Red Claw Shrimp Profile – Detailed Guide

Red Claw Shrimp Profile – Detailed Guide

Red Claw Shrimp or Red Claw Prawn (Macrobrachium dayanum and Macrobrachium assamense) are one the rarest shrimp (prawn) species in the aquarium hobby. If you by chance see them in pet stores, you will be surprised to find out how little is known about them.

Unlike most shrimp species of genus Macrobrachium, which constitute one of the major sources of nutritive materials for humans, Red Claw Shrimp are feasible for ornamental farming. These crustaceans possess certain characteristics such as small size, high fecundity, low aggressiveness, and interesting coloration.

Unfortunately, the information about these species is scanty. Nonetheless, in this species profile, I have done my best to gather all information regarding Red Claw Shrimp including their behavior, life span, growth, feeding, handling, etc.

In reality, the name ‘Red Claw Shrimp’ is not correct. These crustaceans belong to the genus Macrobrachium. So, they are prawns.

Nonetheless, this name stuck to these animals. Therefore,  in this article I will be using the terms ‘Shrimp’ and ‘Prawn’ as synonyms even though, technically, these are not the same.

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Quick Notes about Red Claw Shrimp

Name Red Claw Shrimp
Other Names
Red Clawed Shrimp, Red Claw Prawn, Red Clawed Prawn, Chocolate shrimp, or Red Rusty shrimp
Scientific Name Macrobrachium dayanum and Macrobrachium assamense
Type Freshwater
Tank size (minimum) 10 gallons (~40 liters)
Keeping Easy-Medium
Breeding Medium-Difficult
Size 2 – 3 inches (5 – 7.5 cm)
Optimal Temperature 68 – 82°F (20 – 28°C).
Optimal PH 7.0 – 8.5
Optimal GH 6 – 20
Optimal KH 4 – 16
Nitrate Less than 20 ppm
Diet Omnivore / Carnivore
Temperament Aggressive
Life span up to 3 years
Color Form Translucent, blue, light straw, or brown in color with pink spots on the body

Taxonomy of Red Claw shrimp

Freshwater prawns of the genus Macrobrachium are decapod crustaceans belonging to the Palaemonidae family. This genus is considered as a descendant of a marine ancestor. 

Macrobrachium prawns have acquired freshwater habitat by immigration from the Oceans and seas to the interior of the land through river systems. Nonetheless, the process of adaptation to freshwater is not complete yet, because many species are still dependent on brackish water for breeding.

Macrobrachium dayanum and Macrobrachium assamense are one of a few species that have become completely acclimatized to freshwater and can be found in inland rivers and streams. These two species are extremely similar.

The Macrobrachium assamense species is divided into two subspecies:

  • Macrobrachium assamense assamese
  • Macrobrachium assamense peninsular

From the morphological data, it has been concluded that different body parts show a similar pattern of relationship in shape and size, which indicate that it is in fact a single prawn species

Note: The differences between these subspecies are minor. For example, Macrobrachium assamense assamese has a slightly longer rostrum (0.6–0.8 times as long as the carapace vs. 0.5-0.6 times in M. a. peninsularis); and more elongated carpus (3.5–4.0 times as long as broad vs. 3.0–3.5 in M. a. peninsularis).

Distribution and Natural Habitat of Red Claw Shrimp

Red claw shrimp have a very limited distribution range.

Macrobrachium assamense is indigenous to North India (the Peninsular region) and found in the Khoh river from the Garhwal region.

Macrobrachium dayanum can be found in the southern part of India, the Bengal gulf, the Kaira River, and the Rajshahi area of Bangladesh.

They are bottom feeders and are typically found in stagnant water or slow streams and rivers under the crevices of stones, logs, dead leaves, and grassy vegetation.

Description of Red Claw Shrimp

Red Claw Shrimp Profile – Detailed Guide - adult
photo credit W. Klotz

The size of both species (Macrobrachium dayanum and Macrobrachium assamense) varies from a range of 2 to 3 inches (5 – 7.5 cm) in total length and total weight ranges from 3 to 7g.

Macrobrachium dayanum differs from Macrobrachium assamense by having stouter carpus of the second cheliped in adult males.

The carapace as well as the abdomen region are relatively translucent and can be banded with red and white lines.

Depending on the age and environment, they can be blue, light straw, or brown in color with pink spots on the body. The tips of walking legs are red.

Note: As juveniles, they are generally brown or creamy in color.

Males become glossy and bluish-grey in color with red claws during the breeding season.

Lifespan of Red Claw Shrimp

Currently, there is no data available on the maximum lifespan for Red claw shrimp in the wild.

However, under optimal conditions, once a proper aquarium is set up and optimum living conditions are met, they can live up to 3 years.

Typical Behavior of Red Claw Shrimp

Red claw shrimp are aggressive and territorial. They are not social and do not like to be kept in dense groups.

Males readily display aggressive behavior towards anything around them. There is a very high chance that they will attack small prey in the tank, such as dwarf shrimp, snails, and even small fish. It makes them a really bad choice for a peaceful community tank!

Important: the genus Macrobrachium is territorialists, aggressive and cannibalistic. As they get bigger they obviously get more dangerous.

Red claw shrimp are nocturnal animals. They become active almost exclusively at twilight and in darkness. A nocturnal lifestyle is absolutely normal behavior. In nature, it is mainly associated with attempting to avoid visual predators whilst feeding.

Features:

  • Social: No
  • Active: No
  • Peaceful: No
  • Burrowers: No

Diet of Red Claw Shrimp

Like most Macrobrachium, Red claw shrimp are omnivores to carnivores in their feeding habits. They eat just anything that comes in their way.

In the wild, they adapted themselves to a wide range of food of both plant and animal origin. Gut analysis showed that these prawns readily consume detritus, diatoms, aquatic plants, algae, small invertebrates (like worms, snails, or aquatic insects), as well as small bottom-dwelling fish. Even sand was found in their stomachs.

In the aquarium, suggested foods for your Red claw shrimp are:

Nonetheless, these species do not require only organic foods. They also accept frozen and commercial food as well as vegetables. You will want to feed them with (links to Amazon):

Red claw shrimp are aggressive eaters and very greedy. They will try to take as much food as they can carry, even if it is way more than they can actually eat.

Features:

  • Diet Type: Omnivore / Carnivore
  • Food Preference: Organic food
  • Feeding Frequency: 3 – 4 times a week for adults. Daily for juveniles.

Are Red Claw Shrimp Plants Safe?

Not exactly. Sure they will not completely destroy your planted tanks as crayfish or crabs do but they may eat, cut, and shred some of your plants.

Great options for these species are:

  • plastic plants,
  • floating plants,
  • strong plants (such as Anubias, Java fern, etc.)
  • cheap plants that you are ready to lose.

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Red Claw Shrimp: Calcium and Molting Cycle

All crustaceans have a hard multi-layered exoskeleton (shell). However, exoskeletons do not grow as the animal inside them grows. Therefore, our shrimp are forced to molt as they grow bigger.

Calcium (Ca) is an essential component of the exoskeleton composition. So, growing a new exoskeleton requires a high amount of Ca to facilitate calcification. The process of molting puts shrimp in a vulnerable state.

When Red claw shrimp are about to molt they become less active, stop eating, and seek shelter. Otherwise, they can easily fall prey to their tankmates.

It is crucial that Red claw shrimp get enough calcium. We can do that by regularly feeding specialized invert foods or calcium-rich vegetables. 

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Do not forget that calcium plays a huge role for crustaceans. Therefore. I highly recommend reading my article “How to Supplement Shrimp and Snails with Calcium”.

Caring and Keeping Red Claw shrimp

First of all, it is never recommended to add shrimp into the tank if it is not cycled yet. High ammonia and nitrates will kill them.

A stable nitrogen cycle and stable water parameters are key in shrimp breeding!

Second, if you are planning to keep multiple Red claw shrimp, make sure that most of them are females. A good setup is having one male to about 1 – 2 females. It can reduce the level of aggression.

Tank size:

The minimum recommended tank size for keeping Red claw shrimp (1 male and 1 female) is a 10-gallon (~40 L) tank.

Having a larger tank is always preferable for the stability of water chemistry. In addition, the bigger the tank, the better it may be to set up with diverse areas for them to hide.

If you are going to breed Red claw shrimp, you should consider having a separate tank for offspring.

Water Parameters: 

Temperature: the genus Macrobrachium is restricted to warmer areas. Thus, the ideal temperature for Macrobrachium dayanum and Macrobrachium assamense is between 68 – 82°F (20 – 28°C).

Nonetheless, it does not mean that the temperature in your tank can fluctuate that much in short periods of time! They do not like sudden temperature fluctuations.

Shrimp taxonomist Werner Klotz noticed that Red claw shrimp require at least subtropical water temperatures throughout the year.  At temperatures below about 59°F (15°C), they largely stop the activity and die below 50°F (10°C).

pH: Red claw shrimp will appreciate water with a slightly hard pH, in the range of 7.0 to 8.5.

Hardness: These shrimp prefer hard water. They need water hardness between the ranges of 6 – 20 GH and 4 – 16 KH.

Lighting:

No special requirements. If you have plants, lighting should be adapted to their needs.

Although Red claw shrimp are nocturnal animals and they do not really depend on light. Their activity pattern is synchronized with the light/dark and feeding cycles.       

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Substrate:

In their natural habitat, Red claw shrimp prefer areas with gravel, cobbles, and bedrock with a little amount of sand, as the substrate.

One of the best things about rocky substrate is that it breaks a line of sight. Red claw shrimp are less aggressive when they do not see the target. So, it will be safer for other tank mates as well.

Filtration:

There are no special requirements as well. As long as you have got the filter that works great with the size of the tank you have got you will be fine.

Personally, I would always recommend using sponge filters or matten filters for any small tank setups.

These filters are cheap, easy to maintain, and clean; they provide a lot of surfaces to graze on. They are also great for hiding.

Note: Sometimes adult Red claw shrimp may chip and chew on the sponge filter. Just keep that in mind.

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Decorations (hiding places):

Decorations provide hiding places (shelter and protection) and minimize their stress. This is especially crucial for the molting process. Cannibalism after molting can become a big problem.

There should be plenty of dark areas for them to hide.

Red claw shrimp will appreciate all types of leaves, rocks, bricks, driftwood, PVC pipes, plastic mesh, and other decorations to enrich the environment in your tank.

Note: If you are planning to house several Red claw shrimp, each of them needs hiding places to feel secure in different parts of the tank! Keep in mind that they are territorial and do not really like neighbors.

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Acclimation:

Regardless of their hardiness, it will be better to acclimate them before placing them in the tank

Do it very slowly to prevent any unnecessary stress. In general, 2 – 3 hours will be good enough.

Breeding Red Claw shrimp

Red claw shrimp have abbreviated larval development and can easily breed in freshwater aquaria.

There are four distinct phases in the Macrobrachium dayanum and Macrobrachium assamense life cycle:

1.    egg,
2.    larva (zoea),
3.    post larva,
4.    adult.

The time spent in each phase and its growth rate is affected by the diet and environmental factor (such as temperature).

Sexing:

Both males and females of Red claw shrimp attained maturity at the age of about 5 months (male 2 inches (5 cm) in length; female 1.6 inches (4 cm) in length).

Red claw shrimp have sexual dimorphism. It is prominent in adults.

  • Size. Sexual dimorphism is observed with males slightly larger and heavier than females. The cephalothorax and second walking legs are also larger and thicker in males than in females.
  • Claws. Mature males can be easily recognized by their longer and stronger chelipeds with larger spines than in the case of females.
  • The genital pore. The genital pore of the male is in between the base of the fifth walking leg but in females, the genital pore is at the base of the third walking leg having a gap in between them as compared to the males. The presence of an appendix masculine in the second pleopods of the males.
  • Pleopods. The pleopods of the female form a brood chamber in which the eggs are carried between egg laying and hatching. The first, second, and third abdominal pleura of the female are elongated and broad and form a brood chamber for incubating eggs.
  • Ovaries. An ovigerous female can easily be identified by the orange color of ovaries that occupy a large portion of the cephalothorax.

Mating and Spawning:

The male shows peculiar behavior or tactics during mating such as protecting or guarding the female with its large claws and aggressive behavior from other males. The female does not move and stays very calm near or under the male.

 Spawning takes place after 18 – 22 hours of mating.

At the time of spawning female bends forward to keep contact with the ventral thoracic region to form a ʻUʼ shaped structure. Therefore, the eggs were extruded directly into the brood chamber passing through the female genital pore.

Eggs:

The fertilized eggs are deep green color, about 2.5-3.0 mm in length and 1.52-2.0 mm in breadth.

According to the study, fecundity in Macrobrachium assamense ranges from 13 to 102. In Macrobrachium dayanum, the number of eggs ranges from 43 to 195.

In Red claw shrimp, fecundity is strongly correlated to the size of sexually mature females. Large females can carry more eggs.

Eggs in all stages of development are elliptical. The egg diameter ranges from 0.42 to 0.8 mm.

Depending on the temperature, incubation lasts from 14 to 24 days. For example, it takes around 14–18 days at the temperature of 79 – 84°F (26–28°C).

Eggs slowly change to yellow after a few days and develop black eyes during the final stage of development. The color of the eggs becomes gradually lighter. When larvae are fully grown, the color became whitish grey.

Hatching:

Hatching takes about 1-2 hours. It was observed that eggs do not hatch at a temperature below 77°F (25°C) or above 86°F (30°C).

Larvae are very active after hatching and instantly live benthically.

Red claw shrimp larvae should be fed daily (ideally twice). The trick is not to feed so much that the water quality deteriorates too much.

Feed them with:

  • newly hatched brine shrimp,
  • some kind of artificial food for fish larvae (Like 50 or 100-micron golden pearls).

Red Claw Shrimp and Suitable Tankmates

Red claw shrimp are territorial and aggressive, it can be risky to house multiple shrimp in the same tank. Males, in particular, are extremely likely to fight and eventually kill one another when housed together.

Ideally, these shrimp are usually better in solitary confinement. Multiple Red claw shrimp should be kept in groups of one male with multiple females.

Keep in mind that, Red claw shrimp will compete with their tankmates for food. It can also affect their behavior. To mitigate this possibility, it is important to make sure that they are well-fed at all times.

Fish:

While they can coexist with fish, there is always a risk of predatory behavior. Therefore, those species should be chosen with care.

The problem is that large and/or aggressive fish should be avoided. At the same time, small (like Neon tetras, Guppies, etc.) and bottom-dwelling fish will disappear over time.

Note: Thing is, most fish are most vulnerable at night while resting near the substrate and that is exactly the time when Red claw shrimp are most active. 

Dwarf Shrimp and Snails:

Invertebrates like dwarf shrimp and snails are best avoided as Red claw shrimp will likely begin to prey on them and wipe them out eventually. Even Amano shrimp may get caught.

Bad Tank Mates: 

You need to avoid keeping Red claw shrimp with:

In Conclusion

With their striking appearance, Red claw shrimp will definitely be an attractive addition to any freshwater aquarium.

They are opportunistic omnivore and can feed on a variety of food items. All these features make them low-maintenance animals even for beginner aquarists.

The biggest concern is their aggression, as they may attack other fish, snails, frogs, shrimp, and even dwarf crayfish.

References:

  1. Bahuguna, Pankaj, and Rakesh Kumar. “Studies on sexual dimorphism in fresh water prawn, Macrobrachium assamense peninsularie from Garhwal Himalaya, India.”  J. Environ. Rehabi. and Conserv4, no. 2 (2013): 11-14.
  2. Kumar, Koshal, C. B. Kotnala, and A. R. Rana. “Morphometric study on Macrobrachium assamense peninsulare (Tiwari, 1958) from Rawasan stream of Garhwal Himalaya, Uttarakhand, India.” Int J Adv Res2, no. 8 (2014): 317-322.
  3. Cai, Yixiong, Phaibul Naiyanetr and Peter K. L. Ng. “The freshwater prawns of the genus Macrobrachium Bate, 1868, of Thailand (Crustacea: Decapoda: Palaemonidae).” Journal of Natural History38 (2004): 581-649.
  4. Pankaj, Bahuguna, and Kumar Rakesh. “Fecundity of fresh water prawn Macrobrachium Assamense Penensularae from Khoh River, India.”
  5. Kumar, Koshal, Anita Rawat Rana, and Chandra Bhanu Kotnala. “EVALUATION OF FEEDING INDICES TO ANALYSE THE FOOD PREFERENCE AND FEEDING RATE OF MACROBRACHIUM ASSAMENSE PENINSULARE (TIWARI, 1958) FROM RAWASAN STREAM OF GARHWAL, CENTRAL HIMALAYA, INDIA.”
  6. Seema, Langer, Bakhtiyar Yahya, and Lakhnotra Rewa. “Replacement of fishmeal with locally available ingredients in diet composition of Macrobrachium dayanum.” African Journal of Agricultural Research6, no. 5 (2011): 1080-1084.
  7. Bakhtiyar, Yahya. (2009). Studies on the morphometry of Macrobrachium dayanum (Decapoda, Palaemonidae).. Biosciences Biotechnology Research Asia. 6. 131-138.
  8. Sharma, Apurva & Langer, Seema. (2022). Description of appendages characterizing sex differentiation in Himalayan prawn, Macrobrachium dayanum international journal of recent description of appendages characterizing sex differentiation Macrobrachium dayanum.
  9. Bhuiyan, Abdus Salam, Gulsan Arzu, and Sharmin Siddique Bhuiyan. “The Correlation between Fecundity with Length and Weight of Macrobrachium dayanum (Hall) from the River Padma, Rajshahi, Bangladesh.” Journal of Bio-Science15 (2007): 173-174.  

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