2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Escarpia laminata tubular worm. On the right - representatives marked with a dye to study annual growth
American scientists have studied the life cycle of a population of tubular worms of the species Escarpia laminata and found that they are one of the longest-living creatures on Earth. By tracing changes in the length of the tubular worm's body and simulating its growth over time, the researchers found that members of this species can live up to 250 years. The article was published in the journal The Science of Nature and is available on the Springer website.
The depths of the ocean are home to many long-lived organisms due to the low probability of death from predators and the presence of cold seeps - areas in the seabed through which substances enter the water that provide a favorable environment for autotrophs. The nourishment of tubular worms depends on the autotrophic microbes living inside them, which oxidize methane and hydrogen sulfide (volcanic substances that enter the water through cold seeps), which are necessary for their life. The stability of life in symbiosis with bacteria and the low temperature of the sea depths are reliable sources of longevity, therefore tubular worms, in particular representatives of the species Lamellibrachia luymesi and Seepiophila jonesi, can live up to two hundred years.
The authors of the new work investigated a poorly studied species of tubular worms living in the depths of the ocean - Escarpia laminata. Representatives of this species live at a depth of 1000 to 3300 meters at the bottom of the Gulf of Mexico. For this species of tubular worms, scientists applied the same method of studying annual growth that was used to study the tubular worms of the species L. luymesi. 356 E. laminata were measured in situ, labeled with a blue waterproof acid dye, and collected one year later. An unpainted area that appeared during this time on the body of the worm was an indicator of the annual growth of each individual representative.
Plot of exponential distribution of annual growth (centimeters per year, Y-axis) of E. laminata versus original measured length (centimeters, X-axis)
With the annual growth data for the tubular worm, the researchers simulated the growth of E. laminata. The simulation method was based on studies of another tubular worm, L. luymesi. Scientists measured the average age of both an individual member of each population and the average age within one population.
It turned out that the average age of one tubular worm with a length of 50 centimeters is 116.1 years (for comparison, with the same length, the age of representatives of L. luymesi and S. jonesi is estimated at 21 years and 96 years, respectively). The longest (and, accordingly, the longest-lived) of the collected representatives of E. laminata turned out to be more than 250 years old.
Scientists suggest that the reason for the longevity of tubular worms is a decrease in metabolic rate, which became possible due to an increase in the depth of the species.
With an age of more than 250 years, the tubular worm E. laminata is second only to one well-known long-lived invertebrate - the mollusk Artica islandica, which can be more than 500 years old. You can read about the vertebrate long-liver, the Greenland polar shark, in our article.