Perna Viridis (Asian Green Mussel
This is a writing sample from Scripted writer Lucy Hutchison
Species Classification
The Perna Viridis of class Bivalvia (Subclass Pteriomorphia), commonly known as the Asian Green Mussel, is an invasive species first introduced into Australia through biofouling ships transporting of south east Asian ports. (NIMPIS - Australian Government , 2020) This species is classed as invasive through extensive and harmful affects the species has inflicted economically, socially, and environmentally, including out competing native Australian species and modifying northern Queensland marine ecosystems.
Appearance
Adults are commonly found to reach 165cm in length, incurred beaks with an either straight or weakly convex ventral margin. The outer surface of the species' shell are smooth and coated in periostracum (epidermis) usually found in a shade of vivid green. (CABI International , 2015)
Reproductive Characteristics
Perna viridis are commonly found to have high reproduction rates in waters containing salinity levels of 18-33ppt with temperatures ranging in 11-32 oC. (Australian Government , 2015) The fertilization of the species perna viridis is external. Both reproductive systems of the mussel are distributed int the water where they are fertilized into veliger larvae. They then remain in a 'water column' for up to two weeks, further settling as juveniles. (Biosecurity Queensland Government , n.d.)
Life Span
The perna viridis has a typical lifespan of 2-3 years, the time varying on water temperatures, salinity levels an overall weathering conditions, as well as the impact of surrounding invasive and native marine species. (ISSG, 2021)
Main Context
The species Perna Viridis is native to Indo-Pacific, specifically the Persian Gulf to the Gulf of Thailand through to the south of Indonesia. It has been introduced to several parts of the world, China, Japan, Australia, the Caribbean, Polynesia, South America and southeastern United States.
The species was introduced to these areas through biofouling on ships, the occurrence in which an accumulation of algae, microorganism, small marine animals, plants and algae on unwanted surfaces, most commonly found on water inlets, pipework, ships and buoys.
The first sighting occurred in the Caribbean, 1990, where the population continued to grow through to 2000 where it was sighted in many coastal waters of Australia, Venezuela, Jamaica, and Florida. In recent years, the green mussel has been spotted in north waters of coastal Queensland several times, including 2017 (Weipa), 2019 (Mornington Island and Escape River) and 2020 where they were found on biofouling ships. The first sighting of the introduced species was n 2007, one year after South Carolina's outbreak. (Queensland Government , 2021)
Due to the lack in information on green mussel settlements throughout Australia, it is unclear and estimate for the settled population. However, in recent years over three hundred have been discovered in organized groups throughout the sighting points considered above.
The species is considered to thrive in temperatures of 10°C–42°C, in coastal waters with wide salinity levels of 14-45ppt. The average salinity levels of seawater in northern Queensland is 35ppt, allowing the Perna Viridis to survive easily in the environment. The species is commonly found at high water flow, 30cm below tide level, settling on rocky surfaces or deep in sandy/muddy areas of beaches, making up majority of Queensland's coastal environment. (EDIS, 2018)
This tolerance graph above defines the maximum and minimum temperature (Celsius) living conditions an Asian green mussel can endure. With a minimum living temperature of 6°C and a maximum of 37°C. This temperature ability has a wide range and focuses mainly on more northern and tropical areas of country waters. This is one of the many reasons the green mussel is extremely successful in the northern Australian marine environment, and able to out-compete many other species.
This tolerance graph shows the maximum and minimum salinity levels of the water (PPT parts per thousand). The maximum salinity levels are at 80ppt with a minimum salinity of 24ppt. This allows the green mussel to adapt perfectly in the northern Queensland waters with an average salinity level of 35ppt. This allows them to adapt perfectly in the northern Queensland waters with an average salinity level of 35ppt. This makes for a comfortable environment for this species of mussel.
The Asian green mussel accumulates high concentrations of toxic material and heavy metals, poisoning humans, and native species in the area. This allows the species to out compete others, providing a safe environment throughout Queensland's coastal waters to thrive in. In Australia, current measures are being taken to destroy these invasive populations of Asian green mussel. Slipway operators, vessel inspectors and owners are working to thoroughly clean and check boats for signs of green mussel biofouling, as well as many other invasive marine species.
The food web above shows the overall transfer of energy within the cycle of marine life surrounding the Asian Green Mussel. The Wild Dog, Wedge-tail Eagle, Black Birds and Freshwater Snakes are tertiary consumers, with the lower organisms such as Marine Rotifer's acting as primary consumers. In ecological niches and food webs, Tertiary consumers are animals sitting at the top of the food chain and are the last to receive energy through consuming. Primary producers (autotrophs) produce their own food and energy commonly through photosynthesis and transfer this energy further up the food chain, where animals decompose and transfer smaller amounts back towards the primary producers. This shows the transfer of energy within the food web decreasing as the organism itself increases, outlining how heat and kilojoules are shown moving.
The species has a negative effect on Australia's ecosystem, as the species takes needed energy and consumable energy of native marine organisms, further increasing the invasive species population while disrupting the overall food web and ecosystem of northern Queensland waters and marine systems. The green mussel has become extremely successful in these food chains as the species has been recorded as carriers of Lea plague disease (HCPD). This disease, when transferred to other animals, targets digestive glands and alimentary tract.
This chain shows the ecosystem chain in which a perna viridis (Asian Green Mussel) exists in within Australia. The food chain above shows the energy transferred as it's consumed by higher consumers, starting from Autotrophs (produces their own food through photosynthesis), transferring into Heterotrophs with sub branches of primary, secondary, tertiary, and quaternary consumers. As energy is sent through the chain it lessens every time, the organism using majority of the energy consumed to produce heat and bodily functions running. In order for quaternary consumers to exist in a certain environment, extremely large amounts of Autotrophs/producers are required to transfer as much energy as possible to up to tertiary consumers through primary and secondary consumers.
The species Perna Viridis, commonly known as the Asian Green mussel is a secondary consumer within the ecosystem. The invasive species uses a mixture of adaptations such as toxic excretion of heavy metals and hard outer shells to repel and outcompete separate native species.
Bibliography
Australian Government . (2015, December ). _Rapid response manual for Mytilopsis Sallei and Perna Viridis _. Retrieved from Marine Pests: https://www.marinepests.gov.au/sites/default/files/Documents/empplan-rapid-response-manual-mytilopsis-sallei-perna-viridis.pdf
Biosecurity Queensland Government . (n.d.). Asian green mussel (Perna viridis). Retrieved from Asian Green Mussel : https://www.daf.qld.gov.au/__data/assets/pdf_file/0008/68615/ipa-asian-green-mussel.pdf
CABI International . (2015, November 25). Perna veridis (Asian Green Mussel). Retrieved from Invasive Species Compendium : https://www.cabi.org/isc/datasheet/70090
EDIS. (2018, October). SGEF 175: Invasive Species of Florida's Coastal Waters: The Asian Green Mussel (Perna viridis). Retrieved from EDIS: https://edis.ifas.ufl.edu/sg094#FIGURE%206
ISSG. (2021). Perna viridis. Retrieved from GLOBAL INVASIVE SPECIES DATABASE: http://www.iucngisd.org/gisd/species.php?sc=731#:~:text=The%20life%20span%20of%20P,is%20typically%202%2D3%20years.
Jayaprakash, R. (2020, July 4). Partial Purification and Characterization of Bioactive Peptides from Cooked New Zealand Green-Lipped Mussel (Perna canaliculus) Protein Hydrolyzates. Retrieved from MDPI: https://www.mdpi.com/2304-8158/9/7/879/htm
McGuire, M. (2018). Invasive Species of Florida's Coastal Waters: The Asian Green Mussel (Perna viridis)1. Retrieved from EDIS: https://edis.ifas.ufl.edu/sg094#FIGURE%206
NIMPIS - Australian Government . (2020, August 20). _Species - Perna viridis _. Retrieved from NIMPIS: https://nimpis.marinepests.gov.au/species/species/35
Queensland Government . (2021, January 4). _Asian green mussel _. Retrieved from Buisness Queensland : https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/pests/invasive-animals/prohibited/asian-green-mussel
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