A deadly parasite on the back of shrimp
Shrimp is considered one of the most delicious types of seafood, and it is a very popular meal in India, China, and many other countries. It contains various nutrients such as magnesium, iron, zinc, phosphorus, sodium, and potassium.
This is how it is on the dining table, but it differs in the depths of the water. There are parasites that feed on and live on the backs of freshwater shrimp, consuming their food and compromising their health, ultimately resulting in their deaths.
Despite the environmental risks posed by shrimp aquaculture, little is known about the effects of the relationship between shrimp and parasites. The parasite, Tachia Chinensis, clings to either the left or right side of the shrimp's head, feeding on it during its growth stages. This poses a significant threat to numerous freshwater shrimp farming projects in East Asia. For example, between 0.62% and 4.42% of shrimp farming projects in China were infected, causing huge losses. There is limited knowledge on the preference of the parasite, the effect of potential parasites on shrimp, and methods of preventing infection. Therefore, previous research has focused on the distribution of shrimp and the sites of this parasite in the surrounding environment.
In this regard, Dr. Muhammad bin Khalfan Al-Wahaibi from the Center of Excellence for Marine Biotechnology has conducted a study to examine the correlation between freshwater shrimp and an external parasitic isopod. This isopod has been responsible for the decline of a significant number of fish in Lake Qarun, located in Fayoum, Upper Egypt, as well as in other areas. Shrimp play an important role in various river and freshwater ecosystems worldwide. It is often used as fishing bait or as an ornament.
The methodology was based on defining the parasite's selection of the appropriate size of shrimp. This was done by examining wild samples and conducting laboratory tests to determine the method of infection. The potential effects of the parasite on shrimp growth were studied.
The results showed that, after collecting samples from the wild, the parasite exhibits a preference for shrimp of varying sizes depending on its own size at a particular stage. Infection occurred in 37.5% to 96.2% of "Posecidence" shrimp and 3.8% to 62.5% of "Neocardina" shrimp.
The behavior of this parasite indicates its selection of the appropriate size and its tendency to infect shrimp species whose carapace is slightly longer than its own body length. It also showed a significant response to the largest hosting option. So, when provided with pairs of shrimp with different carapace lengths, it always chose the larger shrimp. Moreover, the results of predation experiments between the shrimp and the parasite showed that all shrimp species used were able to attack the parasite. However, the shrimp species "Procambrus Clarkie" consumed the largest percentage of the parasite within a shorter time frame (specifically, within one hour).
It is noteworthy that the research findings are consistent with previous studies conducted on "Tachia Chinesys," hypothetically. This flexibility in selection aids in the spread of this parasite across various environments. Although shrimp are rare in freshwater in Oman, the findings could help mitigate current and future problems caused by parasites in Omani projects for the cultivation of freshwater and marine crustaceans and fish.