A groundbreaking study led by ecologists at the University of Georgia has unveiled the discovery of two previously unrecognized species of black bass, named Bartram’s bass (Micropterus pucpuggy) and Altamaha bass (Micropterus calliurus). This revelation, published in the journal Zootaxa, challenges long-held assumptions about the taxonomy of black bass species in the southeastern United States and opens new avenues for conservation and ecological research within Atlantic Slope river systems across Georgia, South Carolina, and North Carolina.
The significance of uncovering these new species lies not only in their distinctiveness but also in their historical obscurity. While the fish themselves have been known to local anglers and ecologists for decades, they were previously lumped under the broad category of redeye bass. The first encounter with Bartram’s bass dates back to the 1980s when ecologist Bud Freeman was shown a specimen in a cooler by a couple fishing in Georgia’s Broad River. Although Freeman recognized its uniqueness immediately, the fish was lost to consumption — an incident that underscores how rare species can sometimes slip through scientific documentation due to a lack of immediate specimen collection.
In the years since that initial encounter, Sandra Freeman and her team have systematically collected specimens from multiple river basins. Bartram’s bass were sampled from 14 locations across the Savannah and Saluda River basins, while Altamaha bass were gathered from an equal number of collection sites within the Altamaha and Ogeechee River basins. This methodical sampling allowed the researchers to obtain a comprehensive understanding of their distribution, morphological variation, and ecological preferences within their native habitats.
Morphological analysis revealed distinguishable features separating these two species from their previously presumed conspecific redeye bass counterparts. Bartram’s bass display a striking light gold coloration complemented by dark brown blotches along their flanks, rosy-pink fins, an intricately mottled belly, and carmine-red eyes circling black pupils fringed with thin gold margins. Notably, this species possesses a distinct oval-shaped tooth patch within its oral cavity and can grow up to 15 inches in length. In contrast, Altamaha bass exhibit a lighter gold scale pattern with olive-tinted margins, darker brown side blotches, orange-edged fins, and red eyes similarly framed with a slender golden ring. These individuals tend to reach slightly smaller sizes, maxing out at approximately 14 inches in length.
However, the study did not rely solely on these phenotypic markers. The researchers employed cutting-edge genetic methods to confirm species boundaries and prevent the erroneous inclusion of hybrid individuals. The team analyzed both mitochondrial DNA sequences and nuclear genome fragments through sophisticated bioinformatics pipelines to establish genetic distinctiveness across the sampled specimens. This robust approach involved assessing genetic data from more than 100 individuals directly associated with the new species descriptions and integrating a dataset that encompassed over 570 fish, including black bass species such as smallmouth, largemouth, redeye, shoal, Tallapoosa, northern spotted, and Alabama bass for context.
This genetic characterization marks a dramatic shift from traditional taxonomic protocols that predominantly depended on morphological counting and measurements. As Mary Freeman, a co-author of the study, explained, the integration of genomic techniques has enhanced the precision with which species are delineated, effectively preventing the contamination of specimen pools by hybrids or cryptic taxa. This rigorous foundation establishes a firm baseline for monitoring future evolutionary trends, especially concerning hybridization risks fomented by environmental disturbances and human-induced changes.
The habitats of Bartram’s and Altamaha bass are riverine ecosystems characterized by pools and runs within rocky shoal environments, which provide essential shelter and feeding grounds. Unfortunately, these habitats have faced significant alteration over recent decades due to sedimentation driven by land-use changes, agricultural runoff, and fragmentation caused by dam construction. These anthropogenic impacts have compromised the ecological niches of these species, making them increasingly vulnerable to hybridization events triggered by the introduction of non-native Micropterus species into their pristine environments.
The threat of hybridization carries profound implications for the survival of these newly recognized species. As human activity breaks down natural extrinsic barriers, gene flow among previously isolated bass lineages escalates, threatening to erode their evolutionary distinctiveness. The recognition and formal naming of Bartram’s bass and Altamaha bass spotlight these conservation challenges and emphasize the urgent need to protect these delicate riverine systems to preserve biodiversity and evolutionary heritage.
The etymology behind the names of these bass adds cultural and historical depth to their discovery. Bartram’s bass honors William Bartram, an 18th-century naturalist whose travels through the Southeastern United States between 1773 and 1776 documented numerous plants, animals, and fishes previously unknown to European colonists. The scientific epithet pucpuggy pays tribute to the Seminole-Creek inhabitants of Florida, where the chief’s moniker “Puc Puggy” translates as “Flower Hunter.” This nomenclature beautifully interweaves indigenous heritage with natural history. Altamaha bass, by contrast, derives its name from Greek roots—calli- meaning beautiful, and -urus meaning tail—reflecting its vivid fin coloration.
The research team behind this multinational collaborative effort includes experts from various institutions, demonstrating the interdisciplinary nature of modern biodiversity research. Alongside the University of Georgia’s Odum School of Ecology and Department of Genetics, contributors hail from the South Carolina Department of Natural Resources, Oxford College of Emory University, and the University of North Georgia. The wide-ranging institutional support underscores the shared responsibility in documenting and conserving the biodiversity of the Southeastern United States.
Funding for this comprehensive project was provided through a Competitive State Wildlife Grant supported by state natural resources departments, spotlighting the importance of state-level financial investment in understanding and preserving regional ecosystems. The publication of these findings in Zootaxa, a preeminent journal focusing on zoological taxonomy, further cements this discovery’s scientific credibility and impact on the field.
In summary, the revelation of Bartram’s bass and Altamaha bass as evolutionarily distinct, genetically verified species not only refines the taxonomy of the black bass complex but also serves as a poignant reminder of the fragility of river ecosystems in a rapidly changing world. This study exemplifies how traditional field observations, when combined with advanced genomic tools, can unearth hidden diversity and inform strategies to safeguard aquatic biodiversity. As river landscapes continue to evolve under human pressures, such baseline characterizations become invaluable benchmarks in the pursuit of sustaining the richness of life that these waters harbor.
Subject of Research: New species discovery and genetic characterization of black bass (Micropterus) in Atlantic Slope river drainages
Article Title: Two new species of Micropterus (Centrarchidae) endemic to Atlantic Slope river drainages in Georgia, South Carolina and North Carolina, U.S.A.
News Publication Date: 1-Aug-2025
Web References:
DOI: 10.11646/zootaxa.5683.1.3
References:
Freeman, B., Petersen, K.N., Hilburn, B.G., Freeman, M.C., Wares, J.P., Scott, M.C., Bayona-Vásquez, N.J., & Taylor, A.T. (2025). Two new species of Micropterus (Centrarchidae) endemic to Atlantic Slope river drainages in Georgia, South Carolina and North Carolina, U.S.A. Zootaxa, 5683(1), 1–x.
Keywords:
Black bass; Micropterus; species discovery; genetic characterization; hybridization; freshwater fish; Atlantic Slope rivers; biodiversity; taxonomy; conservation biology; riverine habitats; evolutionary distinctiveness
