Leptomedusae - Old scientific engraving - Ernst Haeckel, Kunstformen der Natur

Engraving reproduction of: Leptomedusae

Original title Leptomedusae - Faltenquallen

Poster of Aequorea - Jellyfish of the class Medusae or Craspedotes (Order of Bladder Jellyfish)

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This information is over 120 years old and some of it may be outdated!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

 Cnidarian Phylum (Cnidaria)
Class of Jellyfish - Craspedotae
Leptomedusae Order (Leptomedusae)
Family of Sun Jellyfish (Aequoridae)

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

The sun jellyfish (Aequoridae), which are shown in this plate, are distinguished from other leptomedusae by the considerable size and unusual number of radial canals running along the underside of the gelatinous umbrella; seen from below (Figs. 1, 3), it resembles a sunflower with numerous rays. While in most other jellyfish the number of radial canals is four or eight, here it amounts to 32-64 or even more than one hundred. The circular gelatinous umbrella of these sun jellyfish (Umbrella) is usually flat and discoid (Figs. 1-3), more rarely in the shape of a high, domed bell (Figs. 4-6). The domed upper surface (Exumbrella) is sometimes crossed by radial ribs, like a crystal plate (Figs. 2, 5). On the concave lower surface (Subumbrella) are the annular muscles that contract the umbrella and cause its swimming movement by expelling water from the umbrella cavity. In the center of the underside of the umbrella is a flat, circular stomach cavity; this opens with a very extensible mouth, surrounded by a crown of thin, movable buccal lobes (Figs. 1, 3). Sometimes the latter are located at the lower end of a gelatinous, inverted-cone-shaped stalk, which protrudes widely downward from the umbrella cavity (Figs. 5, 6). The radial canals, which arise from the periphery of the stomach, first ascend along the stomach stalk, then curve outward at the top and run over the subumbrella to the edge of the umbrella; here they unite into an annular canal. The nerve ring is also found on this, as well as a crown of statocysts; towards the inside is a horizontal swimming veil (Velum, Figs. 1, 3). The numerous tentacles or prehensile filaments which extend from the edge of the umbrella perform the most graceful undulating movements during swimming. The Aequoridae are of separate sexes like most other jellyfish; the gonads here are small sausage-shaped sacs which produce eggs in the female and sperm in the male; they are situated either at the beginning of the radial canals (Fig. 6), or in the course or at the end of these (Figs. 1, 3, 5). The color of the delicate transparent Aequoridae is most often bluish or slightly reddish.

Species present on the naturalist plate of Leptomedusae - Aequorea :

• Aequorea discus
• Zygocanna diploconus
• Polycanna germanica
• Zygocannula diploconus
• Orchistoma elegans