Written by Mark Sabaj, PhD, Curator of Ichthyology
Our story begins in the year 1878 with the birth of Henry Weed Fowler in Holmesburg, a village on the right bank of the Delaware River that had been incorporated into Philadelphia twenty-four years earlier.
Shortly before his 15th birthday, the precocious Fowler wrote a letter to the Academy’s Board of Curators. “Gentlemen,” he began, “Having determined to devote my life to the study of Natural History, I respectfully apply for a studentship at the Academy of Natural Sciences.”
The following year, Fowler became a Jessup student supported by a trust established in 1860 by the daughter and two sons of Augustus Edward Jessup, a geologist, paper manufacturer and Academy member. Jessup intended the trust to serve “the assistance of poor young men desiring to study natural history.” Later, in 1893, Clara Jessup Moore enriched the trust to support young women similarly inclined.
Fowler would remain closely tied to the Academy for the next 70 years and served as Curator of Fishes from 1902 until his death in 1965. During that time, he authored at least 666 publications totaling more than 19,000 pages. Fowler also assembled one of the most important collections of preserved fishes in the world. This collection served his naming and description of over 1871 new genera, subgenera, species and subspecies.
However, only 37% of Fowler’s names remain in use today due to the rules of taxonomy. Why?
When two or more names are proposed for the same taxon, only the oldest published name is used. The younger names, called synonyms, are generally forgotten. So, based on our current understanding of the diversity of fishes, nearly two-thirds of the taxa that Fowler named as new were in fact previously named by other authors.
Our recent study, published in the Proceedings of the Academy of Natural Sciences of Philadelphia, concerned the status of a name that Fowler proposed in 1943 for a new subspecies of small tetra, Moenkhausia lepidura ocoae. He based this name on a single specimen sent to him by Brother Nicéforo María, a French naturalist and Catholic priest stationed in Colombia. At that time, it was not uncommon for an ichthyologist to name a new species based on a single specimen, especially if it was from a remote part of the world. Although Fowler’s name sank into obscurity, his specimen remains preserved in the Academy Fish Collection as the unique holotype of Fowler’s species.
Sixty-five years later, two Brazilian ichthyologists, Ricardo Benine and Guilherme Lopes, named another new species of small tetra, Hyphessobrycon otrynus, based on specimens from Venezuela. Apparently, they were unaware of the small tetra previously described by Fowler.
While visiting the Academy collection, lead author Flávio Lima noticed a resemblance between the small tetras described by Fowler and the two Brazilians. This connection prompted the convocation of a team of tetra specialists to carefully examine over 3,000 specimens preserved among 16 museums in five countries on three continents.
Our study first revealed that Fowler’s ocoae is not properly placed in the genus Moenkhausia, but rather the genus Hyphessobrycon. This places Fowler’s species is in the same genus as the species described by the Brazilian ichthyologists.
Next, we took various shape measurements, made counts of various anatomical features, and noted various details in pigmentation for those 3,000 museum specimens. This analysis allowed us to properly distinguish Fowler’s species from all other species of small tetra. Furthermore, we found no significant differences between the two small tetra described by Fowler in 1943 and by Benine and Lopes in 2008, respectively.
Therefore, the valid name for this small tetra is Fowler’s Hyphessobrycon ocoae, unless of course an older name is found for this same fish.
Our study also revealed that Fowler’s tetra is not limited to one site in Colombia and another in Venezuela. Rather, it is widely distributed across much of the llanos portion of the Orinoco basin. There are also historical records for Lake Valencia in northern Venezuela, although its persistence there could not be confirmed. This isolated lake has been heavily impacted by pollution and many of its fishes are now gone.
So, what is the relevance of this and similar studies?
In a recent article published in the scientific journal Nature, Dahseng Lui stressed that “Taxonomy is crucial for biodiversity conservation — if we can’t properly identify animals, plants and fungi, we can’t find ways to preserve them.”
To this I would add that natural history collections are crucial for taxonomy. A lot of words, both written and spoken, have been devoted to the importance of natural history collections and research. This message is often and unfortunately paired with dire warnings of dwindling resources and support.
Despite all the attention, a true understanding of such importance is often restricted to those deeply engaged in the work itself. Such work begins with genuine curiosity about a highly complex subject — the natural world. That curiosity leads to careful study and data gathering to separate what is known from what is unknown and questionable.
And with collaboration, the sum of knowledge of becomes greater than its parts. The last step, communication via talks, publications and blog posts, invites others to advance or question such knowledge.
Natural history collections and research are a powerful way to develop and master many types of skills. This effort is self-rewarding and can be of service and inspiration to others, as it was for Henry Fowler.
A thank you to co-authors Flávio C.T. Lima, Alexander Urbano-Bonilla, Rafaela P. Ota, Lais Reia and Ricardo C. Benine.
You can support the Academy’s research efforts to understand the natural world and inspire everyone to care for it by becoming a member or donating to our scientific collections.
Tú también puedes apoyar los proyectos de investigación de la Academia, y así ayudar a entender y proteger la riqueza natural convirtiéndote en miembro o haciendo una donación a nuestras colecciones científicas.