Members of the phylum Nematoda are also known as roundworms. Though they are often referred to as “worms”, they aren’t closely related to earthworms. They do have a slender and elongated shape, however. They are common animals. The group contains both parasites and free-living species that live in a wide variety of environments. They range from microscopic in size to several feet in length. The photo below shows a different species of nematode from the ones discovered in Mono Lake, but it gives the general idea of a roundworm's appearance.
 |
| A scanning electron micrograph of a soybean cyst nematode and its egg Agricultural Research Service, public domain license |
Mono Lake is located near the town of Lee Vining in Mono County, California. Like the nematodes that live there, the lake is interesting. It has a surface area of around 70 square miles and has no outlet. Its salinity is three times greater than that of sea water. Its pH of 10 makes it an alkaline or basic environment. Despite its seemingly inhospitable nature, the lake contains life. Caltech researchers have recently discovered that eight species of nematodes live in the lake, including the one described above. Before the discovery, only two animal species (a brine shrimp and a diving fly) plus algae and bacteria were known to live in the lake. The newly-discovered nematodes include predators, parasites, and ones that “graze” on microbes.
 |
| An aerial view of Mono Lake in California Ron Reiring, CC BY 2.0 license |
The researchers have been able to culture one of the eight nematode species that they discovered in the lake. They’ve placed this animal in the genus Auanema but haven’t given it a species name yet. Its resilience to arsenic may be an adaptation that enables it to survive in the lake. It’s classified as an extremophile, or one that can live under extreme conditions compared to those required by humans. Its mouth structure suggests that it’s a microbe grazer.
The species exists in three forms: female, male, and hermaphrodite. A hermaphrodite contains both female and male reproductive organs. The eggs hatch inside the roundworm that bears them, who gives birth to live young. A relative of the species in Mono Lake (Auanema rhodensis) also exists in three forms. In this species, the females produce eggs, the males produce sperm, and the hermaphrodites can produce eggs and sperm. The identity of the chromosomes in the gametes, and the possible genders of the offspring in each parental combination appear to be unusual, however. The species was first discovered in 2018 and is still being studied. The studies might apply to the species found in Mono Lake, though this isn’t necessarily true.
Learning about the living creatures in the lake is a very interesting endeavor and could also be useful, for multiple reasons. Understanding how the animals survive in their seemingly harsh environment could be important with respect to organisms that have benefits for humans. Understanding the details of the worm's reproductive system could also be important, even with respect to human biology.
It’s not outside the realm of possibility that understanding chromosome behaviour in nematodes could explain some situations in humans. The species has X and Y sex chromosomes, as humans do. In general, the cells of female humans have two X chromosomes and the cells of males have an X and a Y chromosome. Some of us have a slightly different chromosome collection, however. The variations in Auanema may help us to understand this situation and perhaps even lead to benefits in humans. Even if this isn't the case, the new species of Auanema sounds like an intriguing animal that is worth studying.
References
- Otherworldly worms detected in Mono Lake from the Science Daily news service
- Some facts about nematodes from the Encyclopaedia Britannica
- Information about Auanema rhodensis from the phys.org news service
- Mono Lake facts from Carleton College
No comments:
Post a Comment