is divided into two subclasses, the leeches or Hirudinea and the bristleworms or Chaetopoda. The skin of the former is smooth and devoid of setae, which distinguishes the latter. These chitinous setae are extremely varied in shape, size, and arrangement. They are small and poorly developed in the sparsely populated bristleworms (Oligochaeta), which include the earthworm (Lumbricus), among others. In contrast, they are large and numerous in the bristle-rich bristleworms (Polychaeta), where they are located on special feet (parapodia) absent in the sparsely populated bristleworms. Usually, two pairs of crotch feet are present on each body segment, sometimes with only one pair. The feet usually bear external gills, sensory filaments, and other appendages. The bristleworms (Polychaeta) all live in the sea and are divided into two form-rich orders: the predatory worms and the tubeworms. The predatory worms (Errantia or Rapacia, Fig. 5-7) move freely in the sea by crawling or swimming and bear gills on most segments. As voracious predators, they have a well-developed head, often armed with mandibles. On the other hand, tubeworms (Tubicolae or Sedentaria, Fig. 1-4) live attached to the seabed; their head is rudimentary and bears large gills, but they do not have mandibles.

Species present on the Polychaeta - Sabella naturalist board :

• Sabella spectabilis
• Serpula contortuplicata
• Spirographis spallanzanii
• Terebella emmalina
• Eunice Magnifica
• Hermione hystricella
• Chloëia euglochis