here is an example of the verse portrait of the Jellyfish: "They're almost only H2O,/ With tiny bits of solids;/ Some of them can even glow!/ No bones, nor brain, nor heart have they;/ Yet, sensing chemicals, light, and sway,/Their
nerve net tells of passing prey./ Some can sting by shooting 'darts'/ Of poison from their tentacles;/ If ever you are stung, it smarts!/ They live their lives on broadest scales:/ From mere hours, to a year;/ Small as mites, to big as whales!" The poem is accompanied by three magical underwater portraits in shades of blue, aqua, peach, and black and white.
Additionally, we find evidence of catechol-containing proteins associated with the
nerve net beneath the locomotory comb rows of P.
Thomas Holstein of the Centre for Organismal Studies demonstrated how the origin of nerve cell centralization can be traced back to the diffuse
nerve net of simple and original lower animals like the sea anemone.
Comb jellies also possess a simple form of nervous system, called a
nerve net, and their genome contains many of the genes involved in the nervous system.
I like the Portuguese singer Dulce Ponte and also
Nerve Net by Brian Eno.
The nerve cells connect loosely as a "
nerve net," but the animal can survive without this primitive nervous system.
The swim system includes a cluster of pacemaker cells in each rhopalium; a conducting system in the nerve ring, which links the rhopalial pacemakers but also distributes excitatory impulses to the subumbrella; and a subumbrellar motor
nerve net, which synaptically activates the circular muscle that lines the bell cavity (Satterlie, 1979; Eichinger and Satterlie, 2014).
The scyphozoan solution involves the use of such a diffuse, non-polarized
nerve net for distribution of motor commands (Mayer, 1910; Bozler, 1926a, b; Horridge, 1956a).
In cubomedusae, the FMRFamidergic system in the subumbrella is almost exclusively contained within the rhopalia and nerve ring, without the diffuse
nerve net organization seen in scyphomedusae (Satterlie, 2002, 2011).
Frequency-dependent facilitation has been described in the swim muscle of Carybdea, as well as apparently asymmetric enhanced contractions in response to quick "double pulses" in the motor
nerve net (Satterlie, 1979, 2002).
This
nerve net was particularly dense, however, at the base of the capitate portion of the tentacle, immediately under the cluster of cnidocytes (Fig.
They were first seen in some of the 20-d cuticle stage hydra, and in later stages both the number of RFamide-positive neurons and the complexity of the RFamide-positive
nerve net increased (Figs.