A scientific consortium at the CSIRO has successfully elucidated the complete genetic makeup of the spotted handfish (Brachionichthys hirsutus), a marine fish species indigenous to Tasmania facing critical endangerment.
Brachionichthys hirsutus represents a scarce member of the benthic fish within the handfish family, Brachionichthyidae.
This unique ichthyological specimen is exclusively found inhabiting the Derwent River estuary in Tasmania and its adjacent environs, typically residing at depths ranging from 5 to 10 meters (16-33 feet).
Initially cataloged in 1804, the Brachionichthys hirsutus exhibits significantly modified pectoral appendages, which bear a resemblance to hands and facilitate its locomotion across the seabed. The organism’s sustenance comprises diminutive mollusks, crustaceans, and polychaete annelids.
The Brachionichthys hirsutus is designated as Critically Endangered according to the IUCN Red List 2020, with scientific projections indicating a wild population numbering fewer than 2,000 individuals. The precipitous decline in its numbers is ascribed to historical fishing practices, urban encroachment, climatic shifts, and the introduction of non-native species.
“The deciphered genomic sequence will be instrumental in bolstering current initiatives aimed at increasing population figures and maintaining genetic variability,” stated Gunjan Pandey, a researcher at CSIRO. “The genome provides essential insights into an organism’s functional mechanisms, serving as a bedrock for comprehending gene expression in daily life and illuminating its evolutionary trajectory.” Pandey further elaborated, “With the complete genome, we can enhance species identification, oversee populations, and even ascertain the fish’s projected lifespan.”
“This wealth of genetic data will be pivotal in shaping long-term conservation strategies,” added Carlie Devine, another CSIRO researcher. “Conservation efforts are progressively incorporating genetic methodologies, acknowledging that a multidisciplinary approach, synergizing with ecological research, is fundamental for the efficacious preservation of species at risk.”
“Marine fauna, such as the spotted handfish, present considerable challenges in research endeavors. The deoxyribonucleic acid degrades rapidly and becomes susceptible to contamination from microbial agents, rendering the assembly of an unadulterated genome exceedingly arduous.”
The research team successfully reconstructed the full genome by utilizing a minimal quantity of degraded DNA through an innovative low-input sequencing protocol. “We are among a select group of three research units globally employing this specialized methodology,” Dr. Pandey remarked. “We meticulously tailored the entire procedure, from laboratory setup to bioinformatics software, to achieve high-fidelity genome sequencing from suboptimal DNA samples. What previously required six to twelve months can now be completed within a few days. This advanced technology holds immense potential for our comprehension and conservation of endangered species across Australia and indeed, worldwide.”
