Trochidrobia
Found in Lake Eyre artisan springs in the Great Artesian Basin in South Australia,[2] genus species of fresh-water snails scientifically known as Trochidrobia are endemic to the area.[3] Trochidrobia Inflata, Minuta, Punicea and Smithi are different species of the fresh-water snails.
| Trochidrobia | |
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| Genus: | Trochidrobia |
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| Trochidrobia punicea Ponder, Hershler & Jenkins, 1989 | |
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Description
Different genus species of Trochidrobia have different characteristics that distinguishes them from each other.
Trochidrobia Inflata
The genus species of Trochidrobia Inflata found in Lake Eyre artisan springs in the Great Artisan Basin in South Australia have certain characteristics that make them different from the other species of the fresh-water molluscs. The name, Inflata, has been derived from the characteristic of their inflated shell.[4] Trochidrobia Inflata are found in the same geographical locations as the Minuta species of the fresh-water molluscs, in shallow waters of the lower part of the springs outflow.[4] This specific genus species is found in the Freeling Springs complex in the northern part of Lake Eyre supergroup. Trochidrobia Inflata have small but wide umbilicus and a relatively larger spire as compared to other species. The average adult size can reach about 1.5 – 1.7mm in diameter.[4]
Trochidrobia Minuta
The name for this species has been giving due to the size of this genus fresh-water molluscs, Minuta – derived from minute.[4] This species of fresh-water snails is the smallest species of Trochidrobia. Trochidrobia Minuta are found in the same geographical location as Trochidrobia Inflata, in Freeling Springs. This genus species of Trochidrobia have a wide hole at the centre of the shell and a shorter and flatter spire. The average diameter of adults for this species is about 1.2mm.[4] The species is coloured Yellowish White to Pale Brown. The head and foot are pigmented heavily.[4]
Trochidrobia Punicea
Genus species of Trochidrobia Punicea are located in the southern and middle part of Artesian springs system in the northern part of Southern Australia. The species is usually found completely exposed surfaces on the water.[4] Although they look similar to other species of fresh-water molluscs, they are anatomically different. Trochidrobia Punicea have a short spire and an open centre of the shell. The name Punicea has been derived from Purple-Red in Latin which is a reference to the shell of this species which is Purple/Red in colour. The diameter for the fresh-water mollusc reaches a maximum of 2.2mm. The operculum is oval shaped.[4] The head and foot of this genus usually has dark pigmentation. This is the only species of Trochidrobia that shows an attractiveness towards light [4]
Trochidrobia Smithi
Trochidrobia Smithi is found in the Middle Springs, Southern-Western Springs and the Northern Springs in the Artesian Springs system. This specific species is identical to other species visually, however, the anatomy is different.[4] These Trochidrobia have shells with short spire and an open umbilicus that reaches a maximum diameter of 2.1mm.[4] The average adult size for this genus species is between 1.7mm to 2.1mm. The head and foot are virtually similar to Trochidrobia Punicea as the genus has uniform dark pigmentation.[4]
Distribution
Different species of Trochidrobia can be found in different parts of the Lake Eyre artisan springs in South Australia. The differentiation between the genus species can be linked to the distance between the different spring groups.[3]
The species of Trochidrobia Punicea can be found throughout the southern and central spring groups as far as Coward Springs.[3] However, it does not include Beresford Springs in Artisan Basin where Trochidrobia Punicea is replaced by the genus species of Trochidrobia Smithi. These species of fresh-water molluscs can also be found in the South Western Springs and Northern Springs. Further studies by Ponder et al 1995 suggest that these two species of Trochidrobia, T. Smithi and T. Punicea, are distributed widely in unconnected springs throughout the Great Artisan Basin in South Australia.[3] The widespread distribution has been present since the initial colonisation of the springs in the basin. Furthermore, the distributions of other species of these fresh-water snails can be explained by “either the previously widespread lineages were trapped in desert springs and then permanently isolated from each other or dispersal has occurred after spring colonisation due to either climate-led population connectivity, or through chance colonisation or divergence”.[2]
Taxonomy
Trochidrobia belong to Kingdom Animalia meaning they are eukaryotic multicellular organisms that belong to the biological kingdom.[5] This kingdom includes mostly all animals, making a few exemptions, that can breathe oxygen, are able to move, reproduce sexually and consume organic materials.[6]
In the Kingdom Animalia, Trochidrobia are part of the second largest Phylum of Mollusca[3] for invertebrate animals, after the Arthropoda.[7] The members of this phylum are called Molluscs and there are estimated to be about 60 000 to 100 000 fossil species in this group.[7]
Since genus Trochidrobia are fresh-water snails, they are part of the Gastropoda Class in the taxonomy under Phylum.[5]
Further in the taxonomy, Trochidrobia are part of the Caenogastropoda, Hypsogastropoda and Littorinimorpha groups.[3] These large groups are diverse and contain mostly sea snails and other aquatic gastropods. In some cases, these groups include fresh-water snails.[6]
The genus species belong to the super family of Truncatelloidea and the family of Tateidae. This family includes very small gastropods molluscs with an operculum.[6] The operculum is like a trapdoor, which exists in many fresh-water snails.[8]
Ecology
Fresh-water snails are an important part of the aquatic ecosystems.[9] In general, many of these species spent almost all of their lives within a few metre squares of their habitat. This makes them extremely susceptible to degradation to their localised environmental habitat.[10] These species are sometimes known as “natures ultimate grazers”. Most of these species’ feed on periphytic or epiphytic algae.[10] Fresh-water molluscs are also an important part of the dietary requirements for many animals such as cray fish, fish, turtles, and ducks.[10] In general, the aquatic gastropods have low ecological tolerances.
Since Trochidrobia have an operculum, they are able to extract oxygen from the water using a single gill. They have separate sexes, internal fertilization, and a short reproductive season.[5] Copulation of the aquatic molluscs takes place with the reciprocal exchange of sperm packets and eggs are typically laid in a slimy mass attached to the underlying layer of the soil.[5]
References
- Ponder W., Hershler R. & Jenkins B. (1989). "An endemic radiation of hydrobiid snails from artesian springs in northern South Australia: their taxonomy, physiology, distribution and anatomy". Malacologia 31(1): 1–140, p 59.
- Nicholas P. Murphy, Martin F. Breed, Michelle T. Guzik, Steven J. B. Cooper, & Andrew D. Austin. (2012). Trapped in desert springs: Phylogeography of Australian desert spring snails. Journal of Biogeography, 39(9), 1573–1582. https://doi.org/10.1111/j.1365-2699.2012.02725.x
- Ponder, W. F., Eggler, P., & Colgan, D. J. (1995). Genetic differentiation of aquatic snails (Gastropoda: Hydrobiidae) from artesian springs in arid Australia. Biological Journal of the Linnean Society, 56(4), 553–596. https://doi.org/10.1111/j.1095-8312.1995.tb01110.x
- Ponder, W., Hershler, R., & Jenkins, B. (1989). An endemic radiation of hydrobiid snails from artesian springs in northern South Australia: their taxonomy, physiology, distribution and anatomy. Malacologia, 31, 1-140.
- Ponder, W. F., Hallan, A., Shea, M. E., Clark, S. A., Richards, K., Klunzinger, M. W., and Kessner, V. 2020. Australian Freshwater Molluscs. Revision 1.
- Morrison-Scott, T. C. S. (1962). Principles of Animal Taxonomy. Nature (London), 193(4817), 717–718.
- Katharine G. Field, Gary J. Olsen, David J. Lane, Stephen J. Giovannoni, Michael T. Ghiselin, Elizabeth C. Raff, … Rudolf A. Raff. (1988). Molecular Phylogeny of the Animal Kingdom. Science (American Association for the Advancement of Science), 239(4841), 748–753. https://doi.org/10.1126/science.3277277
- Cheng. J, Daniel. M (n.d). Operculum, Radiology Reference Article, Radiopaedia.org. Retrieved 26 April 2021, from https://radiopaedia.org/articles/operculum.
- Freshwater Snails. (n.d). Retrieved 26 April 2021, Retrieved from https://molluskconservation.org
- Dillon, R. T. (2000). The ecology of freshwater molluscs. Cambridge: Cambridge University Press.
R. A. Rossini, R. J. Fensham, B. Stewart-Koster, T. Gotch, & M. J. Kennard. (2018). Biogeographical patterns of endemic diversity and its conservation in Australia’s artesian desert springs. Diversity & Distributions, 24(9/10), 1199–1216. https://doi.org/10.1111/ddi.12757
Fensham R.J, Ponder, W.F. and Fairfax, R.J. (2010). Recovery plan for the community of native species dependent on natural discharge of groundwater from the Great Artesian Basin. Report to Department of the Environment, Water, Heritage and the Arts, Canberra. Queensland Department of Environment and Resource Management, Brisbane.