“Fortunately, in the 1980s, giant manta rays were rarely caught. But the very fact that they were caught had something to do with their rarity. Today, under the protection of the Mexican government, their numbers appear to be recovering, although some manta rays continue to be illegally caught.” (Photo Jeff Schweitzer)
A zoologist reports the identification of a new species that fishermen of the Ensenada de los Muertos in Mexico called tortillas until the 1980s
We were in the early 80’s, I was in my early 30’s and I was in Mexico, in Baja California, collecting data for my marine biology thesis. I was enrolled in a doctoral program at the Scripps Institution of Oceanography in San Diego, California and had decided to do a thesis on manta rays. More precisely, I would have made the thesis about the entire family of mobulas, which includes manta rays and are colossal representatives of which they are (a manta can reach a width of seven meters and a weight of three tons). It is a very special family of rays, not only because of the large sizes that they can reach, but also because they live far from the seabed and near the sea surface, eating plankton and small fish, which they feed with their large mouths catch by special structures that filter the progills and have two appendages on the sides of the head, which has earned them the unflattering nickname “monkfish”. Little or nothing was known about mobulas at the time, and a few species are known to exist in the seas of Baja California.
It was January when I left San Diego aboard the Fling, a dilapidated sailboat provided to me for my transportation, lodging, and base of operations, and over the course of a few weeks I had sailed south along the desert coast from Baja to around Cabo San Circumnavigating Lucas at the tip of the peninsula. From there it went up into the Sea of Cortez to the turquoise waters of the Ensenada de los Muertos – a slightly macabre name but a wonderful place – which would form the basis of my field work.
At that time, Baja California was still a very wild, deserted and depopulated region, but with an overwhelmingly fascinating nature. I had previously devoured John Steinbeck’s The Log from the Sea of Cortez, an account of a voyage made by the writer who followed biologist Ed Ricketts forty years before me. They, too, had sailed from California to the Gulf of California in search of marine life. This reading helped me to choose the place where I wanted to collect the data for my thesis, even if the reality turned out to be even more exciting than the description. The Sea of Cortez was full of life. The evening sky was constantly littered with theories of large seabirds moving from one side of the horizon to the other, and everywhere I looked I saw the calm surface of the sea tremble with the presence of mysterious beings who, hidden in the depths, wavy.
My goal was to collect data on captured mobula fishermen. I had to identify the different species, measure them, examine their stomachs to understand what they eat and examine their reproductive organs to describe their biology. The coast of the Baja California peninsula teems with small fishing villages that function a bit like separate tribes, each made up of related families with special skills in catching specific prey. For my purposes, I had identified the community of Punta Arena de la Ventana, founded by great shark and ray fishermen, so that appealed to me.
I was immediately accepted as an element that appeared out of nowhere and invaded their everyday landscape, animated by completely incomprehensible motivations. But in my (perceived) insanity, the lack of my gringo accent made me seem completely harmless, even captivating, and there was no lack of opportunities to share moments of beautiful conviviality with Marcelo, Fernando and Juanillo at sunset, moistened by copious beers . We should add that the wonder at my passion for mobulas wasn’t limited to my relationships with Mexican fishermen, but continued for decades to come wherever I moved, including the hyper-cultural areas of Milan where I now live.
In February the Mobulae were still rare, but as the water warmed up they began to end up in fishermen’s nets and I soon got quite busy. They went out at dawn in their fiberglass boats called pangas to check the nets and when they returned to shore they found their “calzoncillo” friend (meaning me – the only person in shorts) armed with a centimeter cue stick and a noose began his investigations into the unfortunate mobile phones that had ended up in the networks during the night. The fishermen let me measure the specimens before filleting them; After processing, the cadavers were then available again for all other examinations that were part of my protocol.
“Before I filleted their catches, the fishermen would let me measure them. Sometimes I needed help with the endeavor, as in this case with an adult specimen of Mobula mobular» (Photo Fay Wolfson)
At the end of April, fate forced a radical change in my organization. I was en route from Ensenada de los Muertos to the small town of La Paz, where I would regularly pick up supplies. The transfer required a seven-hour crossing, which I preferred to do at night because at night an annoying thermal breeze from the north died down, slowing my progress and drenching the boat with sea spray. Around three in the morning I decided to make myself some coffee, but when I activated the water pump a spark started a fire. After realizing that the fire extinguishers I had on board were ineffective, I had just enough time to gather documents, money and valuable data and take refuge on the dinghy I was towing before the flames died Reached the gas cylinder in the kitchen and burst into flames. Hurled into a thousand pieces in a cloud of fire. Playa del Coyote was five nautical miles away and I rowed there in a few hours, just before dawn. Fortunately, my research activities were not affected by the unfortunate event. I settled in San Juan de los Planes, the place closest to Punta Arena beach. From then on, I rode a bike that my friend Marcelo lent me to Fisherman’s Beach along an 18km dirt road.
Day by day the fishermen caught more and more Mobula. Before leaving San Diego, I had researched what species I might find in the Sea of Cortez, and it turned out that I could find two: the giant manta ray, Mobula birostris, and the smaller manta ray, Mobula lucasana, as it was called observed near Cabo San Lucas. Fisher friends disagreed; according to them there were even five species, and since they had never heard of Linnaeus and his binomial nomenclature with which science has classified the entire living world, they knew them as: Manta, Cubana de Lomo Azul, Cubana de Lomo Blanco , vaquetilla and tortilla. By this point I had developed more confidence in them than in scientific publications, and that was a very good idea because over time all these different mobulas were scattered on the sand of the beach before my eyes. I remember those moments of discovery well because the excitement I felt then still gives me goosebumps forty years later.
“Despite the need to work on the mobulas that have been fished and the interest that their study aroused, for me this activity was a constant source of internal conflict because I could not be insensitive to the annihilation of beings so special, so large.” and so beautiful: as in the case of this giant manta rays» (photo Jeff Schweitzer)
Only one of the types the fishermen had told me about – the tortilla – was missing. The name they gave it derived from the fact that it was the smallest species, just over a meter wide, very sociable, often jumping out of the water and landing on the surface with its belly spread, which was very much like a “ciack” to hear what their wives do when they make tortillas. So where were those tortillas, I asked around. The fishermen looked up: “They haven’t arrived yet,” they said. Nothing, not a trace of it. But one day, back on the beach of Ensenada de los Muertos, I found a lot of Mobula carcasses that some fishermen had left there after being filleted. They were very different from the species I had documented up to that point: although fully grown, they were much smaller than the others, and even at death had retained a brownish color of the back, unmatched by any previous species. I finally got to know the tortilla, even if the available specimens were too worn to be of much scientific use.
A few months later, now back in San Diego, I managed to snag a couple of specimens in perfect condition via the Punta Arena fishermen and was able to begin analyzing my specimens collected in Baja to try to make an accurate inventory to create from Mobula species. worldwide. For many reasons, it was not an easy matter. Since the birth of modern zoology in the late 18th century, whenever a zoologist came across a mobula specimen, he would describe it in a publication and give it a name of his own initiative. The result was that over sixty designations have accumulated over time without sufficient evidence that that particular species had already been described by anyone else. Other factors also contributed to the confusion. The first was that the various mobulae, with the exception of the giant manta rays, were very similar at first glance and one needed to know which details to focus on in the description in order to highlight the often subtle differences. The other element that made the confusion almost indecipherable was the poor quality of most of these ancient descriptions, from which it was not possible to clearly understand what species they referred to. Valuable tools that could have cleared many doubts, such as photographic documentation (not to mention DNA analysis, extremely useful but only practiced in recent years), came on the market much later and were in not available on the first “good” description of each species, meaning the one that counts.
To make matters worse, communication between colleagues was difficult and slow and could only be done by letter. It was the state I was in too, although that was only forty years ago. At that time, faxing was still in its infancy, while electronic mail was still a long way off – not to mention the Internet. Thus the zoologists were forced to work in a state of solitude, which could only be compensated for by the very slow correspondence by mail or on rare occasions at congresses. Today we take it for granted that we can video call for free with anyone anywhere in the world we are in; and share photos, videos, genetic analysis, and anything else that can help classify the species. It seems impossible that this was all science fiction just forty years ago.
The slowness of communication reduced the time I had, which wasn’t much anyway since I had to graduate. For this reason, I was forced to engage in a form of “museum tourism”, personally visiting the most important ichthyological collections on five continents, starting with those of San Francisco, Los Angeles, Harvard, New York, then moving on to London, Paris , Leiden and finally to Hurghada in Egypt, Chennai (then called Madras), Perth and Sydney. The aim was to study the morphological features of the Mobula specimens preserved in these museums and to verify that these matched the scheme that was forming in my mind for the composition of the Mobulidae family. At the end of all the inspections, confirmed by consulting all possible texts physically preserved in the most unlikely scientific libraries, I was able to reduce the list of about sixty different descriptions to nine “good” ways.
It was only at the end of this review that I was able to review my Mexican field experiences and give names of global importance to the specimens caught by fishermen.
So:
• The manta ray was the simplest of them all: Large as it was, there was never any doubt that it was the giant manta ray, Mobula birostris, found in tropical waters around the world.
• It turned out that the cubana de lomo azùl was Mobula thurstoni with a circumtropical distribution. Of this species, Mobula lucasana turned out to be a recent synonym.
• The Cubana de Lomo Blanco was the Mobula mobular, also cosmopolitan, and the only species that also occurred here in the Mediterranean.
• The vaquetilla was instead the Mobula tarapacana: another species widespread in all tropical waters.
The tortilla was left over. I searched and searched and concluded that a species so small and gregarious as that found in the eastern Pacific had never been described. Superficially, it resembled other small species found only in the tropical waters of the Atlantic and Indian Oceans, albeit with notable differences. After all possible verifications, the tortilla was a new species in the sense that no Westerner had yet officially classified it. It fell to me to describe it and to give it a scientific name in the work I was preparing in the Zoological Journal of the Linnean Society.
At first I was tempted to call the new style Mobula tortilla, as a gesture of acknowledgment of the traditional knowledge of people who had dabbled in it long before me. Ultimately, however, I decided to call it Mobula munkiana, in homage to my master, the oceanographer Walter Munk, whose memory binds me in eternal gratitude because thanks to his help, advice and paternal affection I managed to become a marine ecologist to establish.
I am well aware that the practice of naming a new species after an individual is now often considered inadvisable, as discussed in a recent Post article from which this post is derived. Still, I decided to associate the tortilla’s name with a character that was so important to me. During the last years of his very long life together we organized a trip to Baja California in search of the mobulas that bear his name and I cannot forget the look of delight that formed on his face as an old scientist when he saw one springing out of water with large splashes just a few meters away.
“Walter Munk was 98 years old when we went to the Sea of Cortez together to visit the mobulas that bore his name. This trip was a source of indescribable joy for both of them» (Photo Octavio Aburto)
In the years that followed, Munk’s Mobula became a celebrity. They often group in huge groups, sometimes consisting of tens of thousands of individuals, many eager to perform acrobatic leaps out of the water to spectacular effect, which are detailed in some of the best-known naturalistic documentaries today. Mobula sightings in the Sea of Cortez are now a growing tourism industry in the La Paz area, with interesting implications for the local economy. It seems hard to believe that just a few years ago only isolated groups of artisanal fishermen, who they called tortillas, knew of their existence.
Today, scientific knowledge of mobulae has grown significantly compared to what was known about these species when I began studying them 40 years ago. In recent years, a new generation of researchers have dedicated themselves with skill and passion to conservation projects in different parts of the world, enriching knowledge of new elements on the foundations I have created. There is an urgent need for it. Because only one young is born at a time, and not even every year, the Mobulas are particularly vulnerable due to their biology, and the different species are all threatened by human activities, especially fishing. The Mexican government recently declared them under “special protection”. Most notably, the order in the taxonomy of the family has given international conservation instruments such as the Washington Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Bonn Convention on Migratory Species (CMS) the ability to list them as protected species, with the positive effect of the conservation obligation in the individual member countries of these conventions.
Giuseppe Notarbartolo of Sciara
He is a marine ecologist who has dedicated his life to studying and protecting whales, dolphins, seals, sharks and rays. He founded the Tethys Institute in Milan in 1986 and proposed the establishment of the Pelagos Marine Mammals Sanctuary in the Mediterranean, the first marine sanctuary established outside national jurisdiction. Continue with the post