Marmite lures discovery from lake depths

Dr. Roe Stuart discovered a potential new species of fish in the depths of New Zealand's lakes, defying expectations of what could exist in such remote aquatic environments. The lakes of Aotearoa are known for their extreme depths, with Lake Manapōuri reaching 467 meters (1,532 feet) and Lake Te Anau measuring an impressive 430 meters (1,411 feet), significantly surpassing the previous depth record of 90 meters (300 feet) for fish life in New Zealand's lakes.

During a postdoctoral research stint at Lake Champlain in the U.S., Stuart questioned the lack of knowledge about the creatures inhabiting Aotearoa's lakes. To uncover this hidden biodiversity, Stuart employed a unique baiting method—using Marmite, a breakfast spread often associated with the creation of taniwhas in New Zealand folklore.

The team set traps at various depths using 2 kilometers (1.2 miles) of rope and found fish in all of them upon retrieving them the following day. The retrieved fish included native bullies and galaxiids, small, iridescent climbing fish typically found as whitebait, but those found in the deep lakes exhibited unusual characteristics.

These deep-water galaxiids had notably large eyes and sensory pores on top of their heads, traits that suggest adaptation to the dark, oxygen-rich environment found all the way down in these lakes. While genetic testing is needed to confirm whether these fish represent a new species, Stuart's discovery highlights the importance of exploring these deep-water lakes for conservation purposes.

Understanding what lives in these remote environments is crucial for effective management and protection of these iconic water bodies. Stuart's passion for these understudied creatures, depicted through tattoos in his lab, underscores the need to shed light on the overlooked and underappreciated life forms dwelling in our rivers and lakes.