The Antilles and treasures… the Antilles and treasures….these are perhaps the most frequent associations everyone makes with the group of islands in the Caribbean Sea, whether due to the genius of Robert Louis Stevenson or the charisma of Jack Sparrow or, really, because of a certain historic truth glorified by film and literature about pirates and buccaneers, who swarmed the Caribbean attracted by riches plundered from the supposed “New World.”

The Antilles are, indeed, a place of exquisite treasures, some well-known and recognized, but others (many) are still hidden to the eyes of humanity. I’m not referring to doubloons and pearls here, but to marvelous, unequaled nature, particularly its “living nature” or biodiversity.

Even since scientists began to classify and study biological diversity in the Antilles, they became aware of its uniqueness and richness. Botanists were astonished by its flora and several zoological icons enchanted scholars and naturalists. The world learned about the existence, just to give you a few examples, of giant insect-eating mammals (Solenodon cubanus and Solenodon paradoxus), teeny birds (Mellisuga helenae), frogs (Eleutherodactylus limbatus), bats (Nyctiellus lepidus), charismatic iguanas (Cyclura nubila), endemic crocodiles (Crocodylus rhombifer), fantastic lizards (Anolis spp.) and extraordinary blind fish who live in caves (Lucifuga dentata and Lucifuga subterranea), all of whom inhabit these beautiful islands of sun and beaches.

Examples of the marvelous vertebrate fauna of the Antilles: A: Cuban solenodon (Solenodon cubanus); B: butterfly bat (Nyctiellus lepidus); C: bee hummingbird (Mellisuga helenae). Photo credits, A: Lázaro Echenique; B: Carlos A. Mancina; C: Aslam Ibrahim Castellón Maure.

However, in more than two-and-a half centuries of zoological nomenclature, the catalog of the terrestrial fauna of the Antilles we’ve managed to name is very unbalanced in favor of the diversity of “vertebrate” animals in detriment to the much more numerous “invertebrates.” This is a worldwide phenomenon known in some scientific circles as the “bias of the megafauna.” In the Antilles, few exceptions escape this panorama among the terrestrial arthropods, those invertebrate animals with an exoskeleton of chitin and a segmented body. Among these exceptions are daytime butterflies (Rhopalocera), some groups of beetles (for example, Cerambycidae) and scorpions. The degree of inventory of other groups of arthropods varies from island to island; the great majority are scarcely registered or totally unknown. Indeed, if one thing is completely certain, it is that as you walk, enjoy, explore or rest in the exuberant nature of any of the islands of the Antilles, around you are dozens or even hundreds of new species of arthropods completely unknown to science. A true hidden treasure!

And when we talk about hidden animals, we are referring not only to the fact that science has not yet categorized them, but also to the fact that there are literally many groups of arthropods who live in the dry leaves of the forest floors, the inside of fallen trunks, beneath those trees and under rocks, in cracks and all sorts of underground habitats, including deep within caves formed in the abundant carbonated rocks of the Antillean archipelago. That’s another reason these groups of arthropods are also unknown. It’s not easy to catch them, and biologists often have to spend hours in these habitats scrutinizing cryptic species, sorting through dry leaves to later place them in funnels or on white trays and extract the specimens. Or they might have to learn techniques of speleology—cave study and exploration—to pluck these treasures from the belly of the earth.

Above, from left to right, sorting through dry leaves with a sifter, together with the recently late and renowned arachnology curator of the American Museum of Natural History, Norman Platnick, concentrating on the leaf pile on a tray, assembling the portable Berlese funnels for the passive extraction of the arthropods present in the leaf pile. Below: Harvard Professor Gonzalo Giribet and George Washington University Professor Gustavo Hormiga actively capturing the arthropods from the leaf pile with the aid of a white tray, University of São Paulo Ph.D. student Flávia Pellegatti Franco collecting arthropods from the depths of a cave.

But before you think that my words about hidden treasures are pure romantic fantasies of a fanatic nature lover, let me give you some examples of a zoological group to which I have dedicated the last 30 years of my life: the Opiliones (commonly known as “Harvestmen” or “Daddy Long Legs”). This fascinating group of arthropods is related to spiders and scorpions, but it is an independent group. Thus, we have spiders, scorpions, and opiliones, among other groups, which are included in the most inclusive category called the Arachnid Class.

Well, getting back to opilionids, the Antilles and its hidden treasure, I’m going to tell you a bit about the daddy long legs of the Neoscotolemon genus. But my history with them does not begin here and does not start with this name. It begins at the beginning of the 90s, when I was a young and curious biology student in Cuba. Together with my classmates, we visited several caves near the town of “La Salud” south of Havana. There, in a cave named Inzunza, we collected several opilionids that we tried to identify when we got back to the classroom. It’s impossible to convey the fascination and astonishment I felt when I observed these opiliones for the first time under a stereo-microscope! What an incredible animal and what powerful front appendages! I later learned the technical name, pedipalps, but I never lost the astonishment.

Two new species of Neoscotolemon I found under the same wet tree trunk in la Sierra de la Guira, Pinar del Río, Cuba. A: 2.5 mm body specimen. B: 1.5 mm specimen.

At that moment, I felt the overwhelming necessity to know what it was, to know the name of this fantastic species….at that moment my “gene of taxonomy” had expressed itself compulsively. And at that very moment, the tribulations inherent in the life of a taxonomist began and have not left me to this very day. Effectively, although you might not believe it, the often vilified field of taxonomy is perhaps one of the most difficult, integral and fascinating specialities that a biologist can have. But let’s not stray from our route; in another opportunity, we’ll be able to discuss taxonomy, taxonomists and the taxonomic impediment, all of which are stimulating topics.

Returning to our Cuban opilionid, after a lot of research, visiting libraries and seeking advice, above all from my dear Professor Luis F. de Armas, I came to the conclusion that it was one of the species that had been collected in Cuba by the renowned Spanish docent, entomologist and politician Cándido Luis Bolívar y Pieltáin in 1943. The specimens collected by Bolívar were studied by the U.S. spider experts Clarence and Marie Goodnight in 1945 who described one genus and two species: the genus Rula and the species Rula cotilla and Rula bolivari. I was intrigued because I believed I had collected, for the second time in history, specimens of Rula cotilla for the first time in 45 years!

Micro-photographs of Rula bolivari taken with an electronic microscope with an electronic scanner. A: dorsal view. B: side view. The appendages on the left side were removed to get a better view of the morphological characteristics of the body from a side view. Micro-photographs Daniel N. Proud.

However, continuing with my bibliographic investigation, I learned that years later, the same authors determined that both species of Rula were, in fact, one species called Stygnomma spinifera (described originally by Alpheus Spring Packard, Jr. in 1888, under the name Phalangodes spinifera) that was distributed throughout Florida, as well as in Cuba and also the Yucatan Peninsula. My illusions were crushed! My beautiful Cuban opilionid was not so rare after all. I was far from knowing that this history had hardly begun.

In 1993, I had the opportunity to train with Dr. Emilio Maury, specialist in Opiliones at the Argentine Museum of Natural Sciences Bernardino Rivadavia, who was extraordinarily kind in asking on loan for the types of species described by Packard and the Goodnight couple and… Surprise! What had been thought to be Stygnomma spinifera were actually four distinct species. That is, Rula cotilla and Rula bolivari were valid and distinct from each other and Stygnomma spinifera described from Florida and Yucatán were also two distinct species. My happiness didn’t last for very long, because soon other doubts arose, such as what kind of harvestmen really belonged to the genus Stygnomma. The answer came only seven years later when I visited the Senckenberg Natural History Museum in Frankfurt, Germany, and could ascertain that the true Stygnomma species lived exclusively in South America and were very different from Rula. That same year, I visited the Harvard Museum of Comparative Zoology and discovered that the two Rula species were very similar to two other Cuban species: Neoscotolemon pictipes and Vlachiolus vojtechi. The first, Neoscotolemon pictipes, had been described (under the genus Scotolemon) by Nathan Banks, a U.S. spider expert in 1908, and the second, Vlachiolus vojtechi, by Vladimír Šilhavý, a Czech doctor and specialist in Opiliones in 1979.

More than a decade since that young biology student (me) collected an opilionid in a Cuban cave, I was close to discovering its classification! To correctly name it, I had to pick between three genera: Rula, Vlachiolus and Neoscotolemon. To resolve these questions, there’s a “book of laws” called the International Code of Zoological Nomenclature that regulates the system of naming in that field. In one of its articles, the code establishes “The Principle of Priority”, that is, the valid name is the first one described (= the valid name of a taxon is the oldest available name applied to it). Since Neoscotolemon was described in 1912, Rula in 1945, and Vlachiolus in 1979, this first genus name has priority over the others. Therefore, in conclusion, all of these species turned out to be Neoscotolemon! Yikes! I hope you readers have been able to follow this tortuous labyrinth! I think this example from real life, extending for more than a decade, illustrates perfectly how being a taxonomist is not an easy task and how we need to have qualities of Sherlock Holmes and lawyers mixed into one.

Finally I knew that what we had in Cuba were four species of Neoscotolemon and I now knew how to recognize them. From that moment on, I began to collect them all over the island and to revise the rich collection deposited in the Cuban Institute of Ecology and Systematics. New species of Neoscotolemon began to appear all over the place! The high species richness, the low distributional range of each one (restricted to a few km squares), and the variety of morphological characteristics were notable. The greatest diversity was found in the western part of the island, but specimens also appeared in the center and the eastern part of Cuba, on the Isle of Youth and in the Sabana-Camaguey Keys. One, two, three… 50 new species on an island where, for more than a century, only four had been identified. They had been just there, right in front of our very noses…better said, below our noses and some literally hidden below the earth adapted to live exclusively in caves, waiting to be detected. All together, a gigantic treasure.

The circles on the map and the photographs of specimens show the distribution and external morphology through a side view of Nescotolemon species. The black circles represent species known today and the red circles indicate species that are new to science that are in the process of being officially described and named. The black star represents where the cave-dwelling Stygnomma fiskei is found, while the red stars show related epigeous (those found in superficial environments) species that science still has to describe. Photos: Vanesa Mamani and Daniel N. Proud.

Recently, and thanks in part to collection efforts of the CarBio project, headed up by Ingi Agnarsson of the University of Iceland and Greta Binford of Lewis and Clark, we have been able to carry out the first phylogenetic (hypothesis of evolutionary relationships among biological entities) analysis of the Neoscotolemon species. We keep on being surprised. Now we know that the group began to diversify in Cuba some 34 million years ago and that the species in Florida and the Yucatan are the results of recent dispersions from Cuba to both peninsulas. We also know that the closer related harvestmen of Neoscotolemon are a cave-dwelling species in Jamaica, Stygnomma fiskei—described by the Spanish opilionid expert María Rambla Castells in 1969—and two new species to be described from Jamaica and Haiti.

As you can see, the number of officially recognized species is miniscule and very many of those discovered still have to be categorized. It took a long time to forge the bases to a reliable identification, but it’s now being established and we are beginning to move forward. Together with colleagues and students, we are hard at work so that soon, all of these new species will officially enter into the catalog of Antillean biodiversity.

Let us now write about the opilionids of the Island of Reggae, Jamaica, and learn about its hidden treasures. For example, let’s look at the species of the genera Akdalima, Reventula and Ethobunus. Two of the Opiliones experts cited above were responsible for describing the Jamaican species in these categories. María Rambla worked with material collected in 1968 by Stewart B. Peck of Carleton University and Alan Fiske of UCLA, during a quick six-day collection visit to seven caves in the western half of the island. In 1969, Rambla published the description of Cynortina pecki and Cynortina goodnighti, which are currently in the genus Ethobunus. One of them, Ethobunus pecki, is totally blind (!), it doesn’t have a retina, but also doesn’t have any signs of ocular structure, something called “anophthalmia”. This characteristic, together with other morphological traits such as lack of pigment and lengthening of appendages (legs and pedipalps, two kinds of the cephalothorax appendages) reflect the adaptation process to live exclusively in the cave environment. On the other hand, Ethobunus goodnighti, presents functional eyes (with a retina), pigmented body and short appendages, which makes us think that it is not an exclusively cave-dwelling species and therefore can have populations outside the caves. Vladimír Šilhavý, studying the opiliones in the collections of the Harvard Museum of Comparative Zoology, described the species Akdalima jamaicana, which he placed in the Akdalima genus that he himself had created two years before for a Mexican opilionid from Chiapas. Also, he described the genus and new species Reventula amabilis from the John Crow mountains in Jamaica’s eastern highland region.

More than fifty years after Šilhavý’s description, I had the amazing opportunity to join a scientific expedition to Jamaica organized by the CarBio project. This excursion wasn’t as short as Stewart Peck’s six-day whirlwind, but it wasn’t very long either: 20 days of collecting that allowed us to experience several places throughout the island. However, with only this small effort of obtaining samples, we managed to quadruple the insular diversity known of Akdalima, Reventula and Ethobunus, going from four to 15 species, including a new genus for science.

The Akdalima representatives, with our collection of its eight new species, surprised us by being all native to the island, which made us suspect there were a lot more species to be found in still unsampled areas. We also found out through phylogenetic analysis that Jamaica’s Akdalima was more closely related to the country’s Reventula (with also two new species!) than it was with the “true” Akdalima from Chiapas, Mexico. Now we’ll have to investigate whether the Jamaican species are Reventula or if we have to describe and name a whole new genus… we’re working on it. Three new species of Ethobunus have also been added to the two previously known species on the island. They are extraordinary in their external morphology and genitals and definitely are not related to the “true” Ethobunus from Costa Rica and Panama. Again, the hard work of defining a genus name for those species is in front of us.

The circles on the map and the photographs show the distribution and external morphology from a lateral view of the Akdalima species in Jamaica. The black circle represents Akdalima jamaicana and the red circles are species new to science in the process of description. The stars show the distribution and external morphology from a lateral view of the Reventula species. The black star represents Reventula amabilis and the red stars correspond to new species. The black triangles Ethobunus pecki and Ethobunus goodnighti and the red ones, three new species. The brown inverted triangles mark where the two new species of the previously unknown genus. Photos: Daniel N. Proud.

Just as in Cuba, the number of unknown species is by far greater than the known ones. What particularly strikes me is that in the case of Jamaica, it only took a short 20-day expedition to gather more than had been done in almost half a century. How much more could we discover with a systematic and extensive sampling, with taxonomic work prioritizing Antillean ground arachnids!

I believe the two examples I’ve given you should be enough to convince you about the enormous unknown biodiversity of the Antilles, but I don’t want to finish without talking about the marvelous island of Hispaniola, made up of the Dominican Republic and Haiti. This is an island of mountains that reach 10,000 feet, home to the most unknown diversity of opilionids in the entire Antilles. Some opilionids have been discovered first through their fossilized species, trapped in the famous Miocene amber deposits, some 15 to 20 million years old, even before their living species. This is precisely the case of the fossil specimen of the Kimula genus, which had been reported by James C. Cokendolpher of Texas Tech University and George O. Poinar, Jr. of Oregon State in 1992. The fossil was the only known Dominican species of opilionid from this genus. That was the case for eight years when, in 2000, I described Kimula cokendolpheri, together with my Cuban colleague and Professor Luis F. de Armas. Until now, Kimula cokendolpheri it’s still the only known living species of this genus on the island. However, (and you’ve probably suspected what I’m going to describe), the collections of the National Museum of Natural History Prof. Eugenio de Jesús Marcano in Santo Domingo, Dominican Republic, houses more than 50 specimens belonging to several new living species. There are at least six new species of Kimula. I had the opportunity to identify these species virtually and, I hope, in the not-too-distant future, I will have the opportunity to study them.

Opilionid specimen in the collection of the Museum of Natural History Prof. Eugenio de Jesús Marcano in Santo Domingo, Dominican Republic, corresponds to an unclassified living species of the genus Kimula. Photo: Solanlly Carrero Jiménez.

Let’s go back then to the beginning of our history: the Antilles and treasures… Antilles and treasures….Without a single doubt! An immense richness of hundreds of species that have survived hidden from science in the depths of the forests, mountains and caves. They are treasures of disparate evolutionary and biogeographic lineages; treasures stored in insular museums of biodiversity and form part of one of the most spectacular evolutionary laboratories in the world. The discovery of these treasures is fundamental to help us understand how the product of the beautiful phenomenon of life on our planet lived, lives and will continue to live.