Difference between crawfish and prawn

Appearance: Crawfish has feather liked gills, whereas prawn has branching gills.
Crawfish brood their eggs and babies on pleopad, whereas prawns release their eggs into the water.

Taste: Crawfish are usually less tough and more subtle compared to shrimp. Crawfish generally has a sweet taste and it is full of meat.

Why do people love crawfish?

“Crawfish are close to becoming a national dish in China, where breeding them has become a huge industry (South China Morning Post, 2018)”

“The crawfish market has doubled in size from 5 years ago to 1.1 million tons, while the overall worth of the industry has skyrocketed 80% from a year ago to $38.6 billion (Nikkei Asia, 2018).”

The opportunity to farm crawfishes is to increase supply and meet demand. The demand is exceptionally strong in China and various countries in Asia, where live crawfishes are preferred. It is considered as premium seafood product and the dish offers the best platform for people to socialize. It is not unusual to see diners busy with their phones instead of chatting with each other while eating. If they eat crawfish, using their phones becomes difficult, as they have to use their hands to pull off shells.

Crawfish used to be only a midnight snacks, but has become a formal dish for dinner.

Afterall, the main reason for the popularity of crawfish is its taste, which appears to be universally accepted by all diners.

How to differentiate between Male and Female crawfish

Another way to tell the gender is by looking at the underside of their bodies.

For female crawfish, there will be 2 holes and for male crawfish, there will be 2 pultruding reproductive organs as seen in the picture below.

Life Cycle of a crawfish

There is a total of 4 stages in a life cycle of a crawfish – Adults, Eggs, Fries and Juvenile.

Adult stage

It takes 4-6 months for crawfishes to reach adulthood and sexual maturity. Adults will actively look to mate. Females will lure males with their urine and males mate by dominating, flipping females over for fertilization. In 4-6 weeks, the developing eggs will be transferred to the outside of the female’s body and glued via an adhesive called “glair” to the female tail. In captivity, a mature adult can reach a length of 12inches and weigh up to 250g.

Eggs

Female crawfish carries the eggs inside her body for 4-6 weeks and is capable of holding 400-1000 eggs each time. The incubation periods between 22 and 42 weeks in 5 stages.

Stage 1: Light cream/Yellow in color (day 1-3)

Stage 2: Dark brown/Grey in color (day 12-14)

Stage 3: Eye spots and little tails are formed (day 20-23)

Stage 4: Eggs will hatch and turn Orange-Red in color (day 28-35)

Stage 5: Fries are released from their mother (day 35-40)

Fries

After hatching from the eggs, the fries feed on their yolk, growing eyes and tails resembling a crawfish. The fries will stay with their mother for 7-14 days before abandoning her in search for food. During this period, the fries are extremely vulnerable and, being cannibalistic in nature, they will attempt to feed on each other if there is a lack of food.

Juvenile

As crawfish matures, their body elongate and start to look for food like fishes and plants. In order for them to grow, they undergo the moulting process where they will grow by 20-30% each time. After 50 days, the male crawfish will also start to develop its signature bright red pigmentation on their claws.

Crawfish Nutrition Facts

Vitamins – A serving of crawfish fulfils is 30% of your body’s daily requirement for vitamins. These vitamins are essential for our nervous system function, turning the food you eat into energy and keeping your liver, skin, eyes and hair healthy.

Minerals – Do you know that crawfishes are a good source of phosphorus? Phosphorus helps our body create and store energy, strengthen bones, teeth and assist with muscle and nerve function. The high level of zinc found in crawfishes help with wound healing and building up our immunity system.

Keeping crawfish as pet

An air pump and filter would be vital as you need to provide ample amount of oxygen and clean the water to ensure they live in a comfortable environment. Remember, crawfish can live on land for up to 24hours as long their exoskeleton is wet. Don’t be afraid if you need to leave it outside while you clean the tank.

Crawfish eat almost anything and everything. You can feed them with normal pellets, fruits, vegetables and even leftover food like ikan bilis and chicken meat as long as they are not oily. Take note, if you want to feed raw meat, make sure to scoop it away if the crawfish cannot finish as it will cause the water to turn foul.
Crawfishes love hiding in the dark, if you have multiple crawfishes, do remember to add some rocks or pipes into the tank for them to hide and sleep.

Different types of crawfish cuisine around the world

In France, they prefer to cook it with garnish base which is called “à la Nantuaise”.
In China, people love spicy stir-fry which is called “Mala”, often paired it with beer.
In Russia and Ukraine, they usually boil it and considered as an appetizer which they enjoyed it with beer and liquor.

In Sweden and Finland, they pair it with vodka or akvavit chaser.

People love eating crawfish so much that they actually have crawfish festivals for all crawfish lovers to gather and enjoy. There will be music, dance, contest and even a parade in addition to delicious food usually celebrating for 2-3 days.

About Cherax Quadricarinatus

Cherax Quadricarinatus is a species of crawfish, resembling that of a small lobster. It is often called crayfish, crawdads, mudbugs, yabbies and freshwater lobsters.
These crawfishes live in freshwater habitats and originates from swamp lands. However, due to its popular demand as a source of food, we have seen many modern crawfish rearing farms propping up all around the world.

Crawfish Facts

Crawfish takes approximately 6 months to grow from an egg to a mature adult reaching a size of 20cm (8 inch), and weigh an estimated 100 -150g. These hardy creatures have an average lifespan of up to 5 years living in optimal conditions.
Their bodies are categorized into 2 sections – the midsection and the segmented body. Crawfishes come in various colors and they are usually sandy yellow, green, red or dark brown in color.

Crawfish head is shaped with a sharp snout and the compound eyes are on movable stalks. Their exoskeleton (body covering) is thin but tough. They have 5 pairs of legs. The front pair is its powerful pincer which are essential tools for defense, food gathering and object manipulation. Subsequent 5 pairs of legs under the abdomen is used for swimming and circulating water for respiration, breathing through their feather-like gills.

Crawfishes are nocturnal creatures. Rarely seen during the day but coming to life at night, scurrying and scavenging for food. You can see them actively crawling all around but when danger arises, they flap their strong tail and disappear in a blink of an eye.

A peek into a Singapore firm’s revolutionary modular crawfish hatcher

Despite the global growth in the popularity of crawfish farming in recent years, two major challenges are faced. Most traditional farmers face the problems of limited knowledge of crawfish breeding and the hefty labor cost of manually separating fry from adults to prevent filial cannibalism. Since 2018, Singapore Crawfish Pte Ltd. vowed to search for a solution to help traditional crawfish farmers solve their problems. After years of research and rigorous testing and multiple project failures, finally, in 2020 they managed to produce a modular Auto Birthing System (ABS™), one that is not only cost-efficient, space conducive but also can be easily maintained and is highly modular. The patented system can provide a quantifiable and sustainable way to produce a constant number of crawfish fry daily. Fry mortality decreases significantly and this technology could change the face of global aquaculture since it aims to solve five main problems:

1. The high cost of traditional crawfish hatcheries.
2. The immense labor required to extract or separate crawfish fry.
3. The high mortality of crawfish fry face when mishandled.
4. The unstable production and supply of crawfish fry in traditional farms.
5. The difficulties in scaling up or down for traditional crawfish hatcheries.

Improving the breeding process

The main objective is to improve the survival and stable reproduction rates of crawfish that increase the profitability and sustainability for farmers, even those with limited knowledge, infrastructure and resources. The traditional method of stripping eggs from the adults and putting the eggs on trays stresses both adults and eggs. The new system is way more reliable and efficient compared to the traditional methods of extracting crawfish fry where mortality can spike up to 80%, especially when mishandled and exposed to bacteria. To date, most crawfish farmers have to manually harvest the eggs and the process is labor-intensive. A crayfish female spawns up to three times a year, producing up to 1,200 eggs each time – thus removing eggs from thousands of crawfishes can be a momentous task. The ABS™ system looks like a few simple rows of tanks joint together but the magic happens within where genetically selected male and female crawfishes are carefully stocked within at the exact ratio in an environment made suited for reproduction and breeding.

Specific feed formula

Broodstock are fed a highly nutritious, specialized feed which increases their fecundity rates, a special formula made in-house by Singapore Crawfish. Their specialized feed is unique in a few ways since it increases the growth rate of crawfish by up to 100%, stimulates mating and reproduction, increases the number of eggs produced by up to 200% and does not pollute the water environment.

Modular system

The new system is modular and can be stacked or upgraded at any time to maximize value through economies of scale. It requires minimal technical expertise, enabling any users to upgrade their existing system without having to disrupt their operations. It is paired with a fully self-contained land-based recirculating aquaculture system (RAS) that removes the sludge and keeps the water clean. It is most suited for commercial farmers who want to have a stable and quantifiable source of fry to provide and distribute to the local market or farmers.

Market perspectives

The company is looking for franchises in different countries. With an entry cost of $1,000,000, farmers will be able to produce a minimum of 20,000 fry per day and 7.3 million fry per year. Investors can look at breaking even within 18 months and start having revenues of $1,000,000 starting the second year. The company will have a limited number of hatcheries in each market to prevent price wars and competition. Currently, Singapore Crawfish only offers their ABS™ hatchery through pre-orders and ships the product to any international buyer within 30 days. The company has an especially large potential impact in emerging markets like Malaysia where their crawfish industry is booming and eventually plans to have their hatchery franchises all over the world. The company is also working with two major genetic companies to develop stronger- and faster-growing strains. They are testing the concept of having genetically-mapped crawfish that is tolerant to various environmental conditions such as temperature and pH fluctuations and expect to have its genetically-enhanced crawfish by 2022.