In a remarkable discovery emerging from the depths of Papua New Guinea’s coastal waters, scientists have identified a new species of walking shark—an extraordinary elasmobranch distinguished by its ability to “walk” across coral reefs using its uniquely adapted fins. This nocturnal species, now formally recognized as Hemiscyllium dudgeonae or Dudgeon’s Walking Shark, was named in honor of Dr. Christine Dudgeon from the University of the Sunshine Coast, who played a pivotal role in its identification and research. The discovery not only expands the known biodiversity of this cryptic genus but also brings urgent attention to the ecological fragility of these specialized marine environments.
The genus Hemiscyllium, commonly known as walking sharks or epaulette sharks, is renowned for its evolutionary adaptation wherein all four pectoral and pelvic fins function akin to limbs, allowing these sharks to ambulate across tidal reef flats during low tides. Unlike most sharks, these creatures exhibit strong limb-like fin movements, enabling them to exploit intertidal zones where there is little competition and fewer predators. This locomotory mechanism reflects a fascinating example of convergent evolutionary traits akin to the tetrapod gait, offering insights into locomotion biology and the evolutionary precursors that may have led to terrestrial vertebrates.
During a focused exploration in Milne Bay and adjacent marine habitats, the research team, led by Dr. Dudgeon and including PhD candidate Jess Blakeway, performed meticulous observational studies using night dives to track and capture elusive walking sharks. Employing non-invasive methods such as careful hand capture and reef walking, the team was able to observe behavioral patterns, collect biometric data, and extract tissue samples vital for genetic analysis. This approach minimized environmental disturbance, prioritizing both animal welfare and ecological preservation.
The specimen that initiated the discovery process was immediately striking due to its distinctive pigmentation patterns, diverging significantly from known epaulette species. Characterized by an intricate array of white dashes along its brown body rather than the more common leopard-like spots, this phenotypic discrepancy suggested the presence of an unclassified taxon. Subsequent sampling revealed a total of twelve individuals exhibiting consistent morphological traits, bolstering the hypothesis of a novel species harboring a restricted geographical distribution.
Advanced molecular techniques were pivotal in confirming the taxonomic status of H. dudgeonae. Genetic analyses performed on blood and tissue samples revealed unique DNA sequences differentiating this species from its congeners, corroborating morphological findings. These genetic markers are indispensable for elucidating phylogenetic relationships within the Hemiscylliidae family and serve as key tools for conservation strategies, enabling precise species identification even in varied life stages or cryptic populations.
The localized habitat range of Dudgeon’s Walking Shark, confined to the southeastern waters of Papua New Guinea, underscores its ecological vulnerability. The limited distribution, combined with ongoing environmental stressors such as coral reef degradation, fishing pressures, and the impacts of climate change, notably sea temperature fluctuations, elevate the species’ risk status. These factors jeopardize not only the species’ survival but also the broader integrity of reef ecosystems which serve as critical biodiversity hotspots and carbon sinks.
From an ecological perspective, H. dudgeonae contributes to the functional dynamics of reef communities, predominantly through its diet of benthic invertebrates. As a mesopredator, it occupies a vital trophic niche by regulating prey populations, thus maintaining ecological equilibrium. Its slow, deliberate gait, reminiscent of terrestrial creatures, has earned it the local moniker “kadedekedewa,” loosely translating to “dog shark” or “lazy shark,” reflecting its methodical movement across reef substrates.
The research has profound implications for conservation biology, particularly in informing assessments for the International Union for Conservation of Nature (IUCN) Red List. Given the restricted range and environmental threats, there is an imperative need to evaluate the conservation status of H. dudgeonae rigorously. Ongoing and future expeditions planned by the research team aim to generate comprehensive population and habitat vulnerability data, which will be integral for policy formation and protective measures.
This discovery also updates the scientific understanding of the biogeographic distribution of walking sharks in the Papua New Guinean region. Contrary to previous assumptions that species distributions were delineated by natural barriers such as rivers or deep-water channels, evidence now suggests an overlap in habitats among several species, albeit without co-occurrence, suggesting niche partitioning driven by ecological or behavioral mechanisms.
Collaboration was a cornerstone of this research, involving institutions and experts across disciplines and continents. The team included prominent figures such as Professor Kathy Townsend of UniSC and Dr. Mark Erdmann of Re:wild and the California Academy of Sciences, alongside local experts and institutions. Such transdisciplinary efforts enhance the scientific robustness of the findings and foster capacity building within the region.
The funding and logistical support that propelled this research were generously provided by Conservation International, the Australia Pacific Science Foundation, the Shark Foundation, and the VanDyson Marine Fund. In-kind facilitation by regional entities like Coral Islands Ltd and Loloata Island Resort further exemplified the significance of partnerships in marine biodiversity initiatives.
Published in the Journal of the Ocean Science Foundation, this study marks a significant contribution to marine taxonomy and conservation science. It reaffirms the ongoing need for detailed field surveys, molecular techniques, and interdisciplinary collaboration to uncover and protect the hidden diversity of marine ecosystems that remain vulnerable in the face of anthropogenic change.
Subject of Research: Animals
Article Title: A review of walking shark (Hemiscylliidae: Hemiscyllium) distributions in Papua New Guinea and description of a new species
News Publication Date: 15-Jun-2026
Web References: DOI 10.5281/zenodo.20575428
Image Credits: Photo by Nesha Ichida, featuring Dr. Chris Dudgeon with the newly discovered shark species.
Keywords
Walking shark, Hemiscyllium dudgeonae, Papua New Guinea, marine biodiversity, elasmobranch genetics, coral reef ecology, species discovery, phylogenetics, conservation biology, IUCN Red List, epaulette shark, nocturnal marine species
