JoJo’s Bizarre Adventure by Hirohiko Araki is one of the strangest series ever created and, for this reason, it splits the audience into hardcore fans and haters. I found it brilliant, so, I’m definitely in the first category! When I watched the anime, I appreciated it so much that I decided to continue the story of the Joestar bloodline by reading the manga. Stone Ocean, the sixth story arc, is full of sci-fi references and many of the Stands present in this season are inspired by scientific concepts. In my opinion, Rikiel’s power towers above the others thanks to its particular inspiration and its masterful realization. This minor antagonist is also interesting in terms of character development. During his introduction, he is described as a coward that suffers since childhood from panic attacks which cause his eyelids to fall, his hands to sweat and his knees to give out. The encounter with father Pucci changes him deeply and it triggers his development into a brave and skilled fighter. The priest reveals him that Sky High, his Stand, enable him to control the bizarre animals known as Rods.
This revelation allows Rikiel to understand the real nature of his panic attacks: those creatures were attracted by his latent powers and they target him causing the symptoms. After learning to control his Stand, Rikiel acquires the courage to fight for the cause of father Pucci and he becomes one of the deadliest characters in the arc.
Anyway, what are the Rods? Do they exist in the real-life?
Well, Rods exist in real life and, at the same time, they don’t. They are visual artefacts produced by the passage of flying insects on screen. The motion blur generated by these animals results in the elongated figures that often appear in outdoor photos and videos. Yet, some pseudoscientists wrongly identified them as paranormal creatures and they started to call them Rods, Sky Fishes or Solar Entities. Therefore, these poor optical effects ended up in the same club of Nessie, Bigfoot and Roswell Greys. Araki transformed these cryptids in “real animals” by including them in the world of JoJo’s Bizarre Adventures. He also decided to add a panel to explain the fictional biology of these creatures, including some information regarding their lifestyle, anatomy, evolution and ecology. Here, Rods are presented as elusive creatures able to fly at 200 km/h. They also survive by absorbing the heat of other organisms thanks to special epithelial cells. This peculiar ectoparasitic process normally doesn’t damage their prey unless many Rods attack the same organism, or they target a specific area of the body. Indeed, the coordinated attack of a single organism can paralyze it and cause the same symptoms of Rikiel’s panic attacks. On the other hand, the excessive heat sucking from a single body part can render it more prone to disease and failure. Rikiel uses his Stand to control the Rods and turn them into lethal heat-seeker weapons. Probably, the creatures follow his orders because they see him as the leader of the swarm and, for this reason, they tend to obey only when he is self-confident. Sky Fish’s anatomy is pretty unusual, it has four pairs of wings moving like propellers, a mouth positioned in the middle of the body and heat-sensitive organs on both ends. These creatures don’t have a head/tail symmetry, they can move in both directions and the flapping of wings cause them to spin in the air like projectiles. They fly endlessly for their entire life from the hatch of their eggs until death, even sexual intercourse happens in mid-air. Clearly, an organism like Sky Fish cannot exist in the real-life but still, this explanation fits perfectly in the universe of JoJo where science and mysticism form a well-balanced cocktail.
So, let’s continue the “what if game” started by Araki. If these bizarre creatures exist, where do they fit into the tree of life?
Classifying Rods is not that simple, they are peculiar organisms with odd anatomy and even stranger physiology, so, the speculations must be done carefully. The best way to do it is according to the rules of taxonomy, the science of biological classification. Taxonomists systematize organisms according to their evolutionary relationship, and they try to construct a sort of family tree of the species that live on this planet, the tree of life. For this purpose, the information provided by Stone Ocean manga may be helpful. In fact, the panel states that Rods might descend from a group of organisms known as Anomalocarids and they could have developed the ability to fly during the Jurassic Period. The Anomalocarids existed for real, they were a successful order which dominated the oceans from Cambrian to Early Devonian (from 521 to 400 million years ago). They were also known as Radiodonta because of their round jaws (oral cone) surrounded by a ring of tooth plates. Their body was covered in a thick cuticle and it was subdivided in head and trunk. The head bore two stalked compound eyes, two frontal appendages covered in spines and the previously cited oral cone. Instead, the segmented trunk was equipped with swimming flaps and gill-like structures known as setal blades. The anatomy of these animals may seem strange to us, but it allowed high manoeuvrability, perceptive vision and manipulation dexterity. These skills, together with their massive size respect to other creatures of the same epoch, enabled many species of this group to become apex predators. Indeed, the most famous radiodont, Anomalocaris canadensis, was one of the first predators in the history of the animal kingdom. However, not all the species behaved in this way, some were sediment sifters while others became filter-feeders by evolving frontal appendages with a structure similar to the baleen of modern whales. This fascinating order of extinct animals was related to modern arthropods (insects, myriapods, crustaceans and arachnids) and so, they are placed in the Panarthropoda clade. If Sky Fishes are descendant of a species in the Radiodonta order, they should be classified in Panarthropoda as well.
So, case closed! Or Maybe not… Something seems fishy!
During the battle, one Rod dies and decomposes instantly afterwards without leaving any trace. This information is reported also in the panel and that’s why nobody has found some proves of Sky Fish’s existence. A fossil cannot form if there is no corpse in the sediment, and it isn’t possible to take a sample of DNA if it disintegrates in a matter of seconds. So, without these specimens how could they reconstructed the evolutionary history of Rods? Even in the world of Jojo, this seems pretty odd. The panel comes again to rescue by underlying that all the information available are speculations of Emporio, one of the protagonists of the series. Therefore, these data aren’t reliable and it’s better to look at the Sky Fishes during the arc in order to find some clues that may help in the classification process. In this way, it will be like observing an animal in its natural environment.
So, let’s play the mad taxonomists! Don’t worry about the errors, the Rods are too busy non-existing to bother.
By observing Rikiel’s fight, I noted various details that could be useful. First off, during the Rods decomposition process, it’s possible to glimpse some of their organs and an internal skeleton that resembles a fishbone. Moreover, their movement suggests a smooth skin without any hard exoskeleton or any external segmentation. These features are enough to classify Sky Fishes as vertebrates and to say that they don’t belong to the Panarthropoda clade. Another key to understanding their placement in the tree of life could be represented by the mouth. Rods have a circular jawless mouth, a feature typical of one group of vertebrates known as Agnatha, the jawless fish. These fishes originated in the late Cambrian (535 million years ago) and they are still around today, represented by lampreys (order Petromyzontiformes) and hagfish (order Myxiniformes). In the past, this group was rich in diversity and it included scaleless, scaly and even armoured fish. Today the extant forms are characterized by an eel-like slender body with naked skin and a cartilaginous skeleton. Many species of lampreys are parasitic, and they use their circular mouth covered in keratinized teeth as a sucker to feed on the body fluids of their host. On the other hand, the majority of hagfishes are predators or scavengers, they use their tongue equipped with keratinized plates to rasp pieces of flesh from their prey. Another important difference between these orders of animals is that hagfish are almost completely blind due to their degenerate eyes while lampreys have a keen sense of vision. So, Rods could actually be sky fishes that share a common ancestor with hagfishes and lampreys. Maybe they could have some highly derived characters such as the heat-absorbing cells, the absence of eyes and the ability to fly while retaining the main features of a jawless fish.
The only thing that still puzzles me is the lack of a head/tail symmetry and the central position of the mouth. In fact, the cephalization, the concentration of brain, sense organs and mouth in the frontal end is a key feature of most animals including vertebrates. However, some animals, such as the sea stars, evolved a radial symmetry as a derived character and so, this is also possible for the rods. Another hypothesis could be that the lack of cephalization is only apparent due to superficial characters. For example, a rostrum on the front of the head, similar to that of swordfish, could mislead the position of the mouth on the body. This characteristic, together with the progressive loss of other features that distinguish the head from the tail and the development of the heat sense organs on both ends could have allowed these animals to look and behave as acephalic animals.
So, the idea of Rods as highly modified jawless fish seems satisfactory to me, but I don’t think other scientists will try to analyse further this subject. Anyway, now that the placement of Sky Fish in the tree of life seems reasonable, it’s time to find a proper scientific name. I would like to propose the name Bacillopteryx rikielii that could be translated into “Rikiel’s flying rod”. In fact, the first term (the generic name) is composed by the Latin world “bacillus” which means wand or rod and by the Greek term “pteryx” meaning “wing” or “feather”. On the other hand, the second name (the specific epithet) is dedicated to Rikiel. This choice comes from the habit of taxonomist to dedicate the specific epithet to a mentor, a famous personality or the discoverer of the species itself. I think that Rikiel definitely deserves to appear in the scientific name of the Sky Fish since without its arch we wouldn’t even know these bizarre creatures and their odd history.
- Hickman C. P., Roberts, L. S., & Larson, A.,1997, Integrated principles of zoology.
- Van Roy, Peter; Daley, Allison C.; Briggs, Derek E. G. (2015). “Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps”, Nature
- Ortega-Hernández, Javier (2014). “Making sense of ‘lower’ and ‘upper’ stem-group Euarthropoda, with comments on the strict use of the name Arthropoda von Siebold, 1848”. Biological Reviews of the Cambridge Philosophical Society.
- Special thanks to Matteo Bondini for its beautiful “the Rods” that he realized under my request.
- The other images present in the story come from https://commons.wikimedia.org/ and they are free to use under the license creative commons.