Difference between Shrimp & Prawn

Drawing illustrating the differences between a shrimp (left) and a prawn (right).

Most people are confused about the differences between a shrimp and a prawn, physically they look alike. Some of us were taught in schools that larger shrimps are called prawns, whereas smaller ones are called shrimps. Since most prawns belong to the Penaeidae family, it is easy to tell the difference between a shrimp and a prawn. Prawns have all the abdominal side plates overlapping tile-like from the front, while shrimps have only the second abdominal plate overlapping the front and back.

With aquatic plants landscaping getting more popular and the introduction of freshwater shrimp as an algae cleaner, aquarium hobbyists are constantly in search of new varieties and information; the demand for shrimps has been increasing in the past few years. Although all freshwater shrimps are omnivorous (scavenger) and will feed on literally anything that are left over, they generally prefer vegetable matter when it's available.

Molting

As the exoskeleton (commonly know as shell) of a shrimp is rigid and hard, shedding the shell is essential for it to grow. This process is called Molting. New layer of soft shell is constantly growing underneath the existing exoskeleton until a hormone is released to encourage the molting process.

In the course of molting, the shrimp will pull back and emerge out of the old shell via a split between the Carapace and Abdomen region. The soft and discolored new shell requires a few hours to harden. During this period, the shrimp becomes lethargic and vulnerable to attack, and death can also easily occur due to bad water conditions.

Crystal Black Shrimp feeding on a molted shell.

Most shrimps regard their own old shell as one of their food sources, hence removing the old shell is not necessary.

Breeding

Breeding freshwater shrimps is either very easy or complex, depending on the species. Some can be easily breed with freshwater, while others requires brackish water or even full strength salt water. The two forms of reproduction are the primitive form and the higher order form.

Typically in primitive reproduction, small eggs or larvae are released into brackish or full salt water environment. The eggs will hatch into larvae and will go through several stages of development before they can live in freshwater. With each stage, the larvae molt and add new body segment to the existing body. The complexity of creating this required environment makes it almost impossible for hobbyists to breed freshwater shrimps in this form. Furthermore, the larvae will require special algae or tiny planktonic food that live in such environment.

In higher order form, the eggs are larger and will hatch into a fully developed offspring similar to their parents. Although much smaller in size, these tiny shrimps live in the same environment with the adult shrimps. These type of shrimps are easy to breed by hobbyists, as there are no special requirements on environment and food for the baby shrimps.

Environment

The environment for each freshwater shrimp species varies from different water condition like pH, temperature, water hardness, etc. Nevertheless, water condition should be free of ammonia and nitrite as these are fatal to the health of shrimps, hence investing in a good filtration system is paramount. The tank setup should preferably have plants, rocks and driftwoods to cater for hiding places, especially if other small animals co-exist in the tank.